Convection Currents

I know that heat rises, and cold air given a path to do so, will replace it. If heat is blocked from going up through a door, and you open a large vent at the top of a nearby wall, and another at the bottom, will the heat eventually fill the other room.

I have two unheated basements, and due to the limited opening of a fireplace, cannot fit a free standing coal stove, unless I get shorter legs on the Vigilant II or a fireplace insert. On the other hand, if I take out a wood stove in the smaller basement, and replace it with either the Mark I, II, or III, the heat would likely overheat the room, not to mention the bathroom at the top of the stairs. So I was hoping to find that I could open up a couple of wall registers, and if necessary use in wall fans to move a substantial amount of heat into the other unheated basement. By then opening the other basement door, or placing a few ceiling registers the heat could rise into the front part of my home.

Any chance of that?

I don't fully understand what you mean by wall register? Are they open grills, or attached to heating ducts? Alot of people run into the same problems. Getting the heat isnt a problem, but getting it where it needs to go is. If you had large return ducts in the space near but not too close to the coal burner, the furnace blower could be ran constantly to eventually recircuate the heat through the home. The biggest problem there is you need draft, and you don't want to depressurize the room and lose the draft. I have a large home, 2 stories and I was needing to heat the whole thing. What I came up with was installing a wood/coal furnace into the ductwork in the basement. Every room in the house is toasty and warm. Even the old basement is warm. We had no other options. Whatever you choose, Good Luck!

In my case, there are no ducts anywhere. I'm sure that I could solve my transfer of heat concerns if there were, but unless there is a simple way of installing them without hiring HV specialists, it is not a consideration at this time.

When I mention registers, I am referring to the same vents that you typically would place in the ceiling above a stove, only instead in the wall. What I am not familiar enough with however, is that magical number or size that allows cold air to return, and hot air to move on out. As for pressurizing the room, I am not sure how that is determined, and welcome your response as to how to figure it out.

I have considered opening a door between the two basements, only I then have to have a mason build a sill , since the basement wall is a load bearing one, and in fact was an outside wall before the previous owner expanded his home and built out and over. With that, I have two separate basements, each with a staircase and each with a door to the outside.

Having seen diagrams of the best layouts for moving heat, I would probably guess my layout to be among the worst. Is there a science or an art to figuring it out?

Thanks!

hey john,sounds like quite a pickle you have,is that wall poured concrete of is it cement blocks?blocks would be easier to remove for a door or wall register...i have seen wall registers in some older homes,for your application I would get the ones with a fan built in,would building a chimney in the part you want to heat be an option?

I actually have a chimney in both basements. The larger basement is accessed from a door leading from a short hall, next to my boy's rooms, and off of the entrance to the dining room. There is a very inefficient sliding glass door to the outside, about 10 feet from the exisiting fireplace hearth. It is at this location, I have had my Vermont Casting's Defiant Encore, and am looking to fill with either a wood/coal, wood only, or coal only stove or insert. The problem however is that it is only 28 inches tall and 35 inches wide. Yes, an insert will fit, but for the moment, cannot afford a new one.

As for my office basement, it too has a flue, and is currently hooked up to a large Fisher wood stove. Though I know it is not very efficient, I am able to burn just about anything in it, including my office papers that otherwise I would have to shred, or recycle. Across from where the stove is, there is a staircase up to the first floor. There is no door there, rather it goes into a very small washroom, and then with bifold doors, into a bathroom which also in unheated. When I burn wood in the winter, that bathroom is nice and cozy. When I don't it is downright freezing, until a small electric heater pumps some heat into it...and then, it fights with the cold that tries to infiltrate from the unheated washroom and basement below. Right next to where the Fisher sits diagonally in the corner, is a door to the outside, where I have a stack of hardwood stacked, and could easily store coal as well.

Within the basement/offic masonary chimney is another terracotta flue, which has been unused all the time I have lived in the house, and will see the Defiant Encore moved into the room above, which is my living room. Currently, my Whitfield Pellet stove resides there and is direct vented around the chimney.The living room is directly over the basement office, and if I were to open vents from below, would only be heating that room even more.... unless the added heat would cause a bigger convection current to move out of that room? could it do that?

As to the solid basement wall that separates the two basements, it is cinder block. I once tried to knock out a block when I first purchased the Defiant Encore, thinking I could move the heat with a single block removed. Fact is, I didn't have the proper tools to remove it all, and in the end, was told that more than a block or two, and I would want to have a sill installed, since it was a load bearing wall.

From what I gather, heat wants to rise and will do so, given a path. My real dilemna however is finding a way for it to also move sideways, as well as replace the heat with cold, in order to create the currents to reach other parts of the house. I hope to have both a wood stove cranking the better part of the winter, as well as the option of a coal in either my office of semi finished basement. There is this possibility where 3 stoves will be burning this winter.

