Here's an example of a thermosiphon in use for an outdoor shower. The beauty of this system is that when the sun goes down and the siphoning stops, the hot water stays in the tank.. the system is in equilibrium. It' won't siphon cold water from the collector into the tank or let the hot water flow back into the collector.
The collector is an old glass door, and a box with 7 rows of 1" black poly pipe. I couldn't put the vertical pipes any closer together to get more surface area since the T's which connect them are so wide. I could potentially increase the performance with another row offset and on top of what's there but it's toasty enough for now with at least 4hrs of direct sunlight. On cloudy days, which we get plenty of in VT, it will make warm water but nothing to brag about.
The tank is a repurposed 15gal cooler with lid. I'd say its probably R-5. The insulation really does make a big difference. I've tried similar set ups with buckets and barrels and they radiate away too much heat. Inside the tank is a standpipe going through the bottom to the showerhead. Basically all I'm doing is filling the system and as the water level comes up, the hot water on top flow out through the standpipe into the showerhead, The inlet flow has to be adjusted so you don't add more than what can drain out or it overflows.
This shower experiment has been a success and 100% turn key for two summers. It has to be drained when the temps are below freezing so I'm itching to get an old hot water tank with better insulation and add a winter heating loop off of my woodstove chimney pipe for year round hot water.
1 дек 2017
