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Topic: Aqua-Hot Fan Speed Controller Install (Read 968 times) previous topic - next topic

Aqua-Hot Fan Speed Controller Install

To me, the AH heat exchanger fans are too loud.

I ordered PWM speed controllers from this guy for $8 (Chinese, of course - sorry Roger, just can't spring $62 for an official AH controller).

DC 10A 12V 24V 36V 25kHz Motor Speed Driver Adjuster PWM Control Controller |

Installation is duck soup.  The hard part is getting to the wires on the back of the heat exchanger.  I did the kitchen one first as all I had to do was pull out a drawer.

The three pics tell the story better than any words.

Works great.

On the heat exchangers where I can't get to the wires (bath and bedroom ones are under the washer), I will probably go down in the AH bay and install the controllers there.  Makes changing speeds a bit difficult, but might be worth it.  I can always rip it out if I don't like. [Edit 12/12: Got to all the wires.  Didn't have to go down to bay.  Still working on dash. ]


Jim McNeece
2003 U320 40'
2017 Chevy Colorado Tow

Re: Aqua-Hot Fan Speed Controller Install

Reply #1 –
Glad to see that. Ours are very quiet with the exception of the dash. Can't wait to get this done.
Rick & Rhonda
2003 U320 4220  Build #6199
Was
91 36' GV 300 Caterpillar, 92 40' U280 300 Cummins, 97 36' U295 300 Cummins, 2002
U320 450 Cummins
(Guess we're hooked)

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Re: Aqua-Hot Fan Speed Controller Install

Reply #2 –
All my A-H fans, including the dash, are absolutely silent.  I have to feel the fan air flow to know it's running.
Regards,
Brett

'99 42' Foretravel Xtreme
'14 Brown Motorsports Stacker
'05 Chevy SSR
'02 BMW R1150R

Re: Aqua-Hot Fan Speed Controller Install

Reply #3 –
Jim,
my speed controller arrived Wednesday from somewhere over the rainbow.  $13 for a 15A controller with remote wired knob.  AH parts are very pricey.  When it warms up here (maybe April) I am going to install the speed controller in the Aquahot case and wire up the knob to the small cabinet behind the passenger seat.  The controller will adjust the speed of the kitchen, LR and dash heat exchanger. 

The heat exchangers should have the heat plumbing in series but each has its own power from the AH cabinet and a ground returning to the ground post in the AH cabinet.  The heat exchanger in the dash that blows warm air out of the defrost vents does not blow if the ignition is on.  I have not figured out that bit of wiring puzzle yet

Amos,
the fans do make noise.  You should hear them.  If you don't, maybe there is a problem.  Mine all quit working last spring.  Took me a while to discover that the nut had come off the ground post in the AH case and all of the ground wires from the heat exchanger fans had come off.  The pumps were working so the heat exchangers were warm and some heat came out by convection but no fan.

It would be nice to have a much bigger barn than I have now to store my coach in, one that is heated so I could work on all of these projects all winter.  But then all of my other projects would suffer.  So much to do, so little time.

Roger
Roger Engdahl and Susan Green
2001 U320 3610 #5879 (Home2) - 2014 Jeep Cherokee or 2018 F150
Hastings, MN

Re: Aqua-Hot Fan Speed Controller Install

Reply #4 –
Hmmmm, my AQ fans are blowing, and while they have a little noise associated with them, barely audible in my 2000.
Tim Fiedler    2025 LTV Unity MBL on Order
2000 Chevy Tracker 2 Door Convertible 4WD Now lifted 4.5"
1985 Citroen 2CV6 Charleston
Murphy Rebel on wheels with 175HP Titan
Cessna P337
1980 48' Westport MY (!/4 Share)

Re: Aqua-Hot Fan Speed Controller Install

Reply #5 –
I can hear my aqua hot fans blowing but that is alright with me as it is supposed to get to 0 degrees tonight and I want them to blow all the air they can. So far they are doing a good job.
previous 1984 35 ft ORED 250 HP 3208 Cat       
previous 1998 40 ft U295 CAI 325 hp Cummins
previous 2003 40 Ft u320 build #6140 450 Cummins M11.                                                         
1999 Mazda Miata
Ron, Nancy, Tipper the cat, Max The dog
1997 U 270 36 ft build number 5174 8.3 Cummins

Re: Aqua-Hot Fan Speed Controller Install

Reply #6 –
Well the AH heat exchangers are not silent.  1999 - 2000 - 2001, not sure there was different heat exchangers in these years, maybe.  There have been several variants over time.  In mine, BR, Bath , LR all make about the same level of noise.  In the evening while watching a TV when they come on they make more noise than I would like.  Slower speed, less noise.  They will likely run longer which may actually improve efficiency.  Slowing pump speed down might help as well. 

We have in-floor hydronic heating in our home.  The flow rate through heating loops (as well as water temp and room temp) has a big impact on how much heat gets from the hot water to the floor.  They measure the temp going into the loop and the temp returning and adjust flow rate to get to an optimum temp drop.

Our AH is much quieter than the LP gas furnaces we have had in the past but it is not silent.

