I asked this quite a while back, but it just became an issue again. I have a roommate moving in and his bedroom runs anywhere from 4-6 degrees colder than the rest of the house. He has 2 exterior walls that get no sun to help offset the heat loss in the colder months. If the door is open, it's not too much an issue, but he'll want his privacy as well as keeping my cats out.

When the furnace kicks on if the door is open less than 5 or 6 inches it will blow the door almost shut. If it's barely open, it will blow it latched.

So it has a very high positive pressure in the room. The door is cut about 1/2" above the carpet and I could probably raise it another 1/2". I DON'T want to make a 2" high opening as it would look butt ugly, esp if I replace the carpet with a berber later. Also don't want to put grilles in the door...again for that butt ugly and too commercial look. Can't afford to have returns installed in each room, and beyond my abilities.

So, my thought is to put some grilles/vents from his room to the adjoining bedroom. Probably 2 on each side (4 total). The issue is that this is the wall where the closets are located side by side. You know, the typical arrangement.

I have some space above the closets but that would put the vents directly opposite each other and may be a sounds transmission issue. I'm thinking just put grilles in the stud bays in the closets. Cut the opening a little undersized and use anchors to hold the grilles in place.

I'm sure if I tell him to leave the closet doors ajar, we can do that.

So main issue...should the grilles be low in the hi pressure room (cold air low) and high in the adjoining room or vice versa. Or will it really make any difference.

Any and all suggestions welcome.

 

Ideally low in the cold room so that it's picking up the cool air off the floor, high in the other room to avoid noise tranfer. I'd try to find an interior wall where the closet doors didn't have to be left open. Mobile homes have the large gap under the doors for return and that's something that after you get used to it, you don't even think about it.

 

Yeah, low-high is what I thought since the supplies are mounted high. The cool air in the receiving room will be mixed with the warm from the supply anyway. If i get another roommate in the other bedroom, I'll do the same thing into the kitchen and hallway.

No other wall really available except into a linen closet or bathroom.

 

With that layout, I'd almost consider having dual grilles above the header of the door coming out of the room. Adding a ceiling fan-light would allow the air to circulate. Just a better solution in my eyes as having closets as a choice.

 

Unfortunately...guess where the supplies are located in both rooms? Yep, centered above the doors, same in every room off that hallway. The hall ceiling is about 10" lower than all the rooms to form a sort of chase for the ducts. And I'm sure it's framed around the existing grille.

Fans in all rooms and you are right...set on slow they do help even the temps but also cause a bit of a breeze. Feels fine in the summer of course, not so much in the winter.

This wouldn't be that big a deal, but I need to cut expenses and having the stat set at 70-72 (which my ex- liked) really caused a heat call too often, plus I sleep better in a 66-68 room. New roommate says cold is hard on him (electric blanket or extra quilt maybe...duh?) but if I can cut our costs by 10-15% we both win. Talked about a small heater with a stat...but then the electric will go up I imagine.

Ehhhhh...I'll do the grilles in the closets. Easiest thing to try first.

 

Just did a simple test (I don't have a fancy CFM meter) but I'd have to say the airflow out of the supply dropped to way less than half with the door closed vs open. If I can get the air out, then maybe more will flow in. The 2 exterior walls still have a big impact. The one on the back with NO sun exposure is at about 55 degrees.

 

Tough design to work with all the way around. Sounds like closets may be only option. When I have installed ceiling supplies, I always squared in from the outside corner of the wall and let the return by or behind the door to pull it back through the room.

 

Yeah...I guess a lot of issues with the homes out here that use roof top package units. Personally, I don't know why they wouldn't have just run to the ceiling in each room (instead of the wall like now) instead of using the hallway as a chase for the flex.