Hot answers tagged

9

Okay, so I think I figured out the reason, and I learned a lot about HVAC in the process. The answer is that a ceiling fan is moving air at basically zero "static pressure." Static pressure in an HVAC context means the amount of resistance that the air has to moving. In a free environment, that's zero, or close to it, but in a tightly restricted system of ...


6

It does sound like the biggest opponent the AC is facing is the large picture window. I'm guessing it's just not a well insulated and/or not high-e glass and just letting too much heat in. For starters, close the internal blinds. If that isn't enough, consider some exterior blinds. These aren't terribly expensive and shouldn't be something that the landlord ...


5

Empirical Engineering Answers: Yes: you will save electricity costs by running your blower on low. No: you will not save on gas/oil costs by running your blower on low. Because the slower air velocity over the heat element is transferring fewer BTU units into the circulated air and they simply go up the exhaust pipe. The NET difference of the above two ...


5

Some motors have a start up noise, and is normal for that type of motor. My table saw does this. Starts out a loud 60 Hz hum which quickly increases in frequency as the motor spins up, then gets inaudible or washed out by rushing air when full speed is reached. Motors that do this are not really appropriate for residential blowers. It also possible it's not ...


4

The apartment is gaining more heat throughout the day than the AC is able to remove. Unfortunately, as a renter, there isn't much you can do about this. The real solution is to improve the building's insulation, plant shade trees, replace old windows with Low-E ones, add radiant barriers, etc. But all of those options would lie with the landlord, not you, ...


4

The blower very likely does spin at different speeds when heating vs. cooling. This is not uncommon at all. In heating mode they typically are on a low speed, while in cooling or fan mode they are typically on high speed. As such, it could certainly be the case that there is some imbalance in your blower that excites a harmonic frequency of your furnace at ...


4

Most furnaces use a preset, adjustable, time delay circuit to control the start of the blower motor. Some higher end models may use a temperature sensor to determine when the blower should come on, but this is a less common setup. It's possible that something in the furnace is broken and/or configured incorrectly, but it's more likely that the thermostat has ...


4

Are you looking for something smaller than this? Porter Cable Pancake Air Compressor To get any kind of are pressure / volume, you need a compressor of a decent size. Those little mini compressors can inflate something, but it takes a long time and they don't have the volume of air necessary to blow dust.


4

Squirrel cage blowers make great fans. Black is ground, white-negative and red-positive. Looks like blue, white and red coming from the motor. Read the info on the motor, it should have split capacitor in it, may have to change the wiring from 220 to 110. Looks like a 1/4-1/5 horse. Ask a local HVAC guy, feed his ego and be rewarded. If its a 110 just throw ...


4

I would suggest using a small shopvac instead of an air compressor, for several reasons. Air from compressors contains moisture which can harm electronics. If you want anything more than a few seconds of air, you'll need a compressor with a high CFM output or a large tank. This means more money than you're willing to spend. I've got this 1 gal. compressor, ...


4

If the furnace manufacturer supplies different burners for that unit you may be risking premature failure. The heat exchanger can be overheated and burned out if the blower does not remove enough heat. Proper duct sizing can resolve the issue you are having. Sometimes you have to add more ducts to achieve the proper pressure and velocity.


4

Just because the furnace fan is rated at 3/4 or more horsepower, does not mean that it is actually running at that power level. To clarify this, consider the extreme with an electric motor with nothing connected (just a shaft sticking out) spinning at full speed: it uses almost no power: perhaps as little as 3 watts, even though its ratings plate says 700 ...


3

In addition to DA01's excellent answer, here are a few more suggestions that may give you enough minor improvements to prevent having to upgrade your A/C system. Be sure that the output vents in all rooms are all the way open, and open the interior doors of every room with an output vent (though opening doors may be less important if each room has its own ...


3

This problem can be multi-faceted. Someone could guess all day long as to what the problem(s) is / are and not even come close. Air conditioning isn't something to guess at. It's like having a rattle on a car and taking the approach of replacing one part at a time to find the rattle. It would be cheaper to just buy a new car. ( I give that as an example you ...


