If you think your HVAC unit will distribute the heat from a wood stove.. think again..

[redmanlcs]

Didn't work for me!.....

I live in a singlewide mobile home. Four years ago I installed a wood stove as my only heat source since I was very strapped for cash and the old furnace just wouldn't work, and even if it did work I wouldn't have been able to afford the added cost of running it on electric anyways. The wood stove worked out great other than the problem of the living room being warm while the rooms further away in the back stayed chilly. It wasn't really a big deal since I grew up in a drafty house and I was kinda used to the temp difference throughout the place.

My mother recently had some issues and needed to move in with us. She hated that her bedroom stayed cold so she sprung for a new 2.5 ton self contained unit. I had no problem with that since she is now paying the electric bill. Everyone told us that we could basically heat the whole house now with wood as the fan in the unit would distribute the heat throughout the house. I tried that and it didn't work out so well.

Outside temp is 20 degrees F. The wood stove has the living room up to 90 degrees F. Usually we start opening doors and windows at this time but I decided to try to use the fan in the HVAC unit to heat the other rooms. I turned on the fan and it seemed to feel as if the back rooms wasn't getting any warmer after 10 or so min.. The air return is right beside the stove and with the fan on, the living room did cool down to around 80 F. I placed a thermometer on the register in the back room and it read 30 F. I gave it around 20 min to heat up the ductwork and checked again. Still was reading 30 F. After an hour the thermometer still was reading low 30's while the living room was back down to around 70 F. The fire was dying down and needed a refill so I just shut off the fan and gave up. I don't feel comfortable running the fan 24/7.

Is there a problem somwhere? Does anyone have a setup with a wood stove and HVAC unit that actully heats the whole house?

IN MY OPINION: If you think your HVAC will distribute the heat from the stove throughout your house, you may be mistaken. It don't work for me.

 

[webby3650]

The problem is the self contained unit and the mobile home. With a self contained unit the warm air is drawn outside then forced back into the home. It’s one of the least efficient was to heat and cool a home.

Typically the belly insulation isn’t the best and often even missing on mobile homes. Even in a traditional home people have very mixed results, small fans on low pointing toward the stove works much better.

 

[maple1]

This doesn't sound like a typical HVAC system. Not sure exactly what a 'self contained unit' is though. The basic fact that the register is outputting only 30 degree air points to something wrong somewhere - like bare uninsulated ductwork going through an unheated space. Using HVAC can have mixed results yes, but this sounds like an outlier on the poor side of results. That should be able to be improved somehow - said without really knowing details of this setup/arrangement.

 

[Ashful]

I have had a few friends distribute wood stove heat successfully to even very large (6500+ sq.ft., in two cases) homes, and have seen many more fail. The ones with success seem to be only the ones with all ductwork and air handlers contained within the heated envelope. Ductwork in exterior walls, or an air handler in an un-heated attic space, usually have too much loss to work well, when your inlet air is only 80F.

 

[Dataman]

Box fans work great

 

[kborndale]

Fans blowing cold air from the cold room toward the stove creating a convection loop are going to work the best.

 

[Indiana wood]

The problem is the self contained unit and the mobile home. With a self contained unit the warm air is drawn outside then forced back into the home. It’s one of the least efficient was to heat and cool a home.

Typically the belly insulation isn’t the best and often even missing on mobile homes. Even in a traditional home people have very mixed results, small fans on low pointing toward the stove works much better.

I own a mobile home park and yes all of this is true. Severe heat loss with mobile home duct set up.

 

[Ludlow]

Plus the fact that you expected immediate results. If the bedrooms are below freezing when you turned the fan on it wouldnt ever catch up. Run the furnace to heat the envelope and then switch to fan. Close the supply registers in the living room. I am betting the ductwork is inadequately insulated as well. Bedroom doors cant be closed unless there is a return in each bedroom, which I highly doubt.

 

[Indiana wood]

Plus the fact that you expected immediate results. If the bedrooms are below freezing when you turned the fan on it wouldnt ever catch up. Run the furnace to heat the envelope and then switch to fan. Close the supply registers in the living room. I am betting the ductwork is inadequately insulated as well. Bedroom doors cant be closed unless there is a return in each bedroom, which I highly doubt.

Ductwork in mobile homes is terrible. I would not use it to circulate air. Way too much loss. Fans fans fans only option. Ive been under LOTS of mobiles

 

[webby3650]

A self contained or “package unit” sits outside. The entire furnace Is outside on the ground, it uses 1 central return and 1 supply run that’s then distributed to the main trunk line once it’s under the home. If it is indeed a package unit, it will work to distribute much of anything but cold air.

 

[redmanlcs]

I have been under this thing... the ductwork is uninsulated as well as most of the floors, I thank the cats and rats for tearing up the insulation. Soon as the weather warms up I definitely going to insulate underneath. When we first moved in there was also no underpinning and that called for freezing floors and waterlines. Just me putting decent underpinning has dropped my water pipe freeze point to below 27 F.. as that is when it would freeze up without underpinning. I have no idea what the freeze point is but when it calls for 25F or below I let my water drip. I'm a little disappointed though.. because everyone said that it would work fine. No big deal really as currently we just blow the heat through the hall with a box fan and it works great, well......... much better than the hvac fan.

