Indoor ac unit is making a lot of noise lately. could anyone please tell what may be the problem? thanks,?

Question

Indoor ac unit is making a lot of noise lately. could anyone please tell what may be the problem? thanks,?

Answer 1

HVAC Tech.: You don't describe the noise so lets go with most likely first. The squirrel cage could be rubbing its' housing. the bushings/bearings in the motor could be going out. You didn't say how old it is so rust could have let the blower break away, accumulated dirt in the fins would bounce it as it could be unbalanced. Call a technician to look into it before the noise turns into its' death screams.

Answer 2

Moving less air because of a dirty blower wheel, dirty filter, or too many closed vents causes the fan to spin faster because it is moving less air, doing less work. This increases vibration.

Yes, it can also be that the bearings on the motor are wearing, sloppy, creating that vibration too. Few blower these days are belt driven and have bearings, so I don't suspect that.  

I have seen many things get sucked in to the blower as well, from parts of filters, plastic bags, or packing peanuts that get in to the return air vent.

But noises you mainly just have to find.

Good Luck

Answer 3

Most likely coming from the fan. There are bushings that insulate the fan and fan housing from noise. With the fan running, (be careful with fingers) apply pressure on the body of the fan motor, if this reduces the noise, try tightening the bolts making sure they are equal, if not the fan will scrape on the housing. As you try to adjust these, with the fan OFF, give it a spin and tighten as needed to stop the rubbing.