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creativepart · 10-03-2020, 03:06 PM

My RV has two Coleman Mach 8 heat pumps on the roof. 16 months ago the rear unit sprung a refridgerent leak and had to be replaced.

This summer before our trip I cleaned the roof and decided to clean the A/C coils. My front unit had a 3-blade fan and the little metal "hat" to keep the cover from sinking into the fan.

I noticed the "new" rear unit had a 5-blade fan. So, I thought it needed replaced. When I looked online I saw folks replacing their 6-blade fans for 3-bladed ones. So, I figured I just counted wrong. To remedy the fan blade issue I ordered the 3-blade upgrade kit with the little metal hat.

Today I went up to install the "upgrade" and found it WAS 5 blades after all but more than that it has a plastic guard ringing the fan. too. It also is connected directly to the fan's rotating motor armature with a solid metal cap that looks like it needs a special tool to unscrew. And, there are even small metal balancing weights on some of the blades.

Looking online I see this available on the Mach 8+. It seems much more robust than the 3-blade fan "upgrade." for the Mach 8.

I can't find much more online about the 8+ so I'm not sure what the Plus is?

Here's a photo:

**Lt Dan** · 10-03-2020, 03:15 PM

You have the new upgraded Mach 8 Plus. They totally redesigned the condenser fans which run slower and enclosed them in a plenum. From what I understand the fan blades are no longer replaceable. You have the best setup as is so there is no reason to change. The original Mach 8 units had six blades and were extremely noisy. They redesigned those with the three blade fans which were much quieter, and have now changed the design again to the new style which is supposed to be even quieter. I contacted Coleman to see if my Mach 8s could be upgraded to the new plenum style and they said no.

creativepart · 10-03-2020, 03:18 PM

Thanks LtD!

EVO-Bob · 06-11-2021, 08:26 AM

I just replaced my 5 blade with the 3 blade to reduce the noise on my 2014 Tiffin. You’ll notice a part # on the top of the blade which has a single letter in the middle, I think A-D. I had A and it was replaced with a D. I measured the noise reduction and it was dramatic. With both fans running the noise went from 58 dB to 52 dB. 6 dB may not sound like much, but keep in mind that’s a 4x reduction because sound doubles in volume every 3 dB. For anyone looking to reduce the noise on their Mach 8, you don’t need that Hush kit sold by some. Just replace the blade with a D type.

Even better, we think the AC air appears cooler than it did before the replacement, although I’m not sure because I didn’t think to measure that.

jk5516 · 09-30-2021, 09:34 AM

I as well bought a 3 blade fan only to realize that I have the new 'plus' version which isn't compatible with these 3 blade fans. I find the plus version extremely loud (68db) and really annoying for my camping neighbors. I'm definitely self conscious about it.

Anyone have any tricks for quieting this new 'plus' version?

baraff · 09-30-2021, 09:51 AM

Interesting post. I had our original Coleman replaced in 2017 or 2018. The replacement Mach 8 is extremely noisy, almost a buzzing sound when the fan and compressor kick on. It can be heard from a couple hundred feet away if nothing is blocking the sound.

How does one tell if one has the older one vs the newer, redesigned one? I would change the fan blade out if mine is determined to be the older version. Serial number or model number change?

jk5516 · 09-30-2021, 10:18 AM

Quote:

Originally Posted by baraff

Interesting post. I had our original Coleman replaced in 2017 or 2018. The replacement Mach 8 is extremely noisy, almost a buzzing sound when the fan and compressor kick on. It can be heard from a couple hundred feet away if nothing is blocking the sound.

How does one tell if one has the older one vs the newer, redesigned one? I would change the fan blade out if mine is determined to be the older version. Serial number or model number change?

If your fan blade and blade shroud looks like the picture from post #1 then you have the plus version. Nothing easy can be done (so far).

If you don't have a blade shroud then I think you can just get the D version of the blade (3 blades) to quiet things down significantly. You may already have the D version (will have a D imprinted on the fan blade) - as I understand the newer non 'plus' versions already had that blade.