Forced Air Furnace Blower Question

[the old grind]

how you have it... it can be done and can work. as others have said keep it filtered. and change the filters as needed / when needed.

would suggest adding 2 vents. into the return duct work. 1 near ceiling, and 1 near floor. so you can open/close the vents pending if winter / summer.
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if the ceiling (between basement and main floor) is not insulated. just circulating warm air down stairs with say a floor fan. so the air down stairs rotates in a large vortex / whirl pool like current. down stairs. can allow the heat to move around and go right up through the ceiling. ..

For years, I used a small (10") fan on the basement floor angled up at 45^ or so to move air around 24/7/365. It did wonders to even out the temps and reduce rusting in corners that were no longer damp-ish in moderate weather. For whatever reason, it helped o'all comfort both upstairs and down (open stairway) by the increased circulation and basement heat spread more uniformly beneath the upper floor.

Be sure there are adequate steps taken to equalize air pressure outside to inside either by an unobstructed inlet close to the wood furn or a 'cold air package' fitted to it. IMO there's never too much filtering or circulation, up to the point where one's hat is blown off. tog

 

[wjmst]

Running the blower without the door on (NEVER with a gas furnace) will cause the blower motor to pull too many amps and possibly overheat.

Thanks for the information. I am going to look at making some modifications based upon your suggestions. However, could you explain the above comment in more detail? I don't really understand how not having a door on the blower will cause the motor to pull too many amps.
Thanks

 

[quicksandfarmer]

Thanks for the information. I am going to look at making some modifications based upon your suggestions. However, could you explain the above comment in more detail? I don't really understand how not having a door on the blower will cause the motor to pull too many amps.
Thanks

It's kind of counter-intuitive. A blower motor uses electricity proportional to the amount of work it does. The amount of work it does is determined by the amount of air it moves. The lower the resistance, the more air it moves, the more work it does, the more electricity it consumes. Blowers consume maximum electricity when they face no resistance.

 

[buickanddeere]

Lower resistance on the intake side in particular increases the lbs of air per hour moved.

 

[Deere Dude]

I am running a test right now. I pulled the blower and motor from a gas Lennox furnace and have it on a stand in my garage. I'll see if it burns up.

 

[JRobyn]

I am running a test right now. I pulled the blower and motor from a gas Lennox furnace and have it on a stand in my garage. I'll see if it burns up.

How long you gonna run that test? I would imagine that running a blower motor under "unloaded" conditions might shorten its life from say 25,000 hours to only 15,000.

- Jay

 

[Deere Dude]

How long you gonna run that test? I would imagine that running a blower motor under "unloaded" conditions might shorten its life from say 25,000 hours to only 15,000.

- Jay

The test (not really a test) is using a fan from the furnace just blowing it across the shop. After running it half a day the motor is to hot to touch. I would not imagine that is normal.

This is a fan with the motor incorporated into the unit and it is not a fan with a pulley, belt and motor. Whoops, I have it running right now. I better go and see if it is smoking.

 

[buickanddeere]

The test (not really a test) is using a fan from the furnace just blowing it across the shop. After running it half a day the motor is to hot to touch. I would not imagine that is normal.

This is a fan with the motor incorporated into the unit and it is not a fan with a pulley, belt and motor. Whoops, I have it running right now. I better go and see if it is smoking.

Touching the motor with your hand is not a test. Why not measure the current and rpm ?

 

[dadster4]

A few answered your question already...no resistance to airflow (no door on) leads to the blower moving more air than designed, thus drawing more amps than design, thus running hotter and shortening motor life. Running a blower "wild" is nice for a shop fan or temporary air movement, but ruining your furnace blower should be avoided. Variable speed (not multi speed) blower motors in better furnaces cost upwards of $500 or more, so using one of these with the door off could be very costly. Deere Dude still in the shop?
Anyone else running a test can check the amp draw on a properly installed blower and one running wild and see the difference easily.

 

[ray66v]

As stated, blower door off, is a bad idea.

Your return duct system works best with a certain amount of negative pressure.

Modern systems are carefully calculated using this negative pressure, to achieve proper airflow, even in the rooms at the furthest from the furnace.

Any changes made to that system, can throw it off balance, and reduce heating or cooling performance, in parts of the system.

You should be careful when blocking, or creating new openings for cold air returns.

Adding a new return opening in the basement, before the filter, should give you the effect you want. Just don't make a lot of changes to the system at once, until you have time to access the effects of those changes.

The first opening I would probably add in a basement is, a small grill, low on the cold air return drop. This gets the stagnant air on the floor moving.

If the basement was not part of the system before, you are now heating and cooling the air in that space directly, to some extent. So keep in mind, a small amount of energy goes into doing that.