Wood heat during the day, HVAC at night... no more cold mornings is a godsend, plus not having to build a fire first thing in the morning without my first cup of coffee is great as well. Just wanted to point out that being able to use the HVAC fan to circulate the wood heat is pretty much hit and miss... don't count on it working with every install.

 

[redmanlcs]

Oh.. I told the installers that I needed a new trunk line built but they wouldn't hear of it... they said the old one looks fine... well I know myself it is cut in places accidently when cutting the floor out for replacement and hit it with a sawsall. After they left I crawled under and taped up the couple spots that I know had been cut. I'm yet to crawl under this thing when the heat is on and see how many leaks I have. A good thermo cam would be nice to have about now so I can check for heat loss. When they told my mother that they would build a new trunk but it would be an extra 3 to 5 hundred dollars she scoffed at that and took their word.

When the temp gets anywhere below 30. F,,, the HVAC runs constantly between the defrost cycle and the heat cycle... but no aux heat has kicked on yet even at 14.F.. thats a plus .

 

[redmanlcs]

When I caught the installers snorting pills under the house I knew that this install is probably going to be iffy. Being a prior HVAC installer myself I kept a pretty good eye on them and didn't notice anything that I personally haven't done myself... except for the drug use part.

 

[john26]

Try skirting the mobile home with hay bales; it may not be enough to circulate hot air but it will help keep cold air from blowing under.

 

[webby3650]

Try skirting the mobile home with hay bales; it may not be enough to circulate hot air but it will help keep cold air from blowing under.

Better yet, insulate the belly of the home and install a proper vapor barrier, that along with good vinyl skirting there will be no problems.

 

[webby3650]

underpinning. I have no idea what the freeze point is but when it calls for 25F or below I let my water drip

Can’t do that with a mobile home either. The entire drain line is above grade, so you slowly make an ice dam, then it backs up into the house. If you haven’t had long periods of extreme cold you might have been good, but if the temps stay low you’ll really regret this decision.

 

[davidmsem]

Box fans work great

This winter I decided to use some box fans to move air from my downstairs toward the upstairs in my two-story colonial. I'm getting about 3° more temperature upstairs with a few box fans. Simple and it works

 

[Ashful]

I’ve never even been in a mobile home, so take this advice for what it’s worth, but I have spent more hours under old houses than almost any non-pro you’ll ever meet. If I had a need to insulate your place, winter is exactly when I’d do it. No snakes, no bugs, and hopefully no rats. Sounds like miserable work to attempt in summer, or any milder weather.

 

[maple1]

I'm a little disappointed though.. because everyone said that it would work fine.

But did everyone know the state of your HVAC/ducting setup?

 

[Rob711]

What’s under pinning? And how does it help retain heat. Also a plus one on insulating in winter.

 

[Grizzerbear]

What’s under pinning? And how does it help retain heat. Also a plus one on insulating in winter.

Around here it is like soffit looking sheet metal. Helps break the wind that is about it.

 

[kborndale]

I have been under this thing... the ductwork is uninsulated as well as most of the floors, I thank the cats and rats for tearing up the insulation. Soon as the weather warms up I definitely going to insulate underneath. When we first moved in there was also no underpinning and that called for freezing floors and waterlines. Just me putting decent underpinning has dropped my water pipe freeze point to below 27 F.. as that is when it would freeze up without underpinning. I have no idea what the freeze point is but when it calls for 25F or below I let my water drip. I'm a little disappointed though.. because everyone said that it would work fine. No big deal really as currently we just blow the heat through the hall with a box fan and it works great, well......... much better than the hvac fan.

Wood heat during the day, HVAC at night... no more cold mornings is a godsend, plus not having to build a fire first thing in the morning without my first cup of coffee is great as well. Just wanted to point out that being able to use the HVAC fan to circulate the wood heat is pretty much hit and miss... don't count on it working with every install.

Are you trying to blow the heat towards the cold rooms with the fans? You should go in the opposite direction and blow the cold air from the rooms towards the stove. Its easier and more effective to move the cold air.

 

[Easy Livin’ 3000]

Ok, so waiting for it to warm up to insulate. Think that through a little more.

A little suffering in the cold to get it insulated and a lot less $uffering for the rest of the winter. Get 'er done!

 

[webby3650]

What’s under pinning? And how does it help retain heat. Also a plus one on insulating in winter.

It’s typically vinyl, some people make their own out of metal or something. It needs to be able to move up and down since it’s above the frost line, when people install it incorrectly or make their own, it cant move so it buckles then the wind blows it away. That’s why it’s typically missing. Stopping the wind is it’s number one job, keeping critters from tearing the insulation down is number 2.
That’s the house trailer lesson of the day!

 

[begreen]

It’s typically vinyl, some people make their own out of metal or something. It needs to be able to move up and down since it’s above the frost line, when people install it incorrectly or make their own, it cant move so it buckles then the wind blows it away. That’s why it’s typically missing. Stopping the wind is it’s number one job, keeping critters from tearing the insulation down is number 2.
That’s the house trailer lesson of the day!

Yes, I have seen a lot of crawlspace ductwork stripped of insulation by rodents, our house included. They must be using it to insulate their nests.