Squirrel Cage Type Blower for Heater

[pittwagen]

Just curious to know if the blower wheel is aluminum or plastic on the Jabsco 35115-0020. It is not mentioned in the Jabsco specs on their site. They do mention a max. temp of 130 deg. F.

I see about 140 deg. at the defroster vents and maybe 155 deg. at the footwell (low 40's outside temp.) with mine but the airflow is poor. It has been much colder here recently but I have not retested.

I found a similar unit locally but the blower wheel was plastic so I thought I would keep looking for one that at least had the aluminum blower wheel.

[skid]

I am thinking that its probably plastic.
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'71 Westfalia

[notchboy]

I just ordered one to do the same install. It will be here the 5th. Even if this dosnt last more than a couple of years, Im still hoping that its better than the fart fan thats there now
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[pittwagen]

Here are the specs on the flange mount unit. No mention of the blower wheel but it is not black like the rest of the unit.

http://www.go2marine.com/docs/mfr/jabsco/198753F.pdf

The duty cycle is 1000 hrs. That's a lot of bus driving. If the volume of air is significantly improved one wouldn't need the heater temp fully on either.

Trying to find one locally!!

[Wildthings]

On the 4 inch Jasco unit the blower is plastic. From the picture of the 3" unit it looks to be plastic as well. The 4" unit is 11 amps while the 3" unit is 4.5 amps, so there should be a big difference in performance. Don't know that the 4" would be justified though.

I would think that the plastic would hold up well enough if my idea were followed. The idea is to create an intentional suction leak by wiring the rear diverter so it is always open a bit. On my system this dropped the temps to 140° at the defroster vent (40°F ambient) and so far has allowed a plastic blower to survive. Note that I am also only running one heater box into the center pipe, so it is easier for a forward mounted blower to draw a vacuum on the diverter valve than when both heater boxes are connected to the center pipe.

[Stuartzickefoose]

[Wildthings]

The way I have it set up they are both running far more air than the stock system allowed for. I wouldn't consider what little bit of flow difference you might see from side to side an issue.

[pittwagen]

Does anyone know the cfm of the stock 72-79 blower in the engine compartment? It seems to put out a good quantity of air. As we have discussed, the downfall of the stock system appears to be airflow not heat, at least that is what I experience.

The early ones are all metal, thus avoiding the heat issue and I think one should be able to plumb a second one into the existing piping at the front under the floor as busman78 has done with the bilge blower. It could be controlled separately via switch and relay or controlled by the existing switch with a relay.

I don't know how much airflow from the existing system would be affected by the resistance of the second squirrel cage and piping though.

Thoughts?

[SGKent]

[pittwagen]

Sorry, I should have explained. The blower is going in my 79 with T4 engine under the front floor. A second blower to pull the air from the rear. As for the piping, I'll likely just go to the muffler shop and get a piece of 3 - 3 1/2 tubing and if needed I'll have them enlarge the end to fit the inlet on the blower and the pipe in the floor of the bus.

And as you suggest a Y or something similar for the two squirrel cage outlets into the pipe in the floor plus some flexible air hose. I can fab pretty much anything here. Just going to have to fit the unit up under the floor to see if there is enough room.

[Wildthings]

Why don't you just haunt the wrecking yards a bit and see what you can find in the way of a heater motor that will do the job for you. Seems like using a bus fan with two outlets would be rather problematic.

BTW the aux fans used on 411/412 squarebacks only had one outlet, but I don't remember if they were plastic or metal.

I have a 4-5 hours of use on my inline plastic bilge blower at this point out of around 1500 miles of driving since I put it in. By having it suck some cool air in through floor heater vent it seems to be working within its designed temperature range. Someone using Busman78 fan set up should be able to accomplish the same, just wire the rear diverter valve open a bit. Running the one heater box directly into the back of the Bus really seems to be the cat's meow. I can feel a light movement of air from this heater outlet (located under the rearmost seat) while sitting all the way forward in the driver's seat.

I never thought I would ever again consider reinstalling the OEM aux fan in my bay, but with the split heater system and front mounted inline booster fan, it think I may be able to increase the heat flow into the cab still a bit more. Straight highway driving at 20°F is shirt sleeve comfortable right now, but around town driving is still a bit chilly. I think the booster fan would help during the stop and go.

[SGKent]

Wildthings probably has the best set up on late bays as to heater boost. I don't think 1979 has rear ducts. My 1977 doesn't.
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“Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin

[pittwagen]

Thanks for the replies!!

I have been looking for an all metal housing but no luck yet. I've even thought of looking at an early water cooled blower and then fabbing a housing. Looked at some 115v housing as well. There are no T4's around here. Think there might have been one at our Great Canadian VW show last summer.

There is a swap meet this weekend and the fellow organizing it has a ton of Porsche parts for sale. Any thought on what I might look for?

No rear heat ducts and the one under the middle seat has been sealed and capped as I have installed a floor and camper interior.

I haven't had time to crawl under and have a look yet to see how the OE fan housing might fit. We've had a lot of rain recently and right now it's snowing so the ambition level is low.

Thanks again and please keep the ideas coming.

[Wildthings]

[jamesdagg]