An HVAC load calculation (also called a Manual J calculation) uses a variety of factors about your home to determine how much heating and cooling your home actually needs. Based on how much heating and cooling your home needs, your HVAC technician can determine the correct size HVAC system for your specific home. Technicians measure various aspects of your home such as:
- Square footage
- Number of windows
- Size of windows
- Number of doors
- The R-value of your insulation
- Number of floors
- Number of rooms
- Number of appliances that give off heat (clothes dryer, oven/range)
- Type and color of the roof
- Type of foundation
- How much heat loss the house experiences
- Amount of shade the house gets from trees
Why Do I Need an HVAC Load Calculation?
Ensuring you get the right sized system for your house is very important in a few different ways. Let’s look at what happens when you have the wrong sized system. If your system is too small, it will run constantly without ever reaching a comfortable temperature. This results in very high energy bills and excessive wear and tear on the HVAC system. If you get a system that is too large for your home, it cycles on and off quickly (called short cycling) because it reaches the desired temperature quickly but this can cause hot and cold spots in your home. A system that is too large can also leave your indoor air feeling clammy as it doesn’t run long enough to properly dehumidify the air. Larger systems are also more expensive to install.
Having the right sized system is essential to the most efficient operation, best dehumidifying and the most comfortable temperatures for your home. The right sized system will also last you for its entire lifespan as long as you keep it properly maintained by a professional. When you’re ready to install a new HVAC system, we’ll do an HVAC load calculation to ensure you get the right sized system for your unique home. That’s cool!