Manual J load calculationSelecting a new HVAC system almost always requires a Manual J load calculation to find the best fit for your home. Manual J takes into account the factors that influence how much cooling and heating your home needs on the hottest and coldest days of the year.

What’s Included

The overall energy efficiency of your home is the primary component of the load calculation. The amount of insulation, window characteristics, air leakage in the home’s envelope all contribute significantly to its heating and cooling load. The design of the floorplan, number of stories and your family’s temperature preferences also contribute to the size of the new system you need.

How It’s Conducted

HVAC professionals use Manual J load calculation software to find the best size for your home. They will measure the window sizes, determine insulation values, along with estimating air infiltration, for each room in your home. Once they finish, the software returns a recommendation for the new system.

The sister software for Manual J, Manual D, helps the HVAC team determine the best size for the ductwork. Manual S helps them determine the best system for your home based on the climate characteristics.

Why It’s Important

HVAC equipment that’s too small or large for a home won’t run as efficiently or durably. Those that are too small won’t be able to keep up with the most extreme temperatures this region sees. One that’s too large will run in short cycles, which reduces system life, your comfort and drives up energy consumption. In the summer, your home will be more humid and in the winter, some rooms could be chillier than others.

The Manual J calculation helps you learn where your home has weaknesses in its energy efficiency. You’ll have a clear idea of where you need to seal air leaks, add insulation, and deal with the windows. The time and effort will increase your comfort and lower energy costs.

If you’d like more information about the Manual J load calculation, contact the experts at Mowery Heating, Cooling and Plumbing. We provide HVAC services for Indianapolis homeowners.