Roger
Roger Engdahl and Susan Green
2001 U320 3610 #5879 (Home2) - 2014 Jeep Cherokee or 2018 F150
Hastings, MN

Re: Aqua-Hot Fan Speed Controller Install

Reply #7 –
Ok, I got sidetracked over on the other thread about what type of HX was in the dash and started posting about speed control.  Those posts more appropriately belong here.  So, I will catch this thread up with information I have received from SGM, the company that made the dash air/heating module.

I've attached two schematics from SGM, one is the wiring diagram and other is information on the speed reducing resistor they placed in some models of the dash air.  This speed reducing resistor is a wire-wound power resistor and is located inside the return air plenum in order to keep it cool.  It looks like it has to dump about 5 watts of heat.

According to the engineer at SGM, it is not possible to control the speed by adding a PWM - there is no access to the individual winding ground wires.  So, the only choice for speed control is to add another (more) power resistor(s) in series with the existing one.  Since SGM thought it necessary to put their resistor inside the return air plenum for adequate cooling, I assume any resistor(s) I add should go inside the plenum as well. 

At this point in time, I am not willing to go to this much work - I have too many other issues that NEED to be worked.  I might revisit this issue next year.  In the meantime I'm just going to put an on/off switch on the H1A wire.  That way I can just turn off the dash blower when I don't want all that noise.

Jim McNeece
2003 U320 40'
2017 Chevy Colorado Tow

Re: Aqua-Hot Fan Speed Controller Install

Reply #8 –
Quote from: Home2fromHastings –
Well the AH heat exchangers are not silent. 

I wonder from your info if there are different noise level units installed in different years?

My 97 is very quiet.  Maybe lower heat output?  Smaller a/h?  I think mine is 1400 watt and 35,000  btu's.  The later units I think are bigger.  Maybe bigger heat exchangers and fans went with the possible higher capacity units?

Bigger coaches with slide outs may need a bigger capacity system like the dash ac/heat units increased since my 97

James would know as would mike grimes.

Bob
"Riding and rejoicing"
Bob
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4

Re: Aqua-Hot Fan Speed Controller Install

Reply #9 –
I'm done. 

Installed simple on/off rocker switch in the H1A line.  The H1A line does NOT power the blower fan, it only closes a relay that provides the power to the blower, so there is little current on this line.

Photos attached. 

The wife is not too particularly happy about my temporary "mounting".
Jim McNeece
2003 U320 40'
2017 Chevy Colorado Tow

Re: Aqua-Hot Fan Speed Controller Install

Reply #10 –
Jim, if you lived here in rural Grady County all you'd need to make that a professional install is a zip tie.
Rick & Rhonda
2003 U320 4220  Build #6199
Was
91 36' GV 300 Caterpillar, 92 40' U280 300 Cummins, 97 36' U295 300 Cummins, 2002
U320 450 Cummins
(Guess we're hooked)

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Re: Aqua-Hot Fan Speed Controller Install

Reply #11 –
Jim, I wonder if the idea of switching the H1A power off to the relay to stop the fan couldn't also be extended to switching off the override when the ignition is on so that the AH would add to the front heat from heat exchanger?  I guess I am not sure if the AH and engine heat and AC exchangers are in a plenum pressurized by the fan whose air flow is redirected by flapper valves in the front ventilation duct work. 

Probably way overcomplicating all of this.  Maybe just switching the front fan off is enough when we want to reduce sound levels.  The switch could be wired in the H1A line in the AH case as well,  might be easier than pulling the dash apart.

Thanks for the research effort.  I appreciate it.
Roger Engdahl and Susan Green
2001 U320 3610 #5879 (Home2) - 2014 Jeep Cherokee or 2018 F150
Hastings, MN

Re: Aqua-Hot Fan Speed Controller Install

Reply #12 –
There is only one fan in the dash heater.  There are two heating heat exchangers in the dash - the engine one and the AquaHot one.  If the AquaHot living room heat is activated, the AquaHot heat exchanger in the dash gets hot AquaHot coolant circulated through it.  This indeed adds more heat to the dash. 

Jim
Jim McNeece
2003 U320 40'
2017 Chevy Colorado Tow

Re: Aqua-Hot Fan Speed Controller Install

Reply #13 –
In looking at the photos of the eBay shots the board has very good size traces to handle the current flow. I work on a lot of equipment that has similar boards with way less guality. From mexico or China. Looks to be a good find. Interested to know if there is an amp draw change with lower speed. Lower speed could also get a lot better heat transfer. Just depends how well ah looked at that developing it. I might purchase a few to try. Thanks
99 U320 40
97 Jeep wrangler toad
Now full time 8 months
Starting a new brick and wood home
Chattanooga, Tn
 

Re: Aqua-Hot Fan Speed Controller Install

Reply #14 –
The 4 I installed seem to be working just fine.  Nice to be able to make the blowers nearly silent while still putting out warm air.

The on/off switch on the dash blower has proven to be a good solution.  I turn on the dash blower to get things warmed up, then shut it off and let the Cozy's (on a low speed setting) keep the place cozy.

Jim McNeece
2003 U320 40'
2017 Chevy Colorado Tow