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Batteries die in 10 minutes

Everybody......make sure your battery clamps are tight too, my varistream minimun voltage gave me hell a few months ago, tightened the clamps up and never had a prob since lol

.........and it you have those crocodile clamps, replace them with a proper battery clamp. In the early days we used those for convenience but they end up giving us all sorts of problems.

 
I haven't forgotten, I'll still upload those pics and video.

Just thought I'd report in.

Did a massive house today.

Had to do the fascias, soffits, sills, frames and windows. Hadn't been done in 2 years. 5 Hours...

Didn't run out of hot water or battery power!

Turns out... Inside the Webasto, if I shut the switch that feeds the second pump, the water in the remaining pipe gets much hotter.

There was hail and thunder today. But steam was coming off those windows /emoticons/smile.png

 
Well you were right! Thankfully.I did a big house with the Webasto 9kw on and the battery was fine.

I did the job on my own off the second pump.

I noticed that the water was warm for a while and then the temperature dropped quite a bit - to somewhere between 20-35 degrees Celsius. But when I went to the Webasto, it was saying a lot hotter than that around 70 degrees. I was imagining that the water was going to be a little warmer really. Am I missing something?

Where you refering to this scenario when you said this?:

I had a push on yesterday and finished putting my Webasto Thermo Top C diesel heater with 3 x 20 plate heat exchangers together and giving it a ‘bench test’.

Over the years I kept hearing about the cycling some owners of these diesel heaters were experiencing and the subsequent coking up, so my solution was to build in a 3rd heat exchanger that can be used to 'dump' excess heat back into the tank.

This 3rd heat exchanger will have its own pump controlled by a digital temperature controller.

This is supposed to be a 2 man setup. I setup a hose to the first heat exchanger that was directed back to the tank with no mixer valve on it. The second heat exchanger was coupled to my pump and this was connected through a mixer valve. The third heat exchanger also has a mixer valve on it but this wasn't connected up.

However, whilst it was running today, I noticed that the 5kw Webasto Thermo Top C diesel heater was only just able to keep up with one pole continuously running, raising the water temperature drawn from the van’s tank from about 9 degrees to 35 degrees. But there was nothing else left in the system for a second pole, and certainly none left to dumped back into the tank.

Whilst switching the water off at the tap and moving around and switching it back on will give to a bit of time to catch up, I doubt there will be much more for a second pole.

What I did notice is that the flow of water through the brush head jets at 35 degrees is much higher than when the water is cold, so was able to turn my flow down quite a bit, from 5 on my Varistream to 3. The glass used in our front windows in very hydrophobic and I feel that the warmer water flowed better when rinsing the window.

The next step is to build it into a cabinet which will allow me to make the unit more compact. I will have to weld up a steel frame for it to be mounted on as it is rather heavy.

 
I haven't forgotten, I'll still upload those pics and video.Just thought I'd report in.

Did a massive house today.

Had to do the fascias, soffits, sills, frames and windows. Hadn't been done in 2 years. 5 Hours...

Didn't run out of hot water or battery power!

Turns out... Inside the Webasto, if I shut the switch that feeds the second pump, the water in the remaining pipe gets much hotter.

There was hail and thunder today. But steam was coming off those windows /emoticons/smile.png
I'm jealous. It will be interesting to see how well it works with both of you working together.

 
it doesnt work as well with two. the temperature drops a lot. just about enough to prevent it freezing for two people on an icy day. but that's it. about 20-30 degrees as it comes out both hoses.

 
it doesnt work as well with two. the temperature drops a lot. just about enough to prevent it freezing for two people on an icy day. but that's it. about 20-30 degrees as it comes out both hoses.
Yesterday was quite an eye opener for me from a practicality side. A 5kw heater pushes out 17000 btu's per hour, so this heater will in theory power 3 single panel radiators (300 x 1800) in a boat and have a little to spare to heat the water in a calorifier. Webasto advertise this.

I can't believe a single 20 plate heat exchanger using a mixer valve will zap all that heat so quickly just raising the temperature of 1.5 litres of water a minute by 25 degrees or that a 5kw diesel heater won't keep up with the water flowing continuously.

Years back I used the formula pt = 4.2 x l x T /3600

Pt = the heat required, L is the litres of water to be heated and T is the temperature rise required.

So at 1.5 litres of water per minute and raising the water temperature by 25 degrees C, the formula should look like this;

pt = 4.2 x 90 x 25 / 3600

pt = 2.625 kw.

Even raising the water flow to 2 litres a minute will need 3.5 kw to do this.

So there is no reason why this shouldn't be able to supply 1 user and still have a little in reserve. So either there is something I'm overlooking or the heater isn't working properly/efficiently. Or is it a case of what works in theory/on paper may be different to what's experienced in reality. I imagine that this could be what happens all the time designing Formula 1 cars. What works in the wind tunnel doesn't on the track.

