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HVAC Forums => HVAC Help => Topic started by: nash668 on May 03, 2015, 07:43:56 PM

Title: Sizing An AC
Post by: nash668 on May 03, 2015, 07:43:56 PM
How does one size an A/C? Planning on installing one in my house in up coming weeks.

Any help would be appreciated.

Thanks!
Title: Re: Sizing An AC
Post by: Admin on May 04, 2015, 06:09:44 AM
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.  ;D
Title: Re: Sizing An AC
Post by: nash668 on May 04, 2015, 06:28:31 PM
Built in 2011, so new house.

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