Friday, August 06, 2010
When it Comes to Central Air Conditioning, Size Matters!
Two of the most common mistakes people make when purchasing central air conditioning are 1). Getting a system that is too large for the size and style of their house, or 2). Getting a system that is too small. This usually happens when an air conditioning contractor recommends an oversized unit, telling you that “bigger is better.” Or when a contractor tries to sell you a smaller unit so that they can underbid other contractors and make sure they get the job by offering you a bargain.
Here's the truth: When it comes to central air conditioning systems, bigger isn't better; it’s just more expensive. And smaller may save you some money upfront, but you almost always get what you pay for.
Consider some of the problems you can get into from buying an oversized or undersized air conditioner...
Air Conditioner Too Big:
An oversized central air condtioning system will turn on and off much too frequently, which will wear down your equipment and waste electricity. Plus, the larger system will cost you more upfront and more to operate.
This frequent cycling on and off will also make your indoor temperatures fluctuate up and down more, resulting in a less comfortable environment. The oversize unit will lower temperature too quickly and then turn off before removing the appropriate amount of humidity. This is another reason why homes with oversize units feel cold and damp -- the humidity is never removed!
The EPA (Environmental Protection Agency) estimates that nearly half of all existing air conditioning equipment is over-sized They estimate that this costs homeowners 20% each year in wasted energy!
Air Conditioner Too Small:
An undersized central air conditioning system will cause your air conditioner to overwork and may fail to keep your home adequately cool. A small air conditioning unit will lower humidity, but will not lower the temperature enough, so the air will feel dry but warm. Pluse the air conditoning system will run constantly; over-running your central air conditioning equipment will lead to premature breakdowns and a short lifespan.
And even if you get the right size air conditioning equipment, you also have to beware of “buying too small” when it comes to your air duct or airflow system. According to the National Comfort Institute states, it’s not unusual to see return air systems undersized by 30-50%. In fact, many common central air conditioning equipment problems including compressor burnout, frozen indoor air conditioning coils -- are often a result of improperly placed and installed air distribution systems.
Be Like Goldilocks!
The central air conditioning system that is ideal for your home comfort and budget is neither “too big” nor “too small,” but is “just right”. When shopping for a new central air conditioning system, be sure that your air conditioning contractor performs a thorough analysis and measurement of your home from top to bottom -- including your air ducts and air flow system.
Also, as part of this analysis, make sure that your central air conditioning contractor performs a load calculation. This is a mathematical computation that allows a contrcator to precisely estimate the performance needed to adequately cool your home and the capacity that will be required for your new air conditioning equipment to deliver that performance. A load calculation is good way for you to make sure that the central air conditioning equipment you’re buying is not over-sized or under-sized. Be sure to ask for a copy of the load calculation to be submitted with the proposal; this will assure you that the contractor takes capacity design seriously and that he’s not just going through the motions.
Related Air Conditioning Information from Horizon Services...