What is HVAC Load Calculation?

What is HVAC Load Calculation?

Lisa Crosley, President, Lifestyle Comfort Solutions, explains that selecting the right size heating/cooling system for your home isn’t rocket science, but it is building science!

When it comes to home comfort, bigger is not better! In fact, the US Department of Energy estimates that the majority of heating/cooling systems in American homes are over-sized.

Over-sized equipment results in more frequent maintenance, uneven temperatures, and uncomfortable humidity in the home.

Lifestyle Comfort Solutions embraces an industry best practice called Load calculation when helping its clients select the perfect heating/cooling system for their home or business.

What is Load Calculation?

A load calculation, sometimes referred to as a Manual J calculation, is a mathematical formula which takes into consideration critical factors in home comfort and performance such as:

  • Total Square footage of the building, and how it is distributed between living and attic space
  • Number of windows, doors, entry ways, and other penetrations in the thermal envelope (your walls, floors, and ceilings)
  • Year-round weather data
  • Insulation: location, type, application, and other factors
  • Lifestyle and building use
  • Landscaping around the home
  • Condition and size of duct work
  • Window coverings

That’s a lot to consider. But a load calculation determines the best size, application, and HVAC system to achieve your goals for comfort and energy usage. Moreover, a load calculation helps to pinpoint large scale issues which may require repair for you to enjoy ultimate comfort.

How is a Load Calculation Completed?

In some instances, Lifestyle Comfort Solutions can make an accurate load calculation from its offices, using blueprints and information the homeowner provides, and through public county records.

In some instances, we’ll visit your home to gather necessary information.


Some heating/cooling companies offer online price calculators or recommend replacement equipment based on what is currently installed in the home.

Others depend on a rule of thumb.

Lifestyle Comfort Solutions realizes that next to purchasing a home and a car, the purchase of a heating/cooling system for your home is often the most expensive single purchase many homeowners will ever face. Some may be faced with purchasing a new system just once in their lifetime.

With a 10-15-year life expectancy of your heating/cooling equipment, you’ll live with your decision a long while. Take the time to get it right.

To learn more about load calculation, and Lifestyle Comfort Solutions’ season after season commitment to comfort, call us at 937.202.4520 or visit www.lifestylecomfortsolutions.com