What would the minimum furnace output be for a 2100 square ft. modern house?

Question

What would the minimum furnace output be for a 2100 square ft. modern house?

Answer 1

Depends where you live, how well the house is insulated, sq ft of glass and exposure.  It is probably somewhere just over 100 MBTUH MINIMUM if you live some place it does not get too cold, but you really need a load calculation of your house to get the real number.

Your local contractor will usually do this for free because of course they want to sell you something.  Get a couple of estimates and get references.  The lowest price will not always be the best deal.

Answer 2

USA   Controlfreak38 is right.  Have a heat loss calculation performed.  That will give you the exact capacity you need.  Most places do it for free when you order the system from them.

Answer 3

You need a qualified HVAC person to provide a heat load calculations to determine the proper size and type of furnace.

Example: a standard gas forced air furnace (80% AFUE) with 80,000 Btu input actually provides 64,000 Output. A 90% condensing furnace with 80,000 Btu's input provides 72,000 Output.

Dont buy a furnace based on square footage only....get the heat load done.