Construction question. Cold air return

Our house is almost 80 years old. When it was built it was built with a separate garage. about 10 years later they built an apartment over the garage and closed in the space between house and garage. So, if you can imagine it, at the front of the house on the left - in that space - there is now an interior staircase up to the apartment. At the back of the house "under" the staircase is the rest of that closed in space. It is about 4' X 10' and is kind of a mud room - three doors, 1 to outside, 1 to garage, 1 into the house.

I am currently refinishing this space to make it more a part of the house. It will still only be a mudroom but will be finished and tiled properly with likely a bar fridge and wine cooler.

Initially I planned to put a small electric heater in there for winter but, SWMBO would prefer we run ducting into the space. Not impossible as it turns out. However, for a space that small do I need a cold air return?

I can do it reasonable easily but would rather not have to.

Thoughts?

My thoughts, if the room is open to the rest of the house probably not.
But then again you need to do the math to figure what your system is rated to

Depends a lot on both how air-tight the space is (which as Don said, depends in turn on whether you close the doors), and how well insulated. Plus, I guess, how much differential from the house you are willing to tolerate.

IOW, with no return path, it won't get as much heat. How much it gets will depend.

Not knowing the layout, but if the area outside the door has moving air, (returning air), then a vent could be put in the lower section of the door or interior wall, the door being easier, to pull excess air from the room and the flow would be unrestricted. Not fancy, but it works. Just a suggestion and cost saving compared to installing return air ducting. PJ

My little bit of advice is... Talk with an HVAC guy. And...Don't open the box containing the 30' length of insulated flexible ducting until you are ready to install it! Just sayin.

elrey said:

My little bit of advice is... Talk with an HVAC guy. And...Don't open the box containing the 30' length of insulated flexible ducting until you are ready to install it! Just sayin.

Click to expand...

Oh come on where is the fun in that.

Instructions - we don't need no stinkin' instructions!

I just had some experience with this, as we are working on our 70 year old house we bought last year (six months into my 2 month project and almost done!). Agree with all the prior comments, it will work better if you do a return duct or a vent through the door. I know there is science and equations that can be applied to all this, but a little common sense goes a long way. Mostly I got a kick out of the flexible duct comment. Remember those little gag cameras and gadgets they used to sell that had the little spring snake pop out?

30 some odd years ago when my lovely bride burned my house down (well, top half off this 1929 vintage farmhouse), while the contractors had the walls open, my brother and I put duct feed runs in the walls, ceilings and floors.
There are no cold air returns as a dedicated item in the entire house.
What we did was, with the furnace in the basement, we cut two holes in the basement access door, screwed louver panels over the holes (both sides), and return is down the stairs from second story, 180 through front room, into kitchen, hang a right down the hall, and into basement door.

Duct away into the room....put a louver panel in the door, wall, or wherever on the interior door side and let the air return just follow the natural course back to one of your dedicated cold air returns.