[Jim Davis]

A couple of simple fixes for this kind of a problem.

On the air intake, have a tee installed indoors on the intake line just inside the wall. If the intake becomes plugged or restricted the proper amount of air will be drawn from inside and the air will actually be tempered which will improve the efficiency of the furnace.

The vent can be terminated with a swing tee, going up a down. Then a short piece of pipe can be installed on the top of the tee to extend it up. Most of the time the furnace will vent out the bottom but should the snow start to cover it up it will vent out the top. The temperature of the flue gas 110-130 degrees should be enough to thaw it out during the run mode and keep it open.

 

[larobj63]

A couple of simple fixes for this kind of a problem.

On the air intake, have a tee installed indoors on the intake line just inside the wall. If the intake becomes plugged or restricted the proper amount of air will be drawn from inside and the air will actually be tempered which will improve the efficiency of the furnace.

Interesting. That would work, but you essentially just put a 2" hole in the wall that's always wide open.

 

[Jim Davis]

Interesting. That would work, but you essentially just put a 2" hole in the wall that's always wide open.

The air intake already goes through the wall. You are just adding an open tee to that pipe. Because the tee opening faces up it creates a cold air trap which would only let air in if house is extremely leaky. In that case air has to come from somewhere. If there is a water heater in the same area that would be a good thing.

 

[larobj63]

The air intake already goes through the wall. You are just adding an open tee to that pipe. Because the tee opening faces up it creates a cold air trap which would only let air in if house is extremely leaky. In that case air has to come from somewhere. If there is a water heater in the same area that would be a good thing.

"Cold air trap"

I know ther's already a hole there, but it's not wide open!

I think in practice you would feel quite a draft from the open tee inside, which communicates directly with the great outdoors. Any breeze outside creates a pressure difference next to the building sure to overpower the "cold air trap" and induce flow.

Not worth argueing over - I do thinks it's a viable option if the problem couldn't be solved in a more conventional way...

 

[Jim Davis]

In Massachusetts they have a code that makes them hang a sign 8 feet above their plastic vents that says "Vent below, do not block" for the snow to read.

How many homes have 2 - 6" pipes, one high and one low that are open holes through the wall or open grilles?

Most simple, inexpensive and viable solution other than disconnecting the intake pipe all together, but that can cause additional problems.

 

[arfstrom]

Hoar Frost, temp fixes?

I just did a search for "high efficiency furnace venting frost" I found alot of people have / had the same problem I am having. I have a High 93% efficient funace, and the intake gets full of frost on the coldest of nights.

I have used a hair dryer to blow backwards to push the frost out. since then I dont think it matters. (I used the hair dryer to push air in the exhaust pipe.)

I have put a ceramic air heater under the venting pipes in side the house, right under the pipes, where the PVC exits the house.

We (my wife and I) have used a Dryer lint filter cleaner, (bristle flexible brush that can be used to get the lint bunnies out of the dryer for the longer dryer filter types.

What every we choose to do, we have to cycle the power to get immediated (with in 15 minutest) reset cycle. Since it takes 15 minutes, (I will get distracted, and that 15 minutes gets extended by hours.) Would it make more sense to put a inferred heater next to intake pipe, or wrap that pipe with heater tape?

Problems since installed 2002 Feb.

Tobie

 

[beenthere]

Would it make more sense to put a inferred heater next to intake pipe, or wrap that pipe with heater tape?

Problems since installed 2002 Feb.

Tobie

Makes more sense to start your own thread instead of hi jacking someone elses.
Makes more sense to have the vent and intake pipes redone right.

 

[Carnak]

concentrics are only good if you can come out above the snow line.......



if you must come out low and go up the only way to do it is 2 pipes and insulate them.

when you can get four feet of snow, drifts and the furnace is in the basement all schemes will get blocked by snow and that is why you have to educate people to keep the termination clear.

Sometimes they need to be told twice and a bill for shovelling your way to the vent termination usually emphasizes the concept enough that you do not get called back again to clear out the vent and a path to it.

 

[t527ed]

when you can get four feet of snow, drifts and the furnace is in the basement all schemes will get blocked by snow and that is why you have to educate people to keep the termination clear.

Sometimes they need to be told twice and a bill for shovelling your way to the vent termination usually emphasizes the concept enough that you do not get called back again to clear out the vent and a path to it.

where you can get 4' of snow your termination should be 5' high to pass code.


drifts happen and customer should be warned to watch for them.

 

[dan sw fl]

HELP YOURself

Hoar frost forms when warmer air with water vapor in it hits a colder surface. Ice crystals form by a process of sublimation --

(anyone know whether that would be a big concern -- I mean I would assume it's not something you would want but is it really bad or just not a good idea?).

Eric

Concern? YES !

This Whole Hoar Whore story will always lead to Horrible High efficiency Home Heating operation until these two air holes are separated by an honest, high class heating tech.

What the H is this installation ?

 

[Carnak]

where you can get 4' of snow your termination should be 5' high to pass code.


drifts happen and customer should be warned to watch for them.

never going to be above the snow line coming out of a basement, not anywhere that has significant snow

snorkelling up looks stupid and will be prone to hoarfrost, concentric seems to work down to about -25F based on my experience back in the day

 

[energy star]

I never like installing an exhaust that close to a door. That exhaust could be getting caught inbetween the steps and the unit. Just my .02

 

[arfstrom]

Hoar Frost, temp fixes? got it fixed

Sorry about hijacking, in my previous msg I stated the Hoar frost issue. I found the book, and discovered that the HVAC technicians reversed the PVC tubing. The Intake air is suppose to be the shorter of the 2. Just a elbow bent down. The Exhaust can be longer. due to hotter than ambient temp. so that crystals/hoar frost will not form on the longer tube.

Hope this helps.
Tobie

Instructions, why didn't my HVAC techs read it to begin with????