Upgrade terrible condenser fan on home heatpump

[oil pan 4]

Looks like my central heatpumps outside fan died it's been sounding rough this year so no surpris. I noticed the fan was of particularly terrible design.
2 blades stamped flat sheet metal. Like it's the 1970s or something.
$15 box fans from Walmart have balanced airfoils shaped for reduced noise and increased efficiency. Maybe a 4 ton outdoor unit should too?
Is there any where that sells HVAC parts and at least pretends like the outside fan is an important part?

 

[facility1]

providing the fan blades are clean and the unit, and not hitting anything. but still noisy? , the bearings might be shot,or need some oil (if its not too late),,,look up a hvac supply house in your area, along with brand,modle serial number etc of unit and Moter size and number,,just check around, removing the blade maybe difficult, if so get a replacement Moter and fan blade, it's not very hard to change, or call for hvac company for $ervice.

 

[oil pan 4]

providing the fan blades are clean and the unit, and not hitting anything. but still noisy? , the bearings might be shot,or need some oil (if its not too late),,,look up a hvac supply house in your area, along with brand,modle serial number etc of unit and Moter size and number,,just check around, removing the blade maybe difficult, if so get a replacement Moter and fan blade, it's not very hard to change, or call for hvac company for $ervice.

Bearings are fine, motor windings are open. I'm thinking I should just be able to order a 22 inch 1/3hp fan (just a guess) for an 1,800 rpm motor that doesn't look like an after thought.
Looks like an aluminum fan hub on a steel motor shaft, so I'm not expecting it to separate and if it does, probably won't be in one piece or otherwise still be useable.
All the important parts of the house have mini split heatpumps tand it's supposed to cool off this week so no rush.
I don't trust any of the HVAC companies around here. I'll need replacement fan and they'll try to sell me a new HVAC system for 5 figures. Best case scenario I get charged $500+ for a $40 part with a 20 minute install.

 

[PontiacHO]

Looks like my central heatpumps outside fan died it's been sounding rough this year so no surpris. I noticed the fan was of particularly terrible design.
2 blades stamped flat sheet metal. Like it's the 1970s or something.
$15 box fans from Walmart have balanced airfoils shaped for reduced noise and increased efficiency. Maybe a 4 ton outdoor unit should too?
Is there any where that sells HVAC parts and at least pretends like the outside fan is an important part?

Grainger

 

[captainbeandip]

They do make specially shaped condenser fan blades that are designed to be quieter. Here's a picture of one that I lifted from Grainger's website. When you are picking out a fan blade you need to know diameter, rpm's of the motor, horsepower and rotation. You can't, for example, put a fan blade that's designed for 3/4HP onto a 1/3HP motor, and/or one that's designed for 850RPM's onto 1200RPM motor.

Speaking of that, lowering RPM is also a known way to decrease noise. If you currently have a 1200RPM motor, you can change out to a 850RPM one, with a blade that's designed to go with it, that's made to move the same amount of air. It can get tricky to find a good combination that will move the same amount of CFMs without overloading the motor, and while also being quieter. It's your equipment and money though, so if you want to do a little experimenting, go for it!

 

[Rand]

Looks like my central heatpumps outside fan died it's been sounding rough this year so no surpris. I noticed the fan was of particularly terrible design.
2 blades stamped flat sheet metal. Like it's the 1970s or something.
$15 box fans from Walmart have balanced airfoils shaped for reduced noise and increased efficiency. Maybe a 4 ton outdoor unit should too?
Is there any where that sells HVAC parts and at least pretends like the outside fan is an important part?

Fan blade(s) are sold separately from the motor... so even if you bought a new motor you would be expected to reuse the old blades.

you need all the specs but its not too hard to match something up... but also pretty easy to screw something up.

 

[oil pan 4]

Fan blade(s) are sold separately from the motor... so even if you bought a new motor you would be expected to reuse the old blades.

you need all the specs but its not too hard to match something up... but also pretty easy to screw something up.

View attachment 237322

I find those terms acceptable.

 

[walterjay]

Yes...go Grainger.

 

[Rand]

I find those terms acceptable.

You need to match up the amps on the motor, the fan diameter with the unit, and the fan style with the RPM/hp of motor to start with.
There may be some leeway on the motor amps.. as long as its not way off.

Disclaimer: not a pro.. on mine the compressor makes as much or more noise than the fan.

 

[oil pan 4]

They do make specially shaped condenser fan blades that are designed to be quieter. Here's a picture of one that I lifted from Grainger's website. When you are picking out a fan blade you need to know diameter, rpm's of the motor, horsepower and rotation. You can't, for example, put a fan blade that's designed for 3/4HP onto a 1/3HP motor, and/or one that's designed for 850RPM's onto 1200RPM motor.

Speaking of that, lowering RPM is also a known way to decrease noise. If you currently have a 1200RPM motor, you can change out to a 850RPM one, with a blade that's designed to go with it, that's made to move the same amount of air. It can get tricky to find a good combination that will move the same amount of CFMs without overloading the motor, and while also being quieter. It's your equipment and money though, so if you want to do a little experimenting, go for it!

I've done it before. The equipment I was working on had an 1,800rpm condenser fan motor that had burned up, the company sent a replacement 3,600rpm motor. When I called and said the old motor was 1,800, all the other machines like had 1,800rpm motors, was told the correct motor was sent and to use it. I use it and kept tripping breakers. Then it was "oh yeah that was supposed to be a 1,800rpm motor, so why did you use a 3,600rpm motor".

 

[oil pan 4]

You need to match up the amps on the motor, the fan diameter with the unit, and the fan style with the RPM/hp of motor to start with.
There may be some leeway on the motor amps.. as long as its not way off.

Disclaimer: not a pro.. on mine the compressor makes as much or more noise than the fan.

Mine for the last year or so the fan makes way more noise than the compressor.
I thought the compressor was going out.
Now that the fan is dead I can barely hear the compressor.
I've got 3 box fans sucking and blowing in unison to make it work at night.
3 Walmart box fans are louder than the compressor.

 

[oil pan 4]

I'm thinking the fan motor isn't original and when it got replaced the HVAC guy just used what they had on the truck. So that sound I was hearing was just a fan motor running in perpetual overload.
One of the many reasons I don't trust HVAC people around here.
Probably toss in a 900rpm motor and power factor correct as needed if needed.

 

[Snagglefoot]

Here are my blades on my 2012 3.5 ton American Standard heat pump. It’s just a 2 blade design but seems to do the job.