Looking for some who can guide me on a passive solar hot water out door shower . Currently have 30 metres of 20mm black irrigation pipe rolled up on a wooden panel facing south and in full sun gives out about 25 lts of scalding water !!!. Question is , how can i save more hot water in a couple of barrels above the outdoor shower , how can i make the hot water heat up the storage barrels , looking for ideas on the real cheap and how can i control the temp by mixing with the cold input to the coil . It works great but needs more work , HELP.
The fluid in your coil (absorber) will not thermo-siphon and will need to be circulated in order to spread the heat into a larger volume of water and the temp will even out and performance (heat gain will improve)
Our outdoor solar shower for spring to fall had a 4'x 20' pool heating collector as the heater. It would make 150°f water from 50 deg water by noon, 48 gallons.
The Batch type heater with storage and absorber used water heater tank in a box, can be made with a used doorwall as the cover. These typically have 2"-4" insulation and are very successful and uncomplicated. They have some cold tolerance but freeze protection gets tricky without an insulated cover that can be closed at the proper time.
We installed a float and flag system made from a car radio antenna screwed onto a lid atop a partially filled glass bottle. This indicated fill level from a distance at a glance, so we could chore hound around while we manually fill.
The booster pump was an inexpensive centrifugal pump that discharged heated water to a gardeners spray wand with a splitter that we could adjust on offs and flows from the cold (well) side and hot side to temper the water if needed.
The differential controller has a high temp limit, but we store much more heat in the same volume of water by raising the temp... this requires that you check temps carefully by instrument and feel before jumping in and that you never let un-trained people or the young just have at it. Its kinda one or the other i go for storage density and capacity.
This shower system cost a couple fittings to throw together and was built entirely of scrap from solar installs, a pool heater i picked from the curbside on garbage day, old batteries, a second hand inverter, pumps, and one of our pv panels mounted on a balasted shipping pallet! It was a full bathroom with composting toilet and motion activated lights!
This was built for a family that was staying at our place while finding a home. The pop up campers they had were inadequate in the washroom department.
5 people used this rig for 6 months and until about mid to end of october showers got shaky and we added a livestock bucket heater/de icer as a backup. Some of the best showers ever in our quasi outdoor shower.
It works. You have to get a feeling for how much to fill it seasonally for a good shower that day or just keep the level you know will get reasonably warm and accept it as your shower.
Ill never forget the caribbean showers a friend used a t a vacation resort. The showers were hand pumped up to the roof at night or early in the morning and filled a black barrel that gravity feeds your shower.
The equator is a good place for this, but seasonally, it will work most anywhere with good sun.
This translates to a batch heater and evolves to pumped and flowing water and insulated and glass covered enclosure that boosts gain and limits loss for year round operation in many areas.
Steve Stolz wrote:The solar shower I used did not have any pump, it only used the water pressure from the inlet pipe. The same pressure you would find in your house. Why don't you connect your "coil" to the tank and your water input to your coil (sort of a pre-heater)
But it did have a pump.. the well pump.
Heating shower volumes of water in a single pass requires clever heat exchange. Flow rate must be extremely low or exchanger capacity large.
He basically only has the water in the pipe as storage and low controlability of temp, these make steam!
I have used the internal volume of our pool collector for a shower. It holds about 1.75 gallons of water and this has proved to be enough. The scald though if you leave it a couple minutes too long before hosing off.