Help with placing heat registers in my floor..

grantiman

I want to cut my hot and cold air return registers through my sub floor before a start installing my vinyl plank flooring, have no idea where they should be placed. Can someone help and show me where would be the best locations in each room? Disregard the "furnace closet" on my floor plan, we were originally going to install it there but I found out I have "I" beam running directly under the floor, furnace will now be installed in the basement. Any help would be greatly appreciated..

EBEBRATT-Ed

Supply air ducts go under the areas with the highest heat loss under windows and near doors. Always on exterior walls. Returns go on the interior walls.

Also, have you had a heat loss done? And sized everything correctly?

grantiman

I had a heating contractor do a heat loss and size the furnace for me. He's backed up on work and can't give me a hand until next month, he told me if I wanted I could cut the registers in the floor but never told me where. I has some concerns about where to place them in my kitchen, hallways, and living room. In the living room I'll have a couch going against my exterior wall right under the window. In the kitchen it would have to go on the far end exterior wall, wasn't sure if it would heat the kitchen all the way to the other end or if I'll have a cold spot. My one hallway there are only interior walls except for my entrance hallway.

EdTheHeaterMan

Depending on the size of the furnace and the needed cubic foot per minute (CFM) required for the space, and if there is going to be air conditioning added at any time. I might select a 4"x10" floor register. that is a standard size with all types of options to match the color of the floor in each room. The smaller rooms like mud room and bath room is usually easiest to place the floor register on the wall that the door opens to. there will never be a closet or shelf or furniture placed in that location. In the larger rooms place the floor registers by the windows or on either side of the window. Just figure out how far apart needed to accommodate the furniture. Place a register in front of the stationary portion of the patio door. If both doors open then select the one that is used less.



Returns are in blue. Supplies are in red. The returns are larger to accommodate ALL the air from the ten or more supply registers. For example: if you have a 100,000 BTU input furnace you might need 1300 CFM air flow. If each 6” supply duct can handle 100 CFM of air flow, then you will have to have between 11 to 14 supply openings. That will be a very quiet system. Sometimes for economic reasons, a builder might design a system with 150 CFM per 4x10 opening. That will be noisy but it will work and only require 8 or 9 openings. So it is up to the designer of the system how many openings you will need.

I like to use 5” duct for the small rooms and provide only 50 CFM in those rooms. I may use a 7” duct in a kitchen because there are less places on the floor that are usable. But I might use a 4x12 opening with a 7” duct.

Here is my diagram based on a 80,000 BTU furnace. 900 CFM total for the supply openings, 900 CFM total for the returns. try to place the bedroom returns in the same joist bay, that will make it easy to connect the returns in te basement without needing to have a duct connection below the floor joist leaving more head room for a future finished basement. Your furnace may be smaller and require less openings.

JUGHNE

Does your front door have a sidelight panel?

Are you able to cut your returns into the wall? Meaning that you cut the lower wall plate out and use that opening for the baseboard grill type return air.....or do you plan to cut floor grills in for the return?

grantiman

I do have a 1 sidelight panel on the front door, only a 1/2 panel. I can't cut any heat or returns into my wall, I'll have to use either floor or baseboard registers. My heating guy said I was going to need a 57,000 btu furnace, I'll probably have to go with a 60,000 96%. I've been getting pros and cons on which style furnace, some say single stage, others say 2 stage burner, I don't plan on A/C. This is only a retirement home that I plan on staying in a few months in the winter and possibly moving within a couple years. Looking for a basic furnace to heat the home, finding out that those 2 stage gas valves or 2 stage burners are more expensive. We did find a furnace which is a brand he installs a lot and never had no problems, it's right in my price range too.

https://hvacdirect.com/60-000-btu-96-afue-upflow-single-stage-goodman-gas-furnace-gmes960603bn.html

EdTheHeaterMan

Based on the furnace and the needed cubic foot per minute (CFM) required for the space, I might select a 4"x10" floor register. that is a standard size with all types of options to match the color of the floor in each room. The smaller rooms like mud room and bath room is usually easiest to place the floor register on the wall that the door opens to. There will never be a closet or shelf or furniture placed in that location. In the larger rooms place the floor registers by the windows or on either side of the window. Just figure out how far apart needed to accommodate the furniture.



