HVAC Sizing 1

[jobeth]

I am interested in sizing a home air conditioning / heat pump system. Is there any standard information I can get inexpensivly to do the sizing of equipment and duct work?

 

[kmuhsen]

You can buy ASHRAE fundemental volume which icludes all information you might need in your design.<br>Please visit <A HREF="

http://www.ashrae.org"

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http://www.ashrae.org</A>

to get information how to buy these books

 

[Steverino]

If you are not experienced in HVAC systems design, check your yellow pages.&nbsp;&nbsp;Contact your local heat pump contractor.&nbsp;&nbsp;They are usually more than willing to work with you on load calcs, equipment selection, duct layout, well field design, etc.&nbsp;&nbsp;You could do it yourself, but if something goes wrong, you only have yourself to blame.

 

Jobeth, Their are many different factors that affect the heat pump units size (local weather, your building envelope, number of people occupieng the house, house square foot area, total glass window square foot area, solar heat gain through wall, windows, and roof).&nbsp;&nbsp;<br><br>Local weather is important when sizing heating and cooling equipmnet.&nbsp;&nbsp;<br><br>A rule of thumb that is used in the HVAC industry is approximateley 400-450 CFM/Square foot. CFM (cubic feet per minute). First calcualte the total square foot area of you home. Then divide that value by 400 CFM/Square foot to attain a conservitave estimate of the cooling tonnage that your heat pump equipment will have to provied.<br><br>When sizing your heating equipmet in California we use 30 BTU/square foot.<br><br>Multiply your total square foot area by 30 and this will give you your total heating capacity [Btu].<br><br>For a residential aplication you should consider a natural gas furnace with an A-frame coils w/ a condensing unit for cooling.&nbsp;&nbsp;If natural gas heating is available it will save you money on your utility bill.&nbsp;&nbsp;You should also make sure that the EER (energy efficiency ratio) on your condensing unit is as high as you can afford to purchace.&nbsp;&nbsp;A standard unit has an EER of 9, while a high efficiecy unit has an EER of 11 or 12.&nbsp;&nbsp;The energy efficient unit will cost more upfront, but it will save you momey for the entire life span of the equipment.<br><br>Refer to the DOE (department of Energy) website to get more details on estimating the HVAC equipment for your house.

 

[jobeth]

Thank you all for your advice. <p>William H. Bernhart, P.E.<br><a href=mailto: > </a><br><a href= > </a><br>

 

[mwolf]

I am interested in purchasing a space heater for my home. Is there a rule of thumb for how many BTU are required per square foot that anyone is aware of? Any other method to ensure correct sizing? Thanks