Change 2nd Vent in the master to a Return?

Joey-D

My 2 story brick colonial was built in 1942. The upstairs is hot in the summer and cold in the winter. There are 3 bedroom and 1 bath upstair. The master bedroom is the room that is always the most off in temperature. It has two register in the room, directly across from each other at the baseboard. If I took one register and moved it higher up on the wall and then reconnected in the basement as a return, would that help? Here is a picture of the upstairs. The green blocks are vents and the red blocks are returns. The 2 returns are connected as one and is way undersized. Thoughts? The furnace and ac are within 2 years old, properly sized for the house and are 98% efficient units.

Doc Holliday

What would it take to just add a complete new return in the master, leaving the two supplies as is? That's what I would do. You don't want to restrict the positive air flow from the supply side as you will begin to have refrigerant problems, less efficient evaporation//coil capacity/eventual compressor failure if you do and judging by your stating that your return not having enough air who's to say your supply already isn't too small as well?

You can never have too much return air so you can not mess anything up, you can royally screw up a system on the supply side.

beenthere

Yep, you need to add a return. Converting one of the supplies to a return will leave with a room that still doesn't heat or cool properly.

Joey-D

I damn near gutted this house when i bought it 4 years ago, but I had never slept in it before that. Wish I would have. So getting a return up there is not happening since all walls and ceilings on all floors are finished. Any ideas for balancing the upstairs with the down stairs? Especially the master? We leave all the doors open all the time, only our bedroom doors get closed at night. The overall foot print of the upstairs is only 24x24.

Doc Holliday

Nope. You have to spend money on it and do it right or you will always have problems.

Unless you want to add a mini split air conditioner to that room. Good thing about that is you can have two or three blowers so you can mount them anywhere for different rooms all on one condenser. And they're ductless. And then if one a/c system fails you have the other one to count on.

beenthere

Are the bedroom doors under cut? If not an under cut will help some. Might want to add a return to the first flor also, so that the unit gets more air to be able to supply more air. Do the supplies have dampers in them at the take offs?

Joey-D

Doors are cut and I have hardwood floors so no restriction under the doors. 2 main floor returns. No dampers in the supply's although I have tried closing registers at random to equal out the upstairs. I especially keep the one near the thermostat closed.

beenthere

Open the door to your basement, remove the panel from the blower compartment, hold in the blower safety switch and have someone turn the fan switch to on, and then have them go an see if more air is blowing out the registers in that bedroom.