So I have spent some time yesterday obsessing over various water heaters, and my conclusion was that it's hard to find a good water heater, especially at a good price.
I will summarize my findings below.
LP RV Tank Water Heaters: These come in 6 gallon or 10 gallon and are vented towards the outside. New they cost $600+ and used they go for about 200-300.
-They are reliable and replacement parts are standard so they are relatively easy to repair.
-They are designed to operate in RV's
-They will limit the quality/duration of shower one takes and will make back to back showers difficult without compromising ones (your wife's) shower times.
-They are limited by their tank size, they use more propane than a tankless LP water heater because they keep the water in their tank at a steady temperature.
LP RV tankless "on demand" water heaters: These cost $1000+ new, I don't see these used. Different water heaters will have different Gallons Per Minute ratings.
-They are efficient with propane use and will not be using propane when idling.
-Their output are only limited to your water source size.
-Their parts are specialized and exclusive to the manufacturer, making supply limited and repairs costly.
-Some claim that the quality of water is compromised by their mysterious heating process
Residential tankless "on demand" water heaters: These cost $100+ new. They are available as electric or LP gas, the electric water heaters use 10,000 watts+
-They are cheap
-The cheap ones have a lot of reports of breaking easily.
-many complain the vent costs more than the water heater themselves.
-all of the RV tankless cons included
Residential Tank Water heaters:
I have read about these being used in skoolies (such as Turfs bookmobile) but I know very little about these being used in skoolies, so I will not PRO/CON these.
After reading all of these I recall someone talking about their off grid shower on reddit, link here
using an electric water bed heater as a heating element in combination with an Insulated RV holding tank. Which I found to be very intriguing.
-Low cost, relatively low energy usage(they reported using about 700watts a day via 120v for the shower).
-Does not use propane
-Plastic Tanks maybe not designed to heat up to 100 degrees
-Takes up space.
Things to note:
- "In an average home, showers are typically the third largest water use after toilets and clothes washers. The average American shower uses 17.2 gallons (65.1 liters) and lasts for 8.2 minutes at average flow rate of 2.1 gallons per minute (gpm) (7.9 lpm)." Source
-Low flow showers use 1.5 GPM
What I am hoping is for
1. Your input and opinions
2. Your experiences with good water heaters and bad water heaters and how long you've used it for, model numbers and brands would be appreciated as well.