Air condition repair
Helpful information regarding air conditioning:
Modern air conditioning systems have come a long way. Today, a lot of attention is being paid to moisture control, as well as to temperature. And thankfully, stirred by increasing energy costs, better and more efficient units are being built. Heat pumps, capable of providing both cooling and heating, are becoming more popular and are replacing separate units, often with a great savings in power.
There are very few climates where at least some heating and/or cooling isn't required. Even if you happen to be one of the few who doesn't use the heating/cooling system often, your home almost certainly has all of the components in one form or another.
HOW IT WORKS ?
An air conditioner or heat pump works by expanding and contracting gases, and by the movement of heat from one place to another. As gas is compressed, it generates heat. As it expands, it creates cold and is capable of absorbing heat. This simple principle is what is behind all refrigeration units, whether it be the refrigerator or freezer in your home, or the air conditioner.
The tubes of the air conditioning unit are filled with a gas. This gas is usually either Freon-12 or Freon-22. The Freon gets squeezed and condensed into a liquid state by a compressor and a high-pressure condenser. It expands into a gas (evaporates) alternately in the low-pressure evaporator side of the system. To cause the high pressure, a compressor is used to literally squeeze the Freon gas. Heat is drawn away by a condenser fan blowing across the coils. The heat dispersion is further increased by the use of thousands of metal fins. It's important to keep these fins clean (but clean them gently), otherwise the heat cannot be effectively transferred away.
As the liquid passes through the tubing, it not only loses heat, it loses pressure. The low-pressure side, called the evaporator, turns the liquid into a gas, which cools as it expands. The tubes get cold, and another fan blows the cold air where it is wanted.
This is obviously a closed system. If the Freon leaks out, the system will become less and less efficient and will eventually stop. It's very possible that the compressor will be damaged or destroyed as a result. The compressor itself, which looks like a large cylinder in most units, is hermetically sealed. Repair of the compressor itself is not possible. If the compressor fails, replacement is the only valid solution (although the old compressor might have a trade-in value).
The air movement of the home is also a relatively enclosed system. This allows the air-conditioning system to also work as a dehumidifier. The inside air moves through the air return and across the evaporator (cooling) coils. This drop in temperature also condenses out much of the humidity. The cooler, dryer air is then blown back into the house.
In essence then, the system has two overall parts — the coolant system and the air handling system. The coolant system consists of a compressor, a high-pressure side (the condenser), a fan to blow away the heat, usually some kind of inline filter and drier, usually some kind of sight bubble, a capillary tube or loop, a low-pressure side (the evaporator) and the gas inside. The air handling side consists of a fan to move the air, the incoming and return air ducting, and at least one air filter.
On the simplest units, including all window air conditioners, all of this will be in a single chassis located outside the home. Other units will be split, with the condenser located outside and the evaporator located inside, often in the attic.
To control everything, at least one adjustable thermostat will be located in the home usually close to the air return. This thermostat is almost always of the bimetallic variety. As the temperature inside reaches the set level, the contacts turn the compressor and fans on. Once the air is cool enough, contact is broken and the system is shut off.
The thermostat circuit is quite often supplied by a low voltage (24 volts ac) transformer, usually located within the air conditioning cabinet. Because of the low voltage, very small wires can be used in the walls, and any danger to the homeowner is greatly decreased. Whole-house systems have a setting to keep the house fan on all the time. This helps to keep the air in the house moving. Warm air rises, while cooler air drops. The air movement from the fan keeps the air in the home mixed. Especially during the hot and humid season, leaving the fan on constantly can actually reduce costs while making your home more comfortable. It also tends to put less wear and tear on the overall system since it doesn't have to cycle as often.
All of the above tips are for informational purposes only. For your safety, we strongly encourage any air conditioning repairs to be performed only by a certified technician.