1. When sizing your Williams furnace, you are welcome to use the free BTU sizing calculator provided by Williams. Please keep in mind, this method will provide a general calculation and is not a substitute for an "engineered calculation."

2. When sizing Mitsubishi Electric products, use the link below to access a BTU calculator provided by Mitsubishi electric. You can use the calculations given to help find the right system for your application.

Additional conditions may factor into your actual cooling or heating needs. Please contact your contractor or Mitsubishi Electric for a more accurate determination of your specific cooling or heating needs.

3. Sizing your heating and/or air conditioning system for you home can be more involved, due to variables to take into account such as insulation, square footage, climate, ceiling height, windows, etc. To help take the guesswork out of all this we have partnered with HVAC Computer Systems Ltd. This in depth sizing software can be purchased and downloaded by clicking on the logo provided below.

The cost is only $49.00.

4. Have a certified contractor visit your home and perform load calculations on site.

Click to purchase