Temperature of immersion

[Davy G]

Why would it? Its still reaching the same temperature, just in a more realistic time frame.

Thats the down fall of the immersion heaters, if you want really hot water they're great upto about 500, but in a 650+ 18+hrs to heat up isn't practical, but 8 or under would be ideal!

It's perfectly practical for me in my 650. I'm not  out there shovelling coal into a furnace all night. I finish work, fill up the tank, plug in. Leave it do its own thing and it's ready for work the same time as I am.

I've seen someone on another forum bragging his system is hot in ten minutes. I don't need instant heat. I need heated water for my days work from start to finish.

Each to their own. ?

 

[Deleted member 257]

not necessarily, 0.9 litres of diesel an hour x 8hrs = 7.2l x £1.25 = £9.

and the £10 is assuming heating from 0, if the water was 10degrees it'd only take 6hrs and cost £8

 

[Davy G]

But what would be the running costs ???? 

I shouldn't think it would be any more expensive to run than a 2kw as it would be on for less time. I say again though. I think 9kw might fry the van.

 

[Deleted member 257]

It's perfectly practical for me in my 650. I'm not  out there shovelling coal into a furnace all night. I finish work, fill up the tank, plug in. Leave it do its own thing and it's ready for work the same time as I am.

I've seen someone on another forum bragging his system is hot in ten minutes. I don't need instant heat. I need heated water for my days work from start to finish.

Each to their own. ?

Im not saying its impractical. but if you are using more water or working longer days theres not always enough time to heat the water for the next day. 

if your want 65degree from 0 in a 650l it'd take over 16hrs using a 3kw. So if i were using 850-1000l a day and working 8hrs with travelling each end of the day a 3kw wont cut it! 

 

[Davy G]

Fair enoughski, we usually do about six hours a day, from home to home, using mostly around 500-600 litres.

 

[Pjj]

I shouldn't think it would be any more expensive to run than a 2kw as it would be on for less time. I say again though. I think 9kw might fry the van.

I have 1000 ltr ,650ltr and600ltr tanks in my vans , if I was a one man band using 500-650 per day I would seriously look into the immersion heater route for warm water if I was on a budget ,but do think a well insulated tank is vital I can heat my 1000 ltr tank to 60 degrees with the boiler and then turn it off but it does cool surprisingly quickly , as it’s not insulated    

 

[Davy G]

I have 1000 ltr ,650ltr and600ltr tanks in my vans , if I was a one man band using 500-650 per day I would seriously look into the immersion heater route for warm water if I was on a budget ,but do think a well insulated tank is vital I can heat my 1000 ltr tank to 60 degrees with the boiler and then turn it off but it does cool surprisingly quickly , as it’s not insulated    

You're absolutely right, Paul. The details are hugely important, and adequate insulation is one of the most important ones, that and allowing enough heating time.

 

[Scots lad]

My tank is insulated with silver bubble wrap but recently put extra on using insulation boards from b &q

They were great but only problem was no heat was escaping to keep hoses from freezing removed a col of small bits still have duvet over reels as well as insulated picnic bag a bit like tyre warmers from formula 1 the bits of board I removed I put under reels for insulation from below had it down at -6/-7 and no frozen hose just need recirculate water before starting 

 

[ched999uk]

My tank is insulated with silver bubble wrap but recently put extra on using insulation boards from b &q

They were great but only problem was no heat was escaping to keep hoses from freezing removed a col of small bits still have duvet over reels as well as insulated picnic bag a bit like tyre warmers from formula 1 the bits of board I removed I put under reels for insulation from below had it down at -6/-7 and no frozen hose just need recirculate water before starting 

I'm not convinced the silver bubble wrap is any good at all, it has no real officially testes insulation values.

While you heating the tank you could make is so your reel plugs back into the tank at opposite end to heater and then run pump for say 1min every 15min to keep warm water circulating in reel.

I think your are right about heat loss through the van floor it's just a giant heat sink pulling out the heat from anything that sits on it.

I read that celotex foam type insulation can support 16 tonnes per square meter. So in theory you could have 50mm under the tank, frame allowing. Polystyrene or expanded foam type insulation is most efficient but not cheapest.

 

[Scots lad]

I'm not convinced the silver bubble wrap is any good at all, it has no real officially testes insulation values.

