Cheaper way to preheat water in aging barrel

[ssevasta]

I was wondering if anyone had come up with a way to preheat their water to 84-86 degrees other than using a standard tank heater or using warm water from their home hot water heater. I'm trying to find a way to reduce my electrical usage. I was wondering if some sort of copper coil with the hot water line running through it would do the trick or at the very least lower the amount of energy it would take for the standard heater to bring the water to 86. I could always unplug the standard heater until the coil brought the temperature up and then plug it back in to heat the water the rest of the way. I typically use between 75 to 90 gallons per day on water changes.

[brewmaster15]

Sean,
If you want to take the edge off your hot water heating... look into DIY passive solar heaters..

http://theselfsufficientliving.com/1...-energy-bills/

In the North east these DIY ones are usable a good part of the year, and if it works for you , you can also improve it by switching to evacuated tubes that will work even in the cold of winter.

al

[ssevasta]

There are some really interesting ideas for projects in that article Al, the only issue for me is that I live in a townhouse and our bylaws have some really strict limitations for what we're allowed to have on our decks or the grounds behind my unit. If I had my own standalone house I would probably have a whole solar array on my roof and all sorts of DIY green projects going on. In the future one day after I move, I would like to incorporate a system like that and I'll make use of that article I'm sure. For now though I'm somewhat limited to something that I can do in the basement where I have my aging barrel. I also have to try to keep the peace with my stepfather who doesn't want the basement "turning into a smelly pet store". That's a whole other can of worms lol

[Leland F.]

Install a gas water heater if you can, if not, you can use your standard electric water heater and make a recirculation line through the barrels with coiled pex or vinyl hose, and recirculate it through your water heater. It'll take all night to heat them, but it'll be cheaper. Insulate the heck out of the barrels and exposed water lines.

-Leland

[Willie]

Changing your heating method is an expensive proposition. I just converted my house to a tankless gas system, which cost ~$20k. For that, I replaced both the boiler for heat AND the electrical hot water heater. Making water changes was not a driver in this decision.

Electrical heaters are the most inefficient of all the power sources. Small heaters are more inefficient than big ones. So heating your water storage unit is more expensive than starting with warm water, regardless of your heating source.

Here are some inexpensive things to do.

1. Wrap your water storage unit with insulation - I used the shiny rolls from Home Depot.
2. Set your water storage off the concrete floor - stick some 2 X 2's under it.
3. Cover the top - Home Depot has pink insulation boards that can be easily cut

Willie

[ssevasta]

The only reason I was apprehensive about starting with warm water from my hot water heater is that I've read that the water can very easily pick up heavy metals in the process. I don't know if there's any truth to this or if it's just an old wives tales per se but any feedback or additional info would be much appreciated.

[Leland F.]

The heated water won't have anymore metals in it than the cold water. Heat speeds chemical reactions, but there shouldn't be any difference. Reverse osmosis water shouldn't be run through metallic water lines though, it will pick up metals and anything in the pipe due to it's lower pH.

-Leland

[ssevasta]

Thank you very much. That alone should save me a ton of money on my bill because I can just mix the hot and cold water until it gets close to the target temperature and let the standard heater do the rest. I'm also going to incorporate some of the other ideas mentioned here like closing the lid.

[ssevasta]

If I were to insulate the sides of the brute garbage can with the stuff from Home Depot wouldn't that make it harder to raise the temperature within? I always thought that insulation helped to keep the contents at the temperature whatever it was to begin with.

[brewmaster15]

If I were to insulate the sides of the brute garbage can with the stuff from Home Depot wouldn't that make it harder to raise the temperature within? I always thought that insulation helped to keep the contents at the temperature whatever it was to begin with.

Sean, it won't make it harder to raise the temp. The insulation will keep the heat from escaping so your heaters work less to achieve the same temp.

al

[ssevasta]

Sean, it won't make it harder to raise the temp. The insulation will keep the heat from escaping so your heaters work less to achieve the same temp.

al

Thanks Al.

[ssevasta]

This got me thinking that it might be a good idea to cut a piece of the insulation from Home Depot and size it as a backboard and external bottom for each of my tanks. It'll also help to evenly distribute the weight onto my stands. I know only covering two sides won't do much but I'm sure it'll add up over time and every little bit helps in the long run.

[Bizarro252]

I did this a while ago because I was curious but never wrote it down, so here we go again, incase you are curious how much it costs to heat your water This is assuming zero heat loss so add in some fudge factor


Q(Energy required in KiloJoules) = cp * m * dT

where

Q = amount of heat (kJ)
cp = specific heat (kJ/kgK)
m = mass (kg)
dT = temperature difference between hot and cold side (K)

and

kilojoules = watts × seconds / 1000

So in this example I am using my stuff, 1x 200watt heater, and 30 gallons (113kg of water) starting at ~20C

Q=4.19*113*(30C-20C)
Q=4,735KJ

4,735,000J = 200 * (s/1000)
s(time in seconds) = 23,670 = 6.575 Hours

200Watts * 6.5757Hours = 1,315 Watt Hours = 1.3KWh - Which where I live is about 10 cents

Hope that helps!


Sources:
Gal water to KG: http://convert-to.com/conversion/wat...er-weight.html
Specific heat of water, and converting to work: http://www.engineeringtoolbox.com/he...rgy-d_292.html
Convert KJ to Watts: http://www.rapidtables.com/convert/e...watt-to-kj.htm

[ssevasta]

Do you guys have any thoughts on using a thermostatic mixing valve so the heaters only have to maintain the temperature rather than heat the water?

[Megalodon]

Stop sending warm water down the drain?

Use a heat exchanger to warm new water with old water.

Or at least keep the old water until it's cooled to room temperature.