Atlanta Air Conditioning Question: What Are Thermostatic Expansion Valves?

Monday, June 25th, 2012

Your Atlanta air conditioner is a complex piece of equipment that can frustrate a homeowner who just wants to understand how it works to better maintain it. To help at least in a small way with this frustration, this post addresses one of the more mysterious and less obvious parts in the air conditioning mystery: thermostatic expansion valves.

A thermostatic expansion valve – sometimes just called a “TEV” – is a smallish valve adjacent to the cooling coil in your AC system. It connects the incoming refrigerant line and the inlet to the cooling coil. Think of it as a gateway for the refrigerant as it comes from the outside, through the lines and is about to enter the air handler at the cooling coil.

Just like a gatekeeper, the TEV’s job is to control what is allowed to enter. It metes the refrigerant into the cooling coil, so that just the right amount gets through. This is important, because having either too much or too little refrigerant circulating through the cooling coil can cause big drop in the performance of your air conditioner, as well as lead to potential damage and necessary repairs.

The TEV is different from some other valves in that it cannot be manually opened or closed as part of the air conditioner’s normal operation. Instead of being like a switch that can be flicked on and off, the TEV plays the role of a meter device, regulating the amount of refrigerant flowing through it and into the cooling coil at any one time.

When the thermostatic expansion valve is not working properly, you may experience AC problems like insufficient cooling, frozen or frosted cooling coils or other performance problems. A licensed Atlanta air conditioning technician will know how to diagnose and fix problems with thermostatic expansion valves. For any problems with your air conditioner, give Cool Air Mechanical a call!

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Atlanta Air Conditioning Guide: Retrofitting Air Handlers for New Air Conditioning Units

Monday, June 18th, 2012

A typical Atlanta air conditioning system consists of an outdoor condenser unit and an indoor air handler unit, which combine to cool and distribute air through your home. But, in cases where you already have a functional air handler, such as part of a heating system, you may not need to install a totally new one when installing air conditioning. Instead, the existing air handler can often be retrofitted to work with the new air conditioning unit.


The typical way to retrofit an air handler to an AC unit is to mount an evaporator coil on top of the existing furnace. The evaporator coil is the component of an AC system which is responsible for cooling and dehumidifying the ambient air – the very process that we think of when we imagine air conditioning.

The problem with simply installing a new evaporator coil and using the existing ductwork and blower fan is that the evaporator coil can be the wrong size, which can lead to performance problems and cause the refrigerant in the coil to freeze. If the evaporator coil is too large for the capacity of the blower fan, the air handler can’t move enough air across the evaporator coil to prevent the freezing, which will halt operation of the air conditioner altogether.


An existing air handler can be retrofitted to accommodate a newer air conditioning unit, as long as the challenges of the size of the evaporator coil are taken into account.

In addition to making sure the coil is not too large in relation to the existing air handler, the velocity of the blower has to be matched to the needs of the coil. A qualified Atlanta air conditioning professional can handle those problems for you during installation, or, in the case that you purchased a home with a retrofit installation, examine an existing system for you to make sure everything is installed properly.

Call Cool Air Mechanical today if you have any questions about Atlanta air conditioning installation!

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Free Estimates!

Friday, June 15th, 2012

Free Estimate | Atlanta | Cool Air Mechanical Heating Cooling and PlumbingAre you interested in a new air conditioning system, air filtration system, water heater, or heating system? Would you like to discuss your options with an educated professional? Visit Cool Air Mechanical today and sign up for a free in-home estimate. Our expert staff will walk you through the best solutions for all of your home comfort needs. We provide top quality HVAC service to the Greater Atlanta area. Our goal is to help all of the area resident enjoy a comfortable, healthy, and efficient environment in their home.

Our customers say that we provide reliable, outstanding service, with excellent customer relations. Our technicians are highly educated and have years of experience in the industry. So if you are thinking about remodeling or upgrading your HVAC system call Cool Air Mechanical today!

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Atlanta Air Conditioner Repair Tip: Common Cause of Short-Cycling

Monday, June 11th, 2012

Air conditioning can make even the hottest summer bearable. If you live in Atlanta or the surrounding area, you know how important it is to keep your air conditioning system functioning effectively. If your air conditioning is turning on and off frequently, otherwise known as short-cycling, it is not only working inefficiently, but it is also wearing down its components quickly. If you notice signs of your air conditioner short-cycling, you should call to have an Atlanta air conditioning professional examine your unit right away.

There are a few main causes of AC short-cycling, many of which are quick and easy fixes:

  1. Refrigerant Leaks: Short-cycling can be caused by a leak in one of the refrigerant lines. While adding more refrigerant will temporarily fix the problem, you will need a professional to find and repair the leak. Only a certified professional should handle refrigerant, and they will be able to charge your unit with the correct amount after they fix the leak.
  2. Ice on the Coils: If your cooling coil has ice or frost build-up, it can cause the unit to turn on and off rapidly. Turning off your AC and letting the ice melt can fix the problem, but you will want a professional to examine the system to find the underlying cause of the icing.
  3. Oversize Air Conditioner: If your air conditioner has always short-cycled, it might be a result of your air conditioner being too large for your home. Bigger is not always better, and an air conditioner that is too large will cause uneven cooling and improper dehumidification as well as short-cycling. An air conditioning contractor can do a load calculation on your home to make sure you get the right unit for your home’s needs.
  4. Control Board Problems: If your AC’s control board or a control switch has been damaged, it can cause erratic starting and stopping cooling cycles. An AC technician will be able to replace a broken board or switch.

While an air conditioner that is short-cycling is still functioning, it is both inefficient and ineffective. Call Cool Air Mechanical today if you notice any signs of your air conditioning malfunctioning!

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Atlanta Air Conditioning Installation Guide: Examine Your Ductwork

Monday, June 4th, 2012

Installing a new air conditioning system is a big deal for most homeowners; it’s a big investment and a piece of equipment that will be in your home for a long time. Replacing your air conditioning system will not only make your home more comfortable, it will also be much more energy efficient than your old unit.

However, before you install your new system there are a few things that you should do. In addition to consulting with an Atlanta air conditioning contractor to find the best AC system for your home’s needs, you should also have your ducts examined.

Air ducts are an essential part of any forced air system. But without regular maintenance, your air ducts can become leaky or broken, resulting in inefficient heating and cooling. They can also accumulate dust and other indoor air pollutants unless they are cleaned on a regular basis. If you are installing a new air conditioning system, it’s a good idea to make sure that your ducts are clean and in good repair. A professional inspection will identify any damage, debris, or other problems that could prevent your AC from functioning effectively.

You also need to make sure that your ducts are the right size for your air conditioner, and that you have enough vents to distribute the air throughout your home. This is only of the many things that your Atlanta air conditioning contractor will check as a part of the installation process. While it might seem like a minor issue, your ductwork can have a big impact on both the comfort of your home and your utility bills.

Properly installed and maintained ductwork is vital for the operation of your HVAC system, including your new central air conditioning unit. If you are thinking about having a new air conditioning system installed, give the professionals at Cool Air Mechanical a call today! We will inspect your home and ductwork to ensure that your new system will work as effectively as possible.

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