fan boosted heaters /demist

[Tristan71]

There separate from the engine cooling air so that sounds like the best idea

 

[ProfessorWheeto]

As mentioned above, using an electric fan off a type four engined bus is the neatest solution.

Block off the two outlets on the fan housing, fit the elec fan and add the two pipes to the heat exchangers to it. You might even find a proper bay fan switch that will look the same as the rest of the dash knobs.

Ambulance fans are for the cold air supply, they fit in the two removable panels on each side of the inside of the front panel.

 

[naskeet]

I think VW did something like this, see below. fitted as standard to ambulance buses. Hence it has the name of ambulance fan, pop up now and again on ebay. they are mounted under the dash.

It looks like someone highjacked by picture! :shock:

yes i have seen the ambulance fans but not many about and pricey

I bought a pair at the Essex VW Club show, for £10, about 10 years ago.

 

[busdiver]

i am going to do a similar thing i have binned heat exchangers for j tubes, so have no dash demist/heat, but installed propex under the bed. going to put a T peice off the heat outlet pipe on the propex to the the original outlet in the floor under the bed and fit a bilge type fan in the upright heat riser tube in cab on a switch to pull warm demist air upto the window. when we are parked or camping turn off fan and hopefully because second pipe is T'd off most hot air will take easy short route out from vent in front of bed.

that's the theory anyhow.

 

[Haveacamper]

Busdiver, i'll let you know my experience.

i dont have heat exchangers and have done somethign very similar to what you describe.

I have blocked off the Y tube that connects to the heat exchangers. i have capped off one of the rear seat heater vents and have plumbed my HS2000 propex into the last remaining heater vent. therfore, i have ALL of my heat travelling up the central heater tube. I have then capped off the part of the heating circuit blows hot air rearward from between the walkthrough that is controlled by the knob under the drivers seat. therefore, i SHOULD have ALL the heat going up the angel of the north and up the dash.

HOWEVER...i barely get heat up to the screen. all i get is literally the heat rising up to the screen. I do need to check that all my ports are completely blocked and that i dont have any air leaks, but i believe that the cause is the pressure drop through the heater system.

i'm not CFD (Computational Fluid Dynamics) expert, but you may need to size the booster fan flow rate to that of your propex system.

either way - subject to me not having any leaks or blockages, a booster fan is needed.

Nathan

 

[Bundy]

I did have very similar set up...
Propex outlet to a Y-piece...one to the rock and roll kickboard, the other to a silicon pipe I threaded through the main metal underfloor pipe all the way to the front totem pole. I insulated the whole thing and did get an improved demist, but not alot of power...did improve if you open the window slightly when driving as it draws the air up the system!
The downside was that the propex kicks out some seriously hot air and it made the whole lot smell of burning silicon...although it wasn't burning.
Anyway, back to just the kickboard outlet now as I'm watercooled and have built a heater box for it and using a bilge fan it works a treat 8)
An in-line bilge fan should help a propex, but get a good one as the fans seem to be glued onto the motor spindle and when they get warm the glue melts and the fan falls off and destroys itself!

Cheers
Al

 

[Haveacamper]

dont poison us Stock people with you water talk - says he with a highly modded bus

i think if i get a 3" blower like this one:
http://www.ebay.co.uk/itm/3-In-Line-Boat-Bilge-Blower-12v-Electric-Turbo-Blower-/110969711645?_trksid=p5197.m1992&_trkparms=aid%3D111000%26algo%3DREC.CURRENT%26ao%3D1%26asc%3D14%26meid%3D3616553987539925683%26pid%3D100015%26prg%3D1006%26rk%3D1%26sd%3D110969711645%26" onclick="window.open(this.href);return false;

then i may be able to chop a section out of my central heater tube and fit the blower over the heater tube - rather than the other way around. then if you wire it up to a dimmer you can change the voltage and therefore change the speed of the fan?

NaFe

 

[Bundy]

dont poison us Stock people with you water talk - says he with a highly modded bus

I did think that might happen :lol:

My fan is similar to that, but the first one just got warm from being near the heater matrix and the blade bit just fell off and ate itself, so with the propex air blowing through it it's gonna get pretty toasty....
Been thinking of that idea for variable fan, but not tried anything yet...it is a bit noisy at full tilt!

Cheers
Al

PS: well done Nathan on the mags...well deserved!

 

[sidecargezzer]

vwheaters.com they make a kit for this very thing

 

[naskeet]

Don't forget, that if your vehicle is air-tight, the heating system flow will be reduced, by your implicit attempt to pressurise the vehicle interior.

There needs to be vents or leakage sites, through which relatively cool stale air, is vented to the external environment or recycle this some of this air through the heating system.

 

[busdiver]

the bilge fan listed at the start of this thread states it is a low ampage and designed for constant running, if you mount it in the dash riser tube i'm thinking would be far enough away from the heat source that it shoould not burn out.

 

[Haveacamper]

i agree that it should not be scorching hot ye.

i did think about fitting it inbetween the angel of the north (totem pole) and the antler horns, but then thought about the noise in the cab area???

also, if you place it this far down stream of the heater then you will not be able to use the rear facing vent that is positioned in the walkthough.

NaFe