Heating costs

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James WF10
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Heating costs

Post by James WF10 »

Hi guys, just found that the site is back up and running and must say that i am so so happy to see it back and see regular names of people who have helped me in the past.
I have a new query which i have been trying to get my head around and work out figures so hoping someone can help me.......
After how harsh last winter was and how lucky i feel i was not to lose any Koi over the winter i have decided to treat them this year and take the chill off this winter with a 2KW heater. its an external heater and i have set it to 10 degress C, its a 3000 gallon pond and i have started the heater to run it all day as of a week ago. What i have just realised tho and not really thought of until now is that i imagine my electric meter will be whirring away nicely racking up a right bill. Ive looked on line about how much its likely to be per day but notheing seems to refer to temp and water volume to keep it heated to a certain temp. I am wondering if anyone could shed any light on it for me please? im reckoning i am better setting it to a lower temp of maybe 6 degrees C? is that about right or is it unlikely to drop below that much anyway with the covers on and is it still too cold for the Koi at that temp?
As always, thanks in advance for anyone offering help and glad to be back on here.
Cheers
James
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Re: Heating costs

Post by Mattybkic »

Hi James I'm new to here so hello.

Not sure on the technical side if costings, but would suggest you contact the supplies such as Elecro. If it us an Elecro their technical depth is very good.

The temp I'm on the understanding you need to keep above is 4*C, so you 6 should be fine and covered too :wink:

Hope that helps :)

Matthew
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Re: Heating costs

Post by Manky Sanke »

James,

You will never get anyone to tell you how much a heater of any type will cost to run unless you can first tell them what the heat losses are.

After the initial heat-up period, all the heater will be doing throughout the winter is making up for heat that has escaped from the pond and this depends on the degree of insulation and the weather on a daily basis. A poorly insulated pond in freezing 'taters weather will need much more heat to maintain its temperature than a well insulated pond, especially if the weather is mild.

There is a rule of thumb based on mathematical calculations: Assuming no heat losses at all, a 1kW heater will raise the temperature of 1,000 gallons of water by 1°C in 317 minutes.

Based on that, we can predict some data with a fair degree of accuracy. For every 1°C the pond will lose per day, an electric heater will need to run for 317 minutes (approximately 5¼ hours), to restore that heat loss. A 1 kW heater will use 5¼ units of electricity in 5¼ hours.

If you could insulate your pond so that it only loses 1°C per day, a 1,000 gallon pond will need a 1 kW heater to run for 5¼ hours which would cost 5¼ units. Your 3,000 gallon pond will need nearly 16 units per day. You can do this either with a 1 kW heater on for 16 hours or a 2 kW heater for 8 hours. Either way, you would still use 16 units so the heating cost will be the same (unless you take into account Economy Seven tariffs which will give you the first 7 hours at half price and the rest at full price).

I could work out the cost quite accurately but for me to calculate a total cost of heating for the winter, you would first need to tell me how much heat you will lose in total over that period and that will depend on insulation and a very accurate prediction of the weather on a daily basis. But for a good estimate, your 3,000 gallons will need 16 units per day for every 1°C it would have lost if the heater was switched off.

I've written all this up with a more detailed explanation here:
http://www.mankysanke.co.uk/html/good_w ... art_7.html
James WF10
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Re: Heating costs

Post by James WF10 »

Thanks for the input guys, it makes a lot more sence now, id not really taken the amount of heat loss into acount. By the looks of it though its likely to be pretty expensive to heat the pond over the winter. Im gonna drop the temp down to 6 and just keep it at that rather than trying to keep it heated at 10, at least it can take the edge off and its back up for if it drops really really cold.
Thanks for the input guys, i appreciate it.
Fingers crossed for a mild winter with no snow!!!!
Efficiencyman
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Re: Heating costs

Post by Efficiencyman »

Let us know how your Leccy bill is adding up! :oops: I would suggest, not to set the stat as low as 6 degs it will cost less, yes but may not be that much beneficial to koi or filter backter as these will die off so much. The koi`s immune system will be so low, but various bugs & bacteria can still be very active at 6 degs if you can afford to keep them feeding ( above 10degs ) then they are taking in a diet of nutrients to keep them heathier and their immune system active. :) My temp so far & today are above 14 degs But as allready mentioned it only really costs what you lose, I cover over when cold and when I built my set up I put 100mm Celotex under floor and all sides next to my fibre glass and have insulated my filter bay. My heat input is very low because I don`t loose much! :wink: My stat indicator is off much of the time! :D
You could fit a meter in circuit with the heater that way you`ll know exact Leccy costs. :idea:
Koi Man Dave
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Re: Heating costs

Post by Koi Man Dave »

Currently running mine at 12 degrees pond covered with plastic corrugated sheets so as to let the gases out, it's costing me approximately 60 pence a day. :D
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Re: Heating costs

Post by Manky Sanke »

What size pond is that, Dave?
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Gazza
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Re: Heating costs

Post by Gazza »

Hi Guys,

I am not sure on how much the pond costs to run (tooooo much probably :shock: :wink: ) but i am holding at 12c and it has been above 12c a few times but the boiler has been cold every time i have been out there :D
Koi Man Dave
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Re: Heating costs

Post by Koi Man Dave »

