[drwindows]

It's an interesting idea, but your calculations are not quite correct.  A 200w heater is not powerful enough.

To raise 1kg (1 litre) of water 1 deg C requires 4186 joules of energy.

therefore, to raise 300 litres 1 deg c requires 4186 x 300 = 1,255,800 joules

to raise 300 litres by 15 deg c would require 18,837,000 joules

Say 19 megajoules for ease.  You need to deliver that amount of energy in about 6 hours.

Since 1watt = 1 joule per second:

6 hrs = 21,600 seconds

so you need a device able to deliver 879 watts of power for 6 hours. 


So for just 300 litres, you'd need AT LEAST a 900w heater, not a 200w one.

Anyonw know how much it costs to run a 900W heater for 6 hours?

[wizard]

Put under floor heating under you tank with insulation under that the mat is 2 sq .metres and will also warm you van it will need a ply skin in top of the mat as we know then are cheap to run and can be left on all night. I am still looking for the fibre optic under floor heating I saw once this can be placed in water and would heat the tank o] to boiling it need be. Has anyone seen this product in the U K I  saw it in South Africa at a home Show it was in a glass tank of water and all the water was boiling. The tank held about 200 litres of water. It was quite safe all the people were touching the water as it was a cold day. 

[SherwoodCleaningSe]

Just took the temp on my tank and it was 50+ after just 2 hours. Interesting point though most sub pumps are rated at upto 35c.

Simon.

[Jack Wallace]

Hey guys,

I can see the reasoning behind using an aquarium heater, It’s a great way of protecting storage/process equipment such as di and pumps, but I can’t see any benefit to it that will keep me working.
The biggest problem I face is water freezing at the brush head and on the glass.
If the aquarium heater can only take the temp up a few degrees then by the time the water has travelled 50 meters or so through the hose which is lying on frozen ground it is going to be back down to almost zero, and as soon as it hits the glass, solid!

[Count Phil]

Dr windows, call 900w a thousand so you have a kilowatt. Thats how much the unit will burn in one hour. Look at you leccy bill to see your cost per kilowatt. Mine is 11p in the day and 4.5p at night. So a 1000 watt heater will cost between 4.5p and 11p per hour to run - assuming it runs at full wack.

The wattage of a device is in kilowatt hours, (how many kws it burns an hour) so 300 watts is 0.3 kwatt hrs 900 is 0.9 etc.

[STEVE-UK]

This sounds like a good idea but whats the advantage of having luke warm water in your tank?

Im no scientest but body temperature is 37 degrees and if you put a dirty dish under the tap it only takes the dirt off when the water is to hot to touch, this is probably around the 80 degrees the other units operate at

sorry to put a downer on it but i think the water will need to be 70-80 degrees and your tanks will have to be tested to see how they react as plastic goes soft under heat

[matt]

This sounds like a good idea but whats the advantage of having luke warm water in your tank?

Im no scientest but body temperature is 37 degrees and if you put a dirty dish under the tap it only takes the dirt off when the water is to hot to touch, this is probably around the 80 degrees the other units operate at

sorry to put a downer on it but i think the water will need to be 70-80 degrees and your tanks will have to be tested to see how they react as plastic goes soft under heat

mosts of the hot water users are running it at way below your 70-80 degrees, most have said they run it luke warm to lower the risk of cracking the window

i have ordered 2, just for a play to see if it alters the ball game a little

[ccmids]

Just took the temp on my tank and it was 50+ after just 2 hours. Interesting point though most sub pumps are rated at upto 35c.

Simon.

how big is the tank in ltrs?

[Nathanael Jones]

Nat

does your stay in the tank all the time ?  ??

from the ebay ad, its the glass version, i guess if its not knocked its strong enough to stay in the tank

Look again,.. its a stainless steel one!

I have it in my static tank in the shed at the moment as I found that 500w wasn't powerful enough to heat my 650 litre tank much at all when it was just plugged in at night and I was worried about my L5 freezing,..
The aquarium heater heats the 1000 litre static tank just enough to keep the frost away from the shed & RO - DI setup, but its not really even what I'd call lukewarm. A 2nd heater would defo be required for that.

[matt]

Nat

does your stay in the tank all the time ?  ??

from the ebay ad, its the glass version, i guess if its not knocked its strong enough to stay in the tank

Look again,.. its a stainless steel one!

