Okay to change Air Return?

[dave]

I'm starting a project to finish my basement and my cold air return runs across my floor joists from one end of the house to the other - front to back. It passes in front of three basement windows and dips under the basement stair landing on the way. My question - one I'm too intimidated to post on that nasty HVAC site - is whether or not it is feasible to just put my cold air return in the basement near the furnace in order to eliminate all the ductwork. I normally wouldn't consider this, but since I am finishing the basement and will keep it the same temp as the rest of the house, I thought it might even help circulate the air throughout the house. In addition, I am installing radiant heat flooring in my kitchen, which is where the cold air return is now. Right now, I have about 40 feet of duct work for one return in my kitchen. Thanks for your help.

[Speedy Jim]

That's poor practice. It means the basement door must be kept open for all the return flow (I'm guessing)

Also, Codes no longer permit the return opening near the furnace (or other burners). See:

m5

Your local Code may be even more restrictive. You might not care, but it can make for a difficult time when you sell the house.

Jim

[dave]

Thanks. If I'm reading that right, it's also a violation of code have the return in the kitchen. Frankly, I'm less concerned with code than with safe and efficient operations. I know that sometimes they are not the same thing. It's a 1942 house. I am eliminating the basement door, and I intend to install a wall between the furnace (and burners) and the return duct - although it would still be only about a three-foot run. Does this help? If not, are there alternatives? Maybe I can reroute the return to my living room at the front of the house? As you can tell, I'm looking for a way to get my windows back in the basement. The 7-foot ceilings down there are low enough already. Thanks again

[Dr. Hardcrab]

The other thing to consider:

If you have your air conditioning tied into the same system, you have to think of it as a WARM air return. If it was in the basement, how would it get rid of the warm air (that rises) upstairs?

[Speedy Jim]

A return in the living rm might be good. Make it a BIG one to handle all the flow though.

That's a difficult design decision, because the path for the return flow affects the comfort of all the rooms. I'm not a HVAC designer so I won't try to guess from here. Jim

[dave]

Thanks for all the advice. You guys are great, and fast. I think I have the perfect place for it in the living room. But I'll call a pro to have a look before I take the sawzall out of its case.

[dave]

Thanks for the advice. I'm less concerned about code than I am the efficiency and safety of the system. What if there is a wall separating the burners from the return - even though its only three feet of duct? I am losing my basement door altogether. Are there any alternatives? Maybe I can redirect the cold air return to my living room at front of house? Again, thanks

[m Ransley]

You may not be as comfortable in heat and wont be as comfortable in AC mode. Ac for my second floor would not cool till a return was installed. Ive experimented temporarily blocking returns in winter only to open them and notice a difference in comfort .

[dave]

My situation is a little different cuz I have a completely different ac/furnace system on my second floor, the return for it is in the staircase. I also think my basement problem was a retrofit because no one would have designed a house with huge ducts in front of windows - basement or not. Sounds like I need a pro to put eyes on things in my house. Thanks again

[mm]

Can't answer your question but my '79 townhouse with heat and AC has only 2 air returns, one in the basement about a foot from the furnace, but on the other side of the one interior wall in the basement, and the other two stories higher in what is the same wall.

Of course there should be separate heating supply ducts and AC supply ducts, and the supply for one should be the return for the others, but despite all this, the place is fine. It's comfortable everywhere in the house.

My only complaint is that I can hear the circulation fan when the heat is on, and sometimes I even shut my bedroom door so I can't hear it.

But my furnace fan only has three possible speeds and only one can be used without changing the connections. It's on the slowest speed, and I tried the other two to make sure. Furnaces a few years newer have several fan speeds and the furnace selects one, or the user can, including a different one for heat and ac.

I't's not a lot of noise - It's never woken me up -- I'm just picky.

Remove NOPSAM to email me. Please let me know if you have posted also.

[hallerb]

I would check with a local HVAC conractor!

At minimum you will need a louver in your basement door so the air can flow easily.

even at that your energy bills may increase, since it may be harder to move air thru the system

do you want bigger energy bills? if so give me your address, i will be happy to send you mine:)

[Bob]

[Speedy Jim]

I don't currently own the book, but the scope of the articles covered is impressive and the explanations are clear. Anyone who has to deal with inspectors regularly should look into it. Jim

[Bob]

Depending on the type and design of your heater, you may also need to be concerned with fumes. After the burner shuts down, residual heat and fumes can sometimes be drawn back down through the heat exchanger and into your duct work system.

[buffalobill]

NO. improper, unsafe, maybe radon, inefficient and expensive to heat cold basement air and send it thru the furnaace to be heated to the house. before you start your basement: