Warm Air Oil Furnace fan settings

Big Ed

Don't forget to also adjust the fan speed for the proper delta T across the heat exchanger,which is posted on all furnaces. This is a must to protect your investment and the warrinty......

bmbradley

Oil Fired Warm Air Fan Settings


I am looking for the "best" or "Recommended" factory settings for the Fan/Limit switch on a Thermo Pride warm air oil fired furnace. Looking for "fan" only. I realize the limit is factory set to 200 degrees and should not be adjusted!

Jim Davis_7

The fan setting should be as low as possible to bring the fan on after the burner starts-around 110-120 degrees and keep it running until it is below 100 degrees. This maximizies heat transfer and keeps the heat exchanger cooler.

Techman

Furnace Fans

Morning!I agree w/ Big ED about the temp rise across the exchanger.To protect the exchanger and your investment also check the fan cycling after a set back.If the cold return air cycles the fan off/on to many times you are killing the exchanger, a continous fan during the warm up from set-back is a better way to go.

zeke

> The fan setting should be as low as possible to

> bring the fan on after the burner starts-around

> 110-120 degrees and keep it running until it is

> below 100 degrees. This maximizies heat transfer

> and keeps the heat exchanger cooler.




I find it hard to believe that you maximze the heat transfer by lowering the flow. The opposite is true since the heat transfer coefficients increase and the average temperature difference between the hot gases and the warmed air increases with increased flow. I would suppose the the reason might have something to do with comfort and the warmer air that you get albeit at a reduced flow velocity. Please correct me if I am wrong.

Paul Fredricks_3

I don't think Jim meant to lower the flow. I think what he was saying was to leave the temperatures set on the low side. The idea being that more heat transfer occurs when the air is kept cooler.

I think.