Returns are in blue. Supplies are in red. The returns are larger to accommodate ALL the air from

With that furnace you have the option of adding AC. You indicated that will never happen in your lifetime. What about after you are finished using it? The diagram changes slightly for AC. and will make for very quiet heating operation.



I base this on the air flow chart in the manual for that furnace.



Red is the CFM for a quiet system withy AC, Blue is the original diagram for heat only.

The return openings will need to be 6x30 for the 900 CFM return but I would purchase the grill before cutting the opening. sometimes the one you want is not available and may take forever to find it. it is better to have the grill in hand before you cit the hole in the floor. Ask me how I know this

https://www.hartandcooley.com/products/265/heavy-duty-steel-floor-grille

JUGHNE

IIWM, I would move the hallway heat run to the outside wall just under the sidelight panel but away from the door as much as possible and still be under the sidelight, this insures no furniture placement there.

Also a toe kick grill run under the kitchen sink is usually a good idea.

It has been done to just cut a 6" round hole in the floor (from the basement) under the sink cabinet.

Then fit a six inch 90 into the hole, cut the 2 x 12 grill in the toe kick.

this will put warm air under the sink and out onto your feet.

I am waiting for someone here to condemn this practice, to feed a supply box without sheet metal lining.

It is done more often than one thinks.

The temp of the air at that point poses no danger of igniting wood....IMO.

I would leave the other supply air in the dining area as shown, maybe make it a 6" also.

grantiman

Kinda understand most of what everyone is talking about, like I said, I'm no heating expert, lol. I have a few more question if you don't mind.
You said that furnace in the link I sent has the option of adding A/C, is that something I would have to do when installing the furnace, or, can the A/C be adding later on if someone else wanted it after I move. Done a lot of looking online for furnaces, all the btu heating calculators at 96% comes up with anywhere between 52,000 to 57,000 btu's I would need, that 60,000 btu furnace I was going to order, would that be too big?

PRR

Yes, the Boss here demanded hot air under the kitchen sink. I brought a 2x10 elbow through the floor, another 2x10 elbow, and 2x10 grille in the toekick. Poorly sealed so the undersink cabinet gets over-warm which is OK (my max hot air temp is like a summer day in Arizona, people live there).

> 6x30 for the 900 CFM return but I would purchase the grill before cutting the opening. Ask me how I know this....

Amen. I have a single floor return (it suits the house), and put more shopping-time into this one hunk of steel than any other piece.

grantiman

Had a lot of help from "Ed The Heater Man" in helping me place my floor heaters, I just have a few questions before I start cutting the holes in my sub floor.
#1- The register in front of my kitchen patio door would have to be moved over in front of the stationary door, the placement shown now would be right in front of my door that opens. If I move it over it'll only be about 4 feet away from the corner register shown, can I move the corner register further down to the middle of the wall?
#2- My kitchen cabinets are already installed, I also have a few water and drain lines running right under where the toe kick would have to go as other people have suggested, can I just leave the register on the other side of the kitchen across from my cabinets as shown?
#3- I wouldn't need a register for my interior hallway going to the living room?
#4- I show 2 cold air returns, 1 in the living room and 1 in the bedroom. I have a entertainment center possibly covering most of the cold return where it's placed now in the living room, the entertainment cabinet has legs on it, would that cold air return still be able to draw enough air under the cabinet?
#5- The other cold air return is in the bedroom, most of the time the bedroom door would be closed, would it still be alright to keep it there seeing it would only be drawing air from the bedroom only, or should it be moved somewhere else?
#6- The cold air return in the living room would need a 6x30 floor grill for 900 CFM, if the return in the bedroom is alright to stay there and wouldn't have to be moved, what size floor grill would I need for 300 CFM?
I appreciate all the help, I just wanted to be sure in case I had to move anything before cutting all my holes, thanks again...