A heat pump is an HVAC system that can both cool and heat your home. Instead of using separate equipment for air conditioning and heating, a heat pump changes its operation according to the season.

Because the Rio Grande Valley has long summers and generally mild winters, heat pumps can be an excellent option for many South Texas homeowners.

How Does a Heat Pump Work?

A heat pump uses refrigerant to move heat from one location to another. Its main components include:

An indoor air handler and evaporator coil

An outdoor heat-pump condenser

A compressor

Refrigerant lines

A reversing valve

A thermostat

The reversing valve changes the direction in which the refrigerant flows. This allows the same HVAC system to provide cooling during summer and heating during winter.

How a Heat Pump Cools Your Home

During the summer, a heat pump operates like a central air conditioner.

The indoor coil absorbs heat and moisture from the air inside your home. Refrigerant carries that heat to the outdoor condenser, where it is released outside. The air handler then circulates cooled and dehumidified air through the duct system.

In simple terms, a heat pump removes heat from your home and transfers it outdoors.

How a Heat Pump Heats Your Home

During cooler weather, the reversing valve changes the direction of refrigerant flow.

The outdoor coil collects available heat from the outside air. The system transfers that heat indoors, and the air handler distributes warm air throughout the home.

A heat pump can collect outdoor heat even when the weather feels cold because heat energy is still present in the air.

Some systems also include electric auxiliary heat strips. These can provide additional heating during unusually cold South Texas weather or when the indoor temperature needs to rise quickly.

Benefits of Installing a Heat Pump

Heating and Cooling From One System

A heat pump provides air conditioning and heating through the same central HVAC system. This gives homeowners year-round comfort without needing separate cooling and heating equipment.

Energy-Efficient Heating

Instead of creating all its heat through electric resistance, a heat pump transfers available heat from outdoors. Under the right conditions, this can use less electricity than relying entirely on electric heat strips.

Actual energy usage depends on equipment efficiency, thermostat settings, ductwork, home construction, outdoor conditions, and installation quality.

Well Suited for the South Texas Climate

Heat pumps perform especially well in areas with long cooling seasons and relatively mild winters. This makes them a practical option for homes throughout the Rio Grande Valley.

Consistent Indoor Comfort

When correctly sized and installed, a heat pump can provide steady heating and cooling while helping maintain more consistent indoor temperatures.

No Natural Gas Required

A central heat pump operates with electricity and does not require a natural-gas connection or combustion inside the home.

Year-Round Operation

Because the same system provides cooling and heating, homeowners can use their heat pump throughout the year. The thermostat automatically controls which mode is needed to maintain the selected indoor temperature.

Proper Heat-Pump Installation Matters

Even high-efficiency equipment can perform poorly when it is incorrectly sized or installed. Heat-pump performance depends on more than the efficiency rating printed on the equipment.

A professional heat-pump installation should include:

Correct sizing based on the home’s heating and cooling requirements

Verification that the ductwork can handle the required airflow

Properly sealed air-handler and duct connections

Correct refrigerant-line installation

Evacuation of the refrigerant circuit with a vacuum pump

Refrigerant charging according to manufacturer specifications

Static-pressure and airflow testing

Proper thermostat and auxiliary-heat settings

Verification of heating, cooling, and defrost operation

Proper condensate drainage

These details can affect comfort, humidity control, energy usage, reliability, and the system’s useful life.

Heat-Pump Maintenance

Since a heat pump provides both heating and cooling, routine maintenance helps keep it operating correctly throughout the year.

Professional maintenance may include:

Cleaning the indoor and outdoor coils

Inspecting the air filter

Cleaning the blower assembly

Flushing the condensate drain

Measuring airflow and static pressure

Inspecting electrical components

Checking refrigerant performance

Testing the thermostat and reversing valve

Verifying auxiliary-heat operation

Testing the defrost cycle

Confirming proper heating and cooling operation

Regular maintenance also gives a technician an opportunity to identify wear before it affects system performance.

Heat-Pump Services in the Rio Grande Valley

JL Cooling & Heating repairs, maintains, and installs residential heat-pump systems throughout San Juan, McAllen, Mission, Pharr, Edinburg, and surrounding Rio Grande Valley communities.

Our technicians evaluate the complete HVAC system, including the air handler, heat-pump condenser, thermostat, electrical components, refrigerant circuit, airflow, and ductwork.

For professional heat-pump repair, maintenance, or installation, call JL Cooling & Heating at 956-569-4838 or visit jlcandh.com.

JL Cooling & Heating — We don’t sell what you don’t need.

Even premium equipment can struggle when the ductwork leaks, airflow is restricted, refrigerant lines become contaminated, or the system is not properly charged and tested.

A complete HVAC installation involves much more than connecting an air handler and condenser. Each step must be completed correctly to protect the equipment and help it deliver its rated performance.

Proper Equipment Sizing Comes First

Before selecting a replacement system, the home’s cooling requirements should be evaluated.

Installing a larger unit is not always better. Oversized equipment may cool the home quickly but shut off before removing enough humidity. Undersized equipment may run continuously and still fail to maintain the desired temperature.

A professional installation should consider:

• A Manual J load calculation
• Manual S equipment selection
• The home’s insulation and air leakage
• Window size and orientation
• Occupancy and internal heat loads
• South Texas temperature and humidity conditions
• Existing duct capacity

Equipment sizing and duct capacity must work together.

No Gaps Between the Air Handler and Ductwork

The air handler must be properly connected and sealed to the return box, supply plenum, filter base, and surrounding ductwork.

Gaps around these connections can allow conditioned air to escape or hot, humid attic air to enter the system.

Air leakage near the air handler may cause:

• Reduced airflow at the registers
• Higher indoor humidity
• Longer AC run times
• Increased energy consumption
• Dust and insulation entering the system
• Condensation around the air handler or duct connections

Metal transitions should fit correctly, and connections should be sealed with approved materials. Tape alone should not be expected to correct a poorly constructed transition or a large gap.

Protect Refrigerant Lines Whenever the System Is Open

Refrigerant tubing should remain capped or sealed whenever it is not actively being connected.

Leaving copper lines open allows moisture, dirt, dust, and other contaminants to enter the refrigeration system. These contaminants may affect the compressor, metering device, oil, and refrigerant.

This is especially important during construction, when dust and debris may be present around the installation area.

Keeping the lines covered is a simple step that can help prevent serious long-term problems.

Flow Nitrogen While Brazing

Brazing refrigerant connections without flowing nitrogen can create oxidation inside the copper tubing. This dark internal buildup can break loose and circulate through the refrigeration system.

Contamination may restrict the TXV or other metering device and interfere with oil circulation.

