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Topic: Aquahot heat exchangers ...

Posted By: 2ndhom on 02/10/09 06:12pm

Have a 2006 Beaver, Monterey 40' 4 slide.
I have very loud running heat exchangers (all 5 of them). Need to kick up the TV volume 6 numbers (I have excellent hearing). Called Aquahot and they think the coach doesn't have their exchangers installed .... the tech says their's run very quiet. Anyone out there experienced a noisey unit? Has anyone ever changed out just the motor of a heat exchanger to gain a quieter unit? I haven't asked the cost of installing 5 new aquahot units. Any input?


Posted By: series60man on 02/10/09 06:40pm

I agree, on my 06 Exec, the fans are almost as loud as the roof air. That is one reason I use portable oil filled radiators. My other complaint is that when the fan comes on, the circulating coolant is cold for a couple of minutes and blows cold air in your face. I am going to install a delay in the system to allow hot coolant to circulate before the fan engages.


Posted By: Lug_Nut on 02/10/09 07:33pm

Mine are real quite (5 units total) But that was'nt the way it was originally. All are original except for the front unit. It sounded like a buzz saw when it was new. Newmar replaced the entire unit, and now it is normal. I heard other front units that were loud too. I don't know why it was that way, but it was.


'07 Newmar Essex 45' ISM 500 4 slides



Posted By: caymann on 02/10/09 08:17pm

I am not sure which heat exchangers you have...I have Cozy exchangers.
Look at the back of the exchangers and check to see if these are using standard computer casing fans. If so you can buy low noise fans for $7 or so a fan and replace the noisy ones you have now. Mine is very quiet.


01'Monaco Executive Tag
RM(S)chassis,Cum-ISM500
04'Dodge Ram 3500,Cum-ISB325
05'BMW F650GS motorcycle


Posted By: John S. on 02/10/09 09:29pm

Mine is quite too. I hear the pump more than I hear the registers running. All but the front dash> That one I had them turn down the speed of the fan. My unit has multi speed fans so I have them set a bit lower and it is quiet.


John
2001 42' Foretravel U320
2007 Bornfree 24 Painted
2001 Jeep Wrangler for 300k miles
2012 Jeep Grand Cherokee Overland
Susie and Dolly (Cavalier King Charles Spaniels) now in our hearts and thoughts
Doodle a Black and Tan Cavalier
Lolly a Ruby Cavalier


Posted By: lenmann on 02/10/09 10:49pm

I have a 2008 Contessa with the same issue. Beaver/Monaco managed costs by installing cheaper HeaterCraft heat exchangers. I am considering the upgrade to the AquaHot Cozy III units although I don't know how much they cost or even if they will fit. The HeaterCraft units use noisier squirrel cage fans vs. the Cozy III which uses quieter low velocity muffin fans. The silent operation reputation of the AH system was one of my primary motivations, guess I should have listened to the heaters as part of the test drive...oh well, just another project.


LenMann
2008 Beaver Contessa 40 Pacifica, Cat C9


Posted By: zmotorsports on 02/11/09 07:43am

2ndhom wrote:

Have a 2006 Beaver, Monterey 40' 4 slide.
I have very loud running heat exchangers (all 5 of them). Need to kick up the TV volume 6 numbers (I have excellent hearing). Called Aquahot and they think the coach doesn't have their exchangers installed .... the tech says their's run very quiet. Anyone out there experienced a noisey unit? Has anyone ever changed out just the motor of a heat exchanger to gain a quieter unit? I haven't asked the cost of installing 5 new aquahot units. Any input?


This topic is ironic because posted question about this a couple of weeks ago. I didn't get much response so I went ahead and did it. I was even going to post a thread about the swap this morning when I noticed this thread.


