Furnace BTU Calculator for Nature’s Comfort

Furnace BTU Calculator for Nature’s Comfort 2017-06-28T22:54:26+00:00

The easiest and best way to establish your BTU requirements is to look at your current furnace.
There is normally a label on the furnace that tells you the BTU output.
If your furnace is 90% efficient, you may have to multiply that amount by 0.90.
If not, call the manufacturer or go to their website with your
model number and they will tell you the rating.

Any furnace rated at 105,000 BTU NET output or less,
can be generally be replaced with our NCB-175,
assuming that it heats your home well now.
Of course if a furnace is oversized (e.g 100,000) and can really
heat your home with 80,000 BTU, then that should be considered.
Use square footage estimates below.

The NCB-175 STORES 220,000 BTU, ready for use, unlike others who give you
phony numbers of what a furnace can do at maximum output, which may be 20 minutes.
Also remember, that the home should be no bigger than 4,000 sq feet, (to use a 175)
unless in a southern climate like AR or in NC. See listings HERE

But remember, it’s more critical to have a heat exchanger with the correct output.
If the heat exchanger is too small, you will never get enough heat,
no matter how big the furnace is!

Check out our furnace BTU calculator below:


Which furnace do YOU need?

Our standard furnace, the NCB-175 is 220,000 REAL BTU – no funny math here!

A smaller one, the NCB-120 is 160,000 BTU for climates way South.

The NCB-250 is 300,000 BTU

The NCB-275G is 380,000 BTU

The NCB-325G is 460,000 BTU

The NCB-400G is 500,000 BTU

furnace btu calculator

Select Insulation Type
Square footage to heat x
Ceiling height (feet)
===>   BTU     (Watts )