Manky Sanke wrote:What size pond is that, Dave?
Pond has 1800 gallons so its not really a great deal of water to heat, i am running a 2kw heater and as i say the pond is covered bead filter wrapped up in bubble wrap i find the heater comes on at night altough if it were a more harsh winter no doubt the costs would double.
Its my first Winter with a heater so i cannot say how much it would cost to run say last years winter no doubt it would have been on majority of the day.
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Re: Heating costs

Post by Manky Sanke »

Thank you that's brilliant,

It's all very well doing water calculations based on mathematics and theory, as I do, but it's nice when they can be be backed up by real life experience. In the link I gave in my first post, I had worked out some guideline running costs for different sized heaters based on an assumed heat loss with a covered and insulated pond. I said that using a 2 kW heater to recover a one degree C heat loss would cost nearly 57 pence per day. You are finding in practise that, with everything insulated, it's costing 60 pence per day but you've got a slightly "draughty" cover because you're using corrugated plastic.

That's close enough for me, but you've no need to have all the corrugations to let bad gasses out. As long as you have an air pump in the pond, even with polycarbonate sheet laid flat onto the pond copings there will be sufficient ventilation to let bad gasses out, (provided you don't screw it down and hermetically seal it or anything equally stupid).

Your corrugations will allow a small amount of wind chill, if you want to reduce the running cost you could try sealing the gaps, maybe by draping some bubble wrap or plain polythene over the ends of the sheets then resting something on it to stop it blowing away. That wouldn't stop gasses getting out but it would prevent the cold wind blowing straight underneath your cover.
Koi Man Dave
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Re: Heating costs

Post by Koi Man Dave »

Hi Manky

I think your calculations are pretty on target for sure , last year I did have bubble wrap over one end as you have explained and to be honest it didn't drop below 5 degrees, had I of done it this year it would be nearer the 57pence a day.
I know i lose heat here and there as I uncover it on Saturday's to have a check up on them whilst doing so losing temparature forcing the heater to pick up the difference.
it's my first year heating so a learning curb for me, I was worried about the costs but given its 60 pence a day I feel that's worth paying to keep them off the bottom.
I think you deserve a pat on the back for your calculations I found it interesting hence the reason why I monitored it just to see.
This was achieved by rigging up a key meter so I know it's accurate, well done to you.
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Re: Heating costs

Post by Brockp »

Hi Guys;

As Manky knows I am using a heat pump with electric backup so cannot answer the question on consumption; and yes Manky I didn't need a complicated control panel I just set the immersion heater stat 3 deg lower than the heatpump and this works fine...thank you :D

My post just adds another complication to the calculation of heating costs and that is that the rate of heat loss will depend on the factors all outlined above but also on the temperature gradient between the pond and the environment, the bigger the temp difference between the pond and the environment the faster you will loose heat.

So far this year it has been luxury before I started bringing the temp down for "their winter" the heat pump was holding the pond at 20 with an average air temp of 6 at night and 12 during the day for about 30p a day. The stat is now set at 9 and no heating has come on for a week but looking at the forecast it will do soon even in the “warm” south.

Peter
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Re: Heating costs

Post by kingfisher »

Manky Sanke wrote:
That's close enough for me, but you've no need to have all the corrugations to let bad gasses out. As long as you have an air pump in the pond, even with polycarbonate sheet laid flat onto the pond copings there will be sufficient ventilation to let bad gasses out, (provided you don't screw it down and hermetically seal it or anything equally stupid).
That is most interesting Syd. Some years ago, I was advised that it was vital to leave a good air gap for gas escape, both over the pond & the filter.
Consequently I have always paid great attention to ensure that
a 10% gap(Relative to total pond surface area)is left between my
polycarb partitions, which are a snug fit on my patio slabs.
I always run an air pump throughout the year & endeavour to
maintain 8 degrees C during the winter by use of an Electro heater.

If, as you advise, I can safely reduce the gaps it will surely save
me money :D

kingfisher
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Re: Heating costs

Post by Efficiencyman »

As this post is about costs it would relevant to have more examples of £`s per month, on
1 - Gas ( nat or bottled )
2 - Heat pump ( either Air or Ground ) ASHP or GSHP
3 - Electric elements
4 - running on day tarrifs
5 - running on off peak
6 - using (free) solar thermal collectors
7 - using (Fit`s) solar PV to run pumps and /or elements, via inverters.

Any facts should also say total gallons, water change/losses, covers, temps attained/maintained, ambient factors, most important insulation. As I seem to have to repeat myself to often, `We only need to replace the heat thats being lost`, minimise that and we are on the way to saving a fortune!
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Re: Heating costs

Post by Efficiencyman »

The cost is saved by not losing the heat. As has been mentioned the boiler thermostat will cut off sooner, if the heat is not being given off through the H/Exchanger. My point is that as Koi hobbyists we do not want fast fluctuating temps etc. Koi need "stable" conditions this is what I have proved, that with my 100mm insulation (minimising loses through floor and walls) enables me to only need a slow thermal exchange via Hepo2 plastic pipe, which is far cheaper than S/S Heat/Ex. My boiler is only `on` for minimal periods because it only needs a litle heat, as I don`t lose it so fast, when ambient temps fall and I then also cover over at night. That`s where efficiencyman wins ! :mrgreen:
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