Venting Help

Hey good morning everyone. I have a standard ranch house, recent construction, in which the upstairs is roughly 1750 sq. ft. My DS 1600 is centered in the basement below the kitchen, (I have attached a picture of the house). As you look at the picture, bedrooms #1, #2 and bath #2 are cooler than the rest of the house. For some reason bedroom #2 is very drafty although I've taken every step to stop unwanted drafts. I decided to cut one register into each of the furthest bedrooms from the stove to evacuate the cold air from the rooms which I guess now act as cold air returns. I cut a 12X14 register into bedroom #2 below the window which works great. If I go into the basement and go up on a ladder, I can feel cool air rushing into the basement from the vent of bedroom #2 which is what I want as the cool air is obviously exiting the room. It is now warm in bedroom #2 and temperatures are consistent. As you can see from the picture the door to the basement is right next to the door of bedroom #2.
Bedroom #1 is not drafty, however I cut a 4X12 register into the room below one of the windows after I saw the results of bedroom #2. It seems that it hasn't made much of a difference in that room or the bathroom that attaches to that room (bath #2). That room is still noticeably cooler. I did go up on the ladder in the basement under that register and there is a only small amount of cooler air felt coming down into the basement but nothing like bedroom #2. There are 2 windows in bedroom #1 so I guess I could drop another 4X12 below the remaining window and see if that helps. It is very windy at my house which faces north so bedrooms 1 and 2 are taking the brunt of the wind. And before I forget, I have to leave the basement door open upstairs in order for any cool air to leave the rooms via the registers. I considered dropping a register in the kitchen above the DS but 1) it's hardwood and I really don't want to cut one in there and 2) I think it would be ridiculously hot. The heat radiates through the floor (uninsulated floor joists) perfectly and it is very nice. I just don't want to start hacking up my floor with registers if someone has a simpler solution. Any help or suggestions are welcomed. Thanks!!

Dustin

Keep in mind filling the upstairs with warm air and the basement with cool air is very much the same, a balancing act as well. You could try covering the larger return vent (12x14) partially with piece of card board etc. Make adjustments and check temps. in the rooms. This may take some time maybe get your hands on a couple cheap thermometers (love the dollar store) and place in the rooms. You can also try running vent from the smaller cool air vent (4x12) close to the basement floor to aid with the "pulling" of the cool air from that room! Good luck and let us know how you make out.

Very true man, I forgot about ducting the smaller register all the way to the floor. Or at least a few feet below the floor joist. Good call on the dollar store I'll be going there later.

i second the suggestion regarding the duct from the vent to the basement floor. That has worked for me in the back bedroom. I can feel the cool air coming out of the flex duct at floor level and as a result it evened out the temp in that back bedroom somewhat. I was able to disconnect the flex duct from the trunk end (and cap the trunk port) to that floor vent and let it hang toward the floor. I just reconnect it with a zip tie in the summer for the central AC.

Yeah I think that was my next plan now that you guys are mentioning it. I'll get some duct work for that register soon and send it to the basement floor. Any other ideas?

Rather than cut up floors, if you have some non-load bearing walls, the cold air registers and ducts can be placed into the wall cavities with the registers mounted down low on the walls. And as already mentioned, then continue the ducting on down to near basement floor level.

Temps within a room can vary quiet a bit. The hand held Infar Red guns are better for walking around larger spaces and see exactly where the cold spots are so you'll know where placing the registers will do the most good. And they've come down in price. Plus, they will give continuous read outs as you scan it around.

Some auto mechanics use IR guns. Got any mechanic friends who will lend you one ?


Paul

Yeah I never thought about putting the registers in the walls. That may be an option too depending on location. I don't know anyone with an IR gun but I could probably just go to Harbor Freight and grab one. Although it has been 55-60 degrees the past 2 days. It's supposed to get chilly again tonight so that return in bedroom #1 may "come to life" as the temps drop.

