By Dave Solberg
Dear Dave,
What is your opinion of the WackO RV A/C Silencer for the Coleman-Mach Air? I have watched installation videos and it appears it directs most of the airflow through the duct system, which makes me wonder if this would create backup pressure on the unit. It appears the reduction in decibels is not that significant quantitatively, but folks report the A/C noise is reduced to their satisfaction. Thanks in advance for your feedback. —Gary, 2021 Jayco Melbourne 24L
Dear Gary,
I met the founder of the WackO® product at the Florida RV SuperShow in Tampa a few years ago in the vendor hall and got the “lowdown” on the product. Since then, I have watched the install videos, reviews, and promotional videos. I thought it was funny the product was called “WackO”, as it reminded me of the ShamWow or Popeil products.
In my opinion, the last time I checked, this product did not reduce the noise. Rather, it was the procedure of taping the poor workmanship of the RV manufacturer with the HVAC foil tape that reduces the noise. The elastomeric filter is not recommended by most air conditioner companies as it restricts airflow more than the cell foam version when it gets dirty.
What is causing the noise?
Original equipment manufacturers (OEMs) of the air conditioners make a generic unit that can be used for direct airflow out of the bottom of the unit or customized for ductwork in the ceiling. The OEM sends the unit with a diverter that needs to be cut to size by the RV manufacturer and installed with HVAC foil tape. This directs the conditioned air to the ductwork throughout the ceiling of the rig.
Unfortunately, most RV manufacturers do not take the time and effort to properly seal all the gaps, holes, and rough spots. Therefore, the air conditioner runs less efficiently and is loud when the air hits certain rough spots and openings. If you watch the video, the majority of time is spent taping the inside of the air chamber. Anyone can do this with some HVAC foil tape from a home improvement store.
Issue with ducted roof air conditioners
This has been an issue with ducted roof air conditioners, as RV manufacturers cut the diverter too small and simply apply one strip of tape at the top. I have found several units locally that had poor air circulation or were blowing warm air. It turned out that the diverter was laying sideways or was detached completely.
I would be a little skeptical about covering the outgoing duct completely, like the install video shows. This would create a block in the airflow and could cause the compressor to freeze up. If you look at the reviews on Amazon or RecPro, they are mostly 4-5 stars. However, this is due to making the unit quieter—which is not from the product but rather the procedure.
Personally, I like the RV Airflow Systems™ product. It inserts a smooth, curved foam module that has been very popular.
It also suggests using HVAC foil tape to cover some of the gaps and holes. In addition, the curved vents increase airflow to the ductwork. You can find it on Amazon here.
Cut to the chase
Personally, I think installing HVAC foil tape to the inside and covering all the gap and holes will reduce the noise and increase the airflow sufficiently. Then just make sure the filter is cleaned periodically, the evaporator coils cleaned and have good airflow, and the mounting bolts are torqued tight each year.
You might also enjoy this from Dave
My RV’s roof air conditioner is so noisy I can’t hear my husband 15 feet away!
Dear Dave,
First on my list is to thank you for ALL of your knowledge. I am wondering why my air conditioners are so loud in my unit and how I can quiet them down? When the air is on I can’t hear my husband talk 15 feet away, or watch television, for that matter. Help. Thank you. —Karen, 40’ 2021 Heartland Cyclone 3713 fifth wheel toy hauler
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I have the Coleman Mach unit on my 21 foot camper. I taped up everything with the foil tape and made my own diverter with some 1 inch foam board. It strikes me as funny that the ac is louder on the inside than outside.
I’m fortunate that my 2015 Cruiser RV Fun Finder has a sliding window at the dinette table. We winter in the south. I made a bracket that hangs on the wall of the window opening, and I put a 6,000 btu window unit in and close off the rest of the opening with plastic. It keeps our trailer cool until the outside temps get into the mid 80’s. It is very quiet and it allows normal conversation. We keep the bedroom and bathroom doors closed during the daytime then open them after the sun goes down. The power pedestal is 50 amps, so I use a 50 to 2 30 amp splitter, running 30 amps to the trailer and the other leg I use a reducer to a 20 amp plug for the window a/c.
We have both the RV Airflow and RV A/C Silencer installed on our front Coleman A/C unit (front living Solitude) and they have made a huge difference! We can now converse and comfortably watch TV at an almost normal volume with the A/C running. Is it silent? Not even close, but it is a lot better than stock.
I did a DIY on my 2 units with foam board and tape. That improved the air flow to the duct system and might have cut a little noise out but sure made them not have to work as hard to cool the camper