Flowing a small amount of dry nitrogen through the tubing while brazing helps keep the inside of the refrigerant lines clean.

The outside of a brazed connection may look good while the inside of the tubing is contaminated. That is why proper installation procedures matter even when customers cannot see them.

Pressure-Test the System for Leaks

Before releasing refrigerant into the completed system, the refrigerant circuit should be pressure-tested with dry nitrogen according to the equipment manufacturer’s requirements.

A pressure test helps identify leaks at:

• Brazed joints
• Service valves
• Fittings
• Indoor coil connections
• Refrigerant-line connections

Finding a leak during installation is much better than discovering it after the system has lost refrigerant and stopped cooling.

Refrigerant should not normally need to be added repeatedly. If a system is low, the cause should be investigated.

Pull and Verify a Deep Vacuum

A vacuum is used to remove air, moisture, and non-condensable gases from the refrigerant system before it is charged and started.

Moisture left inside the system may react with refrigerant and oil, contributing to acid formation, corrosion, restrictions, and compressor damage.

A proper evacuation should be verified with a micron gauge. The system should also be isolated and observed to confirm that it can hold the vacuum within acceptable limits.

Simply attaching a vacuum pump for a set amount of time does not prove that the system is dry, tight, and ready for operation.

Charge the System According to Manufacturer Specifications

The correct refrigerant charge is necessary for proper cooling capacity, efficiency, humidity removal, and compressor protection.

The charge should be verified using the procedure required by the manufacturer. Depending on the equipment and operating conditions, this may include:

• Weighing in refrigerant
• Measuring subcooling
• Measuring superheat
• Checking indoor and outdoor temperatures
• Confirming proper airflow before adjusting the charge

Charging by pressure alone may not provide an accurate result.

An undercharged or overcharged system can cause poor cooling, longer run times, higher energy consumption, and reduced equipment life.

Set the Correct Blower Airflow

Airflow should be adjusted for the installed equipment and the home’s comfort requirements.

Too little airflow can cause:

• Reduced cooling capacity
• Evaporator coil freezing
• High static pressure
• Weak airflow from registers
• Longer run times

Too much airflow may cause:

• Excessive duct noise
• Reduced humidity removal
• Uncomfortable drafts
• Water being pulled from the evaporator coil
• Condensation or drainage problems

Blower settings should not be left at a default position without verifying how the complete system is operating.

Measure Static Pressure

Static pressure measures the resistance the blower encounters while moving air through the HVAC system.

High static pressure may be caused by:

• Undersized return or supply ducts
• Restrictive filters
• Dirty evaporator coils
• Small return grilles
• Closed dampers
• Poorly designed transitions
• Crushed or sharply bent flexible ducts
• Undersized registers
• Excessively long duct runs

A new AC system cannot perform properly if the ductwork cannot move the required airflow.

For example, replacing a 2-ton system with a 4-ton system does not double the capacity of the existing ducts. Ductwork designed to deliver airflow for approximately 2 tons of cooling may remain limited to roughly that airflow even after larger equipment is installed.

The result can be high static pressure, weak airflow, increased blower strain, and equipment that cannot deliver its full rated capacity.

Static-pressure testing helps determine whether the air handler and duct system are working together correctly.

Install the Drain System Correctly

The evaporator coil removes moisture from the air, and that water must drain safely away from the equipment.

The condensate system should have:

• Proper drain-line slope
• The correct trap when required
• Accessible cleanout points
• A properly positioned vent when applicable
• Secondary drainage or overflow protection
• Secure, leak-free connections

Incorrect drainage may cause water leaks, ceiling damage, microbial growth, system shutdowns, or water overflowing from the drain pan.

Verify Electrical Connections

Electrical installation affects both safety and reliability.

The installer should confirm:

• Correct voltage
• Proper breaker and wire sizing
• Secure electrical connections
• Correct disconnect installation
• Proper grounding
• Correct thermostat and low-voltage wiring
• Manufacturer-required overcurrent protection
• Proper heater-strip configuration when installed

Loose or incorrect electrical connections can create excessive heat, equipment damage, intermittent problems, or safety hazards.

Commission and Test the Complete System

The installation is not complete when the equipment turns on. Final testing should verify that the system operates correctly under actual conditions.

Commissioning may include:

• Supply and return temperatures
• Total external static pressure
• Airflow and blower settings
• Refrigerant charge
• Compressor and motor amperage
• Voltage
• Drain operation
• Thermostat configuration
• Heating and cooling operation
• Equipment staging
• Unusual noise or vibration

Recording these readings creates a performance baseline that can be useful during future maintenance and service calls.

Installation Quality Matters More Than the Lowest Price

A lower installation price may look attractive, but important steps require time, training, instruments, and attention to detail.

When these steps are skipped, the customer may later pay through:

• Higher utility bills
• Poor comfort
• High indoor humidity
• Repeated service calls
• Refrigerant leaks
• Airflow problems
• Compressor or blower failure
• Shortened equipment life

A properly installed standard-efficiency system may perform better and last longer than premium equipment installed incorrectly.

Professional AC Installation in the Rio Grande Valley

South Texas air conditioners operate through extreme heat and high humidity. Proper sizing, airflow, duct sealing, evacuation, refrigerant charging, and system testing are essential for reliable performance.

JL Cooling & Heating provides professional air-conditioning installation and replacement services throughout San Juan, McAllen, Mission, Pharr, Edinburg, and surrounding Rio Grande Valley communities.

We evaluate the complete system—not only the equipment being replaced.

Call 956-569-4838 or visit https://jlcandh.com to request an estimate.

JL Cooling & Heating
“We don’t sell what you don’t need.”

This condition is called high static pressure.

An easy way to understand static pressure is to imagine trying to breathe through a small straw. You can still move some air, but it requires more effort. The same thing happens when an HVAC blower tries to push air through undersized or restricted ductwork.

A Larger AC Requires More Airflow

One of the biggest mistakes made during an AC replacement is installing larger equipment without checking whether the existing duct system can handle the additional airflow.

As a general example:

• A 2-ton AC system commonly requires approximately 800 CFM of airflow.
• A 4-ton AC system commonly requires approximately 1,600 CFM of airflow.

Actual airflow requirements can vary based on the equipment, climate, and humidity-control needs, but the difference is significant.

If a 2-ton system is replaced with a 4-ton system while keeping ductwork that was designed to move approximately 800 CFM, the ducts do not suddenly gain the capacity to move 1,600 CFM. The system may still be limited to approximately the airflow capacity of the original 2-ton duct design.

In simple terms, you may have installed 4 tons of cooling equipment, but the duct system may still only have enough airflow capacity for a 2-ton system.

