DV fireplaces - freezing in the winter

[webbie]

I recently received a complaint about this from a Hearth.com reader and was wondering if the technology has advanced over all these years. I know my DV (Valor) is cold as heck when it is not operating! After all, there is nothing between the great outdoors and my house other than a sheet of glass or piece of sheet metal.

Here is my answer to the person with the complaint:
"There are a couple problems here.....

1. The venting of these fireplaces is called Direct vent. It consists of one pipe with two ducts in it - one brings cold air from the outside into the fireplace burner and the other takes the exhaust out. This process happens even when the fireplace is not on, which effectively means your fireplace becomes as cold as the outside air.

2. The "chase" or frame that these fireplaces are built into - sometimes are not properly insulated or sealed. This allows the cold from outside to soak right through the metal walls of the fireplace and then transfer to your house.

(I know, at least one of my "solutions" is very dangerous, but this guy was desperate!)


As far as solutions, there are none which are conventional. Here are my comments:
1. In some weather - and on some fireplaces, the output of the pilot flame can offset some of this cold.
2. If you want to turn the gas pilot off for long periods, you might be able to try two jury-rigs....one would be making some sort of temporary cover for the outside exhaust (obviously dangerous if you should attempt to start the fireplace and forget to remove it) or, better yet, make some kind of an insulated decorative panel to cover the interior of the fireplace when not in use. I have seen some people use magnets to make such a thing stay in place.

Unfortunately, there is no other solutions that I know of.

 

[humpin iron]

Most likely the chase was not insulated and sheetrocked. Code requires the "outside" wall of the living space be insulated, that would be the wall that is the face of the FP. Insulating the chase is like standing in your garage on a cold winter night with the door open vs the door closed. The garage may not be heated, but with the door closed it feels warmer.
Also remember the builder saved $39.43 by NOT insulating and sheetrocking the inside of the chase.

 

[webbie]

My DV is inside the house (in a corner of a room which was finished) - but still cold. It must be air coming in the DV pipe and termination, etc. in my case.

 

[humpin iron]

it's installed on a 45 on an outside corner?

 

[webbie]

Mine is....but many others with different types have the same problem.

 

[humpin iron]

was the true outside wall insulated and rocked before the FP was put in ?

 

[webbie]

I think it was....because they had planned to put a vent-free in....
In my case, I think the cold comes from the fact that both of those corners are exterior walls AND the firestops which the DV goes through are just sheet metal.....last time I looked, sheet metal was not a good insulator. Add that to the cold that siphons through the DV pipe and you have a cold unit.

 

[humpin iron]

We install 200 +/- units per year, if done properly complaints are less than 5 per year. It's far cheaper to do it right the first time than deal with an ongoing problem

 

[brogsie]

I'm a general contractor and we have the same problems with bath fans, dryer vents and stove vents.
The down draft stove vents seem to be especially cold. There is really nothing keeping the cold air out.

 

[stoveguy13]

if the termination cap is not mounted flush to the side of the house and sealed you will get air leaking in from there. the units will always be pulling some cold air in but not enough that it should turn the room cold the glass should make a good seal to the body of the unit to preven that from happening. it is most likely one of the above issues poor insulation or bad install a heat gun to take reading on the wall and around the unit will tell you if you have a insulation issue.

 

[jtp10181]

If installed properly, and if the house walls behind the fireplace are sealed up the same as the rest of the house per building code there should not be ay problems.

Sometimes they can get a little chilly with the new units that have no pilot, but our fancy wall switches have a "cold climate" pilot button for just that purpose.