Frozen intake elbow.

[Needingadvice]

Hello, we live in a 1 year old, energy star home. We have 90+ high efficiency furnace. I noticed this morning we had some water dripping onto the basement floor. Upon closer inspection I seen it was coming from the intake pipe. It was frozen and dripping water. I'll post some pictures to help out. Why would this be happening? It is only -15C outside and gets much colder during Jan and Feb. I'm worried...

[jdblack]

Is your basement conditioned space?



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[qwerty hvac]

It is because it is not insulated.


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[Needingadvice]

By conditioned what do you mean??

[syndicated]

By conditioned what do you mean??

Are you in southern alberta? I ask because its probably the only place it's -15 in all of North America right now.
That pipe should be insulated all the way to your return air trunk, the ice on the pipe is frozen moisture from your home.
If there is a damper on that pipe, (a small handle) closing it may help.

[skippedover]

The cold, below freezing outdoor air is causing the warmer basement air to cool on the pipe surface, which reduces the temperature sufficiently to cause condensate water to form on the pipe. It is further exacerbated because the incoming air is below freezing, causing frost to form on the pipe. I'd recommend an HRV be professionally installed. The HRV (heat recover ventilator) will remove Btu's of heat from air being removed from the home and deposit them into the incoming air, thus warming it to some extent. This will save you some energy rather than having that -15°C cold air going directly into the return air for the home.

[Needingadvice]

Lol, yes we are in Southern Alberta. I contacted my home builders new Hvac company and they said they will come out next week to address the problem. Frustrating considering this is a brand new home...

[syndicated]

I notice by the joists you probably paid more than a couple bucks for that place.

Ask them about putting an hrv in. New homes are too tight for a passive fresh air supply to do any good, especially when they're not installed correctly. If you don't have any luck with them, call my company.

[Needingadvice]

The scary thing in all of this is the seemingly lack of knowledge by the company or more the employees that installed this furnace and ducts. Especially living in southern Alberta where the temps can drop to -35C at times. Makes you wonder what else wasn't done correctly. So should this be something covered by new home warranty?

[Needingadvice]

Thanks syndicated, sounds like a plan. Are they much to install?

[syndicated]

Thanks syndicated, sounds like a plan. Are they much to install?

We can't discuss pricing ofcourse, but they're not too bad.
The frozen pipe issue would be covered by new home warranty. Hrv install wouldn't be. Perhaps you could make an arrangement with the company?
Or if you're near Calgary, call Arpi's.

[Needingadvice]

Thanks a ton everyone for all the great info. I'm down in Lethbridge Syndicated so I'm not sure your company would drive 2 hours for a small job, but I'll mention the HRV to my local company on Tuesday and get a quote.

[pacnw]

in pictures 1 and 3 there is a handle on the duct, CLOSE it!!! you might also go to the outside of the house where the intake to this is and block it with something to keep that air from even getting into the pipe.

a little education;

this is a fresh air intake and not combustion air for the furnace. this can be on any unit,(gas, electric, oil) not just a 90% furnace.

as has been said this needs to be addressed by the installation company. others can speak to the effectiveness of insulation on that pipe, but why bring in cold or hot air to condition it, especially in extreme temperatures!!??

I would think insulation would only shift the freezing/condensation to the return duct where this connects.

[syndicated]

in pictures 1 and 3 there is a handle on the duct, CLOSE it!!!

a little education;

this is a fresh air intake and not combustion air for the furnace. this can be on any unit,(gas, electric, oil) not just a 90% furnace.

as has been said this needs to be addressed by the installation company. others can speak to the effectiveness of insulation on that pipe, but why bring in cold or hot air to condition it, especially in extreme temperatures!!??

Because a fresh air supply no less than 12' upstream of the blower is code in this jurisdiction.
The damper is cut in half to prevent closing off the supply completely.

[Needingadvice]

I like to run my vs speed furnace fan year round, so would closing the damper effect this in anyway??

[syndicated]

I like to run my vs speed furnace fan year round, so would closing the damper effect this in anyway??

It won't affect the fan itself.
I'm not familiar with city code in lethbridge. In Calgary, on a new home, the fresh air intake must be balanced against the exhausted air through range hoods, bathroom fans and any other powered exfiltration of air.
All these systems should also be interlocked together so when one exhaust comes on, a powered intake fan will turn on to make up the lost air.
This is thermally inefficient, hence the HRV.

[Needingadvice]

I think that it was balanced this way when we moved in as when we turned on switch, the bathroom fans went on also. We had ac installed in spring and they made it so we could run furnace fan without activating bathroom fans etc.

[Needingadvice]

Well they came back and fixed the problem I hope. They ended up insulation the pipe itself. Is this a satisfactory fix?

[heaterman]

Check the insulation around the pipe periodically to make sure it is not holding moisture but I would expect with those types of tempuratures that the problem will just move inward toward the duct itself. The HRV is the best solution.

[Needingadvice]

I asked him about an HRV and he said it wouldn't be a good solution. Instead he said he could install a fan in the ducts that would warm the air before it hit the furnace. I don't know enough to know what to do.