Choosing the right Air Conditioner size is important. People usually go with the thought that bigger is better but not with AC. People think that a bigger unit will run less and save them money but in reality it starts and stops way more often which costs more on your energy bills. An Air Conditioner has two main jobs. The first is to cool the house by removing heat from the air. The second is to remove humidity from the air. An AC can remove heat faster than it can remove humidity so run time is crucial. When you have your temperature set at say 68 and it has 50% humidity, that feels way better than 68 and 90% humidity because the AC cant keep up. The larger AC will pull more heat out faster but leave more humidity leaving you feeling sticky and uncomfortable. A smaller system that runs longer removes humidity way better than a large system that starts and stops a lot. Another issue with larger systems is your duct work wasn’t designed to handle the larger load of air flow which makes it run inefficiently and costs you more money. . If you have allergy sufferers, higher humidity from using a larger system provides a ripe environment for dust mites and other allergens to grow and thrive. Every degree cooler you turn your thermostat you are using 10-15% more energy. Uneven temperatures are sometimes caused by over sized units in the home. You will likely have increased noise due to your ducts not being sized properly to handle the amount of air flow the larger unit will put out. Larger AC systems are more costly to buy in the first place and then with all the starting and stopping it does, the wear and tear is higher than on the smaller one that runs longer and more efficiently. You can use a method called Manual J latent cooling load and sensible cooling load to calculate what size is best for your home. The latent cooling load calculates how much moisture your AC should be able to remove under the worst case conditions such as it being hot and wet outside at peak heating in the summer. The sensible cooling load calculates how much heat the AC should be able to remove from your home at peak heating times. You can also use block load and room by room load capacity to figure out what is the best size. Block room would be like calculating for the whole house as if it were one giant open space so you wouldn’t know how much more cooling is needed for the living room versus a bedroom. Room by Room is more detailed and tells you how much air you need in each room.
Other factors in sizing your home for an AC are
-Square Footage
– Ceiling Heights
– Windows, Door, Attic, and Wall Insulation
– Appliances you may have
– How many people live there
– Where you are in the US with humidity and heat
Call Bartlett Heating and Air today to have one of our technicians come out and help you determine the best size AC for your house!