What Happens When the Supply Ducts Are Too Small?

When the blower attempts to force more air through ducts that cannot handle it, pressure builds inside the system. This can cause:

• Weak airflow from supply registers
• Rooms that cool unevenly
• Longer system run times
• Higher electrical consumption
• Excessive noise from ducts and registers
• Poor temperature control
• Reduced cooling capacity
• Increased strain on the blower motor
• Evaporator coil freezing
• Premature equipment failure

The homeowner may believe the new AC is not large enough because the house still does not cool properly. However, the equipment may be large enough—the duct system simply cannot deliver its capacity to the rooms.

Bigger Equipment Can Make the Problem Worse

Installing a larger AC system is not always the solution to a comfort problem.

Larger equipment requires more airflow. If the return, supply trunk, branch ducts, filter, or registers are too small, increasing the equipment size can create even higher static pressure.

The blower may attempt to compensate by working harder, but it cannot overcome a duct system that is physically too restrictive. Depending on the type of blower motor, this may increase energy consumption, reduce airflow, or place additional strain on the motor.

The result may be expensive new equipment that still produces:

• Weak airflow
• Uneven room temperatures
• High humidity
• Excessive noise
• Long run times
• Repeated airflow-related repairs

High Static Pressure Can Reduce Cooling Performance

An air-conditioning system needs the correct amount of air moving across the evaporator coil.

When airflow is too low, the coil may become excessively cold. This can reduce system capacity and may eventually cause the evaporator coil to freeze.

A frozen coil blocks even more airflow, creating a cycle in which the system runs but cannot properly cool the home.

Low airflow can also affect refrigerant readings. That is why airflow and static pressure should be checked before assuming that a system simply needs refrigerant.

The Return Side Matters Too

High static pressure is not limited to the supply ducts. The return side must also be large enough to bring the required amount of air back to the air handler.

Common return-air restrictions include:

• Undersized return grilles
• Small return ducts
• Restrictive air filters
• Dirty filters
• Blocked return grilles
• Poorly designed filter bases
• Sharp duct transitions
• Dirty evaporator coils

A system cannot supply more air than it can receive through the return.

How Is Static Pressure Checked?

An HVAC technician can measure total external static pressure using a manometer. This test shows how much resistance the blower is working against.

Additional testing may include:

• Return and supply static-pressure readings
• Pressure drop across the air filter
• Pressure drop across the evaporator coil
• Airflow measurements
• Blower-speed verification
• Duct and register inspection
• Temperature measurements
• Equipment airflow requirements

Static pressure should be compared with the air handler manufacturer’s approved operating range. A single number should not be judged without considering the equipment specifications and where the readings were taken.

Should the Ductwork Be Checked Before Replacing an AC?

Yes. Before changing equipment size, the contractor should evaluate whether the existing return and supply duct systems can support the new system’s required airflow.

Proper system replacement may require:

• A Manual J load calculation to determine how much heating and cooling the home needs
• Manual S equipment selection
• Duct-sizing and airflow evaluation
• Static-pressure testing
• Return-air improvements
• Larger supply trunks or branch ducts
• Additional or properly sized registers

Equipment size and duct capacity must work together. Installing larger equipment without correcting an undersized duct system may reduce comfort, efficiency, and equipment life.

HVAC Airflow Testing in the Rio Grande Valley

South Texas air conditioners operate under demanding heat and humidity conditions. Proper airflow is especially important when equipment runs for extended periods during the summer.

JL Cooling & Heating evaluates static pressure, airflow, duct sizing, return capacity, and overall AC performance throughout San Juan, McAllen, Mission, Pharr, Edinburg, and surrounding Rio Grande Valley communities.

If your AC has weak airflow, uneven temperatures, excessive noise, high humidity, or long run times, the problem may not be the equipment itself. Your duct system could be restricting its performance.

Call 956-569-4838 or visit https://jlcandh.com to schedule an evaluation.

JL Cooling & Heating
“We don’t sell what you don’t need.”

However, if your AC cannot maintain a reasonable indoor temperature, produces weak airflow, or allows indoor humidity to remain high, there may be another problem affecting its performance.

Why Extreme Heat Makes Your AC Work Harder

Your air conditioner does not create cold air. It removes heat and moisture from inside your home and transfers that heat outdoors.

As the outdoor temperature increases, releasing that heat becomes more difficult. At the same time, additional heat enters the home through the roof, windows, exterior walls, doors, and air leaks.

On a typical summer day, the system may cycle on and off. During a 100°F-plus afternoon, it may need to run much longer to keep up with the increased heat entering the home.

Is It Normal for an AC to Run Continuously?

It can be normal for an air conditioner to run almost continuously during extreme South Texas heat—especially during the hottest hours of the afternoon.

A properly operating and correctly sized system may have long run times while still maintaining a comfortable indoor temperature. Longer cycles can also help remove humidity from the air.

The system should be inspected if:

• The indoor temperature continues rising
• The AC cannot get close to the thermostat setting
• Airflow from the vents is weak
• The home feels humid or uncomfortable
• Ice develops on the refrigerant lines or evaporator coil
• The system repeatedly turns on and off
• The electric bill increases unexpectedly
• Some rooms remain much warmer than others

Common Reasons an AC Struggles in Extreme Heat

Dirty outdoor condenser coil

The outdoor coil releases heat from the refrigerant. Grass clippings, dirt, cottonwood, and other debris can restrict airflow and make it harder for the system to remove heat.

Dirty air filter

A clogged filter reduces the amount of air moving through the system. Low airflow can decrease cooling performance, increase energy consumption, and sometimes contribute to coil freezing.

Low refrigerant

Refrigerant does not normally get “used up.” If the system is low, there may be a leak. Low refrigerant can reduce cooling capacity and cause the AC to run longer without properly cooling the home.

Undersized or restricted ductwork

Even good equipment cannot perform properly if the duct system cannot move the required amount of air. Undersized, damaged, leaking, or poorly installed ducts may cause weak airflow, uneven temperatures, high static pressure, and longer run times.

Air leakage and insufficient insulation

Outside heat and humid air can enter through leaking doors, windows, attic penetrations, recessed lights, and other openings. Poor insulation or attic air sealing can place a significant additional load on the AC system.

Improperly sized equipment

An undersized system may not have enough capacity for the home during extreme conditions. An oversized system can cool too quickly, shut off early, and leave excessive humidity behind.

Proper AC sizing should be based on a Manual J load calculation—not only the home’s square footage or the size of the previous equipment.

Poor maintenance or aging components

Dirty coils, weak capacitors, failing motors, incorrect airflow, and other mechanical or electrical problems can reduce system performance. These issues often become more noticeable when the equipment is under maximum demand.

