What Is The Most Efficient Method Of Heating Large Volumes Of Spa Water?

[Beno]

I'm hoping to get some advice on a the most efficient way to heat large volumes of spa water in a sort of custom built system.

I thinking of running 6 built in 1300-1500 Litre tiled, insulated spa baths which will all possibly join onto one water management system. After each use (hourly sessions) I want the spa to drain completely for a quick wipe down and maintain maximum cleanliness. I am thinking the water will be reused up to a point depending on the amount of use it has had.

One idea is that the water that fills the bath could be heated with a high volume electric or gas instant water heater. I like his idea because this allows the bath to be set to a preferred precise temperature for filling. The water would then be drained, filtered, and treated then stored in a insulated tank until next required. Though the stored water will lose heat over time, if the baths are refilled regularly I see that the water will retain some of its original heat and will need less energy to reheat.

The second idea is to have the water boiled in a electric or gas tank heater. There could be one tank for each bath or maybe one or two large tanks to boil water for all baths. These tanks would be running 24/7 and each bath could fill from these with another small electric or gas heater on the way to achieve the precise preferred temperature. The drained water would again be filtered, treated and transferred back into the heater tanks where it would need to be slightly reheated and maintained again.

Once the water is approaching its maximum usage and needs to be dumped and replaced then using the heater tank method would draw a lot of energy to bring this water back up to temperature. Lets assume this will be up to once or tice a week.

So which do you think would be the most efficient on this scale in the long run? Electric/gas hot water on demand or electric/gas stored hot water?

[Dr. Spa]

See if you can get ahold of the owner of the following company. It sounds like you want to do almost exactly what he's been doing for many years (what country are you from?);

http://watercourseway.com/