Choosing the Right Cooling Option for You.
Types of cooling systems.
Air conditioning, or cooling, is more complicated than heating. Instead of using energy to create heat, air conditioners use energy to take heat away. The most common air conditioning system uses a compressor cycle (similar to the one used by your refrigerator) to transfer heat from your house to the outdoors.
Picture your house as a refrigerator. There is a compressor on the outside filled with a special fluid called a refrigerant. This fluid can change back and forth between liquid and gas. As it changes, it absorbs or releases heat, so it is used to “carry” heat from one place to another, such as from the inside of the refrigerator to the outside.
And the process gets quite a bit more complicated with all the controls and valves involved. But its effect is remarkable. An air conditioner takes heat from a cooler place and dumps it in a warmer place, seemingly working against the laws of physics. What drives the process, of course, is electricity — quite a lot of it, in fact.
Central Air Conditioners and Heat Pumps.
Central air conditioners and heat pumps are designed to cool the entire house. In each system, a large compressor unit located outside drives the process; an indoor coil filled with refrigerant cools air that is then distributed throughout the house via ducts. Heat pumps are like central air conditioners, except that the cycle can be reversed and used for heating during the winter months. (Heat pumps are described in more detail in the heating section.) With a central air conditioner, the same duct system is used with a furnace for forced warm-air heating. In fact, the central air conditioner typically uses the furnace fan to distribute air to the ducts.
How do I know which size air-conditioner will be right for me?
Size matters when you’re buying a window air conditioner. Buy too small and it will struggle to keep the room at a comfortable temperature; buy too big and and the room will cool too quickly without removing enough humidity from the air. Buy just right and you’ll be comfy and save money too.
Window air conditioners typically have cooling capacities ranging from 5,000 to 12,500 British Thermal Units (BTUs). But don’t buy by BTU alone. As a rule of thumb, an air conditioner needs 20 BTU for each square foot of living space but there are other considerations such as the height of your ceiling and the size of your windows and doorways. To measure your room, multiply the length of the room by the width.
For a small bedroom, home office, or guest room you’ll want an air conditioner with good scores for comfort and quiet.
To cool a bigger or busier room, you’ll want to step up to a mid-sized air conditioner.
For a living room or family room, you’ll want a large air conditioner, especially if you have an open floor plan.
Types of air-conditioners.
- Split Systems
It is called a split air conditioner because it has an inside and an outside part.
Most central heating units are of this type.
The reason for the split is that, like other models (especially window units) it keeps the hot outside and the cool inside.
The compressor and the condensing coils are on kept on the outside of the house and the evaporator coils and blower are on the inside of the house.
Gas, a refrigerant, is fed into the compressor where it is pressurized. This also causes the heat in the gas to rise.
The pressurized gas then goes through a succession of tubes that are meant to condense it into a liquid.
The liquid is still pressurized and travels through the condenser tubes until they come to an expansion joint.
The pressurized liquid passes through this point in the process and becomes a gas again as the pressure is rapidly reduced.
During the reduction of pressure the gas also releases a great deal of heat and becomes much cooler (thus, refrigerant).
[split-ac-inside-300] The gas then passes back to the compressor to repeat that process.
Air from the room is drawn into the unit and passes over the evaporator coils.
This action cools the air significantly which is then forced back into the room via the blower.
The air continues to circulate through the air conditioner until a set temperature (set by the thermostat) is reached.
At this point the apparatus shuts off automatically.
- Reverse cycle.
Reverse cycle air conditioners, or heat pumps as they're commonly known, work by extracting heat from outside air and transferring it inside. They use a refrigerant to warm (or cool in summer months) the air that is being drawn inside. They can also filter and dehumidify the air. Heat pump heaters are also generally more efficient than other electric heaters.
Types of reverse cycle air conditioners:
Multi-head split systems
A evaporative air conditioner works the same way. Hot air enters the cooling unit on your roof where it is filtered and cooled as it passes through specially designed moistened Chillcel pads. A fan then blows this beautifully cooled air throughout your home.
Hot air in the house is forced out through open windows and doors providing your entire home with a complete change of air at least every two minutes.
Based on the simple principles of evaporation, hot and dry outside air is pumped through water-soaked pads called Chillcel pads. As the air blows through the Chillcel pads, the water is evaporated and the heat in the air is absorbed, which lowers the air temperature. A fan then pushes the cool air through the ducting system. Breezair cooling units feature a patented centrifugal fan, which can be used in fan only mode (no water) to blow fresh air through your home.
It is important to remember that cooled air inside the building is not recirculated, so a door or window must be left open for this air to escape, providing the whole building with a complete change in air at least every two minutes. Breezair is fresh air.