Hello fellow bored winter RV owners. Those of us that have to park for the winter need little projects to keep us occupied with our RV's!
We have two AC's, a 13.5 direct vent and a 15K ducted. The 13.5 had quite the vibration and about a 150Hz hum to it.
I removed the condenser fan and it ran quite and smooth so I found my culprit! (I also checked the shaft for runout)
After removing the fan, I used a lawn mower blade balancer ($7) to check balance. I used a .5" nylon bushing ($.50) with one side sanded down in order to adapt the "D" shaft shape to the balancer.
Balancer
Here's the bushing clamped into the fan:
On a side note, you can see that they added weight to the blades at the 9:00 and 11:00 positions in an effort to balance the assembly.
The strange thing is, they just didn't add enough weight.
In this pic you can see how I added weight. I used simple speed nut clips on the blades.
AFter reinstalling the fan, the 13.5 unit was amazingly quiet. Almost nothing but "air" sound and no vibration or tone at all.
This worked so well that I decided to take another look at the main AC. It was good but in certain parts of the RV, you could just hear that tone the other one was making. Vibration wasn't bad either but you could feel it on the ceiling in places.
Because this fan blade was much closer to balanced, I just sanded away some of the excess "flash" at the edge of some of the blades to get it balanced. (I may have been able to do the other one this way..)
15K fan after balancing:
The effort this project took was well worth it. Both AC's are noticeably smoother and more quiet. Before the balance, the bedroom AC was so loud that there was no way anyone could sleep in there. Now is sounds like a simple fan.
I've been referring to them as balanced but they aren't perfect. Both fans have about a degree of tilt on the balancer but it's so much better than original that it makes all the difference.
I don't have a pic of them out of balance but they would just completely lean to one side and rest on the table.
So if your looking for a cheap winter project with big payback, give it a go.
Happy new year campers!
Scott
We have two AC's, a 13.5 direct vent and a 15K ducted. The 13.5 had quite the vibration and about a 150Hz hum to it.
I removed the condenser fan and it ran quite and smooth so I found my culprit! (I also checked the shaft for runout)
After removing the fan, I used a lawn mower blade balancer ($7) to check balance. I used a .5" nylon bushing ($.50) with one side sanded down in order to adapt the "D" shaft shape to the balancer.
Balancer
Here's the bushing clamped into the fan:
On a side note, you can see that they added weight to the blades at the 9:00 and 11:00 positions in an effort to balance the assembly.
The strange thing is, they just didn't add enough weight.
In this pic you can see how I added weight. I used simple speed nut clips on the blades.
AFter reinstalling the fan, the 13.5 unit was amazingly quiet. Almost nothing but "air" sound and no vibration or tone at all.
This worked so well that I decided to take another look at the main AC. It was good but in certain parts of the RV, you could just hear that tone the other one was making. Vibration wasn't bad either but you could feel it on the ceiling in places.
Because this fan blade was much closer to balanced, I just sanded away some of the excess "flash" at the edge of some of the blades to get it balanced. (I may have been able to do the other one this way..)
15K fan after balancing:
The effort this project took was well worth it. Both AC's are noticeably smoother and more quiet. Before the balance, the bedroom AC was so loud that there was no way anyone could sleep in there. Now is sounds like a simple fan.
I've been referring to them as balanced but they aren't perfect. Both fans have about a degree of tilt on the balancer but it's so much better than original that it makes all the difference.
I don't have a pic of them out of balance but they would just completely lean to one side and rest on the table.
So if your looking for a cheap winter project with big payback, give it a go.
Happy new year campers!
Scott
