Hot water question

[lukeott]

Let me first start with, this is my first post and even though I've read thru many articles, I can honestly say I'm really lost and imtimindated by all of this. Two monthes ago I had a geo system installed and there's water lines that come off it to go to electric hot water heater to help with heating the water. My old system was a boiler with a hot water maker tank(at least that's what i think it's called). From what i remember this tank was super efficient at keeping the water hot with only losing a degree or two for the day. So my question is, can i use this tank in between the geo and the hot water heater to make it more efficient. Or would this just be a waste of time. My thought is it could kept 50 gallons of hot water before the hot water heater, which when it enters the hot water heater it would already pre heated. Does this make sense or am i just peeing in the wind?

[NiHaoMike]

As long as the old tank is in good condition (it probably isn't if it's really old), you can use it to add storage capacity. Pipe it in the cold, so that the heat pump draws from it and discharges to the existing tank.

[lukeott]

Hello Mike, The tank was installed in 2007 and is in good condition. I should have put that in my first post. Thanks for the reply.

luke

[NiHaoMike]

Then you can use it. Make sure you correctly identify the cold and hot ports (it won't work as well if you get it backwards) and install it so that the cold port goes into the supply and the hot port into the cold port of the existing tank. Then move the intake of the heat pump to the bottom of the added tank or use a tee to connect it to the cold port. Check for leaks, purge air by opening a hot water faucet for a few minutes, and you should be good to go.

You can also turn the thermostats on the existing tank way low to further boost efficiency.

[AC_Hacker]

Originally Posted by lukeott

My thought is it could kept 50 gallons of hot water before the hot water heater, which when it enters the hot water heater it would already pre heated. Does this make sense or am i just peeing in the wind?

Could you give us a little more information?

It sounds like you probably have a ground source heat pump, and some of it's heat output is being used to heat the water in an electric water heater (AKA: "de-superheater") ... the electric element will be available if the water in that tank falls too low.

Am I right so far? It's a pretty efficient system you have on your hands.

You might look at that new water heater itself, for the yellow tag that tells what it's level of performance is. If you're lucky, it will be really efficient. If not, you might spend some money on a water heater insulating cover. If it is really efficient, I think that just about everybody here would agree with me, that you should insulate it even more. An insulation kit is not too expensive. And you might look into putting a nice thick closed-cell foam pad against the bottom of you water heater, too. You'll probably need to make that yourself... 2" thick would be very nice.

So, about your old water tank... it could be configured in various ways. Some of those configurations are not so interesting, but some are very interesting and well worth exploiting.

You'll have to do some research on this one...

If it is just a tank with water-in and water-out and thick insulation, it's not very interesting. You'd be better off selling it together with the boiler, for whatever you can get (make sure that whoever gets the boiler takes the tank too).

If it has a copper coil inside, for exchanging heat into the tank, it is very interesting. You could identify it because it will have 4 fittings for water in and out. Also, you should be able to locate company drawings that would show the coils inside. This would be super valuable for making a solar water heating system. If you have the gumption to make one, there you go. If not, you could sell it to someone who does, as these are fairly expensive.

But I think that you be wasting your time by just adding it to your existing system, unless you come up with some kind of additional alternative heating method, too.

-AC

[waterdigger2]

Dont know how your system is set up. On the pre heat if it runs water through to pre heat it . Have you thought about goin from that elbowin up to the roof or somewhere sunny with some vac tubes with the water goin through em. Youd need to get the water to go slow enough that it would heat durin the day . And some sorta valve that way when you turned it on it would water would push out the tank.

[waterdigger2]

Also super insulatin the tank would prob help like others have said.