Low temp water heating systems????

[W.olly]

The reason i like it on here, this forum, is that there are a lot of knowledgeable folk on here sooooo

Can anyone come up with an idea, either a new one or one that already exists for this

To keep 1300g of water to a temp of 27deg, and i hear you aks what for, well a fish tank. i can get the obvious tank heaters but i would needs 5 500watt heaters, they re not on continues but if i can get a way to reduce the power/cost i would like to give it a go, the tank will cost in electric around £30 pw tor un, thats is the lot 2 sump pumps, 5 500watt heaters. lighting etc etc

So what i am trying to do is to get the running cost down as much as i can, heating first.

so over to the clever tech folk if you will please, not to forget it needs to be fish safe

 

[rtbcomp]

The obvious 1st step is insulation, can you double glaze the tank? Also put a lid on it.

 

[W.olly]

The obvious 1st step is insulation, can you double glaze the tank? Also put a lid on it.

no it will be insulated with minimum 50mm kingspan, thats the easy bit, its the heating i need to sort out as it the most costly running thing on a tank.

 

[AndyStobbs]

Heat your house to 27 degrees instead.

 

[W.olly]

Heat your house to 27 degrees instead.

its not in the house

 

[julianf]

Lots of insulation, as mentioned, and then...

What's your central heating run off? Electricity is about the most expensive way to heat things.

If, for example, you have an oil boiler, you could fit a loop with that, through a flat plate heat exchanger (which are designed for DHW circuits, so, providing your tank isnt marine, it should be fine)

Then pump the water from the tank, very slowly, through the other side of the FPHE, on a thermostat, with the limit stats etc. in place.

You would have to pump it slowly, as it would get heated hot, very quick, so you only want just a trickle going through. Possibly a dosing pump may work well here.

 

[julianf]

ps. im in the process of setting up a 900ltr tank that will be held close to 80c for extended periods.

it has 50mm of cellotex all arround it, and has two domestic radiators hung on the inner sides of the tank - powered from a central heating boiler.

i have the exchangers in the tank (radiators) but, as above, you can situate them outside the tank, and just pump through them.

 

[brightspark]

buy some solar pannels

 

[the snooper]

£30.00 per week divided by say 13p per kwh gives you 230.76 khw divided by 24hours would give you just over 9.5 days with a continuous 1000 watt load.

are you sure your calculations are right I cant see your heaters being on 50% of the time

 

[W.olly]

Lots of insulation, as mentioned, and then...

What's your central heating run off? Electricity is about the most expensive way to heat things.

If, for example, you have an oil boiler, you could fit a loop with that, through a flat plate heat exchanger (which are designed for DHW circuits, so, providing your tank isnt marine, it should be fine)

Then pump the water from the tank, very slowly, through the other side of the FPHE, on a thermostat, with the limit stats etc. in place.

You would have to pump it slowly, as it would get heated hot, very quick, so you only want just a trickle going through. Possibly a dosing pump may work well here.

CH is on gas, and next to where the tank is going though. i like the FPHE thouhg, soemthign to think about,

Solar will not be cheap to set up BB

 

[W.olly]

£30.00 per week divided by say 13p per kwh gives you 230.76 khw divided by 24hours would give you just over 9.5 days with a continuous 1000 watt load.

are you sure your calculations are right I cant see your heaters being on 50% of the time

Thats is the extreme Snooper, i have got it down to £25pw, but the cheaper the more savings the better i got that of a calculator online, we are paying 15p

also the £30 pw week is for the whole tank not just the heaters

 

[the snooper]

plug into next doors problem solved

 

[wookie]

Could you change your plans slightly and have either a cold water or temperate tank instead ? there are tropical fish that can tolerate quite low temps, for example some barbs, tetras & danios are happy down to 15-18 degrees.

Alternately you would have to insulate the room the tank is in very well to minimise heat loss, think how warm your average fish shop is, could you live in a room that warm ? If you can insulate it well enough then the running costs needn't be scary.

 

[W.olly]

Could you change your plans slightly and have either a cold water or temperate tank instead ? there are tropical fish that can tolerate quite low temps, for example some barbs, tetras & danios are happy down to 15-18 degrees.

Alternately you would have to insulate the room the tank is in very well to minimise heat loss, think how warm your average fish shop is, could you live in a room that warm ? If you can insulate it well enough then the running costs needn't be scary.

there is no way i am building a tank this big for a million fish 1inch long, lol, but in the future if i ever get fed up of big fish. you never know would be good i guess with shoals of fish.
The tank will be in an extension in its own room with just 2 viewing windows into the extension, the tank room will be fully insulated on walls ceiling and also floor, this will help yes.

What do you think the saving will be in this then, will a better more efficient way to heat the tank be worth it? as to 5 500watt aquarium heaters?

i am just thinkign ahead here as it is all in planing so i know what to get/do.

 

[W.olly]

plug into next doors problem solved

there is a lamppost on the corner lol, just not much of a sparky

 

[daleyd]

Could you add a home made supplementary heater? I've seen some solar pool heaters made from old radiators and double glazed windows. As said above electric is an expensive heating method, but it is controllable, if you could minimise the time the electric heaters are on by using "free" energy then that could amount to a decent saving. (I don't have any personal experience of these btw, but I just thought it might be an avenue to explore)

 

[brightspark]

put it this way your not going to get anything for nothing unless u get a woodburner or a waste oil burner and u get your fuel free

 

[W.olly]

put it this way your not going to get anything for nothing unless u get a woodburner or a waste oil burner and u get your fuel free

to right, we live in the UK, nuff said

 

[AndyStobbs]

Why should anyone subsidise your hobby? In the UK or not.

 

[julianf]

Trouble with both solar and sold fuel is that they are unregulated, which means expense in order to buffer / smooth the performance.

We heat our house here on, at present, exclusively solid fuel. One day ill get around to putting up all the solar panels too... that, or we will move first, and ill take them with me!

Anyhow, solid fuel will be loads of bother, and solar will require another large tank as a thermal store, and all the additional stuff that goes with it (controllers, pumps, etc. and then you still need the heat exchanger)


If your CH is gas, you could...

...dig a trench to the tank building
lay some pipe in there, wide enough to carry 2-off 15mm PEX and associated insulation.
im not so familiar with gas, but tee off before the CH solenoid, and fit another soleniod
mount the FPHE close to the gas boiler, and pump the water from the tank, through the PEX pipe, to the fphe (you will need to filter this well before, as you dont want the fphe silting up)

you would need a low flow through the setup - too much and your pump will cycle all the time (control the flow from a stat in the tank)

you could use a PID and set the hysteresis using that

If you pump the water from the boiler, to the FHPE, through the trench, you will suffer much more heat loss - that's why i suggest pumping the tank water to the boiler, rather then the other way arround.