What could cause this?

SlamDunk

The company that is mentioned in article is top notch. Comments?

http://www.wral.com/homeowners-find-green-heating-units-can-t-take-the-cold/14598654/

Jamie Hall

But suh... it nevah gets cold heah...

JUGHNE

And we never have trouble with the AC drain line when it dumps outside, so why wouldn't it work for the furnace condensate??

This is maybe new technology for the area and perhaps it used to seldom freeze there.
I have one wall dump drain up here in NE; but I added a cond pump so it shoots out the condensate in batches and has plenty of height inside for the tubing to drain out. It is on the north in the shade above snow line and so far (20 years) has not frozen shut.
This would be an interesting study of condensing furnaces located in cold attics. The garage installs probably just have problems with the drain itself. But how about the cold attic units? Did they freeze internally only because the drain backed up? From the video it looked like they might run the drain into the DWV thru the roof, that might work there but not here.

SWEI

This is not rocket science. Sounds like somebody was new to condensing appliances and did not take their climate into consideration.

SlamDunk

I'm not familiar with condensing appliances. It sounded like a miserable experience. On the one hand, you want to save fuel costs with higher energy efficiency appliances. On the other, I wonder if higher efficiencies are worthwhile during our annual two week cold snaps? Since Carrier is involved, I wonder what could have been done differently.

Zman

It looks like the builder is using a loose interpretation of "Green Home"
Installing the furnace, AC and ducts in a unconditioned attic is a major waste.
Installing the condensate line in an unconditioned space and having it drain to the outside is what is causing all the hubbub.
It is hard to believe that a large reputable HVAC company did not see this coming.

JUGHNE

Probably all furnace manf have something in the I&O manual about freezing temps for condensation drains. Nordyne does mention heat tapes or at least cautions about freezing drains.

We must realize that at that location and south of there that there are few basements. You even see water heaters in the cold attic in Mississippi. (Usually OK there).

Just a new learning curve that we could all learn from.

The Federal Govt has hopes of eliminating new installs of 80% furnaces in the future (from the north tier of states anyway.)

Matt_67

Many condensing furnaces require minimum 50 to 55 degree ambient temps and minimum return air temps as well. Up north we are not looking forward to the 80% ban - too many camps / summer places. When they shut the heat off nobody thinks to drain the condensate traps.

SWEI

Good point on the infrequent occupancy applications.

ROI is all about area under the curve and if there aren't enough operating hours, the return is lousy. Environmental impact is also proportional to both size and hours of operation. Full cost accounting, anyone?

MikeJ

1) how can a heating company not for see a problem like this, 2) why take so long for a solution. Use self regulating heat tape and insulated the lines. was able to keep water draining in blast freezers with this method. Live in Raleigh NC for a while. The furnaces were either in a crawl space or in the attic. One thing i always did like was the fact that every two story house had two systems.
One in crawl space, one in attic,
Crawl space use to have what were called love stones, sure hurt crawling on them.

SlamDunk

My guess is they built to MI 's specs.

4Johnpipe

This is absolutely installer error. the building / mechanical inspector should never have passed a job with condensate in an unconditioned space. I was called out to my mother in laws retirement community for the same thing. They installed furnaces in the attic and the condensate froze. I had 3 within eye sight of each other and there were 2 other contractors on the same block. I authored a letter and formal complaint to the builder and the township. This never should have been installed and never should have passed inspection!!!

SlamDunk

Inspections down here are hit and miss. Some inspectors will find problems to be corrected and others will pass from ten feet away. It's been in the local paper, during the economic downturn, inspectors had nothing to do. Now, they can't keep up because there is a building boom. Then again, this was an unusually cold and prolonged winter. Maybe statisticly, it was ok to install the way they did?

4Johnpipe

If you think about it where they installed those units in the attic above the insulation or outside of the insulation / thermal barrier. They effectively installed those units outside with an overhang to prevent rain from hitting them.
I simple insulated wall around the units would have prevented this. Oh but that means they actually will have to pipe the combustion air to the outside and spend and extra $20.00 in pipe and fittings.

SlamDunk

I understand now. Unfortunately the article gave high efficiency furnaces a bad rap. that's why I asked. thanks

kcopp

Another example of the "drive by media" not doing research.....

4Johnpipe

This example ties back into other discussions on other forums regarding the "costs" involved to install a properly designed and installed forced air system (with gas furnace) verse a the same for a hydronic system. I have rarely seen a duct-ed system installed in my area that meets all of the manufacturers and IECC code requirements. In fact most do not meet the majority of these requirements. I have 1 builder that understands this and sells his product as such. We usually install radiant heating or some form of hydronic for this builder.

unclejohn

What do you expect from a builder that didn't even run the air intake to the outside, that's not very green burning inside air for combustion.

hheaddon

Also looked like a lot of flex duct around those units in the attic. From the little i saw, low bid and the builder should have known better.