Air Conditioning – It’s not the heat… It’s the humidity…
A cool and comfortable home depends on precise control of humidity as well as temperature, and only a properly designed and installed air conditioning system can achieve this.
How Air Conditioners Work
Air conditioners work by transferring the heat from the space they service to another, while also removing humidity. An air conditioner works very much like a refrigerator using the process of refrigeration to provide cooling for space or an entire home.
There are several types of cooling units, but in Ottawa, the most common way to cool a home is by using a mechanical air conditioner which incorporates a compressor, coils and refrigerants. Various configurations include window units,Central Air Conditioners, packaged air conditioners, packaged terminal or incremental air conditioners similar to what you would see in a hotel, and Ductless Air Conditioners.
Portable Air Conditioners are also available. Many of these also work as Heat Pumps. .
Air conditioners use refrigerant that is pumped through indoor and outdoor coils where the refrigerant pressures are varied causing it to condense and evaporate so it can can either absorb heat or get dispel heat. The air conditioning process requires some primary components for it to work effectively, and each of these components will have a bearing on the overall effectiveness and efficiency of the air conditioning system.
Air Conditioner Compressors
Air conditioners use several different types of compressors, including scroll compressors, reciprocating compressors, rotary compressors, screw compressors, and centrifugal compressors. different compressors are better suited for various applications, but residential air conditioners in Ottawa typically use scroll compressors or rotary type compressors.
The compressor is similar to a pump which pumps cool refrigerant vapor from the air conditioner evaporator coil, then compresses the vapor to hot gas at high pressure. This high temperature vapor is pumped to the air conditioner condenser coils.
The air conditioner condenser coils receive the hot vapor from the compressor and discharge the heat, which cools the refrigerant causing it to condense into a liquid by removing the heat that was absorbed by the refrigerant from the evaporator coils.
Air Conditioner – Metering Devices
In order to ensure the condensing and evaporation is done in the most efficient manner possible, the refrigerant flow must be metered as it flows through the system. Most air conditioners in Ottawa today use devices call thermostatic expansion valves (TXV). As the liquid refrigerant leaves the air conditioner condenser it is pumped to the metering device located at the inlet of the evaporator coil. The metering device restricts the refrigerant flow, allowing only the right amount to flow through it. With a TXV, the amount of refrigerant flow is based on the actual work, or energy required to cool the home. Previously, capillaries tubes and orifices were used according to the capacity of the air conditioning system, not the actual cooling required. A TXV provides for a significant improvement in efficiency.
Air Conditioner Evaporator Coils
In an air conditioner system, the evaporator coils function is to absorbing heat. As air passes over the evaporator coils a heat exchange process takes place between the air and the refrigerant. While traveling through the tubes in the coil, the refrigerant evaporates, absorbing the heat from the air being pushed across the coils. The air conditioner evaporator coil conditions the air in two ways. The temperature of the evaporators coil is below the dew point. of the air, meaning it will caused moisture, or humidity, in the air to condense into water. The process results in sensible cooling as well as latent heat removal. The latent heat removal is part of the process of drawing moisture out of the air, while the sensible cooling is dropping the actual temperature of the air. So, it really is the humidity, not the heat. On a hot and humid summer day, both types of heat removal are required to make you more comfortable.
All the air conditioner components, properly matched and operating together are necessary to make any air conditioner system work. It is critical that they be engineered and matched as a system. When looking to buy an air conditioner in Ottawa, be sure to inquire about all the components and how the air conditioning contractor intends to match up the system.
Resources are available from AHRI (Air-Conditioning, Heating, and Refrigeration Institute), who independently test and rate the efficiency of air conditioners with specific coils and air handler or furnace combinations. Most available air conditioning rebates rely on the AHRI certification numbers for the specific combinations of air conditioning and heating equipment to verify that the actual operating efficiency of the system complies with the rebate requirements.
To learn more about Air Conditioning for your home in Ottawa, Kanata or Orleans, why not contact Below Zero Heating & Air Conditioning Today!