I think that may be true if the system was 100% efficent.

Consider if you narrow the pipe further, what would happen. Would the fan continue to circulate the same volume? Narrow the pipe down to the extreme of being blocked, would the fan still rotate?

Steve

As the pipe decreases in diameter, the pressure required to maintain the same flow would increase due to the increase in friction. The fan would not be able to increase pressure therefore the flow rate through the smaller pipe would actually decrease.

Think about filling a bucket with an open ended water hose. Not a lot of pressure but the bucket will fill quickly. Now stick your thumb on the end of the hose and you'll get a nice high pressure jet to reach further away , but not much volume of water.

I was thinking if I doubled up on the pipe work and the outlets then I would still have the roughly the same volume of heated air come out.?

Ian

I would think about the cost, and if a better alternative might work just as well look at the WINTERWARM WWFH 20E this might just fit in end locker under the table,
just a thought..

Hi Erik

I'm sure that a plinth heater would be a possible solution if I only wanted to go down the electric heat route. I just want to improve the performance of my existing gas Truma. I think Truma say the TEB3 fan increases performance by 20%. Doesn't sound much!! But being able to have heat outlets at both ends and the middle of the van sounds like the main benefit. My main problem is getting the ducting from the back of the wardrobe over/past the wheel arch, through the 'bathroom under the toilet and pop out in the front seat area. In my case this is area is quite busy with the 30litre water tank and10L water heater in there.
So the plan is...... I've bought 1.5 metres of Truma 65mm ducting for £5. ill try a trial fit and pull/push this into place after removing the 30L water tank for access.
If it's too difficult I'll obtain some of the 50mm Eberspacher ducting and try that. Hopefully someone else has already achieved this successfully and can give some hints and tips. The pics provided by Steve are a great help. Once i've got the ducting in then i'll buy the fan!!!

Ian

Hi Im still continuing with my exploration to fit a fan to the Truma and run in the 65mm ducting to the necessary outlets. I was pleased to find that the wheel arch adjacent to the body panels have a semi round channel in it to allow the ducting to sit neatly. I can push in about a metre of ducting quite easilyfrom the wardrobe end. I reckon that takes me up to under the toilet cassette area. The next plan is to remove the 30 litre water tank from under the front seat that butts up against the bathroom bulkhead. My intention would then be to pull the ducting into seat area and job done. So I've done all the disconnections strapping, piping and electrical from the water tank so i can lift it out.. That's were the plan has ground to a halt!! It appears that the tank is bonded to the floor with black sikaflex or something similar. Is that normal?? If any one is draining down their system for winter would like to take look in their tank and tell me if they can see similar rings/squidges of black sealer under their tank I would be grateful. Or if anyone has removed their 30ltr tank how they went about it. any responses would be great.

Guitar string and a couple of rings or toggles at the ends a bit like a cheese wire.. Will need to be crimped or similar because there’s a good bit of force needed.
I did this on the solar panel brackets on a previous van some years ago.

Hi Colin. thanks for your suggestion. I was being lazy and just looking for an easy solution. Yes, the tank does have the cut out at the back of the water tank so there is a route. However its very close to the 10L water heater and difficult to get a straight access to pull or push the ducting. I'm back to the idea of getting some eberspacher 50mm ducting and hoping I can pull it through, I'm still optimistic, I'm also waiting on the arrival of 5 Metre of the Truma 65mm ducting which should arrive early in the week. So I'll give that a go but am cautious of getting it stuck and blocking the route through. It's probably an easy job for a gynaecologist!!

Ian

Thanks Steve that's another good idea, and I've watched them cut a windscreen out of a VW California using a similar method, and you're right it takes a lot of effort. I'll keep trying the easier options (relatively speaking) before I need to get the cheese wire out!! You'd think Hymer would add £10 on to the price of a new van and say it was Truma fan ready.



Ian

HI Colin thanks for another good suggestion, but I don't think it will work. The route through isn't straight it follows the round shape of the wheel arch then down under the flooring of the toilet cassette before emerging behind the fresh water tank.. Removing the tank would have removed about 2 feet of travel. Unfortunately the exit point for the ducting at the back of the tank is almost blocked by the Truma water heater. I'll try and send a couple of pictures tomorrow.

Ian