Gas Furnace Installation Costs

Hi.

This isn't so much a Do-it-yourself question so much as it's a "how much to have someone else do-it-for-me" one.

I've bought a house recently that has the original furnace in it....from 1983, meaning the thing's 25 years old. It's apparently been problem free and correctly maintained, but at that age it's also living on borrowed time and sending a lot of heat (and my $20 bills with it) up the chimney. Living in Canada with winters where the overnight temp sits below -20C for a couple months at a time, furnace efficiency can save a lot of money.

That, and the gov't here is offering about $2,000 worth of rebates to swap out the old furnace/air conditioner with a new, high efficiency (mine 92% AFUE/13 SEER) set up.

Anyways, the Ducane stuff I'm getting comes with a name of a company that will install the equipment. Here's the "problem". I have no idea what a fair price for installation is. If the guy tells me it'll cost $XXXX, absent education, I'll believe him and pay the bill. I also have no idea what's a reasonable cost to have the furnace/ac sized. I'm hoping everything is pretty much just a straight swap with minimal duct work (maybe some to remove a real cold zone in the basement). Lastly, I have no idea how to tell if this company's any good, or whether I should shop around and see if any other company might be interested in installing my equipment.

So....anyone have any rough idea's to what to expect for costs (rough ranges and whatnot), and what to ask/look for with the installer? I appreciate all input....I don't know much with regards to this and so I'm REALLY at the mercy of the installer here.

Thanks.

 

I had a Lennox model G60DFV-36A-070 80% AFUE, two-stage variable speed blower gas furnace installed in March of 2006. The total cost was $2,800. US.

I had five different companies bid on this job and none of them offered to do a heat loss calibration but they all asked me if the current furnace kept me warm without complaint and if any major work had been done to the house that would reduce the amount of heat required like new windows or added insulation. I finally asked one of the salesmen why nobody was offering to do a heat loss calculation and the response was that knowing the typical insulation and construction of the year my house was built along with the size of the present furnace and the knowledge that no improvements or changes had been made to the house they were pretty confident on sizing the furnace the same as the original.

Being a (retired) engineer who dealt with heating systems (albeit on a commercial/industrial size) I wasn't too happy with this answer but as it turned out all the proposals were for the smallest furnace made with the criteria (two stage, variable speed blower and downflow) I had requested.

The only thing that had to be modified in my case was a new transitional duct from the existing electronic air filter to the top of the furnace and the normal electrical and gas piping connections.


In your case I would recommend that you have a 90+% AFUE, two-stage with a variable speed blower. I would recommend that you insist on a complete "Manual J" heat loss calculation to determine the required size of furnace rather than assuming the original was correctly sized. This is especially important if any changes have been done to the house that would materially change the heat loss calculation from the original.

Try to get them to run the heat loss calculation using design temperatures that are specific to your lifestyle and the actual outside temperatures that you experience AT YOUR HOUSE. All too often the "standard" design temperature inside is 74 degrees F. (a temperature that would have me sweating and wearing nothing but underwear) and the "standard" outside temperature is the coldest temperature measured in the last fifty years in the closest major city. I my area they use 5 degrees F. for the outside temperature and I have never seen it that cold in my more than fifty years of living in this area.

If you do not use the design temperatures (both inside and outside) that truly exist for your lifestyle and area then in all probability the heat loss calculation will oversize your heating requirement by as much as 10 to 20 percent so do not add anything to it for the "just in case" cold weather. You are far better off using supplemental heat or wearing a sweater for that one day, or week, out of fifty years that you experience record breaking cold.

 

Thanks for the reply furd...I'm really in the dark here. Good point on getting the house re-calculated. The house has recently had all new windows installed, and there has been some semi-major reno's done.

I'm still trying to get a hold of the one guy who's name I have. Granted I'm not in a rush per-se, but I do want it done before Sept.

Last question...I went to look at what I have currently. It's a Borg Warner, model # PU2GD10N10501A. I searched the model #, came up empty, so I searched Borg Warner...they do exist, but doesn't seem like they've made furnaces in years. Anyways, the rated output is listed as 23.33 KW or 79 MBH....I have no idea what that translates to in BTU's....anyone help me with this?

 

The M in 79 MBH is an abbreviation for 1000 so 79 MBH translates to 79,000 BTUs per hour output, not all that big of a furnace.

There are roughly 3400 BTUs in a kilowatt (KW) so that 23.33 KW translates to 79,322 BTUs per hour.

My furnace has a rated output on high fire of 66,000 BTUs and the next size up is rated at high fire 72,000 BTUs and on low 48,000 BTUs. I don't offhand know what a upflow or 90+% model might be rated.

Sizing of the furnace is a bit less critical when you have two stage firing because you size the maximum (high fire) rate to the calculated heat loss and the furnace usually fires at the low fire setting.