Will Lowering the Thermostat Cool the House Faster?

No. Setting the thermostat much lower does not make a standard air conditioner produce colder air or cool the home faster.

If the house is 78°F, changing the setting from 75°F to 65°F will generally cause the system to run longer. It will not increase the equipment’s cooling capacity.

A better approach is to select a reasonable temperature and allow the system to operate. If the indoor temperature continues rising, the system or home may need to be evaluated.

The Thermostat Is Only Part of the Story

Indoor comfort depends on both temperature and humidity. A home at 74°F with excessive humidity may feel less comfortable than a properly dehumidified home at a slightly higher temperature.

High indoor humidity during long AC cycles may indicate:

• Outside air entering the home
• Duct leakage in an attic or unconditioned space
• Incorrect equipment sizing
• Improper airflow settings
• An equipment or refrigerant problem
• Excessive moisture entering from another source

How to Help Your AC During 100°F Weather

Homeowners can reduce some of the heat load by:

• Replacing dirty air filters
• Keeping the outdoor unit clear of weeds and debris
• Closing curtains or blinds on sun-exposed windows
• Keeping exterior doors and windows closed
• Using ceiling fans in occupied rooms
• Avoiding unnecessary oven or clothes-dryer use during peak afternoon heat
• Scheduling professional maintenance
• Sealing air leaks and improving insulation when necessary

Never cover the outdoor condenser or block its airflow while it is operating.

When Should You Call an HVAC Professional?

Consider scheduling an AC inspection if the system runs continuously but cannot maintain temperature, the airflow is weak, indoor humidity remains high, or cooling performance has changed noticeably.

A complete evaluation should look beyond the thermostat. It may include:

• Supply and return airflow
• Temperature difference
• Refrigerant performance
• Indoor and outdoor coil condition
• Static pressure
• Duct restrictions or leakage
• Electrical components
• Equipment capacity and sizing
• Heat and moisture entering the home

Finding the actual cause is important. Replacing equipment without checking airflow, ductwork, sizing, and the condition of the home may leave the original comfort problem unresolved.

AC Service in San Juan and the Rio Grande Valley

JL Cooling & Heating provides residential and commercial air-conditioning service throughout San Juan, McAllen, Mission, Pharr, Edinburg, and surrounding Rio Grande Valley communities.

If your AC struggles during extreme South Texas heat, we can evaluate the complete system and explain what is affecting its performance.

Call 956-569-4838 or visit https://jlcandh.com to schedule service.

JL Cooling & Heating
“We don’t sell what you don’t need.”

In the Rio Grande Valley, air conditioners must handle high temperatures and heavy humidity. However, installing the largest system available is not always the answer. The equipment must be properly matched to the home and its ductwork.

Why AC Size Matters

Air-conditioning capacity is measured in tons. One ton of cooling equals approximately 12,000 BTUs per hour, but the correct size cannot be determined by square footage alone.

Several factors affect how much cooling a home needs, including:

• Square footage and ceiling height
• Window sizes and directions
• Insulation levels
• Air leakage
• Roof color and construction
• Number of occupants
• Heat-producing appliances
• Ductwork location and condition
• Outdoor conditions in South Texas

A professional Manual J load calculation evaluates these factors to determine the home’s actual cooling requirements.

Signs Your AC May Be Too Small

An undersized air conditioner does not have enough capacity to properly cool the home under normal design conditions.

Common signs include:

The AC Runs Constantly

An undersized system may run for long periods without reaching the thermostat setting. Longer cycles are normal during extremely hot South Texas afternoons, but a system that consistently falls behind may need to be evaluated.

The Home Does Not Reach the Thermostat Setting

If the thermostat is set to 74°F but the indoor temperature remains several degrees higher, the system may not have enough capacity. Refrigerant problems, dirty coils, poor airflow, duct leakage, and inadequate insulation can cause similar symptoms.

Some Rooms Remain Too Warm

Rooms with large windows, high ceilings, poor insulation, or inadequate ductwork may remain warmer than the rest of the home. This does not always mean the entire AC system is too small—it could be an airflow or duct-design problem.

Electricity Bills Are Higher Than Expected

A system that operates continuously can consume more electricity. However, high utility bills may also be caused by dirty equipment, duct leakage, poor insulation, low refrigerant, or incorrect thermostat settings.

The System Struggles During the Afternoon

An undersized system may keep the home comfortable in the morning but lose ground as outdoor temperatures and solar heat increase.

Signs Your AC May Be Too Large

Many homeowners believe a larger AC will cool the home better. In reality, oversized equipment can create serious comfort and humidity problems.

The System Turns On and Off Frequently

An oversized air conditioner may lower the temperature too quickly and shut off before completing a proper cooling cycle. This is called short cycling.

Frequent starting and stopping can increase wear on compressors, contactors, capacitors, and other components.

The Home Feels Cool but Humid

The evaporator coil needs sufficient run time to remove moisture from the air. If an oversized system shuts off too quickly, the thermostat may reach its setting while indoor humidity remains high.

This can make a South Texas home feel sticky or uncomfortable even at a lower temperature.

Temperatures Change Quickly

An oversized system may create noticeable temperature swings. The home becomes cold quickly, then warms up again, causing the equipment to start another short cycle.

Some Areas Feel Too Cold

A system that delivers too much cooling too quickly can make rooms near the air handler or larger supply vents uncomfortable while distant rooms remain warm.

The Equipment Is Loud When It Starts

Larger equipment requires more airflow. If the existing ductwork cannot support it, you may hear excessive air noise, whistling vents, or a loud return grille.

Ductwork Can Make a Correctly Sized AC Perform Poorly

The equipment is only one part of the system. Improperly sized, damaged, leaking, or restrictive ductwork can create symptoms that look like an equipment-sizing problem.

For example, undersized ducts can cause:

• Weak airflow
• High static pressure
• Uneven temperatures
• Excessive noise
• Longer run times
• Frozen evaporator coils
• Increased blower motor strain

Before recommending larger or smaller equipment, the duct system and airflow should also be inspected.

Can AC Size Be Determined by Square Footage?

Square footage can provide a rough starting point, but it should not be the only factor used to select equipment.

Two homes with the same square footage can have very different cooling loads. A shaded, well-insulated home with energy-efficient windows may need less cooling than a similar-sized home with poor insulation, air leakage, high ceilings, and large west-facing windows.

Rules such as “one ton for every certain number of square feet” can easily lead to oversized or undersized equipment.

