HVAC Sizing Question - HVAC - DIY Chatroom Home Improvement Forum

Go Back   DIY Chatroom Home Improvement Forum > Home Improvement > HVAC


Thread Tools Display Modes
Old 11-03-2010, 06:39 AM   #1
Join Date: Nov 2010
Posts: 1
Rewards Points: 10

HVAC Sizing Question

I live in the Peidmont of NC and just purchased a house built in the Late 50's, a Cinder Block house. still has old windows so it gets cold in hte winter. I am replacing hte HVAC Package unit with a new Package heat pump. the house is 1400 square feet. My question is from my calculations the correct size for HVAC would be 2.5 ton ...BUT I think that I neeed to up it to 3 ton. Please advise


hawks000 is offline   Reply With Quote
Old 11-04-2010, 08:08 AM   #2
Joe F's Avatar
Join Date: Jan 2008
Location: Washington, DC
Posts: 295
Rewards Points: 294

Have your HVAC contractor do a load calculation. Not sure how you came up with 3 Ton, but the correct way is to use Manual J (for cooling) and the corresponding manual for heating. It is a fairly involved process. In the Eastern part of the US, you round down (for cooling) rather than up because of the need to remove moisture from the air.


If you don't stand behind our troops, please feel free to stand in front of them.
Joe F is offline   Reply With Quote
Old 11-04-2010, 08:05 PM   #3
Im a N00b Here!
Join Date: Nov 2010
Location: Charlotte NC
Posts: 7
Rewards Points: 10

I second that suggestion for sure... You can really shoot yourself in the foot when installing a larger unit to an older home as well, as you need more return air for the larger system. Its not just.. "Install a 3-ton"... its Install a 3-ton, add a second return air run to increase the volume going back to the unit so it doesn't turn into a block of ice, and sound like a vacuum cleaner! :-)

Have your contractor run a load is a great way to get it right!
GasFurnaceGuide is offline   Reply With Quote

heatpump , hvac , old house , sizing

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Complicated HVAC / Thermostat Question tlynch99 HVAC 11 10-28-2010 08:12 PM
HVAC Humidifier Question rubicon789 HVAC 8 01-13-2009 11:06 AM
Basement Renovation Question KUIPORNG Remodeling 234 08-26-2008 08:19 AM
Question Re: New Furnace and Duct Sizing DSimo HVAC 3 06-17-2008 07:24 AM
Sub panel sizing and distance question fburke Electrical 13 06-11-2008 06:33 PM

Top of Page | View New Posts


Search Engine Friendly URLs by vBSEO 3.6.1