Solar Water Heter

plongson

Not sure where to put this thread so I'll start here and the Moderator can move if necessary...

Well, here's the deal, and a little background. My pump house was constructed several years ago before we became semi-full-time residents of the place. The plumbing for the well was laid out for fair weather, essentially it was shut off in the winter and I never worried about freezing. This last winter I busted a bunch of pipes and had a heck of a time providing water. The lowest we saw was +5f and many days only in the teens.

My thought is to get the "winter" pipes underground and be able to valve out the "summer" system that supply's the orchard and various stand pipes around the property. So that is what I've done...cut the slab, excavated and poured a vault to have the winter pipes below ground, essentially depending on the protection of the pump house and the earth to prevent freezing. It also has a 2x12 solid plank over the top.

So here is another idea...what about adding a solar water heating element to the south facing roof line and have a pressured glycol or antifreeze system powered by thermal convection and pipes leading to the vault to keep things warm enough not to freeze. Is this over kill? Do you think I'll have enough protection.

Here are a few pictures, whadd'ya think??

Paul






Maybe something like this??

waynefromnscanada

Re: Solar Water Heter

Thermal convection will move heated water UP, but not down from the roof. You would need a circulator pump to force the heated water down to where you needed it.
Regarding your pump pressure switch in the photo. Interesting place for it. It is normally threaded into the brass "T" coming out of the pressure tank, right beside the pressure gauge, in the hole that now has the plug screwed into it. And there is normally no valve, other than a check valve, between the pump and the tank.
Strange looking settup as it is.

plongson

Re: Solar Water Heter

Hey Wayne,
I grabbed that image and didn't create it, it's just for a starter idea...

I see what you'r saying about needing a circ pump, I know how to make the system work with a pump but was wondering if anyone had an idea to have a simple system work purely by convection. The pump house is somewhat removed from the main house and really don't want to re-create a solar power system for this project.

Paul

solarvic

Re: Solar Water Heter

A few questions. Is your slab that the tank sts on at ground lever or is it below ground level? Is the 2 linrs in the pit with the pressure switch the in from pump and out to house? Is the line that goes from pit to behind the pump and thru the wall for your summer irigation? If the answers to my questions about the pipeing is correct I have a couple ideas that I think would work without too much expense or energy use. Make sure you have the water shut off to the summer use pipes and see if you can drain the water from them so they won,t freeze. Get a short heat tape (optional) Put on the brass fitting and go towards pressure switch side. Wrap pipe with fiberglass insulation from tank to pits onboth pipes. Buy some 3 or 4 inch styrofoam insulation and make a removable cover for the pit and build a strofoam box over the tank with a removable section that you can get to valve and lines at bottom of the tank. If it only gets to 5F I don,t think you would need more as long as the pumphouse is tight and you don,t have any drafts. I live in a double wide and have an unheated crawl space basement. My pump and waterlines have no protections and never had any freeze ups yet in 10 years and at least have a few -0F days in the winter. I think been to about -15F a few times. :DSolarvic:D

plongson

Re: Solar Water Heter

Wayne,
1.) tank sets on at ground level
2.) the 2 lines in the pit with the pressure switch the in from pump and out to house
3.) the line that goes from pit to behind the pump and thru the wall for your summer irrigation
4.) the pump house is very solid, draft free and air tight

Ya, the whole idea was to valve out, drain and isolate the summer system.

My original idea was to do what you mentioned and top it off with a 2x12 with foam underneath.

My active mind got working and wonderred if it would be enough for my winter lows around 5*f.

What i should do is go through (suffer, endure, tolerate, etc.) next winter and see how it works. i really don't want to get all technical and such just to winterize 3' of underground water line.

Thanks!!

Paul

westbranch

Re: Solar Water Heter

Paul, do you have 110V in the pump house? I suspect so as your pump switch is there.

So why not use the old 60W INCANDESCENT light bulb trick? It can be set up on a temp switch so that it comes on/off at 35F in the pit.

hth

plongson

Re: Solar Water Heter

Hey WestBranch,

Actually the way the system works is:

I got an Allen-Bradley "Pico" PLC in 12vdc that powers off the 12vdc genset battery.
12vdc supply goes to the pressure switch, switch closes, sends a 12vdc input to the PLC, logic in the PLC starts the genset and allows it to run for 30 seconds then a 12vdc output closes a 12vdc cube relay, that powers 120vac to a contactor to run the 240vac 1ph well pump.

When the pressure opens the pressure switch, the PLC allows for a 5 minute cool down of the genset.



It sounds complicated but the logic I wrote for the PLC was pretty straight forward. I also have the controller doing a bunch of other stuff. The system in automatic acts just like city water feeding my 500 gallon supply tank at the house. It feeds a 120vdc Gundfoss pressure pump (just a DC motor with cube rectifiers) and a big pressure tank (accumulator).



I considered having a temp switch just start the genset when it got cold inside the pump house, but I'm too cheap and don't want to run it x-number of times a day if it gets bone chilling cold.

How do you think it will fair just being buried and a wood/foam lid?? Unfortunately, the shed doesn't have 120vac unless the genset is running...

P..

solarvic

Re: Solar Water Heter

How often does the generator run? I think if you put the foam over the pit the pipes under it won,t freeze. You could get a frostking brand heat tape with a thermostat and install on the pipe. Get some frost king pipe wrap which is fiberglass insulation about 1 1/2 inch wide and a half inch or so thick. You wrap that over the heat tape. Then there is a plastic wrap that wraps over that. Leave the heat tape plugged in and it can warm up the pipe. I think with that you won,t have any pipe freeze ups. The main reason I explained about the frost king heat tape and pipe wrap is for the benifit of people that don,t live in cold climates and might not be familiar with them. :Dsolarvic:D

westbranch

Re: Solar Water Heter

Paul.... and here we were thinking you were living off your solar... look out that was a big bubble that just burst.:roll:.. and that monster kubota!:grr

how big is the power/pump house? What about a dual system, both solar and generator heat into a 2 inch concrete lift on top of the concrete floor? Use an GrFoss Alpha 1 pump or? to circ.

plongson

Re: Solar Water Heter

Haha... We really do live off the solar!! The genset is really to power a pump to water an orchard of apples, pears and cherries. But believe me, we use it sparingly, although it really only burns about 1 gallon/ hour. Not bad considering what I'm getting from it. We always synchronize our high usage days with watering days.

BB.

Re: Solar Water Heter

I am not sure--But I believe that an un-powered setup would include a pit that is below the frost line, with pipes and insulated box (or a large diameter insulated on the outside pipe) from ground to inside the building/home with the water pipe inside the larger pipe.

The idea that the ground is "warm" (relative to freezing), heat rises and keeps the standing water pipes thawed, and cold air sinks back into the pit/hole in the ground to be re-warmed by the earth below.

But I live in California where we have a "hard freeze" (outside and uninsulated garage pipes freeze) about every 20+ years... So not a problem I have much experience with.

We have a few Canadian folks here that can talk about different water system designs to protect against freezing much better than I.

-Bill