I have it in my static tank in the shed at the moment as I found that 500w wasn't powerful enough to heat my 650 litre tank much at all when it was just plugged in at night and I was worried about my L5 freezing,..
The aquarium heater heats the 1000 litre static tank just enough to keep the frost away from the shed & RO - DI setup, but its not really even what I'd call lukewarm. A 2nd heater would defo be required for that.

cheers mate

i thought it looked like the glass type

a even better price then

i ordered 2 of them, double the output, twice as fast to get warmer

i only have 250 - 300 L in the tank most of the time anyways, so should get it up to 32 C over night

[Nathanael Jones]

You have to get an adapter or change the plug on them & the cable is only 4',.. apart from that they're great.

[matt]

You have to get an adapter or change the plug on them & the cable is only 4',.. apart from that they're great.

no probs

i am thinking to wire them in a pair and fit a external socket in my van

[Window Washers]

How long would it take to heat up 2000l of water with these heaters and at what cost ?

[matt]

Unfortunately, if you have two x 200W heaters on overnight, assuming 300 litres and a night 12 hours long, you're going to get a rise of 14 degrees at best even if your tank were perfectly insulated (which it can't be).

As Scotty used to say, "Ye canna break the laws of physics, Captain".

Of course, that temp increase might be enough for what you're looking for.

PW

Just reread, and I think you might be saying you've bought two 500W heaters.  In that case, overnight (12 hours) will raise it 34 deg (assuming perfect insulation, etc).  Assuming decent insulation, you might be there.

It'll use 12KwH, so you're looking around £1.32 in electrickery.  If it saves you a minute or two per job, that should easily pay for itself.  If you could heat it with gas, it'd be about a third of the cost.

PW

indeed 2 X 500 W heaters, @ a few quid, its not going to break the bank

the gas option is the L5 and filling a 100 L holding ( insulated ) tank while i get the kit out

for the cost, it must be worth giving the Aquarium a whirl to see if hot / warm water changes anything

[Spruce]

Dr windows, call 900w a thousand so you have a kilowatt. Thats how much the unit will burn in one hour. Look at you leccy bill to see your cost per kilowatt. Mine is 11p in the day and 4.5p at night. So a 1000 watt heater will cost between 4.5p and 11p per hour to run - assuming it runs at full wack.

The wattage of a device is in kilowatt hours, (how many kws it burns an hour) so 300 watts is 0.3 kwatt hrs 900 is 0.9 etc.

We are on a standard electric meter as most of us are, so the cheap rate electricity doesn't apply as the meter can't decide how much electricity you use at different times of the day.
A multimeter is what you require to take advantage of a cheaper electrical rate (economy 7) at night, but you will be charged for the priviledge of a multimeter- how much though I am not sure.
Spruce

[JSMC]

for me it's not about getting hot water onto the glass but stopping the water from freezing in tank and tank elbow and leading into the strainer. Ice block in my strainer today when i inscrewed it off.

[gewindows]

How long would it take to heat up 2000l of water with these heaters and at what cost ?

Cost wouldnt be too much of an issue, I think you guys'll find that trying to heat 500 litres adequately overnight is going to be like pi$$ing in the wind let  alone 2,000.

If it was that easy to heat water up why do we have feck-off great immersions in our houses powerful enough in an electrical sense to blow your brains out and fry your under-carriage at the same time?

Arent there any other fish keepers on here?

Im just setting up a 2000 litre marine system right now, I dont expect to be able to heat the water overnight to 28 °C let alone 40 °C  or more for window cleaning.

Didnt we go down this avenue about 6 weeks ago?

[matt]

How long would it take to heat up 2000l of water with these heaters and at what cost ?

you just need a immersion heating element ,well i expect for that amount of water you would need 2 or 3

[drwindows]

mosts of the hot water users are running it at way below your 70-80 degrees, most have said they run it luke warm to lower the risk of cracking the window

Thats not true matt, i use mine at about 60 deg c, thats the whole point, its nice and hot.  The glass cracking baloney is a myth, I've never had such a problem.

However, if you're just looking to prevent freezing and want luke-warm water it might work.  But for me, if you're going to go hot water, then its worth getting it properly, and being able to use it nice and hot (not luke warm)

[matt]

mosts of the hot water users are running it at way below your 70-80 degrees, most have said they run it luke warm to lower the risk of cracking the window

Thats not true matt, i use mine at about 60 deg c, thats the whole point, its nice and hot.  The glass cracking baloney is a myth, I've never had such a problem.

However, if you're just looking to prevent freezing and want luke-warm water it might work.  But for me, if you're going to go hot water, then its worth getting it properly, and being able to use it nice and hot (not luke warm)

only a post from yesterday / today

http://www.cleanitup.co.uk/smf/index.php?topic=87070.0