While you heating the tank you could make is so your reel plugs back into the tank at opposite end to heater and then run pump for say 1min every 15min to keep warm water circulating in reel.

I think your are right about heat loss through the van floor it's just a giant heat sink pulling out the heat from anything that sits on it.

I read that celotex foam type insulation can support 16 tonnes per square meter. So in theory you could have 50mm under the tank, frame allowing. Polystyrene or expanded foam type insulation is most efficient but not cheapest.

https://www.diy.com/departments/recticel-instafit-polyurethane-insulation-board-l-1-2m-w-0-45m-t-50mm-of-1/5411545020296_BQ.prd?gclid=CjwKCAiAjeSABhAPEiwAqfxUReY-dHJSjIAM8UUTEBkrn33eHQNmdVfNYFmSax7FRpsUOH8I0HFUFhoCk-wQAvD_BwE.

Is what I used 

 

[ched999uk]

https://www.diy.com/departments/recticel-instafit-polyurethane-insulation-board-l-1-2m-w-0-45m-t-50mm-of-1/5411545020296_BQ.prd?gclid=CjwKCAiAjeSABhAPEiwAqfxUReY-dHJSjIAM8UUTEBkrn33eHQNmdVfNYFmSax7FRpsUOH8I0HFUFhoCk-wQAvD_BwE.

Is what I used 

That's the good stuff ? Not cheap to do the tank but if compared to a lost days work looks better investment.

 

[Scots lad]

Keeps water warm all day 

 

[steve garwood]

Keeps water warm all day 

Do you know what sort of temperature your water is before you set off to work?

 

[steve garwood]

You're absolutely right, Paul. The details are hugely important, and adequate insulation is one of the most important ones, that and allowing enough heating time.

Sorry to be a pain Dave, but what sort of temperature is yours at before you set off?

 

[steve garwood]

My tank is insulated with silver bubble wrap but recently put extra on using insulation boards from b &q

They were great but only problem was no heat was escaping to keep hoses from freezing removed a col of small bits still have duvet over reels as well as insulated picnic bag a bit like tyre warmers from formula 1 the bits of board I removed I put under reels for insulation from below had it down at -6/-7 and no frozen hose just need recirculate water before starting 

How did you attach the boards to your tank please?

Any pictures? ?

 

[Davy G]

Sorry to be a pain Dave, but what sort of temperature is yours at before you set off?

No problem at all, Steve. I took some measurements recently during a cold spell when we were out working, about a month ago. The only one I didn't do funny enough was the starting temperature as I did the checks on a sudden whim in the afternoon.

When we go to the van in the mornings it's like the start of the Whacky Races. We go from tea drinking, Mooch mode to "Right let's get at it and get it done, setting!" No time or thought of taking temperature measurements.

Hence no start temperature recorded. I haven't checked the start temperature for ages. I used to have a temperature gauge wired to the tank but it packed up. I'm very confident that the start temperature is between 60-65c. That's what the gauge used to read. In the winter we turn the thermostat fully on then back just a tad. We reduce the setting when it's not so cold.

When I measured the temperatures recently, I took  them at Noon. The actual measured temperature of the water in the tank was 58c. The temperature at the back door brush after going through the hoses was 45c. The water had been through 6 or 7 metres of 1/2 garden hose in the van, 100 metres of 6mm reel hose and about 10 metres of pole hose.

We had been working for about 2 1/2 hours and completed 10 jobs of various sizes. The last job before the test was with about 50 metres of hose off the reel lying on the cold ground The air temperature was 1c. The temperature in the tank is not much different at the end of a full 6 hour day.

Fair bit of info to get your head round, sorry. But the short answer to your question is : 60~65c in the tank. 40~50c at the brush. Assuming a very well insulated tank of a fairly large capacity. And given enough time to heat up fully.

 

[Scots lad]

Its 65 degrees before I set off ill take pics for you tomorrow  Steve 

 

[Iron Giant]

9kw would fry the van, surely!!

Might be a bit like this Mr Soft

 

[ched999uk]

Might be a bit like this Mr Soft

I was a bit worried to click that link  ?

 

[steve garwood]

Its 65 degrees before I set off ill take pics for you tomorrow  Steve 

Cheers ?

 

[Iron Giant]

I was a bit worried to click that link  ?

I always keep it clean ?