JK's first guinea pig needed!

It will probably be fine but what happens is that if the exhaust air is recirculate into the fresh burner air the unit will trip out as there is insufficient oxygen for the burner. Not a problem when driving but possibly an issue when staionary and more pronounced when cold and the burner isnt as afficient. Would be something to look at if you were having issues with the unit cutting out

 

We used one during the trial as The Gazman's bus is so incredibly neat and tidy that we wanted it to look as nice as possible!

Pretty sure they've always been £36 from us having just had a look back through our system, though

That's a really good point Dicky, and something we'll add to our tech sheets - all this gas stuff is well beyond me (although everyone else seems to find it really obvious!) but we'll be in touch with Propex later today for clarifications on some of the points raised here

No worries, it's worth talking / thinking this stuff through, and it's good to hear what queries and concerns people would like cleared up, too

 

I've got a propex fitted under the rear seat and takes up valuable space and is noisy .I used to have a Carver heater fitted against the passenger seat frame ,in the cargo area, which sucked and exhausted from underneath the van , silent in operation and worked on the run,but alas it broke and at that time the Carver company had just been taken over by Trumatic and parts were unobtainable, hence the propex. Yippee , I've just bought another Carver on e-bay .

 

I was only relating it to overall finish of the job. Even I would try to achieve a less than £36 solution.

 

Either way this is a prototype installation to which JK have very publicly stuck their name. There may well be wrinkles to be sorted out once the system has to work in real life but at least it will be something based on experience rather than sales talk. A step in the right direction I think.

 

Couldn't agree more. I think it's great to see a company using real people (not just friendly customers as Josh pointed out) and getting honest feedback from the group. Obviously they dont have to take any of the advice, but at least they are asking for it.

 

Still not convinced that water can't get in via the air intake.

 

I agree with you that when fording or going through heavy rain and the exchangers get wet then lots of condensation is blown into the heating system but it doesnt happen very often and also the heater is blowing into the tube and not taking its air from the van system. It is possible that some water could get in and a slight possibility that this could get into the corrugated tube but its not that likely that often.

 

With regards to the combustion and exhaust pipes, I had a bus in with the pipes about 3" apart and both facing forward. Not ideal at all. But I asked the customer if they had had problems and none had been reported. I did however move them.

 

I drove through a flood while on holiday and water entered via the heat exchangers. With in a blinking eye steam had covered the front screen. But the exchangers get so hot that the amount of water that entered was evaporated within seconds.

I didn't give my propex exhausts a thought until on site but the system worked faultlessly. A note to self: Always carry something that you can use to block those holes if going through a puddle. I keep cable ties and rubber gloves.

 

I wrote a rather cutting review of these while I was checking if they were still on sale. Now "out of stock" and no review to be seen...
Perhaps a coincidence or maybe someone actually read it and acted at last.

 

@Birdy i didn't think it was wise to have the exhaust under the van? with mine the exhaust is poking out of the sill edge pointing back and the fresh air is collected under the van that way there is no chance of exhaust being re-used or finding it's way into the awning

 

Mine are under the van. I suppose it is possible to cuase some low level pooling of CO in an enclosed space but I tend not to use the heater unless its very cold and not usually when im in bed tbh!

 

Any idea when JK are going to put these on sale??

 

my fear with that length of flexy on any gas heating system would be build up of deposits or lack of cleaning , just an obsevation.

 

Funnily enough, I've just this afternoon been experimenting with mine to see what can be done to quieten it down.

• the case is pretty rigid so not much resonance.

• Lining the internal compartment with hard felt, where the fan rotates, takes some of the fan whine out.

• A small Webasto intake filter (foam-lined) takes some of the induction noise out

• A Webasto exhaust silencer ( 3 x the distance from the outlet) lowers the frequency and reduces output a bit, but not much
• biggest noise reduction achieved when the recirculated air intake and the hot air outlet are both ducted through a straightthrough silencer (bodged from 100mm plastic ducting lined with polyfill)

There's a bit of science involved but easy to get your head round: duct needs to be three times the length of the outlet/inlet O.D. and at least 1 & 1/2 times the diameter, so the gas expands into the silencer. The centre of the silencer should be perforated tubing, same O.D. as the outlet/inlet (I used fine mesh for my bodge)....this allows the gas to expand into the poly fill without impeding air flow....sound energy is given up as heat....

Funny what you get up to when you have a day off....
If it ain't your thing, please don't come back with 'why bother?' etc. etc. i like tinkering...if that makes me a geek, do I care? not one iota

 

more than a metre of flex is a no go with us especially with lots of bends especially up and down which causes traps .

 

Its one thing fannying around in your garage with the unit on the floor....another when it comes to installing it under the bus
Still, I've got something to go on...been looking at low voltage Duct dampers (as you do)....I should get out more

At some point I'd like to knock out a silencing kit for propex, but everyone installs them in different places, and you'll know from your HVAC experience, that size and length matters