We're starting to consider replacing our natural gas furnace- it's a 1965 vintage and we're thinking we might do well to update it
We live in western Montana, wintertime lows average in the teens, but we do periodically see double digits below zero.
The structure is a 1965 doublewide mobile with two stick-built additions, for a total of about 1,300 sq.feet on one level,though we plan to add another 250 sq.feet in the next 2 years- expanding the kitchen and converting the greenhouse to a sunroom- we have upgraded the insulation, especially under the building.... My question is what brand or type of furnace should I be looking at?

The average life of a furnace is around 20-30 years if well maintained.

You got 42 years. WOW and I mean WOW. Are you sure it has not been replaced?

While the dealer I worked for was a Carrier dealer, I am not recommending them specifically. All major manufactures are good and to many to list here. By the way, Carrier makes several different brands under different names.

New furnaces are not your old stand by any more. Today they must meet certain energy saving requirements as well as safety. In the old days, you could swap parts between brands as they were just about universal. Today’s units use parts design by the manufacturer for that particular unit. To get the most btu for gas used. They are computer controlled and parts only fit units they were designed for.

Today’s units get between 85-95% out put. This means for every btu energy input you will get 85-95% heat energy out put. For an example, your furnace now gets around 70%. May be.

This efficiency comes at a price. First is the initial unit cost. Then comes the cost of repairs. You are stuck using that brands parts and controls. You will have to use a dealer to service your unit if you want it done right.

Start by talking with friends and neighbors who have replaced their furnace lately. Then talk to contractors, get their literature and start reading. Get their advice on how to handle your situation with the additions now and planned in the future.

Sizing is going to be your problem. You have added on and are considering adding more. I might conceder a “Zone” system for your house. This type of system uses a nominal size furnace and several zone area thermostats. Only the zone that needs heat/cool will get it. When the area is satisfied, that zone shuts off. If all zones are satisfied, the unit shuts off.

By doing this, you can keep the bed room at 65 degs and the living room at 72 degs. If you like. That is just an example. Also, you are not over heating the area where the thermostat is just to heat that back room.

Sorry if this is long but I wanted you to be informed. If you wish to talk to me one on one, drop me an e-mail address that I have posted.

quote:

Sorry if this is long but I wanted you to be informed.

PLEASE! Don't apologize for being so complete in your reply! That's exactly the sort of thing I need- I think the "Zone" system is something I really need to look into- my spare bedroom certainly does not need to be kept very warm, and that sounds like a great way to reduce "wasted" heat...Thanks for giving me a few avenues to explore before we make a decision.
(And yes, the existing unit IS the original- pretty amazing!)

If the brand name of the furnace rhymes with "Junk-it-all", buying it is a risk. (WoW will gets this.) My new furnace went out after a little over a year's service. Yes, I saved over a thousand when I bought it, but I lost money when looking at the big picture. Spending an extra grand out front means you are paying $50 a year more (based on WoW's 20-year life span) for the reliability and confidence that comes with a higher-end brand. I wiah I had done that.

Here is a web site that may help.

Buy A Furnace

My husband works for a furnace/ AC company and they mostly install Rheam Contour furnaces. I will see if I can snag him tonight and see what he thinks about your specific situation.

Okie dokie, the Furnace Man has spoken. Unfortunately, without actually coming out to your home to do a review and estimate, it’s really hard to say exactly what your best route would be.
A lot of companies around here do free estimates for your home, so if that is an option you could call several companies and compare what they say with what your internet research tells you.
If your situation involved a house, we would absolutely recommend a Rheam Contour or an American Standard, but with a mobile home everything is different. Some manufacturers simply don’t make furnaces for mobile homes, and there are different codes regarding mobile homes -and different codes in different states. A heating and AC company out there would have a better handle on your needs and what sorts of codes you need to be following -and on what is even available.
He was skeptical about a zoning system in a mobile home, as well, as the ductwork would normally run underneath the home in the unheated space, and installing a zoning system that would work effectively could be very difficult. But again, your local companies could take a look at the situation and make a determination.

So I guess really your best bet is to check out the Yellow Pages and have several companies do an estimate to tell you what they think you should do. If you get some more information from them about what they suggest and post it, we might be able to give you some more input. Mobile homes are usually pretty tricky, though.

Good luck!!