Circulating heat in a house with an unusual layout...

[Guenther]

Hello! New to the forums and need some advice. I just recently installed a Drolet Escape insert in my new (to me) home in Conifer, Colorado. My installation includes 17 feet of insulated flex liner and an insulated block off plate above the stove.

My home has an unusual layout... 1410 square feet and 3 levels, each level being 470 square feet with an open stairwell running down the center rear of the house. The top floor is the kitchen/living area to take advantage of the mountain views. This is where the stove is located. The middle floor is where the two bedrooms and bathroom are located. A rec room and the laundry/furnace room are located on the bottom floor. Both the middle and bottom floor are almost completely bermed underground.



With the stove located on the top floor of the house, this area easily gets too hot. I need some advice on how to distribute some of his heat to the lower levels of the house.



Three feet above the stove is an existing 6" duct that runs down to the bottom floor and is tied into the return air of the furnace. However, when the furnace is running hardly any air is being sucked through this duct because there is a much, much larger return air duct located close to the furnace at the very bottom of the stairwell. My thought is to disconnect the small 6" duct from the furnace and install some sort of inline fan. The fan will either blow cool air up to the stove room or suck warm air down to the lower level. The end of the duct at the bottom level will either tie into the existing furnace warm air ducts or simply have a grille at the bottom of the stairwell. Before installing the insert I ran a pair of wires down the old ash clean out to the lower level with the idea of installing some sort of snap disk thermostat to only run the fan when the stove is hot.

So now I need some advice....blow cool air up or suck warm air down. What size fan (cfm)? Will any of this work or am I stuck with an overheated upper level. And yes....I am concerned about safety.

Thanks in advance for any insight,

Guenther

 

[Woody Stover]

Welcome to the forums!
No help on the circulation, but that is a cool house.

 

[Holiday]

Very cool and no help either, I'd probably try blowing cool up and see how it affects things.

 

[Seasoned Oak]

A strong enough fan will blow warm air down. Id try one of those powerful round fans like this.
http://www.northerntool.com/shop/tools/product_200007224_200007224

 

[Dave A.]

How about trying a ceiling fan on top of the open stairway blowing down. If the stairway is really open without risers and only treads or has clear open path, might work or at least help.

Edit: I would try it first hanging it on a secure hook temporarily with temporary wiring to see if it worked before mounting to a permanently installed fan box.

Also like the idea of moving cool air up towards the stove thru ducting system.

 

[rowerwet]

before you put a bunch of effort into moving ducts, and adding fans, cover the big cold air return with paper of plastic and run the exsisting fan for a day or two to see how blowing heat down with that set up works.
my opinion would be to blow cold up, but you aren't going to get the top from being over-heated, IMO unless you make the house like a wind tunnel.

 

[billb3]

The stairway could likely drawing warmer air off the ceilings of each level up and sucking cold air off of both floors down.

I'd try to suck as much air from the hot room down . Whether that's too much fan for that vent is ?????

 

[Backwoods Savage]

Welcome to the forum Guenther.

Nice home but that is a tough call on heating those lower floors. You might have to consider putting a small stove in the bottom level.

As for moving air, keep in mind that it is usually best to move the cool into the warm vs trying to blow warm air into the cooler air. That just don't work well at all because as you know, cooler air is denser than warm air. This is why we usually blow cooler air into the stove room. The cool air will force the warm air out and create a good circulation whereas trying to blow warm air even with a large fan usually don't work. Also, when blowing the cooler air, it usually takes a very small fan running on low speed. However, your situation is unique so it might be interesting to see what other suggest. Good luck.

 

[Sprinter]

It's a tough one for sure. You could try a duct fan, but a 6" would be pretty low CFM and I doubt that it would be very successful. Moving air horizontally is one thing, but you're trying to get hot air to go down and stay there. Don't know how to do that without a lot of brute force, like a big blower and big duct. And even then the air is just going to want to go back up anyway...

I'd suggest just making as small a fire as possible, but your picture looks like you're doing that already. Good luck. It will be interesting to see what you come up with.

 

[Hoozie]

. You could try a duct fan, but a 6" would be pretty low CFM and I doubt that it would be very successful

Think something like this move enough air? (340cfm)
http://www.amazon.com/Panasonic-FV-...d=1381708433&sr=8-4&keywords=panasonic+blower

 

[Sprinter]

Think something like this move enough air? (340cfm)
http://www.amazon.com/Panasonic-FV-30NLF1-WhisperLine-In-Line-6-Inch/dp/B001AHSDQU/ref=sr_1_4?ie=UTF8&qid=1381708433&sr=8-4&keywords=panasonic blower

I have no idea if it would or not, but that's pretty a pretty typical cfm for that kind of blower. It's easy enough to try, but I'd be surprised if were effective in this case.

 

[begreen]

I have to tell you that the return duct right over the stove like that is totally against fire code. Just saying, if there was ever an insurance case that would stand out right away. As you are discovering, it's much easier to work with nature and let hot air rise than try to reverse it. The stove is an area heater. Put it in the area you want to have heated.

 

[Ashful]

I suspect that any effort to bring cold air up, as Holiday and Backwoods suggest, will result in pushing the coolest air from near the floor of your third floor back down thru the stairway, not the warmest air at that level. You're working against nature, here, and your best option really is to move the warm air from high in the third floor (ceiling return) back down to the lowest level. Actually, you're best option is to relocate the stove to a lower level... but I'm sure you already considered and nixed that for other reasons. I agree with rowerwet's idea to block off all or part of the main return, forcing the furnace blower to draw air from this return, as a temporary evaluation of how well this might work. If it's found to show some satisfaction, then it's time to plumb something up to code.