The Proper Way to Size an AC System

A complete evaluation should include:

• A Manual J heating and cooling load calculation
• Review of insulation, windows, orientation, and air leakage
• Inspection of the existing ductwork
• Airflow and static-pressure measurements
• Proper equipment selection using manufacturer performance data
• Manual S equipment selection when applicable
• Consideration of indoor humidity and homeowner comfort needs

The goal is not simply to install equipment that can cool the home. The goal is to select a system that provides proper airflow, temperature control, humidity removal, efficiency, and dependable performance.

Professional AC Sizing in the Rio Grande Valley

If your air conditioner runs constantly, short cycles, leaves the home humid, or cannot maintain an even temperature, improper sizing may be part of the problem. A complete evaluation can help determine whether the cause is equipment capacity, ductwork, airflow, insulation, refrigerant, or another system issue.

JL Cooling & Heating LLC provides professional HVAC evaluations, Manual J load calculations, airflow testing, AC repair, and system installation throughout San Juan, McAllen, Mission, Edinburg, Pharr, and surrounding Rio Grande Valley communities.

Call: 956-569-4838
Visit: https://jlcandh.com

JL Cooling & Heating LLC — We don’t sell what you don’t need.

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This is a common problem in homes throughout San Juan, McAllen, Mission, Edinburg, Pharr, and the Rio Grande Valley. Even a new, high-efficiency air conditioner may struggle when connected to undersized or poorly designed ductwork.

Why Proper Duct Size Matters

Your AC system is designed to move a specific amount of air, measured in cubic feet per minute, or CFM. The duct system must be large enough to carry that airflow without creating excessive resistance.

Think of it like trying to breathe through a small straw. Air can still pass through, but it takes much more effort. The same thing happens when an HVAC blower tries to force air through ducts that are too small.

Problems Caused by Undersized Ductwork

Weak Airflow From the Vents

Small ducts restrict the amount of air reaching each room. You may notice weak airflow from certain vents, especially in rooms farther away from the air handler.

Uneven Temperatures

Some rooms may feel comfortable while others remain warm or humid. Homeowners often blame the AC equipment, but the actual problem may be that the ductwork cannot deliver enough conditioned air to every room.

High Static Pressure

Static pressure is the resistance your HVAC system must overcome to move air. Undersized ducts can create excessive static pressure, making it harder for the blower motor to circulate air.

This can reduce system performance and place additional strain on the blower motor and other components.

Longer Running Times

When the system cannot move enough air, it may take longer to reach the thermostat setting. Longer run times can increase electrical consumption and contribute to higher utility bills during the hot South Texas summer.

Frozen Evaporator Coil

Restricted airflow can cause the evaporator coil to become too cold. Moisture may freeze on the coil and eventually block airflow completely.

A frozen coil does not automatically mean the system is low on refrigerant. Airflow problems—including dirty filters, dirty coils, blower issues, or undersized ductwork—can produce similar symptoms.

Excessive Noise

Whistling vents, loud returns, or rushing-air sounds may indicate that the duct system is trying to move too much air through an opening that is too small.

Poor Humidity Control

Humidity is a major concern in the Rio Grande Valley. Improper airflow can affect the system’s ability to remove moisture and keep the home comfortable.

The result may be a home that reaches the thermostat setting but still feels sticky or humid.

Premature Equipment Wear

A restricted duct system can place unnecessary stress on the blower motor and other HVAC components. Over time, this may contribute to breakdowns, reduced efficiency, and a shorter equipment lifespan.

Will Installing a Bigger AC Fix the Problem?

Not necessarily. Installing larger equipment on the same undersized ductwork can make the problem worse.

A larger system generally requires more airflow. If the existing ducts cannot handle it, static pressure may increase, airflow may remain inadequate, and the new system may still fail to keep the home comfortable.

Before replacing an AC system, the equipment size and duct capacity should be evaluated together. A Manual J load calculation helps determine how much heating and cooling the home needs, while proper airflow measurements help determine whether the duct system can support the selected equipment.

Signs Your Home May Have Undersized Ducts

Your ductwork may need to be evaluated if you notice:

• Weak airflow from multiple vents
• Rooms that are difficult to cool
• Large temperature differences between rooms
• Loud or whistling supply vents
• A noisy return-air grille
• Frequent evaporator coil freezing
• Long AC run times
• High electricity bills
• Excessive indoor humidity
• Blower motor problems
• Problems that started after installing a larger AC system

These symptoms can also have other causes, so the system should be tested before recommending duct replacement or modification.

How We Evaluate an Airflow Problem

At JL Cooling & Heating, we look at the complete HVAC system rather than guessing based on equipment size alone. An airflow evaluation may include:

• Measuring total external static pressure
• Checking supply and return-air restrictions
• Evaluating duct sizes and layout
• Inspecting filters, coils, grilles, and dampers
• Checking blower settings and system airflow
• Comparing the duct system with the equipment’s airflow requirements
• Looking for damaged, disconnected, or collapsed ducts

Depending on the findings, the solution may involve enlarging certain ducts, adding return-air capacity, correcting restrictive transitions, adjusting airflow, or redesigning part of the duct system. A complete duct replacement is not always necessary.

Professional Ductwork and Airflow Evaluation in the Rio Grande Valley

Properly sized ductwork can improve comfort, reduce noise, support better humidity control, and help your HVAC equipment operate as designed.

If your AC runs constantly, has weak airflow, freezes repeatedly, or cannot cool certain rooms, the duct system may be part of the problem.

Contact JL Cooling & Heating LLC for professional HVAC airflow and ductwork service in San Juan, McAllen, Mission, Edinburg, Pharr, and surrounding Rio Grande Valley communities.

Call: 956-569-4838
Visit: https://jlcandh.com

JL Cooling & Heating LLC — We don’t sell what you don’t need.

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Meta description: Learn how undersized air ducts cause weak airflow, uneven cooling, high energy bills, frozen coils, and humidity problems in Rio Grande Valley homes.

Recognizing the warning signs early may help prevent higher electric bills, loss of cooling, and compressor damage—especially during the extreme summer heat of the Rio Grande Valley.

1. Your AC Runs but Does Not Cool the Home

One of the most common warning signs is an air conditioner that runs for long periods without reaching the thermostat setting. The air coming from the vents may feel slightly cool but not cold enough to lower the indoor temperature.

Low refrigerant reduces the system’s ability to absorb heat from inside the home and release it outdoors. However, restricted airflow, dirty coils, duct leakage, and mechanical problems can cause similar symptoms. Testing is necessary before adding refrigerant.

2. Longer Run Times and Higher Electric Bills

An air conditioner with an incorrect refrigerant charge may operate longer while providing less cooling. Longer run times can increase electricity consumption and place additional strain on the compressor and other components.

