With weather as wishy-washy as Virginia, it may seem like a good idea to maximize your HVAC system to ensure that your furnace keeps you warm all winter long and your AC can blast away the heat of summer. But trust us when we say that bigger isn’t always better, especially when it comes to heating and cooling. Here’s why you shouldn’t pick a furnace or AC that is too big for your home and how to pick a correctly-sized HVAC system.
The heating and cooling are weaker
You might think that a bigger and, therefore, more powerful system would mean a higher comfort level for you and your family. Believe it or not, the opposite is true: an oversized system will produce weaker heating and cooling.
Here’s what that would look like: In the winter when the furnace turns on, you get a huge amount of heat but all at once. The system shuts off because the thermostat got all that direct heat and thinks the system has done its job in warming up your home. As a result, there is uneven heating and the entire house doesn’t get warm because the heater hasn’t run long enough to reach every part of every room.
In the summer, you run into the same problem with an AC that is too big and powerful for your home. It comes on strong then shuts off prematurely, never treating and cooling the whole house. Not only is the air too warm but it’s also too humid. An essential part of an air conditioner’s function is dehumidification when it removes excess moisture from the air making it cooler. But this part of the process takes time, time it will never have if the AC continues to turn off right away. The AC will never be able to fully operate and remove the extra water vapor from the air.
The HVAC system will wear out quickly
As the HVAC system continues to operate in this pattern, turning on, blasting heat or air, then turning right back off, it causes the system to wear out very quickly. This is called short-cycling.
An HVAC system usually works with the furnace or AC switching on and off a few times every hour, staying on for at least 15 minutes. When it’s short-cycling as a result of the HVAC system being too large for the home, it switches on and off more frequently than it should. The sudden shifts from hot to cold put strain on the components of your HVAC system. The heat exchanger may crack which means you will need a new furnace. All this extra work can take years off your system, forcing you to replace it prematurely.
Cold air in the winter, hot air in the summer
With an oversized HVAC system, you will probably have the problem of cold air coming out of your vents. Why? Because the furnace is doing its job too efficiently and it’s giving off to much heat all at once. The system pushes the warm air through the ductwork but, in small spaces, the sudden blast of hot air can’t go anywhere so it backs up in the vents and is pushed back to the furnace.
As that thermal energy builds up in the furnace, it can start to damage the system as a whole. Your furnace will then shut off in an attempt to alleviate the issue and then blast cold air to cool itself down and prevent damage. That cold air ends up blowing through your vents and, in the dead of winter, that is the last thing you want.
How to pick the right HVAC system
So, how do you pick an HVAC system that’s right for your home? This is a job for a professional. A professional has the expertise to do a load calculation that takes into account airflow, ductwork, the home’s square footage, and the layout of the rooms. This analysis tells them how much heating and cooling you’ll need in your home and what challenges you may face with circulation.
If you feel you have an HVAC system that is the wrong size for your home or are on the market for the perfect sized HVAC system, give us a call. We’ll help you find the furnace and AC that’s right for your home.