Interim solution: solar camping shower. Advanced Elements 3 gallon one is more than enough for a shower with my long hair. Put it out in the morning, wash-up in the evening when 'yar covered in dirt and garden stuff.

I am on traditional city plumbing and use this as my shower in the summer. It's my challenge to myself to reduce my water use. If I'm really careful I can get by using half of it for a shower so 1.5 gallons and then re-fill and heat again the next day in case I want the full 3 gallon luxury. They cost around 25 dollars for one. So not cheap but I'm on my second summer with this so I'm thinking it will pay for itself in reduced water costs in another... oh 50 years

I could probably get away with using it in the winter if I were willing to put it inside my solar cooker or something insulated with reflectors.

Hi Anna,

I notice that waldeneffect.org no longer connects as a simple http:/ website.

Only connects as https:/ .

Kinda annoying for those of us using simple web browsers.

John

I used to sell these from Sunward Solar but I am no longer affiliated with the company. http://www.gosunward.com/system-information/features/mounting-options/

For your farm I see three big advantages, First - the system is entirely solar powered giving you hot water when the power goes out and keeps your outside energy low or non existent.

Secondly, one of the mounting options allows you to use a steel structure ground mount or "timber frame" option which can be turned into a shed.

Third, the system is hot water tank agnostic. With the larger system, I suspect with one 80gallon electric tank you would probably not need a backup power source even in the winter. So you might not need to flip the electric breaker.

Some people will probably say that you will never use all that hot water because you conserve so much... Thats the point! I believe a tank that size would allow for enough storage for you guys (not the typical family of 4) in the winter months.

This system would be designed for the winter months, so I you find you are creating too much hot water in the summer take more outdoor baths or cover one of the collectors.

Cheers,

-Pat

Hey folks. My family and I live in a dry cabin up here in alaska. We have a 40 gallon fresh water tank that we fill by jugs from a local spring. This runs to a 115 V on-demand water pump designed for RVs. From there, it is split and piped into a mini water heater much like the one you have pictured. It holds 2.5 gallons. I must say, I was skeptical of the performance at first, but have been sold on it for a while now.

It is insulated quite well, and rarely turns on until we drain it of water or use it excessively. The biggest cost is definitely the electricity, but in all honesty, I am not sure if the cost of the electricity would be less if we went back to heating water on the stove every time we need it. Granted, when we would heat water on the stove, we would end up using less hot water due to the sheer trouble and time it took to get hot water. So the cost is somewhat relegated. The only other problem we've had with it is that if we unplug it for a while, it seems to drain itself - we have it in a rubbermaid bin for this reason. I have not figured this one out yet - probably related to the pressure relief valve on top.

This unit has been in place now for about 4 years, with little to no maintenance. It has been very reliable, and incredibly convenient. I don't think you could go wrong with a similar device.

-Colin

Here is a link to a solar dealer in Pennsylvania. He is located halfway through PA and was easy for me to get to. With no tax and shipping cost the price of two SB20 evacuated tubes units was very reasonable. Because there are individual tubes that mount to the manifold, installation can be done by one person and transporting in a small truck or van was easy. especially if you share cost with another individual who wants a set also. http://wearesolar.com/

My solar heater is a active system using a pump but I don't see why you couldn't make it a thermosyphon with drain back capabilities.

My hot water is, 80 gal. elec hot water tank, or "Nyle" heat pump, or wood boiler, or solar hot water depending on what time of the year it is and what is the most cost efficient at the time by setting the thermostats a little lower than the next unit.

I just spent a month in Mexico. My apartment was typical and had a small water heater mounted outside the bathroom. My instructions were to turn it on 5 minutes before I wanted to shower and off immediately. It was entirely satisfactory.

If I were you, I would rig up a solar preheater and the small heater inline (with a bypass) near the point of use. There are plans on line for a reflector type solar heater. An old heater tank on it's side with parabolic reflectors of polished metal. Or the sliding glass door covered box with a hose coiled around inside style. KISS "keep is simple sister!!"

What time of day do you guys usually shower? If it's not morning then I'd bet you could figure out something very simple with solar considering how little hot water you use. For example a garden hose that is 3/4" diameter interior and 100 feet long holds ~2 gallons of water. I'm sure you know how hot water inside a hose gets when left in the sun. The smaller size of the hose is what allows it to heat up quickly.
If you get showers in the morning you could plumb this to something with a little more volume so you could temper that hot water and have the benefit of thermal mass to keep the water hot inside longer(possibly this could be within your green house addition?) An RV pump like a previous commenter mentioned will allow you to get a shower even if you just had it set up to pull water out of the reservoir and pump it through a shower head no mechanical connection would be required you could just drop the hose in take into the reservoir to begin pumping and a diaphram pump (RV type pump) won't get damaged if it runs dry.