I just changed my heat exchangers last night. The factory heat exchanges are made by Heater Craft specifically for Monaco (they even have a Monaco part number on the bottom). Mine were a little louder than I liked (would have to turn the television volume up also) as well as the current draw was .73 amps per register. I started looking at the Cozy III from Aqua-Hot and talked to them about the noise level and they wouldn't comment on the fan volume as compared to the Monaco units but they said they have heard theirs are quieter. After looking at the specification sheet for the Cozy III units it showed 6 watts of power consumption @ 12VDC which equates to .5 amps. I decided to give them a try and ordered five of them last week. When they arrived on Friday two of them were broken in the box (the fans were damaged) so I contacted Aqua-Hot and they were awesome about it. They agreed to send me two new ones out and even voluntarily offered to send them next day air because it was their fault and the box did not appear to be damaged from shipping. They arrived yesterday and I installed them last night. They did make a noticable difference in noise level and the current draw is .49 amps. The amp draw was a 33% reduction which equates to 2.25 amps total for all five heat exchangers (compared to 3.75 amps with the Monaco units). I did not change the bathroom heat exchanger as it is already a smaller unit and is much quieter than the others and only draws .25 amps. If I can be of any more assistance please feel free to contact me if there is something that I have not addressed, Mike.

P.S. on edit let me note that I did take a few pictures of the old units and the new ones if that interests you or not. Let me know and I will post pics tonight if you are interested. Mike.

* This post was edited 02/11/09 07:51am by zmotorsports *


2003 Monaco Dynasty/ 26' Haulmark Edge trailer
2011 Jeep Unlimited Rubicon



Posted By: Bob&AnnaMarie on 02/11/09 09:04am

Mike,

I, for one, would really appreciate more information on your exchange. My 03 Beaver has the HeaterCraft registers and they are noisy too. I was going to change the muffin fans which seem to be the source of the noise. But, it looks like the AquaHot swap out is a better alternative. I would like to know:

1. Were the sizes of the units an exact swap-out or did you have to make changes in the openings?
2. Did you have to change either wiring or pex pipe connections?
3. Did you keep your Heater Craft switches?
4. Did you have to drain any fluid before the exchange?
5. Do you have a kitchen slide, and if so, what did you do for the register under that slide?
6. Can you share the price of the units?

You make this sound like a rather easy change out. How would you rate this project for someone who is fairly comfortable working on his rig, but having never worked on this heater system?

Thanks in advance,
Bob


Posted By: zmotorsports on 02/11/09 10:16am

Bob&AnnaMarie wrote:

Mike,

I, for one, would really appreciate more information on your exchange. My 03 Beaver has the HeaterCraft registers and they are noisy too. I was going to change the muffin fans which seem to be the source of the noise. But, it looks like the AquaHot swap out is a better alternative. I would like to know:

1. Were the sizes of the units an exact swap-out or did you have to make changes in the openings?
2. Did you have to change either wiring or pex pipe connections?
3. Did you keep your Heater Craft switches?
4. Did you have to drain any fluid before the exchange?
5. Do you have a kitchen slide, and if so, what did you do for the register under that slide?
6. Can you share the price of the units?

You make this sound like a rather easy change out. How would you rate this project for someone who is fairly comfortable working on his rig, but having never worked on this heater system?

Thanks in advance,
Bob


Bob, I would gladly give you as much information as you would like.

1. The size is 'almost' identical. The footprint is within 1/2" of the Heater Craft units and the depth and height are the same.
2. The connections were identical. There is a small length of rubber hose (approx. 6") between the heat exchanger barb and the PEX tubing. It actually is a reducer hose because the barb on the heat exchanger is 3/4" and the PEX is 5/8" tubing. There is a clamp on the PEX to rubber connection and a clamp on the rubber hose to barb(heat exchanger) connection.
3. Ours did not have aux. switches on the Heater Craft units, they only had one speed.
4. I put a hose clamp on the rubber hose between the PEX and the heat exchanger pinching the line and then removed the hose clamps. I would then place an absorbant pad under the unit to catch any glycol that may seep out. After removing the line I lost very little (maybe a spoon full or two) from the hose/line and would quickly place my finger over the barb and then install a plastic cap which fit tightly over the barb to aid in trapping the glycol in the heat exchanger. Then do the same to the other line, cut the four wires (two positives and two negatives/ one set for each fan) and remove the unit. Install in reverse order and hook the wires up and remount to floor/cabinet and your done.
5. Our coach does have a kitchen slide so I assume you are referring to the unit in the toe kick under the drawers. This heat exchanger is changed in the same manner you just have to remove the floors of the cabinet on either side of the heat exchanger and the drawers to gain access.
6. The units are $122.67 from Aqua-Hot plus freight. Total out of pocket expense with freight was about $625.00. My buddy told me I was nuts to spend that much on just the complete heat exchangers but the fans don't mount on the two model units the same and I didn't want it to look like anything had been changed. A guy could probably modify the box or enclosure to accept the quieter fans and then just buy the quieter fans from Aqua-Hot but I wanted a cleaner/factory look.

