Anyone using A/C duct work to move hot air off there stove into the rest of the house?

[The Duke]

Okay first time poster. You guys have a great site here!
Can anyone shed some light on my situation... Here is the set up. I have a Lopi wood insert stove (love it) on my 1st Flr. I have the typical center entrance colonial. I have 2 zones of central A/C (1st and 2nd flr). The house has baseboard hot water which has not gotten much use this year (first full season with the stove). Thru a closet on the second flr I could run a (return) duct down to the first Flr to pick up the hot air then using the the fan in the HVAC system I could then pump the hot air into all the upstairs rooms?

Hypothedically if that worked could I then put a thermostat on the fan switch so the 2nd flr would not get too hot.

Please, if anyone could shed some light on this I would be greatful!
Am I crazy?

 

[MountainStoveGuy]

there is to much loss, and not enough heat to effectivly move the air. IF you suck up 75* air in your return, the air would probably be 65* on the supply across the house. Thats why furnaces are not so effecient. they might have a great burn efficiency, but most have a lousy transfer effieicncy.

 

[The Duke]

So the air would have to be in the 80s plus to get 70s. All of the duct work is insulated, does that make a differance?

 

[laynes69]

MSG is right, you will have a great heat loss. Pretty much it could cool the rooms. For me it takes a great amount of heat to heat the home with our wood furnace. On average our heat is close to 95 to 110 degrees from the wood furnace. Anything lower and it would never keep up.

 

[nshif]

Wait for Elk.......

 

[MountainStoveGuy]

That system is very effective for evening out the temperature of the room that the stove is in. Not heating the home. If your stove gets the room so hot that you have to crack a window,the furnace fan would be a effective way to make that room cool again without cracking a window..

 

[The Duke]

That sounds good, we offen regulate the heat with the window. If I keep the first flr hot enough, with a couple of fans I get the heat up stairs as well and it does a pretty good job of keeping the hole house comfortable... that is some rooms HOT and some cool. It keeps the boiler off all day and most of the night without a 2-3AM stoke.

 

[DiscoInferno]

For my Ultima I bought the "central air kit" which is basically just 5" insulated flex duct, a blower, and an adapter to hook it up to the outer shell of the stove (it's a ZC type). You run the flex to the blower, then from the blower to the central air plenum (or to a single register). It should work better because it transfers the very hot air immediately around the stove. I say should, because I haven't finished hooking it up. The house seems to distribute heat passively so well that I keep putting it off. Seems like a waste of money now, although it may be handy if it ever gets really cold here again (say single digits); then it will help keep the furthest rooms a little warmer. May also keep anything from freezing in the (walkout) basement, which is uninsulated and nominally unheated; the only heat is what leaks out of the (insulated but not well-sealed) ductwork.

 

[elkimmeg]

first of all it plain does not work second it is agains all codes to have a retuen within 10 ' of a combustion appliance. you would remove combustion make up air and back draft .
this would draw carbon monoxides into the living space or the return would help spread this deadly gas through out you home By sucking out air should you have an incident with that stove would just reduced your personal safety. Smoke or fire would also be drawn into the system ,but excellerated reducing valuable seconds for safe exit

Next you just created an unbalance in your system that reduces effeciencies of the entire system without complete balancing Finally air removal is useless without a return path.

Air movement is a cycle if one draws air from an area an equal amount must be supplied. Doing things like this, reduces you personal and familly safety. a gamble I am not willing to subject my family to

Whats it been 3 days since some else thinks they have this solution? A lot of sizing and engineering goes into balanced systems. The mistake most make, is thinking in terms of moving lighter warm air and not considering removing the heavier cool air.

This is not a wise move

 

[Gooserider]

We have a gizmo that plugs across the fan terminals of our house thermostat, and runs just the fan for ~5 minutes on and 15 minutes off. It seems to do a reasonbaly decent job of keeping the house temps evened out between the back offices and the living room where the stove is. However it probably is wasting a fair bit of heat, it certainly seems to cool the living room more than it raises the heat in the other rooms, and the draft coming out of the registers is lukewarm at best.

It isn't an ideal solution, but it's better than nothing. - Note that I'm using the stock house HVAC plumbing, I did NOT add any returns, and we don't have any returns close to the stove, so the hazard that Elk mentions about CO and or fire spreading don't apply in a major way.

Gooserider

 

[GadeTerbob]

This post sure caught my eye. We experiencing a power failure in central MO right now which sure cripples a heat pump. Our fireplace is plumbed to provide heat to the central air system and does a pretty fair job of heating the entire house. When the central air fan is running, that is.

Now that the central air fan is not working the cold air return is actually overheating! Not sure what to do about this. It's not life threatening (I think) but the cold air return is certainly warm to the touch. Sure would be interested in seeing the replies.

 

[DonCT]

Warm to the touch and too hot to touch are 2 completely different situations.

Anything above the 120 degree range is the too hot to touch. If it only feels warm, you're ok.

 

[GadeTerbob]

Where the cold air return filter is mounted can be touched continuously. I'd estimate 100 degrees. However, and this is the source of my concern, If I remove the filter and reach into the horizontal air ducts from the air to air heat exchanger, it is much hotter. While a wet finger won't sizzle, you can't maintain contact for very long. I'd estimate 120 or better. It's been like this for 48 hours and I've become concerned enough to call a fireplace pro. If I shut down fireplace, we'll have to abandon house. Outside air temp is +2F. And yes, this post is being made via portable generator.

We just bought this house a year ago and this is my first experience with such a system. I would have thought that there would be a way to isolate the fireplace from the central system, but I certainly can't find it.

 

[begreen]

Can you put a box fan facing the house return air grille? If you can, turn it on high and try running it from the generator with the fan blowing into the grille on high speed. It won't be perfect, but should get the air circulating and reduce duct temps.

In the meantime, examine the distance of the fireplace-to-return duct from combustible surfaces. I would want it to have at least 2-6" clearance for just this kind of circumstance.

 

[GadeTerbob]

The fan is an excellent idea! I guess I was just too task saturated to think of that on my own. The distance from the fireplace to the cold air return, which is located in the ceiling, is about 8 feet. There are two 5" sheet metal ducts that run horizontally from the the cold air return to the shroud around the fireplace chimney. Horizontal ducts are located about 1 foot above ceiling and are insulated.

 

[ourhouse]

Welcome to the fourm Duke. My ceiling fans work great for us.

 

[ourhouse]

Duke what part of the country are you from?

 

[elkimmeg]

You have a real concern if flexible ducts are attached to that system IO definetely forbidden to have flexible ducts in your setup or to use combustiable floor pan joist in your return system
also any metal duct should have 2" clearance to combustiables in your system

I like Be greens suggestion of a fan to cool it down then some serious thinking needs to be done to address how safe your system is and there are methods to isolate it

 

[GadeTerbob]

The fan got us through the night. I'll guranDANGtee you we'll make a new plan for tonight

I also apologize, 'cause I didn't intend to hijack this thread.