That would be true if the idea was to rely on the cooling effect of moving air, which is real. However I suspect that part of the reason for the full time fan is to distribute the cooler air to the areas that are warmer e.g. moving stagnate cool air on the first floor to the warmer air on the second floor or from room to room.
Thanks for the replies but I still feel confused. The home is definitely cooler with the blower running and the compressor does run a lot less. As to using fans, I use them too on the 2nd floor to additionally move the cooler air around as the vents are placed at the floor level. What has seemed to help is that the blower motor moves the cooler air up to the second leval....
Thanks again...
Exactly...
Maybe maybe not.
It will reduce the running time if the problem is hard to heat room(s) (like lots of sunny windows or a second story room), it might increase running time if the air in the room is stratified with hot at the top and cool at people levil. Pushing the cooler air up to the top (roof overhead?) would cause it to absorb more heat from the ceiling - roof.
Well, I think I'll do a compromise solution. I'll shut it all down at night when I go to bed. That way, the blower will be off for 4-6 hours.
If the cold air is dropping to the basement, that 20" fan is not going to help much is it? The blower, OTOH, will lift it to the rooms where it is needed. You need a given amount of energy to move a given amount of air. I don't see the fan doing much to help the situation or to reduce energy cost.
That was not my interpretation at all. Some furnaces have a switch that allows you to run the fan even if the thermostat does not call for heat or cooling. It is separate, mounted on the blower, not the one on the thermostat. That may be the situation here. I've seen systems designed to have constant running blowers for just that reason, to distribute the air and keep the temperature more constant. Some drop to a lower speed setting.
little heat.
It will if there is a cold air return in the basement.
increase
Agreed : )
Any decent thermostat has a switch for automatic operation and fan on, and the fan will operate whether in cool, heat, or off mode. Note I said "decent thermostat." I'm sure there are lots of primitive controls out there, but why one wouldn't spend $40 or so for a modern digital thermostat is beyond me.
The heat added by the blower motor is insignificant. It wont add even a .01 degree to the house temp. On the other hand, running the furnace blower has apparently lowered his house temp and made it more comfortable. You can live like a refugee and think you're saving money (when you're not) or spend an additional $2.00 per month and be comfortable - your choice. Hell, who doesn't piss away $2.00 a month? Come on, get real - save money where it makes a difference, not where it makes you miserable. Eric
Why bother? The duty-cycle on most HVAC fans can more than tolerate constant use. That and the blower fans are relatively inexpensive to replace should it wear out, say, a year earlier than the 20 years it'll probably last.
It might be worth having an HVAC professional come out and survey how the ducting is set up. It's entirely possible that rearranging some ducts might be in order. Or maybe as simple as better managing the airflow through the current registers.
I have a Trane AC/Furnace Its 3 years old now when I had it first installed I had a cooling issue. The HVAC tech came out and suggested to me to leave the fan on 24/7 I do that and closed down some of the vents so the cool air goes up to the 2nd floor and have wall vents now have plastic diverts to blow the air up. To make a long story short the tech also said the newer furnaces blower motors are designed to run 24/7. Even when its cooler out side when the ac is not on and windows open I still run the blower its like running fans low. I run my ac most of the time due to heath reasons my electric bill just is 25 to 30 more than usual.
Mike
plus some furnaces dont like the blower on while the gas is starting up. Not sure about A/C though.
Whats the electricity impact of this?
My best guess is that the blower is under the most strain during startup. Continuous run doesn't start the motor, so you'd get more actual hours of runtime if you just leave it on.
However, those hours of runtime will be condensed into fewer days, weeks, months.
I'm sure there are some motor experts who will have facts, web pages, etc. But such is my guess. I'd say leave the fan on if it makes you more comfortable.
Travis Jordan wrote running the blower to circulate air won't reduce the total load on the compressor.
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Yes it will - in some cases such as a poorly sized blower or a poorly sized AC system. I've know people who had to set the thermostat to 68 in order to keep upstairs rooms at 76 or so. And the basement is around 64. This is compounded when people are active in upstairs rooms with lights, stereos, computers, etc. turned on.
