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Woman Sweating at the Office Because the AC is not Cooling

30 Apr 2021

Author: Jeff O'Hara

Not many places in the United States can match the miserable months of weather we face during the summer months in Houston. The summer weather in the Houston area is legendary, not only in Texas but internationally as well. It’s the subject of jokes from almost every comedian, and virtually every movie about Houston makes the soggy misery of our summers a focal plot point. 

Starting with the 100°+ temperatures we experience for days –or weeks—on end, not to mention the nearly 100% relative humidity we’re treated to all season long, it can take a tremendous toll on your home’s air conditioning system.

Your air conditioner often sends out warning signs when things are about to go horribly wrong. One of the most common signs is that your ac system seems to be running normally but is not cooling the house, but rather pushing lukewarm or merely “cool-ish” air around the house, leaving your home constantly feeling too warm and humid. 

What is Causing My Air Conditioner to Run but Not Cool?

If there were a single, all-encompassing reason that air conditioners blow warm air into your home, the job of the AC tech would be easy. And boring. No, an air conditioner blowing warm air can have multiple causes, and when there are several issues with your AC system, narrowing down the real issue presents a challenge. Nick’s Air Conditioning accepts that challenge with every attic we climb into and every filter we change. 

Here are just a few common causes of why your HVAC system is running but not cooling the house, and what you can do about each one.

Dirty Air Filters

Air filters can become clogged with dust and debris over time, restricting the amount of air being drawn into the system to be cooled. This lack of airflow causes the other components of your AC system to work harder to compensate for and maintain the desired temperature.

  • What Can I Do About Dirty HVAC Filters?

Changing HVAC filters is a simple task that any homeowner can complete in 5 – 10 minutes. Check your old filter for the proper measurement, pick up a quality brand of filter, pull the old one out, and stick the new one in. Check the airflow direction arrow on the sides of the box, as installing a new air filter backward also causes the unit to work harder. 

If you’re unsure how to install your new AC filter properly, have Nick’s Air Conditioning change it as part of an AC maintenance call. While they’re in your home, ask your expert technician to show you the right way to install the new filter.

Refrigerant Leak 

There is never a time when your residential air conditioner should need to have the refrigerant “topped off.” If your system is low on refrigerant, you have a leak. Many unscrupulous HVAC companies often tell you that it’s “totally normal” to add refrigerant regularly. It’s not normal. It’s a problem that needs to be addressed before the lack of refrigerant causes your system to fail.

  • What Can I Do About an AC Refrigerant Leak?

If your system regularly loses refrigerant, it is not a do-it-yourself project, like the air filter. Freon leaks in older systems can damage the environment, and with your AC working harder to keep up, more energy is being wasted by using the leaking unit.

Let Nick’s Air Conditioning thoroughly inspect your AC unit for units by performing pressure checks and taking electrical measurements to find where the fault in the equipment lies. Most of the time, it’s a simple fitting or connector that has worked loose from the heat and needs to be tightened. Leaks from pinholes in the evaporator coil will result in the tech attempting to repair the hole with a spot weld or replace the coil altogether. 

Faulty Compressor

The compressor is the heart of the air conditioning system, responsible for compressing and circulating the refrigerant through the system. The unit cannot produce enough chilled air if the compressor malfunctions, which causes the system to run without cooling the house. A failing compressor can make loud and unusual noises, such as clanking or grinding sounds, indicating that it needs to be repaired or replaced. Over time, the compressor’s seals can become worn or damaged, which can cause refrigerant to leak out of the system.

Conversely, a failing compressor may produce extremely high pressure in the refrigerant lines without a leak. Left alone long enough, the excessive pressure will damage the fittings or the pipe itself. 

  • What Can I Do About a Failing AC Compressor?

If the air conditioning compressor leaks refrigerant, you’ll want to have it inspected and serviced by a qualified HVAC technician. Servicing the parts of or replacing the compressor entirely is not a project for the “do-it-your-self-er.” The job requires specific tools, including calibrated pressure meters and other things like O-ring spreaders and high torque air wrenches that usually aren’t lying around your garage.  

Thermostat Problems

If the compressor works as the heart of your air conditioning system, then the thermostat operates as the brains of the operation. By constantly monitoring the temperature and humidity inside your home, the thermostat makes decisions regarding the comfort level of the house. 

Many thermostats are placed in a spot convenient for the homeowner to see, often in an open area near the kitchen or the home’s front door. The problem with these placements is that they are areas that experience frequent temperature changes due to opening doors or cooking. 

Make sure the thermostat is set to “cool” instead of “heat” or “fan-only” and that the proper temperature is set for the air conditioner to turn on. 

Thermostats have become more technically capable, but with the added features and conveniences often comes a learning curve. If you’re unsure about the proper functionality of your thermostat, it’s recommended that you contact a professional HVAC technician to diagnose and fix the issue.

Undersized Air Conditioner

Adding rooms or an additional floor to your home will result in needing to re-engineer your HVAC system. Adequately sized air conditioning installation involves measuring each room to be cooled and its square footage to be multiplied to arrive at a number calculated into British Thermal Units, or BTUs. An AC that cannot provide the amount of cooling will cause it to run continuously but not actually cool the home.

Uneven Cooling Between Floors.

As HVAC systems age, their performance begins to decline, along with their efficiency. Two-story homes that are crisp and cool on the ground floor yet tropically uncomfortable upstairs need to call a professional HVAC company to determine if the temperature discrepancy is the fault of a failing compressor, evaporator coil, or even damaged ductwork. 

Air Conditioner is Short Cycling.

Short-cycling of your air conditioner is when your AC system turns on, runs for a brief period, and shuts down—long before cooling your living space to the thermostat setting. It will repeat this same cycle for hours, or days during the worst heat of the summer, creating performance and efficiency issues.

There are so many potential causes for a short cycling air conditioner that someone should have written a blog about it. 

When Should I Call a Professional AC Company?

Because uncool air conditioning isn’t cool, it’s a well-known fact in the AC business that the most popular day for an AC system to break down is the first 90+ degree day of the year. That’s when AC maintenance, repair, and installation season officially kicks off, with the sudden run on both parts and our trained AC technicians making it hard to keep up with demand. 

If you suspect an issue with any aspect of your heating or air conditioning system, regardless of the season, call Nick’s Air Conditioning to confirm or calm your worries.

If your AC system fails to cool your home adequately, call the experts at Nick’s Air Conditioning and Heating Services. We can perform AC tune-ups, maintenance, or replace your existing HVAC system with newer, more efficient technology.

Call Nick’s Air Conditioning BEFORE the Summer Rush!

If you suspect an issue with any aspect of your heating or air conditioning system, regardless of the season, call Nick’s Air Conditioning right away. While you’re having your HVAC system checked out, ask your licensed HVAC technician about Nick’s HVAC and Plumbing Maintenance VIP Plan, which provides annual inspections, maintenance, and a host of other benefits.

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