how many vents off a 6" pipe

[cevrard]

Hey all,
My heater is a vintage 1968 oil burner unit and was intstalled by the people that owned the house at the time. The house has a total of 6 registers, and has an individual 6" pipe run to each one. I was wondering if I could double up the registers (put two on each run of duct) and save myself about half the feet of duct work, and possibly some heat loss due to less surface area etc. Also, it would look much better in the basement.

So, does anyone out there know if it is ok to run to registers / vents off of 1 6" duct? Am I even asking the right questions here :)

Thanks for any help!

Chris E.

[Ed Imeduc]

Not sure just what you want to do here. You mean registers for down in the basement?? Or what? lets go this way. No you cant just add on to the 6" pipe for another run.
Now Oil burner furnace 6 6" runs sure dont sound like it is enough comeing off the furnace to me. you need more run there.

ED ;)

[cevrard]

Ed,
I think I explained this badly! :wall: There are six heating vents in the house upstairs (only one floor house) and of course the furnace is in the basement. From the plenum on the furnace there is one 6 inch round duct/pipe leading to each of the vents that heat the upstairs. I figured if I could run two vents off of each 6" duct, I could eliminate 3 of the duct runs. If there is enough air flow in a 6" round pipe for two upstairs vents that is. I measured every thing out and I would be able to remove 18' of the 6" round ducting by doing this. It would clean up the appearance downstairs and I thought it may save energy and heat by having 18' less of pipe exposed to the basement temps.

Does that make sense?

Thanks!

the newbie, Chris

[Jay11J]

Chris,

Run a new run of duct to heat the basement.. If you "remove" the ducts that already there. you are going to cause your furnace to over heat! That is a waste of enegery when it over heats. ALso shorten the life of your heat exchanger.

If you want to "Clean" up the all 6" runs, run one larger trunk down the center of the house, and branch off of there.

I am with Ed earlier, only 6 runs on your system?? YIKES :eek:

How many BTU is your furnace? Does it cycle on and off often?

[cevrard]

Thanks Jay,

That is what I was after. What size trunk would I need to move the air necessary to replace 3 6" ducts?

The bit about overheating is what I was wondering. The furnace is 112,000 BTU's (rings a bell) and the house upstairs (the only part that is heated, basement is not) is only 650 sq feet. The service guy told me that the furnace is too big for the house and that he put the smallest jet he could in it to help.

does this sound right? Could I maybe benefit from trying to heat the basement too?

Jay yes the furnace does cycle frequentely.

Again thanks much Ed and Jay!!! :)

Chris E.

[Jay11J]

I don't have my sizing slide off hand.. it's packed some where since our move..

I would say 8 by 15 should be right.. I am sure the other guys may have something to help you.

Put the heat in the basement if you can.. also with the warm basement, the floor will feel a little warmer too.

how old is the furnace? If it's older, Think about a new one and make sure the size the system right so it won't be over sized.

[Ed Imeduc]

112k btu and 6 --6" runs oh boy. Did he tell you what nozzle he cut it down to? if you want to change the runs around like jay said you will be best to run a trunk line and take off the 6" runs in the top of the duct in the joist. For now Id cut in 1 -10"X6"registers in the heat plenum for down in the basement. Check and see if you have insulation in the joist space right up there on the sill plate all around the home.. let us know what you come up with. You are better off if the furnace runs for a longer time when it comes on.


ED ;)

[cevrard]

Ed, Thanks again. No, the tech didn't tell me what nozzle size he used. He did say it was the smallest he could get away with. Yes I do have insulation above the sill plates but not between the joists all the way across the basement. Great idea on adding a register to the plenum for downstairs. I'm going to do that.

I had another guy tell me that I should be able to get the 3 runs I want off an 8X12 square duct. I think I will stick with Jay's 8X15 though.

In the summer when I run the AC, would I just shut off the vent in the basement? It is nice and cool down there in the summer anyhow.