As we continue with preparations for the arrival of warm weather, we’d like to address a question we often hear from customers: “How cool can an AC make my home?” People often look at the BTUs of an air conditioner, which is a measurement of how many units of heat an AC unit can remove from a house per hour, as an indication of the air conditioner’s cooling power.
This is mostly correct: the BTUs removed per hour measure the air conditioner’s capacity, the amount of work it can do. An AC that is under-capacity, also known as undersized, for a house will not remove enough heat from the building to provide the desired comfort. When our professionals install a new air conditioner for a home, we carefully measure the home’s cooling requirements so we can match the air conditioner’s capacity to it.
However, capacity is unrelated to the question of how cool an air conditioning system can make a house. This is a question of the temperature differential. We’ll explain more below.
What Temperature Differential Means
Where capacity measures how much heat an air conditioner can remove from a house in a specific period, the temperature differential is how much the AC can lower the temperature of the air moving through it compared to the temperature of the air entering it. No matter the capacity of the air conditioner, it has an upper limit of temperature differential of 20°F.
So the short answer to the question in the title is that your AC can make your home 20°F cooler than it is without air conditioning.
An example of this in action: It’s a hot day in the middle of summer, around 90°F. If your house has good insulation to keep out some of the heat and you aren’t receiving extra heat through sunlight on the windows, the indoor temperature will be around 80°F. (Insulation can make a difference of 5 to 15°F). How cool can your AC make your home? The answer is 60°F—which is far colder than you want indoors! You can set the thermostat at 78°F and the air conditioner won’t need to run often to keep the house comfortable.
When you understand the temperature differential, you’ll have a better idea of how to keep your AC from overheating. Pushing the thermostat down too far may put the air conditioner in the situation of trying to achieve a temperature it cannot reach. In some cases, the AC may even freeze. We don’t recommend lowering the thermostat below 68°F, no matter the heat outside.
The Oversized/Undersized Problem
Something to keep in mind: this only applies if the air conditioning system is the right size for the home. An undersized AC will only be able to cool down a small portion of the air. That air will be 20° cooler, but you won’t have much of it and the house will remain too hot.
An oversized AC is not an improvement, since it will cause the cooling system to shut down early and begin to short-cycle, which drains power and causes extreme wear on the air conditioner.
The best way to avoid these situations is to call on our professionals when you need a new air conditioning installation in Hatboro, PA: we’ll see you have an accurate installation and a house you can always make coolly livable.
Rely on Dowd Mechanical Heating & Air Conditioning: A Degree Above the Rest.