Hmmmm.... Hot air heats two ways.... radiant and convection. You have some of each happening. The stove sits downstairs & heats the floors. That heat radiates upwards. The closer you are to the stove, the more radiant heat you get. Hence the center of the house is toasty & the bedrooms on each end come up a bit short on BTU's...but you knew that. When you cut cold air returns you are asking it to make convection....and it does, to a certain extent. In order for cold air to return, that volume of air has to come from somewhere. That somewhere is the cellar door. Yes, the door makes a cold air return, but that's from door knob down, above the door knob you'll find hot air convecting it's way up stairs to replace the cold air going down the vents. So... air being lazy (like I am), it likes to take the shortest, easiest path. In #2 bedroom the duct IS that path. Of course some makes it's way down to bedroom #1, but that's a long hike. Bedroom 3 can only get convection through it's doorway. If you added a vent as far away from the door as possible, surely it will convect better than it does now. ( I like th eidea of putting the vents in the walls, near the floor.... just watch for electric wires.) I had a ranch years back & I cut an inch off the bottom of each bedroom door. That was the cold air return. The ducts I had brought hot air up from the cellar. Depending on this or that, you might find reversal of air flow, depending on how hot the cellar is, and if the bedroom doors are open or shut. If the TOP if the door was trimmed an inch, then you could well have hot air coming up the stairs, over the top of the door, and down the cold air return duct. A candle flames tells air flow pretty well... but be careful!!

Freddy wrote:If you added a vent as far away from the door as possible, surely it will convect better than it does now.

Thanks for your input Freddy. That explains a lot in terms of returns and convection. Do you mean cutting another register somewhere in bedroom #1 to "work with" the register I just cut in? Or cut another register somewhere within the house? I've pretty much resolved the issue in bedroom #2 as far as I can tell. I had a feeling the cold air leaving bedroom #1 was going to be problematic seeing how far away the cellar door is.

I drew in another register just outside the doorway of bedroom #1 in the newly attached photo. In theory, if I dropped a register there would it act as a source of heat similar to the stairwell concept? Would heat coming from the newly added register then "force" or cause the cool air to leave the room via the register I have already cut in under the window? I can see now how it will be difficult to move any volume of cold air from the room if I can't get a significant source to it. Maybe another option to use in conjunction with the ducting would be an inline fan? I'd think that would literally force the cold air from the room via the register. Any thoughts or ideas with that?

Hi Mudflap, what was your primary heating appliance before the coal stove?

MudFlapLip wrote:I drew in another register just outside the doorway of bedroom #1 in the newly attached photo. In theory, if I dropped a register there would it act as a source of heat similar to the stairwell concept? Would heat coming from the newly added register then "force" or cause the cool air to leave the room via the register I have already cut in under the window? I can see now how it will be difficult to move any volume of cold air from the room if I can't get a significant source to it. Maybe another option to use in conjunction with the ducting would be an inline fan? I'd think that would literally force the cold air from the room via the register. Any thoughts or ideas with that?

Yes, a vent without duct work extended down should draw from the warmer basement ceiling area. But how warm is the basement right below where you've drawn the register ? Heat/cold doesn't always go or do what you think. With a cold air return duct extended down near the basement floor the cold air being heavier sinks through the register and the extended duct restricts warm air from coming up through that register. By putting another register on the other side of that room, without extended duct, you'll get circulation by natural convection. But, only if there is a fairly good difference in air temps. While not as strong and quick as forced air, it will work.

However, one problem I see with your register location . If you want to heat #1 bed room, closing the door puts the heat on the wrong side of the door.

I think a study of the first floor and the basement ceiling, using an IR gun will give you a good idea of where the heat is going in the basement, what air temps you can get in those areas, and where you need to channel it upstairs.

Paul

Similar to what your doing.
My kitchen is below my bed room. This house had originally used coal heat. In fact it was owned by the towns two coal dealers. In the kitchen ceiling/bed room floor there is a large register that let the heat from the original kitchen coal range upstairs. When I hooked up my coal range, I just uncapped where the old kitchen range was. The 6 inch thimble in the chimney was still there, so I piped my range to that. Keeps my bed room warm.

However, if I close the bed room door the room gets cold. There is no cold air return other than out into the upstairs hallway and down the back stair case.

We think of hot air as having a lot of force, but it's only force is from being pushed up by colder, heavier air. In other words, hot air does not rise - it's pushed !

With the bed room door closed and the cold air in the bed room being heavier, it wins the "register fight" with the hot air below. The cold air stops the hot air flow through that floor register and the cold air starts going down into the kitchen. Open the bed room door and that cold air moving down through the register immediately stops and hot air again starts coming up into the bed room.

Paul

Have you considered some little fans in a couple of the ducts where you want to get more air flow to even out heat distribution?

michaelanthony wrote:Hi Mudflap, what was your primary heating appliance before the coal stove?

A coal stove has been the only appliance since I've built the house in 2012. I ran a Harman Mark II last year and decided to bump up to a DS1600 this year in late spring. I have electric heat throughout the house but the breakers are off