Sizing An AC

[nash668]

How does one size an A/C? Planning on installing one in my house in up coming weeks.

Any help would be appreciated.

Thanks!

[Admin]

What type of house is it and how old?  Is it a tight house or a loose house?

Measure the square footage, excluding the basement.

Usually you can divide the square footage by 850 for an older loose house, or divide by 950 for a newer tight house.  The answer would be the tonnage that is required.

The HVAC designer would be upset with my advice.  They would use software to do a proper heat gain / heat loss calculation and factor in the number of windows, bedrooms and exposure to sun.

My way is just a basic rule of thumb. 

[nash668]

Built in 2011, so new house.

Perfect thanks for that. I'm sure when you go size a job you get engineers involved.