Question about high efficiency Furnace Exhaust

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I have had two contractors in to price out a new high efficiency (90%) gas furnace for my 25 year old home located in Calgary Alberta. So we get some pretty cold days
Both have said that a new horizontal exhaust is required out the side of the house. Both contractors will also drain condensed water from the furnace to a floor drain inside my basement.
One didn't recommend the high efficiency furnace. He said that the new exhaust will produce a sizable condensation cloud which will frost over a window which is about 3-4 feet above the exhaust. As well he thought condensation would freeze on my neighbors house which is about 6-8 feet away.
Does a high efficiency gas furnace really produce a cloud of condensation? (It gets quite cold here, with a lot of freeze thaw cycles over the winter)
Would the furnace exhaust come out with enough force to frost up my neighbor's exterior wall 6 feet away?
thanks
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Pep wrote:

Yes it does. However...

We have a 90+% efficient furnace and while there is a bit of a cloud it would not frost up a window 6 feet away. I suppoe the ones they recommend could be different, though.
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It is not that bad. I know of two units, one across the street from me, the other is a tenant in our warehouse building. I've never seen condensation on the walls and never saw it go so far that it would be on a neighbor's house.
--
Ed
http://pages.cthome.net/edhome/



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I wonder if he's ever heard of an ELBOW.? Aim it down or sideways and it should avoid both problems. DUH
--
Steve Barker


"Pep" <spp snipped-for-privacy@yahoo.com> wrote in message
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My 93.5% Lennox does not produce enough condensation to cloud anything. Call any manufacturer for recommendations. Do you want to save 12-15% for ever, put in a 94.5% unit. You should not consider anything else but Condensing. I believe in England condensing is Law for replacement. England exports NG and is warmer than the US - Canada, maybe we- U.S. need to learn from the europeans.
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My neighbors house is 4 ft away from my condensing exhaust , no it does not affect it at -15f nor would it affect it at 2ft away if they had any wall insulation or not. You gotta idiot hacko telling you this, must be from the althvac group.
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m Ransley wrote:

Do you know how cold it can get in Calgary? How about -35C with wind chill of -50C-ish? Not all the time but there are days like this. Here in old neighborhood house to house distance is ~10 feet, in higher density new neighborhood it's ~8 feet.
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Tony Hwang wrote:

I live in Saskatoon, so I feel I can comment based on similar weather.
At -35 (windchill of about -45) my condensing furnace did not cause frost on my car ~6ft away or on the window directly above the exhaust. Also, my neighbor's condensing furnace didn't cause frost on my wall which is about 6ft from his house.
Chris
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On Wed, 17 Jan 2007 10:52:48 -0600, Chris Friesen

You're more likely to get frost deposits when the air temp. is rising to right around freezing, and the surfaces are still colder. at -35F, water vapor will freeze too fast to deposit on surfaces.
I still think I'd put the furnace in anyway, and worry about sticking a baffle or something on the output only if it proves to be a problem.
--Goedjn
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On Tue, 16 Jan 2007 22:15:18 -0600, "Steve Barker"

Down or sideways? Duhhhh yourself. Obviously you've never looked at the installation manual on venting a 90% eff furnace. You would have many many callbacks with that "fix". Bubba
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wrote:

My inclination, (without benefit of instructions) would be to 'T' it into a larger pipe, pointed up and down, and open at both ends. But not until a problem became apparent.
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Goedjn wrote:

Thanks for the input everyone. Like some have suggested that particular contractor was pretty negative on the high efficiency furnace. Due to my finished basement any new ducting would be a pain to install compared to a simple mid efficiency furnace.
I did get a total or four bids. Two would only install mid efficiency. (the laziest and least knowledgeable IMHO). The other contractor who would install high efficiency was particularly thorough and followed up well on my questions. And like many have suggest exhaust condensation will likely not be an issue after asking more questions.
So a new Trane XV90 is being installed next week. Anyone know where I can get a Trane installation manual?
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Congratulations on the purchase of your new Trane furnace. I think you were wise to go with a high efficiency model; natural gas prices will continue to trend higher in years to come and so you'll want to squeeze every last BTU from each cubic foot you burn.
There is a link to the owner's manual on this page: http://www.trane.com/Residential/Products/Furnaces/XV90.aspx
Cheers, Paul

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This is the guy who's going to put his gas valve in. Wonder if we'll read about him?
wrote:

--
Fall seven times, stand up eight
--Japanese proverb
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No it's not the same guy. Read.
--
Steve Barker


"Steve Scott" < snipped-for-privacy@twcny.rr.com> wrote in message
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Bubba wrote:

elbow towards the ground IS required. Duh!
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Mine's got a 90 on it. Would you care to elaborate on your incorrect sarcasm?
--
Steve Barker



"Bubba" < snipped-for-privacy@iname.com> wrote in message
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On Thu, 18 Jan 2007 11:14:49 -0600, "Steve Barker"

Then you've got a cheap one piper so I really dont give a shit. Spend some money, dip. Bubba
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I have a high efficiency Amana vented horizontally just above the sill plate. It's 12 degree's f here in Michigan now. There is less condensation coming out than when you start a cold car to give a comparison. i have a bedroom window about 4 feet away that has never had condensation on it. The bushes 1 foot away look no different than those 15 feet away. This will be our 3rd winter on this furnace. I'm happy with it.
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imho:
I have a 90%+ unit, and never saw any of this 'frost'. Now I don't have a window over my flue either, but I do have a wall about a foot away from the exhaust. No frost.
Might want to get that third estimate. Also, check with your accoutant, if you don't get your high effeciancy rating, you might not get the tax credit, and the cost of fuel over the years could have you kicking yourself.
Just thinking out loud....
tom @ www.MedJobSite.com
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