Generally, running the blower fan 24/7 enables these people to raise the thermostat and still get good climate control in the parts of the house that need it. And their electric bills drop.
I believe that he was being advised to run the fan 24/7 during the cooling season. I sounds as if the air in his house quickly stratified during the compressor off cycles. His nice cool air was quickly sinking to the basement. The cheapest way to work around this is to keep the air continuously circulating.
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24-7, in other words, set it at a decent temp. and leve it be. dont cut it on when it is to hot, by that time it has to work twice as hard to catch up. The squirl cage fan stays cool to a certain extent when running, like a car, it blows air over and around the moter to keep it cool. hope this helpedFor some people, running the blower fan 24/7 is very practical. I've been doing it for years. In the past 10 years, my blower fan has been turned off only when I'm working on the system and have to kill the power. I find that this lowers the operating cost of my somewhat undersized AC unit. It also maximized air flow through the furnace filter system, which provides allergy relief.
Furnace blower motors are well designed and intended for a long service life. The only problem with running one 24/7 is the fact that you MUST oil them frequently. Once a year is an absolute minimum. I prefer 3 to 4 times per year. On my furnace, the entire process of removing the fan assembly, oiling both oil ports, and reinstalling the fan assembly only takes 5 minutes. I also oil the fan motor in the AC compressor box a couple of times per year.
By the way, you are asking the question, "does running 24/7 reduce fan motor life?" The more important question is, "does running 24/7 significantly increase the chance that the motor will fail before the furnace is replaced?" Generally, the answer to the second question is "no".
Good luck, Gideon
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Well needless to say that makes a huge difference as the compressor isn't needed as much.
My concern is will this shorten the life of the motor? And, is it ok to leave the fan on 24/7 for 2, 3, 4, 5 days? My thinking is to leave it on for whatever the duration of the heatwave. Correct?
Thanks...
This is Turtle.
What you say is very much True , but I think Travis was speaking of normal run of the mill systems with ok ducting systems.
Now what you have said here , I have been telling customers to do that when they don't have good ductwork and truely works fine.
TURTLE
There are several things to look at here.
1) If you have a temperature balance problem in your house, running the blower 24/7 will help even that out because you will be circulating air when the compressor is off.2) Running the blower geves you a breeze throughout the house, kind of like having a ceiling fan in every room. This will make you feel cooler at any given temperature. However, it will use more electricity than ceiling fans, because it has to push air through the resistance of a duct system.
3) The motor in a furnace is designed to run continuously. You will not hurt it that way. With that use, oil it once per year with 20 or 30 grade non detergent motor oil. Do NOT use WD-40 or penetrating or 3-in-1 oil. Do not oil it too often. more oil will overflow the bearings and gum up the motor by catching dirt and holding it.4) Running the fan that way will allow your filters to catch more dirt, keeping dust levels down.
5) NOW THE BAD PART! When the compressor is off, you will re-evaporate the water left on the coil and in the drain pan, raising the relative humidity in the house 10 to 15 percent. I have tested this using data loggers to record humidity levels in my own house. Lennox has done studies and determined that as well. If you are in a high humidity area, The extra humidity can make you uncomfortable and allow mold growth.6) If you run the fan this way in the winter, the house will feel drafty.
ONE OTHER THING! DO NOT close off the registers in rooms that you are not using. That restricts air flow and can damage the compressor if it is running. Freon flow is what cools the compressor motor, and Freon flow in part is controlled by air flow. Also if air flow dirops too low, you can get liquid Freon back to the compressor, which is very bad for the compressor. The biggest enemy for the furnace fan motor is heat and restricting air flow reduces the amount of heat removed from the motor. At least that is what the A.O Smith motor rep tells me.
So running the furnace fan is a mixed blessing. Whether it is right for you depends on your climate, electric rate and your situation.
I hope this helps.
Stretch
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