I am not a forum regular, but greatly appreciate this knowledge base. Thought I would share some simple noise reduction ideas with good results.
A - How to reduce A/C (air conditioner) noise.
An article in the RV Travel newsletter yesterday promoted use of the WackO A/C noise reduction cover. Looked at the web site and my common sense could not understand how this simple product could reduce nose so well. So I looked at the installation video, and there was the secret – foil tape. Part of the installation procedure is to tape over the quick cool supply vent. Next, I stood under my A/C and noticed that yes, indeed, a lot of noise is created from air trying to push through this vent. The WackO product cost $189, a lot of bucks for the bang. Before spending that kind of money, I thought I should see if taping over the vent would make much of a difference. It does! I bet most of the 10 db noise reduction touted in the product literature comes from this simple step.
The product also stated that their filter was better than the stock filter. I have been cutting my own filters from a bigger sheet for years using much better materials. Not sure of the brand, but it is available in most Walmart's. It has a black plastic grid that I peel off before cutting the filter to size. This probably adds a level of noise reduction too.
Pictures/procedure: The WackO install video is useful Installation - WackOProducts (https://wackoproducts.com/installation/). Pic1 – All you need is a screwdriver, foil tape, and some foam (optional), Pic2 – After removing the cover, simply tape over the outlet. This is the start of the tape job. After taping over the outlet, I had to punch some holes for the cover tabs. Pic3 – To ensure a good seal I also taped over the vent on the cover. Pic4 – (Optional) After replacing the cover I put some foam in the gap between the two chambers. Pic5 – The filters I use, black side down, green side up towards the A/C unit. The layers do a good job of trapping particles.
B – Quieter bedroom air circulation.
I also do not like the noise created by the bedroom ceiling fan, so I bought a USB desk fan. It is much quieter and keeps the bedroom air circulating so it does not get stuffy. I think it works better than the ceiling fan.
I did basically the same thing. I found I had a lot of my supply ducted air going into the return air duct. Sealed up all the openings and it became more efficient and a lot more quite.
Tom,
Thanks for the detailed write-up. This is something I will definitely pursue.
Richard
I did something similar. Sorry I didn't think to take a picture before I was done.
If you look at the picture, I put down a piece of foam and then a piece of 1/4"plywood the size of the vent. I used two white wire ties to snug it together. This effectively closed off the down dump opening like the foil tape shown in post #1. Then I used two pieces of the blue sheet plastic to make the deflector ramp. Small screws at each end and 3 rivets at the peak. A little heat gun helped shape the ramp curves. Then covered it all with the red duct tape. Makes a big difference in noise level and also improves the airflow through the A/C plenum.
I also got up on the roof and adjusted/added some vibration damping to the compressor. That made a big difference in noise level on one of the units.
Rich
So when I replaced my capacitors earlier in the week I forgot to mention that my rear air has always been noisier than the front. A lot. I thought I may still have a mud dauber nest I had missed. Nothing in the squirrel cage but there is a horizontal Freon line running down the left side of the unit to the condenser and there is two vibration dampeners on it, both were loose. Actually just tightened up the tyraps and they didn't break. Also shimmed up the lower compressor mount with a nylon pad and reduced its noise by 40%. It's now the same decibels as the front. Very pleased with those no cost fixes
Scott
My air conditioners are very noisy so I did Toms idea only I used some sound material
I had left over from the generator area. Today I went to check the fans and the mounting
grommets are worn out so I need to find some new ones. Also the rear AC the evaporator
is about 1/3 plugged. I haven't checked the front evaporator yet.
I turned the (grommets) motor mounts and now all I now hear is air movement noise. I found
new ones and will order tonight. Cleaned both evaporators with a vacuum. I'm really pleased
with how they are running and how quiet they are.
Please post part number and link to purchase
Scott
Amazon.com: Dometic 3310725001 Appliance Components Rv : Automotive (https://www.amazon.com/Dometic-3310725001-SERVICE-KIT-MOTOR/dp/B00BWADT14/ref=sr_1_1?dib=eyJ2IjoiMSJ9.vYB8syvmynYIEZXyrGq8xngjgCpzax36sXdkIBfoE4PGjHj071QN20LucGBJIEps.yCr5pYvWb5UUhHVDMRwOwwddNwi_VqE2lxhR_3ZN6IE&dib_tag=se&keywords=Dometic+3310725001&qid=1724069250&sr=8-1)
I typed in Dometic AC parts and this is what came up on Amazon. I hope this helps. My grommets where worn
through to the metal sleeves.
Scott I am only going to change the rear mounts as the front mounts are OK
The front mounts look like a way harder job to change. The rear mounts are really
easy to change.