1 kW·h per hour just running fan

[david8370]

Is it possible that just running the fan on my furnace is using 1 kW·h per hour? Last night before I went to bed, I checked the meter and let the fan run all night. To my surprise, 8 hours later the meter moved 8 kW·h.

I know we have other appliances that draw some energy when they are off (DVRs, computers, etc.), but I was surprised by this.

If it consumes this much energy just to run the fan on my furnace, I may end that practice altogether.

[heaterman]

Would depend, I normally figure .5kw per 24 but all electric using devises can vary. You got a fridge, hot water tank, security lights etc.? Turn off the blower and check it tonight.

[BaldLoonie]

A gas furnace blower motor may run around 700-800 watts so you could round that up to 1 kw per hour. A VS blower running 1/2 speed for constant fan runs under .1 kw per hour by comparison. You may be surprised at how many items in your house are drawing power when off too.

[david8370]

Would depend, I normally figure .5kw per 24 but all electric using devises can vary. You got a fridge, hot water tank, security lights etc.? Turn off the blower and check it tonight.

Thanks. I'll give it a try tonight without the blower on and see what the difference is.

[beenthere]

If you have an electric water heater, it may have come on.
Your refrigerator most likely ran during the night.

[Luis-Pasco]

Thanks. I'll give it a try tonight without the blower on and see what the difference is.

You would be surprised to see what your other appliances are using electricity wise. I just went through this in my whole house.

[Home&Marine]

A 1.5 hp motor is 1.12 Kw! I'm actually surprised that you didn't consume more than 1 kw a night considering computers, HotWater, TV's and wall warts. In most all new TV's the power supply is hot constantly.

[david8370]

.. edit

[david8370]

If you have an electric water heater, it may have come on.
Your refrigerator most likely ran during the night.

I don't have an electric water heater, but how much would a typical side by side use an hour do you think?

[david8370]

A gas furnace blower motor may run around 700-800 watts so you could round that up to 1 kw per hour. A VS blower running 1/2 speed for constant fan runs under .1 kw per hour by comparison. You may be surprised at how many items in your house are drawing power when off too.

My furnace is the Rheem RGRL-90. Can't find anywhere in the documentation how many watts it uses... I know it depends on a lot of things. The fan setting is on low, where I'm at about 1035 cfm based on my ESP.

http://globalimageserver.com/fetchDo...b-ef31233d6cbf

[beenthere]

I don't have an electric water heater, but how much would a typical side by side use an hour do you think?

I'd guess several hundred.

[Home&Marine]

Per you info sheet, your blower is a 3/4 hp so the watts should be 560. I'm still thinking you're about where you should be. I haven't checked my Kw cost today but it was 8 or 9 cents a kw/h last time I looked (several years ago).

Going back to your sheet, they list the motor as 3/4 hp and then [559]

MOTOR H.P. [W]– SPEEDS–TYPE 3/4 [559]-4-PSC (copied and pasted from the sheet)

[david8370]

Per you info sheet, your blower is a 3/4 hp so the watts should be 560. I'm still thinking you're about where you should be. I haven't checked my Kw cost today but it was 8 or 9 cents a kw/h last time I looked (several years ago).

Going back to your sheet, they list the motor as 3/4 hp and then [559]

MOTOR H.P. [W]– SPEEDS–TYPE 3/4 [559]-4-PSC (copied and pasted from the sheet)

Thanks. Does that 559 hold even if it's on the low blower speed?