Thanks for your recommendations. I look forward to solving the puzzle.

John

My father-in-law has registers in the floor, & he hooked up one fan blowing down & one blowing up. In the summer, he turns them on for a few days of free A/C from the cool basement.

Maybe you could rig up the same -- one blowing in the room (bottom) & the other blowing out (top)? Those Harmans also have a blower with 2 ducts just above the door. You could aim the stove in whichever direction to maximize heating.

I knew that there were blowers, but wasn't sure how effective they were. In the case of my pellet stove, since it really didn't radiate heat, the only heat that came from it was by the blowers. In the case of a Harman Mark Series, are the smaller fans powerful enough to get the air moving. I noticed that the Mark III and TLC 2000 had nearly twice the power as the Mark I & II stoves.

I am certainly willing to cut registers in floors, but wondered if I opened some in the walls with fans blowing, if the other basement could heat up to a comfortable level as well.

There is a Harman Elite Stove Insert available on Ebay that could solve all my problems, if I could figure out how to get it home. At the moment, the bid is somewhere around $400, and I imagine a steal even if it went to $600.

I am determined nonetheless to solve this problem, and look to you all for possible solutions. Thanks again for your recommendations!

John

John,

How about cutting two risers in the floor (instead of wall, for path of least resistance) in each basement. Then take out four blocks from the BOTTOM, dispersed in the middle basement wall. With fans in the heated basement shooting up, you might not need fans shooting down on the otherside, the cooler/warm air will find its way down on it's own.

Another idea....
You could go to Home Depot and get 6 or 8" flex insulated duct @ 25' for about $30. Put that thru a closet from the basement up to your second floor, or in a corner of your first floor, then enclose in drywall. It's an easy but effective wat to get heat up to your second story. HD also sells an inline blower that fits those round flex ducts, but I think a fish fart blows stronger.

That sounds like and interesting idea....anyway you could draw that and email it to me [email protected] I am not exactly sure what you mean by risers....of course I know that without any help at all, the heat will rise, and as I stepped into my bathroom a minute ago, thought of starting a wood fire in my office, and floating a balloon with helium to see exactly what path the heat wants to go. Then with a fan in the wash room aimed into the bathroom, and perhaps another one in the front hall, I could assist the current in it's path to other parts of the house.

I'll try to draw a rough sketch of the layout of my house later and try scanning it as an attachment, so you can get a better idea of what I am talking about....though I have a feeling you do completely understand.

And with that I have to say this forum is probably the most helpful I have ever been a member of......

Thanks again all!

John

John,

A riser as I know it is just a vent cut into the floor. You can buy store bought ones with fans built in, or you can make your own easy enough. Buy a 8"x12" floor grate, cut hole in floor the appropriate size for great, set grate and your done. Risers for first to second floor should be boxed out with sheet metal. Keep in mind that sound travels through them, so if you put one in your bedroom, keep the activity down to a dull roar.

You could always go on ebay and buy an air handler ( box with blower that vents hook to) to put in the heated basement and run flex duct off it to each room on the first floor and most rooms on the second floor. It's alot easier to do than you think it is. This would be the best way to do it. There is a good supply house that sells this stuff in Frankford, Sussex Co. called Universal Supply, they're at the junction of 206 & 15.

I built a new spec house and installed the propane hot air heat myself, I got alot of the stuff from Universal. if you are the least bit handy, you can run a vent system, you don't need any special tools or knowledge

I think a air handler and flex ductwork would be one of your best options. If you had returns, I would put them near the outer parts of the house, and put a fan or register in the inner part of the house. The only thing to get good current, you will have to have a fair amount of airflow.

What I do is put the hot air register in the floor under a window on an outside wall & rely on an open air path thru a "centerish" hall & stairway or risers for the return air. It doesn't take alot for the air to find it's way back to the air handler. This is the simplist way to do it without a dedicated return system.

I did the same thing to my house with a 24K BTU air conditioner that I got barely used for $50. I put it thru a window in my utility room, ran insulated flex duct thru the attic to cieling registers by the outer walls of my main rooms. I made a plenum with collars out of thin sheet metal from Home Depot to capture the cold air from the a/c unit. I spent one weekend doing the whole thing and have "central air" for under $200. Nice & balanced cold air, will work the same way for heat, just put the registers in the floors.

Love that flex duct!

Thanks for the tips! I'll check out Home Depot this weekend. I may turn to you again for placement, but have a pretty good idea of the layout of ductwork and registers that you describe. Maybe even a duct cut through to the other basement could help heat the other side, if not provide a cold air return.