Based on this unit running for about 3 hours yesterday, I can only see the unit cycling if the operator spends more time not working. I guess the true test is getting out there in the 'field' and working with it.

To point the fingers back at me, I do concede that a normal 8 hour working day is probably 4 hours on the glass. These figures do make sense when I consider battery useage every couple of days with the battery's state of charge.

 
Spruce.......i reckon you should ask the mods to rename you....to brains lol

I love all this technical stuff, but maths......i get mental block and it hurts my brain

Your equation is missing one thing though i think, water temp of the water to be heated, the colder it is the more energy required to bring it to pt

On the radio the other week i'm sure they said it takes a massive amount more energy to boil a ton of water than it does to melt a ton of steel!!!!!!!

 
Water is funny. It does take more to heat than most other solids and/or fluids. It also retains that heat for longer when compared to the same solids/fluids. Its actually quite amasing stuff.

What the formula needs is the temperature rise required. So my water was 9 degrees and I was raising it to 36 degrees. I used a round figure of 25 although its actually 27.

 
I had a push on yesterday and finished putting my Webasto Thermo Top C diesel heater with 3 x 20 plate heat exchangers together and giving it a ‘bench test’.
Over the years I kept hearing about the cycling some owners of these diesel heaters were experiencing and the subsequent coking up, so my solution was to build in a 3rd heat exchanger that can be used to 'dump' excess heat back into the tank.

This 3rd heat exchanger will have its own pump controlled by a digital temperature controller.

This is supposed to be a 2 man setup. I setup a hose to the first heat exchanger that was directed back to the tank with no mixer valve on it. The second heat exchanger was coupled to my pump and this was connected through a mixer valve. The third heat exchanger also has a mixer valve on it but this wasn't connected up.

However, whilst it was running today, I noticed that the 5kw Webasto Thermo Top C diesel heater was only just able to keep up with one pole continuously running, raising the water temperature drawn from the van’s tank from about 9 degrees to 35 degrees. But there was nothing else left in the system for a second pole, and certainly none left to dumped back into the tank.

Whilst switching the water off at the tap and moving around and switching it back on will give to a bit of time to catch up, I doubt there will be much more for a second pole.

What I did notice is that the flow of water through the brush head jets at 35 degrees is much higher than when the water is cold, so was able to turn my flow down quite a bit, from 5 on my Varistream to 3. The glass used in our front windows in very hydrophobic and I feel that the warmer water flowed better when rinsing the window.

The next step is to build it into a cabinet which will allow me to make the unit more compact. I will have to weld up a steel frame for it to be mounted on as it is rather heavy.
That's a great idea Keir. I do something similar when I'm out working on my own (but I have a two man system). I feed the second hose back into the tank.

I haven't used this long, but I've used it long enough to know that your approach has got one major problem: You're using a 5kw system. That just isn't good enough. It's barely enough for two people. But to feed a 3rd line would be completely beyond it. I'd advise you go for the 9kw system.

 
That's a great idea Keir. I do something similar when I'm out working on my own (but I have a two man system). I feed the second hose back into the tank.I haven't used this long, but I've used it long enough to know that your approach has got one major problem: You're using a 5kw system. That just isn't good enough. It's barely enough for two people. But to feed a 3rd line would be completely beyond it. I'd advise you go for the 9kw system.
Yes. I've come to that realisation. The idea of the 3rd heat exchanger was that when we had finished house No 1 and driving off to do house number 2 it would allow the diesel burner to keep running as once it reached a preset temperature, the third pump would circulate water from the tank, through the heat exchanger and back to the tank. It would syphon off excess heat but would switch off when it reached a lower temperature. This loop would continue until we started using our hose again and this excess heat release wouldn't be necessary. It would stop the diesel heater having to switch off and then restart a few minutes later.

Today I gave it some thought and will probably go to an 8 litre Tankless LPG heater which is popular with most hot water cleaners. I see that the heater is a 16kw which is 3 times more powerful than the diesel heater.

To make a 2 two man system I could adapt the pipe work I have now. This would just replace the diesel heater as the heat source.

I have to think about this.

 
I was told there's some safety issues with the LPG option. But I don't know what they are.