I hope I have explained it well enough because it isn't a difficult job, it is more a matter a accessability. Some of the heat exchangers are rather difficult to get to but a rather simple job altogether. If I can be of further assistance don't hessitate to ask, Mike.


Posted By: Bob&AnnaMarie on 02/11/09 08:36pm

Mike,

Thank you very much for the information. I think you have answered all my questions. I may wait a bit before making the change, but this certainly looks like the way to go. I also saw your other post regarding the specifics of the two units. Your information has been very helpful.

I will certainly let you know if I think I need any additional information, but I think you have covered everything very well. From the pictures on the other thread, it looks like the fans in the AquaHot units are the quieter squirrel cage blowers versus the muffin fans that I have. AquaHot is great about having their manuals on-line. I will download some of these and take a look at the exact measurements.

On edit: I see that they have two low-velocity fans which make them quite. Great idea.

Thanks again for all your information.
Bob

* This post was edited 02/11/09 08:50pm by Bob&AnnaMarie *


Posted By: caymann on 02/12/09 05:24am

Is it not possible to just change the fans on the back of Heatercraft with muffin fans? The Cozy muffin fans are rated at 34dBA, not sure what the heatercraft fans were rated at? Also the airflow (in cfm) between the two could be different. Do you have specs on that?


Posted By: zmotorsports on 02/12/09 06:02am

caymann wrote:

Is it not possible to just change the fans on the back of Heatercraft with muffin fans? The Cozy muffin fans are rated at 34dBA, not sure what the heatercraft fans were rated at? Also the airflow (in cfm) between the two could be different. Do you have specs on that?


You are correct about changing fans not being a direct swap. They could probably be replaced with the Aqua-Hot fans if someone wanted to fabricate an enclosure or box for the back of the Heater Craft units. The Heater Craft heat exchangers are not a squirrel cage desing like someone mentioned earlier they are a 'muffin fan' style as well but just not as quiet.

Where did you get the specs about the Cozy III fans being 34dB? I asked the tech @ Aqua-Hot and he couldn't answer about noise level and the spec sheet just shows N/A for noise level. The airflow is a little different but I cannot find where I saw the speed for the Heater Craft but if my memory is correct I think they were 3600 RPM whereas the Cozy III is rated @ 3150 RPM. This is probably where some of the noise reduction comes from.

I don't want to mislead people about the noise level, the Aqua-Hot fans are not what I would call 'whisper' quiet or you 'have to really listen to hear them'. They are quieter than Monaco's Heater Craft units definately but I don't want someone to install them and then get upset because they can still hear them. I just want to be clear, thanks, Mike.


Posted By: caymann on 02/12/09 09:03pm

Here is the link for the fan at AH website
Click on the picture and it uses DC KOALA KUDC12B4
Now Google this fan and get the DC axial Fans Click on DC axial fans PDF file. Look for the above model number and detailed specs on it.

* This post was edited 02/13/09 05:04am by caymann *


Posted By: 2ndhom on 02/13/09 01:00pm

Excellent input from zmotorsports ... thanks Mike. Has anyone done any fan muffin size homework for inner-change ability to the 2 heat exchangers? Sounds like the fan speed issue is causing the excess noise problem. Anyone have any thoughts as to splicing in a resister to reduce speed. I know some motors are not designed to accomplish the reduced speed ... understand they will burn up the motor. Does anyone have technical knowledge in that field? Thanks everyone for the visibility. Tom


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