If your electric bill increases unexpectedly without a major change in the weather or thermostat settings, the system should be evaluated. Low refrigerant is one possible cause, but it is not the only one.

3. Warm Air Coming From the Vents

The air coming from the supply vents may feel warmer than normal when the system is low on refrigerant. You may also notice that certain rooms are no longer cooling evenly.

Weak airflow by itself does not prove that refrigerant is low. A dirty filter, restricted evaporator coil, blower problem, damaged ductwork, or undersized return can also reduce cooling performance.

4. Ice on the Refrigerant Lines or Evaporator Coil

Low refrigerant can cause the evaporator coil temperature to fall below freezing. Moisture in the air may then freeze on the coil or refrigerant line, creating a layer of ice.

Continuing to operate a frozen system can make the problem worse. If you notice ice, turn off the cooling system and contact a qualified HVAC contractor.

A frozen coil can also be caused by restricted airflow, a dirty coil, a blower problem, closed vents, or duct restrictions. The system should be tested instead of diagnosed by appearance alone.

5. Water Around the Indoor AC Unit

When ice on the evaporator coil begins to melt, the drain pan may receive more water than it can handle. This can create water around the air handler, furnace, or drain line.

Water near the indoor unit can also result from a clogged drain, damaged drain pan, poor equipment leveling, or an improperly installed drain system. Shut the system off if water could damage the home or reach electrical components.

6. Hissing or Bubbling Sounds

A hissing sound near a refrigerant line, coil, or connection may indicate refrigerant escaping through a small opening. A bubbling sound can sometimes occur when refrigerant leaks from part of the system.

Not every unusual sound means there is a refrigerant leak. A technician may need to use electronic leak detection, soap bubbles, nitrogen pressure testing, or another approved method to locate the source.

7. Poor Indoor Humidity Control

Air conditioners in South Texas must remove both heat and moisture. If the refrigerant level or system operation is incorrect, humidity control may suffer. The home may begin to feel sticky or uncomfortable even when the thermostat shows a reasonable temperature.

High indoor humidity can also be related to oversized equipment, excessive airflow, duct leakage, outside-air infiltration, or improper thermostat settings. A complete system evaluation helps identify the actual cause.

8. The Outdoor Unit Runs Constantly or Shuts Down

Low refrigerant may cause the outdoor unit to run for extended periods as it struggles to satisfy the thermostat. Some systems may eventually shut down through a safety control, while others may continue operating under stressful conditions.

Repeatedly resetting the system will not correct the underlying problem and could lead to more expensive damage.

Refrigerant Does Not Normally Need Routine Topping Off

An air-conditioning system is designed as a sealed refrigerant circuit. Under normal conditions, refrigerant circulates through the system and does not get used up.

If a system requires refrigerant repeatedly, simply adding more is not a complete repair. The contractor should determine whether a leak is present, explain the available repair options, and verify the final refrigerant charge according to the equipment manufacturer’s specifications.

Why an Accurate Diagnosis Matters

Several HVAC problems can look like low refrigerant. Before refrigerant is added, a qualified technician should inspect:

• The air filter and evaporator coil
• Blower operation and system airflow
• Supply and return-air temperatures
• Refrigerant pressures and line temperatures
• Superheat or subcooling, when applicable
• Signs of oil or refrigerant leakage
• Duct restrictions and return-air problems
• The condition of the outdoor coil

Adding refrigerant without checking airflow and system conditions can result in an incorrect charge and may not solve the original problem.

AC Refrigerant Leak Testing in the Rio Grande Valley

If your air conditioner is running constantly, blowing warm air, freezing, or no longer controlling humidity, have it inspected before the problem becomes more serious.

JL Cooling & Heating provides air-conditioning diagnostics, refrigerant leak detection, airflow evaluations, and AC repair throughout San Juan, McAllen, Pharr, Mission, Edinburg, Alamo, Donna, Weslaco, and surrounding Rio Grande Valley communities.

We identify the cause of the cooling problem before recommending repairs because we don’t sell what you don’t need.

Visit jlcandh.com or call 956-569-4838 to schedule service.

In the Rio Grande Valley, air conditioners operate through long periods of extreme heat and high humidity. Even high-efficiency equipment may struggle when it is not sized, installed, and adjusted correctly.

The Equipment Is Only Part of the System

An HVAC system is more than the outdoor condenser and indoor air handler. Its performance depends on several factors working together:

• Proper equipment sizing
• Correct ductwork and airflow
• Accurate refrigerant charge
• Safe electrical connections
• Proper condensate drainage
• Correct thermostat and control settings
• Approved equipment matching
• Complete start-up testing

If any of these areas are overlooked, a new system may not deliver the comfort or efficiency the homeowner expected.

Proper Equipment Sizing Matters

A larger air conditioner is not automatically better.

An oversized system may cool the home too quickly and shut off before removing enough moisture. This can leave the home feeling cold but humid. An undersized system may run excessively and struggle to maintain the desired temperature during extreme weather.

A professional contractor should consider the home’s square footage, insulation, windows, orientation, air leakage, occupancy, and other heat-producing factors. When necessary, a Manual J load calculation provides a more accurate way to select equipment than simply installing the same size as the old system.

Airflow and Ductwork Affect the Entire System

New equipment cannot perform correctly if the ductwork is undersized, damaged, leaking, or poorly designed. Restricted airflow can cause:

• Uneven temperatures throughout the home
• Weak airflow from supply vents
• Excessive system noise
• High static pressure
• Longer run times and increased electricity use
• Poor humidity removal
• Frozen evaporator coils
• Additional strain on blower motors and compressors

Before installing new equipment, the contractor should evaluate the return air, supply ducts, filters, grilles, and available airflow. Duct improvements may be necessary for the new system to operate as designed.

The Refrigerant Charge Must Be Correct

Too much or too little refrigerant can reduce performance and place unnecessary stress on the compressor.

The proper refrigerant charge cannot always be confirmed by pressure alone. Start-up procedures may include checking superheat, subcooling, indoor and outdoor temperatures, airflow, and the manufacturer’s charging instructions.

Small installation errors can eventually lead to poor cooling, higher operating costs, and premature component failure.

Drainage and Electrical Work Should Not Be Overlooked

South Texas air conditioners remove a large amount of moisture from indoor air. The drain system must be properly installed, supported, trapped when required, and tested to reduce the risk of leaks, clogs, and water damage.

Electrical connections, disconnects, breakers, wire sizing, grounding, and voltage should also be inspected. Loose or improper connections can create service problems and shorten the life of electrical components.

