Water heater sizing for body spray shower
I am putting in a shower with up to 6 body sprays at 1.8gpm each as well as a shower head at 2.5gpm. Thats 13.3 gallons per minute of ~105Â°F temp. My plumber plans to put in 2 40K BTU 50 gallon water heaters. Obviously this won't be all the time but only when I want to pamper myself. And it wouldn't be at peak demand times of the day.
How do I figure if this is going to be enough to take at least a 10 minute shower? Any recommendations on water heaters? I will mention I also will have a desuperheater with my geothermal unit.