OK to run the blower fan continuously?

[Dick in Wisconsin]

When we run the A/C, we end up with comfortable parts of the house and cold parts.

I know I could probably start to adjust the vents in the floor to balance things ... but what about running the fan continuously?

I've heard that will burn the fan motor up? I contend that is what the fan motor was designed for, the air coming across the fan motor is relatively cool.

What are the thoughts, opinions, and experiences of the HVAC guys on the GJF?

 

[ratdoggy]

My thermostat has a choice of on or auto, so why not leave it on?

 

[rburke65]

I believe that is an acceptable option.

 

[FrankieD]

My Boss's house burned out the blower fan.After I replaced it it run continuously. I checked things out and found that the fan was jumpered to run all the time! The reason for this turned out to be a bad solder joint on the board. I resoldered the board and the fan worked as normal. The fan ran for 12 years non stop! I would say you can do it like you want for the ac season and give it a rest every now and then without much worry.

 

[jomobco]

I just purchased a thermostat which has a fan cycler. You can set 10-120 minutes on and the same for off. When the A/C or heat isn't engaged the fan is still running according to the cycler setting. It really helps equalize the upstairs and basement temps.

 

[CNGsaves]

Yes . . . . My HVAC guy recommended to just turn setting to "On" for the fan during hottest parts of summer to cycle some of cool air from basement up to hotter upstairs (ie keep air moving). Ran it like that many summers (3 mths at a time) for past 15 years on single speed Lennox. Old beast is still running!!

 

[joe_padavano]

I've heard that will burn the fan motor up? I contend that is what the fan motor was designed for, the air coming across the fan motor is relatively cool.

I've heard people say a lot of things that were wrong. Most of them are on the internet now...

The only issue with running the fan continuously is that at some point, many years down the road, you will eventually wear out bearings and brushes (if it's a brush-type motor). That has nothing to do with running the fan by itself, it's just the lifetime of the parts.

 

[Milton Shaw]

I run fan motors continuously on both my units. Ran one over 20 years with out any service. The other one required oiling the bearings some time in the 28 years before I had to replace the whole unit. Running them keeps the temp more even in the house and helps keep the air cleaner.

 

[240sxguy]

My blower has been running constantly for a few years now. It really helps since the opening to my basement has no door and the cold air goes right down stairs. (split entry house). If the blower takes a ****, I'll replace it and do it again

 

[lilredex]

Yes to running your fan continuously year round. After the fan runs for a half hour or so put your hand on the motor .......... if you cannot keep it there comfortably, better slow down the fan or get a bigger motor.


green shot

One word of caution.....if you have sleeve (bronze) bushings like above, they need to be lubricated regularly in order to last. You can also get special quiet rated fan (roller - permanently lubricated) bearings, but they are mucho $$$. The picture shows mine, adapted for a regular grease gun. Those type of bearings were factory packed with grease but need updating if you expect them to last on "continuous".

Drill a pin hole in your new bushing, then install the hole oposite the grease fitting. If you omit that hole, the hydraulic pressure of the grease gun will split open that bushing housing. I grease mine every six months, the hole lets the excess grease escape around the shaft.

This is a fifty year old belt driven fan set up....yours may be different.

 

[dbonne]

I've been working on HVAC systems on the side for 20+ years, running fan motor constantly is not a problem. Of course it will cost you a little for electricity, not a problem for the motor. Squirrel cage fan motors are a funny thing, some will last for 20+ years, some will last a couple of years. Two big determining factors on longevity, one mentioned above is lubrication. The other being keeping your system's filter clean. Clean air will keep motors internals clean, longer bearing life. The motor is cooled by air flow, restricted filters = hotter motor, reduced life.

 

[mbatarga]

I don't think that the solution to resolving temperature variances from one part of the house to the other - such as the OP states - is going to be fixed by running the fan continuously.

I'd expect that the outlet and return ductwork needs to be visited for possible rerouting and or re-sizing. On our previous house, going from the builders' 8" return duct to a 10" return duct in our master bedroom made a huge difference in air temperature.

 

[jomobco]

I should restate. Rather than tearing apart my house built in 1975 which originally didn't come with a/c, in order to properly resize, valve and seal my ductwork I prefer to run my fan as it helps to equalize the temperature more than not doing so. I know it's not the fix that everyone would like but it works for me

I don't think that the solution to resolving temperature variances from one part of the house to the other - such as the OP states - is going to be fixed by running the fan continuously.

I'd expect that the outlet and return ductwork needs to be visited for possible rerouting and or re-sizing. On our previous house, going from the builders' 8" return duct to a 10" return duct in our master bedroom made a huge difference in air temperature.

 

[brewchief]

I don't think that the solution to resolving temperature variances from one part of the house to the other - such as the OP states - is going to be fixed by running the fan continuously.

I'd expect that the outlet and return ductwork needs to be visited for possible rerouting and or re-sizing. On our previous house, going from the builders' 8" return duct to a 10" return duct in our master bedroom made a huge difference in air temperature.

It can make a big difference in some houses and very little in others, we install a lot of furnaces with variable speed blowers and many of our customers have found that running the blower constant helps a good deal, a few report almost no change.

Running it continuous is no problem, I've always felt that more stress is caused by starting and stopping a motor then leaving it run all the time.

 

[larry4406]

I have a bonus room above the garage. Hot air rises, cool air falls. My thermostat for this zone is downstairs. Putting the fan in continuous run lessens the temperature differential.

 

[astroracer]

The fan on my furnace has run continuously since 1985, when we built the house. No issues at all. My house is passive solar and the fan is used to pressurize the interior of the house which keeps drafts and hot/cold air intrusion at bay, depending on the season.

 

[wyliesdiesels]

Running a 100% duty cycle motor continously is easier on the motor than frequently starting and stopping it! Motors like to run. If a motor continously starts and stops it WILL wear out sooner! BUT, if the motor has less than a 100% duty cycle, then it WILL overheat if it runs longer than its duty cycle rating! An HVAC blower motor is typically rated at 100% duty cycle!