DIY Home Improvement, Remodeling & Repair Forum

DIY Home Improvement, Remodeling & Repair Forum (
-   HVAC (
-   -   What BTU need to heating up 3000sf house (

lk2121 03-30-2012 08:49 AM

What BTU need to heating up 3000sf house

Have question about BTU calculation.
Friend of mine look for the house and one that interested in but owner changed HV unit week ago before put on the market and unit looks very small then checked has only 88,000BTU. House is 2980 sf include basement,
Is that enough to heating up the whole house and colling down during the summer?
It is Lennox model number 180, 190 or 195.


paul52446m 03-30-2012 10:03 AM

would need a lot of info to do a heat loss.
What area do you live in, and how cold does it get?
Sq' of out side walls and what insulation in those walls?
Sq' of ceiling and how much insulation in attic?
is basement walls insulated? with whit? and how far above ground are the basement walls
What is the Sq' of windows and how good are the windows.
In a 3000 Sq' home you should be moving 2000 CFM of air to mix the air in the house. That is about the biggest blower you can get in a large furnace.
As you can see it gets real involved engineering out a good system for a home.

classic 04-10-2012 07:06 PM

This is a situation that you need a professional evaluation - you need what the business referrs to as a Manual J heat gain-loss calculation. The furnace deals with the heating (heat loss) side, while the heat gain refers to the cooling requirements. It takes in account insulation, windows, orientation, etc to tell you exactly what you need

I have a feeling that the furnace output of 80 to 90,000 btu might be fine for your area, but you need a professional to check the age and efficiency.

In Pittsburg it may well be worth it to invest in a 95% AFUE furnace (it's so efficient that it vents in PVC pipe) It will save you a ton of money

All times are GMT -6. The time now is 03:39 PM.