 

[Holzwurm]

I have to tell you that the return duct right over the stove like that is totally against fire code.

Does this statement hold true for every state? Could you please post the actual references for that? Here in Michigan I have been told that there is no code against return vents near stoves. But I have not seen any proof of it either way. I would really appreciate clarification on this issue. Thanks!

 

[Sprinter]

Does this statement hold true for every state? Could you please post the actual references for that? Here in Michigan I have been told that there is no code against return vents near stoves. But I have not seen any proof of it either way. I would really appreciate clarification on this issue. Thanks!

I'd be willing to bet it's 10 feet. Check with the Michigan Mechanical Code.

 

[Holzwurm]

I am not a betting man. So have you seen anything in your state on paper yourself? I know a bunch of guys on here keep repeating the 10 foot thing. Maybe I'll start a new thread to get to the bottom of the matter.

 

[begreen]

There are several old threads on the topic. Save some time and look them up.

 

[Nick Mystic]

Regarding closing off the large cold air return on the lower level and only using the small return up near the stove: These cold air return vents are calculated for optimal performance. It's probably okay to temporarily seal off the large return to run a short test to see if you can move any heat that way, but I wouldn't advise using this as a permanent fix. If it does seem to work, then you would need to set up (or enlarge the small return) another return equal to the size of the large one that you eliminated or you risk damaging your central system's fan. When I tried to move heat from my basement stove through my house's duct work using my central system's fan I had very poor results.

 

[Sprinter]

Regarding closing off the large cold air return on the lower level and only using the small return up near the stove: These cold air return vents are calculated for optimal performance. It's probably okay to temporarily seal off the large return to run a short test to see if you can move any heat that way, but I wouldn't advise using this as a permanent fix. If it does seem to work, then you would need to set up (or enlarge the small return) another return equal to the size of the large one that you eliminated or you risk damaging your central system's fan. When I tried to move heat from my basement stove through my house's duct work using my central system's fan I had very poor results.

That seems to be consistent with others' experiences. Moving air through central systems just doesn't seem to work. Unfortunately. I wish it did.

 

[Ashful]

Regarding closing off the large cold air return on the lower level and only using the small return up near the stove: These cold air return vents are calculated for optimal performance. It's probably okay to temporarily seal off the large return to run a short test to see if you can move any heat that way, but I wouldn't advise using this as a permanent fix.

Yep... more importantly, don't run the furnace with the return partially blocked. Your thermostat (on the burner, not on the wall) should trip an over-temp to prevent damage, but this isn't the way you want to intentionally run.

That seems to be consistent with others' experiences. Moving air through central systems just doesn't seem to work.

I was interested in doing this myself, at one time, so I probably read more of these old threads than most. The conclusion I came to, at the time, was that those with ductwork completely enclosed in the heated space reported success with this method. Those with ductwork (or air handlers) located in unheated space (attic, garage, etc.) reported this method not working for them.

 

[Sprinter]

Sprinter said: ↑ That seems to be consistent with others' experiences. Moving air through central systems just doesn't seem to work. I was interested in doing this myself, at one time, so I probably read more of these old threads than most. The conclusion I came to, at the time, was that those with ductwork completely enclosed in the heated space reported success with this method. Those with ductwork (or air handlers) located in unheated space (attic, garage, etc.) reported this method not working for them.

That makes sense. It seems that there is just too much loss in exposed ductwork. Unfortunately, that's the majority. If you can insulate your ducts or if within the structure, you'll probably have a decent shot at it working. The other problem, though, is that if you run your furnace blower all the time, you may risk premature failures. It may not be designed for full time duty. Although my last house with an older NG furnace was really well built.

 

[Ashful]

You may be right. In my case, I was going to control the blower using a pair of thermostats, one in the stove room and another in the cool room toward which I wanted to move the warm air. When the difference between those two rooms became significant, it would trigger the blower to come on. When the difference diminished below a threshold, blower goes off. I could never personally get around the whole fire safety problem, though. Fire in the stove room, furnace blower kicks on, your house turns into a forge... by-bye house. My father witnessed two similar fires, when he used to do fire inspection. In both cases, folks had their powerful whole-house attic exhaust fans tied to thermostats, such that they'd kick on automatically, when the house or attic got above a certain temperature. "Very. Bad. Idea."

 

[Sprinter]

. My father witnessed two similar fires, when he used to do fire inspection. In both cases, folks had their powerful whole-house attic exhaust fans tied to thermostats, such that they'd kick on automatically, when the house or attic got above a certain temperature. "Very. Bad. Idea."

Wow, most attic fans are on thermostats. Are you saying that the attic fans contributed to fire spread after a fire had already ignited from a different source? I could see how that could happen.

 

[Ashful]

Wow, most attic fans are on thermostats. Are you saying that the attic fans contributed to fire spread after a fire had already ignited from a different source?

Yes. I believe that was the report he filed, in both cases.

 

[Sprinter]

Yes. I believe that was the report he filed, in both cases.

Interesting. I was involved in many structure fires where attics helped spread the fire, but I don't recall a case where attic fans were involved. Attic spaces are bad enough, but that definitely would make it worse.