3

You are going to need something with a storage tank. The little "inflater" type compressors basically use the tire, ball, etc. as the storage tank. Because of this, they are not going to be able to blow air with any force. If you're just looking to blow dust from your keyboard, why not use compressed gas in a can? don't try to fill your tires with ...


3

Turn the system off and let it warm up this may take a while if the evaporator coil is frozen up. When a system charge is low icing of the coils is a indication. The fan motor may be bad but once fully defrosted it is possible it will work. (Thermal overload tripped and was just hot because the coils were iced up) . If you can not get into the evaporator ...


3

I think Ed's answer is on point, in fact from your story I don't assume the fan is bad. I think he is spot on, its thermal overload. So, the fan COULD have, or WILL burn out, so, turn the system off. Open all of the registers, let the hot air in. It will need to thaw (almost certainly!) With all that said, I'm also in agreement that the green liquid is ...


3

That is actually a Trane/ American Standard furnace I believe. The cause is most likely the limit switch is getting so hot it is opening causing the fan to turn on to cool the limit switch. They often will open around 130-145 and yours may be a little weak.


2

This could be a bad draft inducer motor. This is a little motor that runs for a short while whenever your thermostat calls for heat and the furnace is in its initial firing + warmup stage. Our furnace failed this component (when it was only around 2yrs old), and the entire house would know when the furnace started running. Vibrations around the equipment ...


2

Turns out someone decided to play with the dip switch on the back of the thermostat and set it to electric heat. Switching it back to gas heat fixed the problem. Luckily it was just a simple solution. :) Thank you for your help.


2

Yes, that should be either plugged, or plumbed as a secondary drain. A 3/4" MNPT plug should do the trick.


2

According to the manufacturer's documentation, your furnace should have a 3 or 4 speed blower motor. The problem is, the furnace control module doesn't use a separate speed when the unit is running in continuous FAN mode. When the R-G circuit is made, the blower motor operates on heating speed. The control module only uses two speeds, one for COOL, and ...


2

It is very unusual but not unheard of to have a furnace hooked up to a heat pump. Usually you would have an air handler and air handlers usually have backup electric heating strips. These heat strips Combined with the 300-400 watts from the blower could easily suck 1700 Watts. The strip heat should not be on when the fan is set to on and the temperature is ...


2

Mark and remove the wires from R and G. Add a jumper wire across R and G. You should hear a click (that's the relay on the board) and the motor should start. If not check your capacitor (little oval device attached to this blower housing) be very careful as capacitors can give you a massive shock even when powered down. They are essentially high capacity, ...


2

The AC coil in your ductwork is freezing due to insufficient airflow across the coil. The coil needs to transfer heat by having airflow across it. If there is no airflow the coil freezes; hence, the ice. The coil is either too dirty for sufficient air to pass through or the fan blowing air isn't working anymore. Thanks, Tom


2

Connect the switch from R to G Wiring a standard light switch between R and G will do what you want -- the switch will perform the exact same function as the fan switch on a thermostat in gas mode. Namely, you'll be able to run the fan without heat by turning the light switch on, but the furnace will run the fan on its own when heat is called for, using ...


2

I too am like you, an old time boiler guy; 40+ years + 11 retired. My comment to you is, if your furnace fan is running on the correct fan speed and the furnace is not too oversized, the heat exchanger should be able to give up (cool down) enough so that there will be a very little waste of energy. The small amount of energy you are trying to remove may be ...


1

That looks like a standard A/C dimmer switch circuit: http://forum.allaboutcircuits.com/threads/potentiometer-w-switch-wiring-for-lamp.79664/ I'd imagine you could replace it with a standard A/C variable motor control like this one: http://www.globalindustrial.com/p/hvac/exhaust-fans/in-line-duct-fans/kb-electronics-vari-speed-ac-motor-speed-control-kbwc-...


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