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Newell Gurus would like to thank Boomer for joining us.

aquahot whisper heater fans
hi all,

in my coach there are 3 different fans supplying air from the aquahot heaters.

1. is the plenum in the bay that is discussed in a different thread in this section.

2. there are whisperfans that are self contained under the kitchen counter, in the bedroom and rear bath. they are wide and narrow. they have two computer like fans mounted to the back to blow air across the coils into the rooms.

3. then there is a similar unit that on mine is in the half bath and in boxes at the driver and passenger ankles. this uses a more squarish unit that has a larger single computer style fan on it.

the unit under the kitchen counter on mine had one of the two fans burned out. you can buy them from aquahot or parts suppliers.

but as usual, i wanted to source them myself.

you have to look at 4 things on these fans.
a. CFM much air they move
b. noise in db. how loud are they
c. current draw
d. temperature rating

the fan that was on the unit originally was a Silentfan SKUD12B4

it was 46CFM, 31db, 2600rpm, 2.9watts and rated at -20 to 70 degrees C. or about -4 to 158 F. the aquahot on mine gets to around 150 degrees at the register for the air coming out.

there are two types of computer fans. one has ball bearings and one has sleeve for a bearing. the sleeve bearing fans are only rated from -20 to 60C or -4 to 140F. so i opted for one like the original that was ball bearing.

Silentfan is no longer available unless you want to buy in quantities of 500-1000 and i didnt figure i could get that many of you to do a group buy. i think i got up to 3 or something like that.

so i compared fans. these are used in a variety of equipments so shopping is plentiful.

for the dual fan smaller whisper heater i ended up with a fan that was sold by it is a 92mm across and 25mm thick. same as the one i took out

the guy who owns it is very helpful and friendly.

i bought the AD0912HB-A73GL

for ten bucks

i bought enough to replace both fans on the unit.

it is 2400rpm, .08amps or about 1 watt, 44CFM, 31db.

as you can see from his site, you can get higher CFM fans, but they are noiser. i wanted it to have the lowest noise with acceptable air flow. so i went with one that was very close to the original.

they are screwed on from the back of the heater unit and didnt take too long to change out. very quiet and nice airflow.

next is the change the noisy fan that is on the unit in the mid bath.

i bought two different fans with different CFM to see how they sounded. it is a 120mm wide and 25mm thick unit. i bought two different ones to try. a 72cfm and 99cfm. of course the more cfm, the louder it is.

it is much more difficult to change since i have to actually take the unit out of the coach since the fan is riveted on and there is no room for power tools in the little area the unit is in.

the bearing are going out on that fan so it works fine but is very noisy.

the others are all ok.

thought you might be interested.


Attached Files Thumbnail(s)
2002 45'8" Newell Coach 608  Series 60 DDEC4/Allison World 6 Speed HD4000MH

Tom, good find. Since I have different coaches here- not at the same time, I can help these folks on their aqua hot fans when needed. Thanks
Ernie Ekberg
Bluebird Wanderlodge
today i took the aquahot heating unit out of the half bath. it is under the sink and i have to say, quite difficult to get out. i took it totally out because the fan was making too much noise for my liking.

i bought two different fans to try on it.

the one that was on it was a Silent Fan SKUDB4 .38a 4.5w 85fCFM, 2650rpm and 39db it is 120mm sq and 25mm thick

the two i bought were this.

fan 1. Current .24 Amps AD1212LB-A71GL ADDA
Speed 1800 RPM at zero static pressure
Flow (max) 71.8CFM at rate voltage
Static Pressure Rise (max) .15 inches of water at rated voltage
Noise 34.4dBA at rated voltage measured one meter to the side.

fan 2. AD1212UB-A71GL
Current, 0.5Amps
Speed, 2500RPM at rated voltage and zero pressure
Flow (Max), 99CFM
Pressure Rise (Max), 0.174inH2O
Noise, 43.3dBA at rated voltage and zero pressure, measured at 1 meter to side

i ended up using the first fan. it was quieter and had similar air flow to the original. even though the specs say it is lower cfm.

the old fan was riveted on. i cut down hex bolts and screwed them directly into the plastic on the new one so it will be changeable now without taking the whole thing out again.

i had to cut the plastic frame to get the mini radiator out so i could get the original rivets out.

then i put it all back together and used hvac foil tape to cover the holes i cut in the plastic. i put foam weatherstripping on the front so it will isolate the sound transfer from the fan vibration.

didnt get a chance to put it back in as i worked on a young guys truck the rest of the day.

here are the pictures.


Attached Files Thumbnail(s)
2002 45'8" Newell Coach 608  Series 60 DDEC4/Allison World 6 Speed HD4000MH

i installed the whisper fan this morning. it is really really hard to get at since it is under the small sink cabinet in the half batch. plus the room is pretty small to be on the floor. worked fine. i did put a finger guard on the back of the fan i installed which is not in the pictures above.

it is very quiet and plenty of airflow.

now i am working on the rfmogul sat dish

2002 45'8" Newell Coach 608  Series 60 DDEC4/Allison World 6 Speed HD4000MH

i did not bleed the air out of the system after taking out and re installing 2 of the heaters. they both heated up just fine after installation so i am thinking the air got pushed out in the tank. only lost ounces out of each one. just basically what is in the radiator and they are quite small.

2002 45'8" Newell Coach 608  Series 60 DDEC4/Allison World 6 Speed HD4000MH

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