Hi folks! I'm looking at the practicalities of a tankless, fully-electric water heater for a camper. I'm wondering if the <3000W varieties will ever feasibly get nice and steaming hot?
I'm working on the math of it, and would appreciate anyone's input, from people who have some electrical knowledge and maybe also some experience with any of these units. Is my math correct here?
I'm limited by the realities of what is the biggest inverter I can get (and care to purchase) = 3000w (continuous draw)
Average shower temp = 113f/45c
Lowest flow rate shower head (that I can find) = 0.5 GPM
Room temp (of water) = 78c/25c (in reality, I believe the water will be colder, ~60f/15c).
Max temp increase @ 0.5gpm = 40f (from a review of Rheem, Stiebel Eltron, Chronomite, and Thermomate heaters -- some of which actually require 3500W)
If temp of water is @ 70f, then the 3000W electric water heater will reach 110f. Just good enough?
Therefore, it looks like unless the water from my freshwater tank is at a nice and high room temp (which I'm dubious about, especially in winter conditions, at night, etc.), it'll be just on the cusp of reaching that hot shower temperature.
Looking at previous forum posts (RVing's and Travlin's) gives me the impression that it's just not going to happen -- they say "lukewarm." (Also, that quartz-based Sio Green doesn't seem to be available on the market anymore...)
I'm interested in the tankless version compared to a mini-tank heater (like a 1.5-4 gallon) as a way to save some space, and because I believe it is more energy efficient for variable-length showers (not knowing if you'll use the entire 4 gallons of hot water in the tank).
Seems as though, if I want to go all electric (without gas/propane, coolant, of some 12v DIY/ sous vide option), then a mini-tank is better? I'd appreciate hearing anyone's thoughts if you're familiar with either the tankless or tank options for the all-electric heaters. Thanks! 😄
I'm working on the math of it, and would appreciate anyone's input, from people who have some electrical knowledge and maybe also some experience with any of these units. Is my math correct here?
I'm limited by the realities of what is the biggest inverter I can get (and care to purchase) = 3000w (continuous draw)
Average shower temp = 113f/45c
Lowest flow rate shower head (that I can find) = 0.5 GPM
Room temp (of water) = 78c/25c (in reality, I believe the water will be colder, ~60f/15c).
Max temp increase @ 0.5gpm = 40f (from a review of Rheem, Stiebel Eltron, Chronomite, and Thermomate heaters -- some of which actually require 3500W)
If temp of water is @ 70f, then the 3000W electric water heater will reach 110f. Just good enough?
Therefore, it looks like unless the water from my freshwater tank is at a nice and high room temp (which I'm dubious about, especially in winter conditions, at night, etc.), it'll be just on the cusp of reaching that hot shower temperature.
Looking at previous forum posts (RVing's and Travlin's) gives me the impression that it's just not going to happen -- they say "lukewarm." (Also, that quartz-based Sio Green doesn't seem to be available on the market anymore...)
I'm interested in the tankless version compared to a mini-tank heater (like a 1.5-4 gallon) as a way to save some space, and because I believe it is more energy efficient for variable-length showers (not knowing if you'll use the entire 4 gallons of hot water in the tank).
Seems as though, if I want to go all electric (without gas/propane, coolant, of some 12v DIY/ sous vide option), then a mini-tank is better? I'd appreciate hearing anyone's thoughts if you're familiar with either the tankless or tank options for the all-electric heaters. Thanks! 😄