Start-Up Testing Makes a Difference

Turning the system on is not the same as properly commissioning it. After installation, the contractor should confirm that the equipment is operating within the manufacturer’s specifications.

Important checks may include:

• Supply and return air temperatures
• Total external static pressure
• System airflow
• Refrigerant readings
• Voltage and amperage
• Thermostat operation
• Condensate drainage
• Heating and cooling operation
• Equipment configuration and control settings

These measurements can identify installation problems before they become expensive repairs or comfort complaints.

Do Not Compare HVAC Estimates by Price Alone

Two estimates may include the same size or brand of equipment while providing very different levels of installation quality.

Before selecting an HVAC contractor, ask:

• Is the proposed system properly sized for my home?
• Are the indoor and outdoor units an approved match?
• Will you inspect the existing ductwork and airflow?
• Are permits or inspections required?
• What electrical work, drain modifications, accessories, and duct changes are included?
• Will the system be tested after installation?
• Who will register the manufacturer’s warranty?
• What labor and workmanship warranties are included?

A detailed estimate makes it easier to understand what you are paying for and prevents important work from being excluded from the comparison.

A Quality Installation Protects Your Investment

Even the best HVAC equipment can perform poorly when installed incorrectly. Proper installation can help provide more consistent comfort, better humidity control, lower energy consumption, fewer service problems, and longer equipment life.

Price is important, but it should not be the only deciding factor. The contractor’s experience, installation procedures, system design, warranty support, and final testing can have a much greater impact on the total cost of owning the system.

JL Cooling & Heating provides professional air-conditioning installation and replacement services throughout San Juan, McAllen, Pharr, Mission, Edinburg, Alamo, Donna, Weslaco, and surrounding Rio Grande Valley communities.

We evaluate equipment sizing, ductwork, airflow, and overall system operation to help homeowners receive the performance they expect from their investment.

To schedule an HVAC evaluation or request an installation estimate, visit jlcandh.com or call 956-569-4838.

Is this equipment still covered by the manufacturer’s warranty?

Recently, a homeowner with a new-construction home contacted us after another contractor told him his air conditioning system was no longer under factory warranty and recommended replacing the system.

Something didn’t sound right to the homeowner.

He knew he had owned the home for less than five years, so he contacted JL Cooling & Heating LLC and asked us to take another look.

We’re glad he did.

We Checked the Warranty Before Recommending Replacement

Instead of assuming the equipment was out of warranty based only on its age, we looked further into the history of the system.

After verifying the information, we determined that warranty coverage was available and were able to submit the condenser fan motor as a manufacturer warranty claim.

That made a significant difference for the homeowner.

The lesson is simple:

Before replacing an AC system because of a failed component, verify the manufacturer’s warranty carefully.

Why AC Warranty Dates Can Be Confusing

Determining the warranty status of HVAC equipment isn’t always as simple as looking at the manufacture date on the serial number.

Depending on the manufacturer, warranty terms, registration status, and circumstances, there may be several dates or records worth investigating.

1. Equipment Manufacture Date

The model and serial number can often be used to determine approximately when the equipment was manufactured.

But the date an air conditioner was manufactured isn’t necessarily the same date the homeowner’s warranty coverage began.

Equipment can be manufactured and then spend time in distribution or inventory before being installed.

2. Equipment Sale or Installation Records

Another important piece of information may be when the equipment was sold or installed.

Invoices, distributor records, registration information, and installation documentation can sometimes help establish the history of the HVAC system.

3. Closing Date on a New-Construction Home

This is particularly important for homeowners purchasing new construction.

The HVAC equipment may have been manufactured and installed months before the homeowner actually closed on the property.

Depending on the manufacturer’s applicable warranty terms, the home’s closing or purchase documentation may be important when establishing the warranty start date.

This is why homeowners should keep their closing documents and HVAC paperwork.

Manufacturer warranty requirements vary, so the actual warranty terms for the specific brand and equipment always need to be verified.

Don’t Assume an Older Manufacture Date Means No Warranty

Imagine an air conditioner manufactured well before a new home was completed.

If someone looks only at the serial number and manufacture date, they could potentially reach the wrong conclusion about warranty coverage.

For new-construction homes, we believe it is worth asking additional questions:

When was the home completed?

When did the homeowner close on the property?

When was the equipment installed or sold?

Was the equipment registered?

What does the manufacturer’s warranty policy say for new construction?

A few extra minutes of investigation could potentially save a homeowner from paying for a part that qualifies for warranty coverage—or from unnecessarily replacing equipment.

HVAC Warranty Registration Can Also Matter

Homeowners should also understand that manufacturer warranties aren’t all the same.

Depending on the manufacturer, equipment registration may affect the length or type of warranty coverage available.

Some manufacturers provide different coverage for properly registered equipment, while other circumstances—such as new construction—may have their own requirements.

That’s why we recommend keeping records of:

• HVAC model and serial numbers
• Installation paperwork
• Warranty registration confirmation
• Builder information
• Purchase invoices when available
• New-home closing documents
• Previous HVAC service records

Having this information available can make warranty verification much easier when a component fails several years later.

A Failed Part Doesn’t Automatically Mean You Need a New AC

There are situations where replacing an older air conditioner makes financial sense.

But a failed motor, circuit board, compressor, coil, or another component shouldn’t automatically become a system replacement without evaluating the equipment first.

We believe homeowners deserve to know their options.

Before recommending replacement, a contractor should consider the age and condition of the equipment, repair cost, refrigerant type, efficiency, history of failures, and available manufacturer warranty coverage.

Sometimes replacement is the right decision.

Sometimes repair is the better decision.

And sometimes the failed component may still be covered by the factory warranty.

Details Matter in HVAC Service

The experience with this homeowner is a good reminder of why asking questions matters.

The first contractor reportedly determined that the equipment didn’t have warranty coverage and attempted to sell the homeowner a replacement system.

The homeowner questioned that conclusion because he knew the home wasn’t even five years old.

After we investigated further, we were able to submit the condenser fan motor for warranty consideration.

Taking the time to verify the details can make a real difference for a homeowner.

At JL Cooling & Heating LLC, our goal isn’t to replace equipment simply because something failed. We want to determine what’s wrong, understand the available options, and provide the homeowner with the information needed to make an informed decision.

Think Your AC Might Still Be Under Warranty?

If you’re having an AC repair problem in San Juan, McAllen, Edinburg, Mission, Pharr, Alamo, or the surrounding Rio Grande Valley, don’t assume your system is out of warranty simply because someone tells you it is.

Especially with a new-construction home, there may be additional information that needs to be considered.

Have your model number, serial number, installation information, and new-home closing date available. The manufacturer’s specific warranty terms can then be reviewed to determine whether coverage may still apply.