To achieve what you are after, instead of a third heat exchanger, I asked Pure Freedom to just fit me 2 male connectors at the top of the tank (the same as what would be at the end of your pole hose. Then they put me in some internal ports too. So I can flick the flow from the tank between the internal and external ports. That way, when I'm done with a job and I put the reels back in the van, I plug them onto the internal port and plug the other end onto the sockets at the top of the tank. That way, the heater keeps working and the water keeps getting cycled and heated. And the hose stays nice and warm too /emoticons/smile.png

 
I'll upload a youtube video showing how it's done as soon as it stops raining for two minutes!! /emoticons/sad.png

 
I was told there's some safety issues with the LPG option. But I don't know what they are.To achieve what you are after, instead of a third heat exchanger, I asked Pure Freedom to just fit me 2 male connectors at the top of the tank (the same as what would be at the end of your pole hose. Then they put me in some internal ports too. So I can flick the flow from the tank between the internal and external ports. That way, when I'm done with a job and I put the reels back in the van, I plug them onto the internal port and plug the other end onto the sockets at the top of the tank. That way, the heater keeps working and the water keeps getting cycled and heated. And the hose stays nice and warm too /emoticons/smile.png

With gas I won't consider an installation that isn't fitted with an exhaust out through the roof. I have the dog with me most days and I would hate him to be gassed whilst I was working around the back of a customers house with hot water.

Diesel is the safer option. I'm also forgetting that my original decision to go with the diesel heater wasn't to steam up the windows, it was rather to just warm the water enough to keep the hoses supple and more managable. (I suffer more with hose induced torrets in the winter than the summer. /emoticons/smile.png)

The first hose we had was minibore from Cleantec. They aren't trading anymore, but this hose was lovely in summer. Unfortunately in the winter it became like bundles of steel wire. Hence the decision for warm water in the winter only.

The latest hose I'm using isn't as rigid in the cold as the Cleantec hose was, so really we don't need water at 35 degrees at the brush head. The water in the tank this summer never got above 20 degrees and that was fine for cleaning. I did pull the hose off the hose reel with hot water running through it and TBH it was like elastic. So in reality, 35 degrees is too hot for our current set up.

The idea of this wasn't to change the reel hose to thermobore, or change brushes that will work well with hot water. So if I focus on the original intention, then the Webasto Thermo Top should manage to supply both hoses at 15 to 20 degrees; which in the dead of winter would be temperature rise of 10 to 15 degrees.

I have also discovered that if I break the adjustment seal which I have done, I can reduce the temperature output of the mixer valve to less than 10 degrees accurately, so that's a plus as the specs say 30 degrees is the lowest adjustment.

 
I haven't forgotten, I'll still upload those pics and video.Just thought I'd report in.

Did a massive house today.

Had to do the fascias, soffits, sills, frames and windows. Hadn't been done in 2 years. 5 Hours...

Didn't run out of hot water or battery power!

Turns out... Inside the Webasto, if I shut the switch that feeds the second pump, the water in the remaining pipe gets much hotter.

There was hail and thunder today. But steam was coming off those windows /emoticons/smile.png
OK. Time for Pics!

Here are some photo's of:

The webasto .

The fittings at the top of the tank where I put the hose ends in to so that I can cycle the heating water.

Pump Controllers

https://skydrive.live.com/redir?resid=CFD67DCE832AB358!1118&authkey=!AMKZqDOUyPvOYnQ&ithint=folder,.jpg

 
Thanks for the pictures.

Its lovely to see a brand new bit of kit. Even although you have been using it, the exhaust hasn't even tarnished yet. I didn't see the heat exchanger or mixer valve, but I also haven't seen a heater with all that insulation before either.

That fitting on the external port isn't right. I don't know if they can be taken apart, but I expect that the plunger has a faulty o Ring on it. I would just order another one and replace it.

Son in law has had the same fitting on his van for a couple of years and it doesn't leak at all. He doesn't use hot water though.

OBTW, I like the idea of those fittings to 'recycle' the heat to tank

 
Thanks for the pictures.
Its lovely to see a brand new bit of kit. Even although you have been using it, the exhaust hasn't even tarnished yet. I didn't see the heat exchanger or mixer valve, but I also haven't seen a heater with all that insulation before either.

That fitting on the external port isn't right. I don't know if they can be taken apart, but I expect that the plunger has a faulty o Ring on it. I would just order another one and replace it.

Son in law has had the same fitting on his van for a couple of years and it doesn't leak at all. He doesn't use hot water though.

OBTW, I like the idea of those fittings to 'recycle' the heat to tank
Pure Freedom gave me advise on sorting the leak that you can see in the video. All you need to do is switch the pump on. That then creates the needed water pressure to produce a tight seal. Works a treat and takes less than a minute. It's easy when you know how!

 
Pure Freedom gave me advise on sorting the leak that you can see in the video. All you need to do is switch the pump on. That then creates the needed water pressure to produce a tight seal. Works a treat and takes less than a minute. It's easy when you know how!
The trick with switching the pump on only seems to do the trick for about 10 minutes.

So I went to plan B: Pure Freedom fit a tap at the bottom of the tank where the pipes come out to feed the pumps. Turn the tap off and it's not possible for the external ports to leak. So that's what I'll be doing from now on at night and over the weekends...

Would have been nice if Pure Freedom fitted an external port that doesn't leak. Now I can begin to see some of the argument that Ionic has against these external bumper ports.

 
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