If possible in the winter it may be nice to be able to locate the reservoir near the wood stove to allow some warm water.

Here's a link to the RV pump I am referring to. http://www.amazon.com/Shurflo-Water-Pump-3-5-gpm/dp/B001QQ0BFQ/ref=sr_1_2?ie=UTF8&qid=1372441491&sr=8-2&keywords=rv+water+pump

I hope some of these help in your final design.

If you want to go pumpless (thermosiphon), the water reservoir should preferably be above the collector. This also prevents heat loss at night. That doesn't fit well with using an in-line heater/storage unit. Additionally, such in-line heaters are not fitted with the extra in-and outlets you need. Also the driving power from the thermosiphon effect is not very large, so you need relatively large diameter piping to reduce resistance. (I've seen old pumpless central heating systems using 2" pipe). In-line water heaters are meant to be used with a mains water supply that has 1-2 atmospheres of pressure, so they built for good heat transfer rather than a small flow resistance.

You want the hot water from the collector to heat up all the water in the tank. If you use a small tank (where the water in- and outlet will by definition be relatively close together) the water might flow relatively straight from the tank inlet to the outlet without mixing well with the rest of the tank.

If your water is "hard", using an open system might not be a good idea. Limescale would clog and eventually block the relatively fine channels in the collector. A closed system with a heat exchanger is probably a better solution.

A collector can get pretty hot, so you should use materials that can deal with hot water. E.g. copper pipes with silver soldered connections. But those shouldn't be used directly in contact with a aluminium collector because of galvanic corrosion.

In short there are some design/engineering issues with solar hot water heater that aren't immediately apparent to the untrained eye.

So if you can afford it, buy a ready made (secondhand?) collector and tank combo. Those are usually made to be installed on the roof (the tank is on top of the collector as shown here) so it doesn't take up space in the house.

I came across the compost pile hot water idea a while back. My idea is that you can run the compost pile system through the dead of winter into the solar hot water systems you are contemplating to add resiliency to the system. You could route the compost hot out through the sun room/ heated portion of the living space to help keep the citrus and seedlings from freezing and then into the solar. The video I found on youtube stated the hot compost pile produced 160 degree water declining to 90 degree water 2 months later. This would get you through the worst of January-March. link http://www.youtube.com/watch?v=-Jm-c9B2_ew

Sorry for any errors, it my first post.

Hi Anna, hi Mark,

When designing your system, do mind the legionaire's disease safety precautions. See http://www.osha.gov/dts/osta/otm/legionnaires/faq.html for a summary.

The big risk is if you store water for several hours or up to a few days. In that case, make sure to heat it to 62°C for a few minutes, two times every day.

Hi guys, I looked at this same problem last winter. The floor underneath my water heater had rotted thru. I took Pan baths for the winter until it got warm enough so i could fix the problem myself. Anyway, I searched for answers to this kind of problem. The best that i could find was on youtube. The guy had an insulated 40gallon gas water tank outside of his home. He built a small enclosure around it to protect it from the weather. He took out the thermocouple and anything else in the way. He built a small fire in the opening at the bottom. He said he didn't need to build a big fire. It acted like a rocket stove. The smoke and heat went up the exhaust pipe in the center of the water tank. In 20 minutes the water would burn his hand. He would then snuff out the fire and use up the hot water. My question to myself is what if it was winter, how do i drain it so it doesn't freeze. My answer, install it upside down on a brick fire pit and set up your pipes the way you want. The pipes at the top of a water heater if upside down will let it drain out completely, no so when right side up. Putting it on a brick fire pit, allows you to make an enclosed fire outside. Of course i haven't seen anyone turn one upside down to do this but it was the only answer i could come up with myself. i would try it too but that would be one more thing to put on a long to-do-list of mine...love your blogging, keep it up.

Reliability is a problem with solar powered systems, which also require either an electric pump or a sometimes difficult to coordinate thermosiphon mechanism.

Old fashioned wood burning water heating systems like many of us old-timers remember are cheap, reliable and efficient. As a kid I remember waking up each winter AM and first thing going down to the basement to stoke the coal burning furnace and then throw a few sticks of scrap wood into the smaller water heater. It took only a few minutes to warm up the 30 (?40) gal tank and we had enough hot water to waste all day.

http://www.pssurvival.com/PS/Hot_Water/How_To_Build_A_Safe_Effective_Wood-Fired_Hot_Water_Heater_2001.pdf