Question about high efficiency Furnace Exhaust

[Pep]

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

[WDS]

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.

[Steve Barker]

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

[houli1955]

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.

[Tom The Great]

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 @

[yourname]

The condensed water is acidic, so if nothing else drains in there and it is cast iron or copper, could very slowly eat it up. My condinsigs at work drain outside, and I get a huge icicle in the winter. They changes it to drain into my slop sink and I keep a bag of marble chips under it in the hope of neutralizing it somewhat. It does eat the rocks away...

Under no conditions let this idiot inside your house again

No, and no.

Actually the condensing furnace exhaust has less moisture in it than the standard[remember the drain?]

[TH]

Be careful of CO if you open the window during the heating season.

[EXT]

I have had a high efficiency furnace for over 20 years, one of the first ones. It exhausts out the side of my basement wall with a "tee" on the end of the pipe to split the exhaust up and down. While there is a cloud of condensation when it is running, it creates no problems, sometimes a small mound of ice on the ground below. It is in a corner of an "L" and does not cause icing on the walls around it. Check other installers, that one doesn't want to install the high-efficiency furnace, probably because he has not learned how to do it properly, which is bad because they have been around for 25 years.

[Bubba]

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

[Goedjn]

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.

[Steve Scott]

[Pep]

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?

[<kjpro]

[Art Todesco]

Except on some models where a 90 degree elbow towards the ground IS required. Duh!

[Rick Blaine]

Certainly in Calgary... I would just point out for the lurkers that the difference in cost between the 80 and 90+ furnaces in the less extreme parts of the continent can make the payback a long, long time. YMMV.

[Steve Barker]

Mine&#39;s got a 90 on it. Would you care to elaborate on your incorrect sarcasm?

[Steve Barker]

No it&#39;s not the same guy. Read.

[Bubba]

Then you&#39;ve got a cheap one piper so I really dont give a shit. Spend some money, dip. Bubba