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In order to know exactly how big (or small) it should be, the contractor needs to calculate how much cooling and heating capacity it must have to keep the occupants comfortable. hvac heat pump reviewsThis is called the load of the home.central ac unit brands The load of the home is partly dependant upon the home’s square footage. car air conditioning units for saleHowever, a true load calculation goes beyond that. An accurate load determination includes building construction; orientation to the sun; “R” value of the insulation; number, size, and placement of rooms; number, size, and placement of windows and doors; types of windows and doors (thermal efficiency); number and arrangement of floors; Residential load calculations make use of mathematical formulas that take all these variables into consideration.

They have been computerized, so they’re not as time-consuming as they were in the past. Determining the load by using rules of thumb almost always leads to an over-sized heating and cooling system, resulting in an increased initial cost, increased monthly utility bills, increased maintenance, and shortened equipment life because the equipment cycles off and on too frequently. Who Does the Load Calculation? The contractor you choose to install your new system should be able to perform these calculations. You may ask him for this service. If he doesn’t want to do it, or says it isn’t necessary, you may want to look for a different contractor. In some areas, the local utility will perform a load calculation – check with your local utility. How Big Is Big? Cooling size is given in tons of cooling; 1 ton = 12,000 Btu/h. 'SEER' (Seasonal Energy Efficiency Ratio) indicates the efficiency of the air conditioning unit, not its capacity. Why it’s Important to Have the Right Sized System

Having the wrong-size heating-cooling system can lead to multiple problems. Over-sizing your cooling system is not a good thing. Without getting into too much detail, your cooling load consists of two parts: We’ve all heard the saying, “It’s not the heat; A cooling system that is too big cools down the temperature very quickly, but it does not run long enough to remove sufficient moisture or “humidity” from the air. The result is you feel cool but clammy. Many people then turn down the thermostat to make the air conditioner run longer, increasing the utility bill. In some cases, the insufficient moisture removal resulting from over-sized cooling equipment can lead to mold growth and other types of moisture-related damage. A correctly sized cooling system runs long enough to “wring” moisture out of the air. This allows you to be comfortable at a slightly higher thermostat setting and allows you to save money on your utility bill. It also takes care of the “mugginess” without making you feel too cold.

Air conditioning systems are sized in “tons,” which is a measure of the rate at which they deliver cooling, not how much they weigh. One ton of cooling is equal to 12,000 Btu/h (British Thermal Units per hour), the rate of cooling required to freeze one ton of ice at 32°F in one day. It is better to have a system that supplies a little less than the required tonnage of cooling, rather than a system that supplies more than the required tonnage of cooling. Heating and Cooling Equipment Efficiency Ratings The table below shows efficiency ratings for good, better and much better heating and cooling equipment. SEER means Seasonal Energy Efficiency Ratio and provides an annual measure of the efficiency of the air conditioner. Higher numbers use less energy. AFUE means Annual Fuel Utilization Efficiency. HSPF means Heating Seasonal Performance Factor. For existing homes, the contractor should also check the condition of your ducts. Ducts deliver heated or cooled air to your rooms.

Ducts that excessively leak air or that do not deliver the right amount of air to each room can increase operational cost from a few percent to over 50%.Picking the right home air conditioner is very easy with the right information. Before buying an air conditioner, find out how many BTUs you need.  This means think of the size of the room, and what the room will be used for. Matching Btu requirements to room size is very important when you buying an air conditioner system. This air conditioner sizing tutorial will explain you how to choose the right air conditioner size. Choosing an air conditioner size that is too small (low BTU rating) for the intended room will leave you feeling hot and flustered! And buying an air conditioner that is too big for the room can have its problems too. So the main question is what does BTU mean? Btu – British Thermal Unit (Btu) is the international measure of energy. A Btu is the amount of heat needed to raise 1 (one) pound of water by 1(one) degree Fahrenheit.

In HVAC industry, Btu's measure the quantity of heat a conditioning unit can remove from a room per hours. One BTU per hour is equal to 0293 watts. As the Btu rating increases, so does the weight, size and cost of the air conditioner. To calculate how many BTU’s you need you can use this table. The following tables are estimates based on average room conditions in a moderate climate. Exceptions are Kitchens – add 4,000 BTU cooling capacity to the recommended size. High Ceilings/Unusual Floor Plans – increase BTU by 10%. Warmer Climates – may require 10-20% additional BTUs per room over regular amount. BTU size too large: A conditioner that has a bigger BTU rating than the room size needs will cycle off too quickly. The unit will not remove the humidity from the air properly. Air Conditioner size too small: A conditioner that has a smaller BTU rating than the room requires will run continuously. The unit will not cool the room adequately.