A little research could potentially save you from an unnecessary expense.

JL Cooling & Heating LLC

We don’t sell what you don’t need.

Sometimes a dehumidifier is the right solution—but not always.

Here in San Juan, McAllen, Edinburg, Mission, Pharr, and throughout the Rio Grande Valley, high outdoor humidity makes moisture control an important part of home comfort. Before adding another piece of equipment, it is important to determine why the indoor humidity is high in the first place.

This is especially important with today’s spray-foam insulated homes.

At JL Cooling & Heating LLC, we believe the first question should be:

Is the home producing a humidity problem, or is the HVAC system not removing enough moisture?

What Should Indoor Humidity Be?

For many homes, an indoor relative humidity around 40% to 60% is generally comfortable, with conditions often feeling better toward the middle of that range.

In South Texas, maintaining lower humidity can be challenging because of our hot and humid climate.

If your home regularly stays above 60% relative humidity, especially while the air conditioner is operating normally, it may be worth investigating the cause.

Simply lowering the thermostat isn’t necessarily the answer.

How Does Your Air Conditioner Remove Humidity?

Your AC system does two jobs:

It lowers the temperature, and it removes moisture from the air.

When warm indoor air passes across the cold evaporator coil, moisture condenses on the coil and drains away through the condensate system.

But the air conditioner needs adequate runtime to remove that moisture.

This is where AC sizing becomes extremely important.

Could Your Air Conditioner Be Too Large?

Yes.

An oversized AC system can cool a house very quickly.

That sounds like a good thing, but it can create a comfort problem.

The thermostat may reach its temperature setting before the air conditioner has operated long enough to remove enough moisture from the air.

The result can be a home that is 72°F or 74°F but still feels humid and uncomfortable.

This is one reason we don’t recommend choosing an air conditioner based only on the size of the old system or the square footage of the house.

A home that had a 4-ton system before doesn’t automatically need another 4-ton system.

Spray-Foam Homes Can Change the Cooling Load

Spray-foam insulation can dramatically change how a house gains and loses heat.

A properly constructed foam-insulated home can have a significantly lower cooling load than a similar home with traditional insulation and a vented attic.

That means equipment sizing becomes even more important.

For example, replacing an older AC system with the same tonnage after a home has been improved with spray foam could potentially leave the house with more cooling capacity than it actually needs.

The AC may satisfy the thermostat quickly while struggling to provide the longer cycles needed for effective moisture removal.

That doesn’t mean spray foam is causing the humidity problem.

It means the house and HVAC system need to work together as a complete system.

Was a Manual J Load Calculation Performed?

Before installing or replacing an HVAC system, one of the most important questions is:

Was a proper Manual J load calculation performed?

A Manual J calculation determines how much heating and cooling the home actually requires.

It considers factors such as:

• Home size and layout
• Insulation type and R-value
• Spray-foam location
• Windows and doors
• Window orientation
• Ceiling height
• Air leakage
• Construction materials
• Occupancy
• Internal heat loads
• Local outdoor design conditions

This is particularly important with spray-foam homes in South Texas.

Simply using a rule such as “one ton per certain number of square feet” doesn’t account for how the house is actually constructed.

What Is Manual S and Why Does It Matter?

Manual J tells us approximately how much heating and cooling the house needs.

Manual S helps us select equipment that can properly meet that calculated load.

These are two different steps.

A contractor shouldn’t simply calculate the load and then choose equipment based only on the tonnage printed on the condenser.

The actual performance of the equipment needs to be considered.

This includes both sensible cooling and latent cooling.

Sensible Cooling

Sensible capacity primarily deals with lowering the temperature.

Latent Cooling

Latent capacity deals with removing moisture from the air.

In a humid climate like the Rio Grande Valley, both matter.

A system can be excellent at lowering temperature but still leave homeowners uncomfortable if moisture removal isn’t adequate.

What About Variable-Speed and Inverter AC Systems?

Two-stage, variable-speed, and inverter HVAC systems can provide advantages for humidity control because they can often operate at reduced capacity for longer periods.

Longer operation can provide more opportunity for moisture to condense on the evaporator coil.

But even advanced equipment needs to be properly sized, configured, and installed.

Installing an oversized inverter system isn’t a substitute for determining the home’s actual cooling requirements.

Could Airflow Be Causing High Humidity?

Equipment size isn’t the only thing we look at.

Airflow can also affect how an air conditioner removes moisture.

The HVAC system needs to be properly configured for the equipment and application. Blower settings, ductwork, static pressure, filtration, evaporator coil performance, and equipment setup can all affect system performance.

Other potential causes of excessive indoor humidity can include:

• Air leaks around doors and windows
• Duct leakage
• Outside-air infiltration
• Improper ventilation
• Bathroom or kitchen moisture
• Condensate drainage problems
• HVAC equipment or control problems
• Incorrect blower settings
• Building-envelope issues

With a spray-foam home, ventilation and building pressure also deserve attention because the house may be considerably tighter than a conventionally insulated home.

So, Do I Need a Whole-Home Dehumidifier?

Possibly—but we shouldn’t automatically start there.

A whole-home dehumidifier can be an excellent solution when a home has a legitimate latent moisture load that the properly sized HVAC system cannot adequately handle on its own.

But if the real problem is an oversized AC system, incorrect airflow, duct leakage, equipment configuration, or another HVAC issue, simply adding a dehumidifier may treat the symptom without addressing the underlying cause.

Before recommending one, we believe it makes sense to ask:

Is the AC properly sized?

Was a Manual J performed?

Was the equipment properly selected using Manual S?

Is the airflow correct?

Is the HVAC system operating as designed?

Is outside moisture entering the home?

How tight is the building envelope?

Once those questions are answered, we can make a better decision about whether additional dehumidification is actually necessary.

High Indoor Humidity in San Juan and the Rio Grande Valley?

If your home is cool but still feels humid, don’t automatically assume you need a bigger air conditioner—or immediately purchase a dehumidifier.

There may be a reason your existing HVAC system isn’t controlling moisture properly.

JL Cooling & Heating LLC can help evaluate AC performance, airflow, equipment sizing, and indoor humidity concerns for homeowners in San Juan, McAllen, Edinburg, Mission, Pharr, Alamo, and surrounding Rio Grande Valley communities.

For new and replacement systems, proper Manual J load calculations and Manual S equipment selection can help ensure that the air conditioner is selected for the home’s actual cooling requirements rather than simply replacing the old equipment with the same tonnage.

The goal isn’t just to make your home cold.

The goal is to make it comfortable.

JL Cooling & Heating LLC

We don’t sell what you don’t need.