60,000 vs 80,000 BTU furnace

[CurbYourEnthusiasm]

One contractor offered a 2 stage 80,000 gas furnace and when I asked him (the other quotations I have are for a 2 stage 60,000 gas furnace) why he - "The furnace that we are going to install will run most of the time on low fire, which is around 50,000 BTU's. We recommend this furnace over a 60,000 BTU because the 60,000 will have to run a lot longer because it will be running on low fire which is around 35,000 BTU."

I liked him a lot; he saw the chimney flue loose (and the house inspector had mentioned it in the report) and he fixed it right away (he just pushed it properly in place). I wonder whether the other contractors saw this 'issue'. So I would have given him the contract even if a few hundred $ more expensive.

But now, I do not know what to believe.

Were all the other contractors wrong by offering a 60,000 *

[Freon]

Where do you live... north pole or south pacific island. I ask because much of the decision for heating is based on the severity of your winters.

What make, model and size is the current furnace. Has it been sufficient at keeping you comfortable on the coldest winter night.

The ideal size for a furnace is based on the coldest winter night. You want a furnace that will run constantly and keep you just comfortable. A furnace that's over sized will cycle on and off reducing overall efficiency not to mention increasing wear and tear. Also, does the existing furnace supply good air flow from all registers. If you reduce the BTU per hour you will also reduce the blower air flow and may find insufficient heating at the rooms on the end of the ducting. Your duct system will dictate the cubic feet per minute of air flow you should have.

[CurbYourEnthusiasm]

The house is around 1,700 square foot and it is near the Vancouver (BC), moderate climate.
I have a very old oil furnace now.

[Freon]

I need to know the BTU per hour INPUT. It should be on a data plate attached to the furnace. Given it's an old furnace it may be between 70 to 80 percent efficient. If you have the make and model, even better. Does this old furnace keep you comfortable.

Since you live in a moderate climate you really don't need a super sexy furnace. Many exotic designs are great on paper but they have the ability to require more maintenance. And the list of qualified service people may be less than for a simple furnace. Air flow is another issue.