So last week I talked about how I was ditching the RV-500 from Precision Temp and moving to a whole new system. Today I thought I’d share a bit about what I decided to go with instead.
After looking around I had narrowed my options to a propane outdoor on demand hot water heater. This did a few things for me:
- It allowed me to regain my under skin storage space
- Choosing an outdoor version keeps venting very simple, indoor versions require bulky venting
- I almost tripled my BTU’s from 55k to 150k that meant I could have hot showers on very cold days
There were two major downsides to this option however. The first was that I was going to have to redo most of my plumbing and gas lines, that meant that it would most likely require a plumber (I don’t like messing with gas lines), which is expensive. Having to hire a plumber isn’t too bad, but the next downside was the real kicker. Because the unit was going to be outdoors, if it drops below 32 degrees, most units have a heater. Heaters are great, because they keep it from freezing, but it’s not great for off grid solar setups.
Winter is a challenging time for solar because the sun is a lower angle, plus its often overcast on many days. Heating also takes up around 20% more power than cooling, so there are times I need to break out the generator.
What sealed the deal for me was when I talked with one plumber that Rinnai (a tankless manufacturer) had a power failure dump valve kit they could add on. Basically what this is two solenoid valves that would close the feed line and open a drain valve to drain the water out of the unit.
This meant that if I knew it was going to freeze that night, I could flip a switch to drain the whole unit after I finished cooking for the evening. If for some reason I forgot or was away, if the power went out, it would automatically drain since the heater couldn’t keep it warm enough.
In total, the unit, the solen0id kit, installation, other parts, and removal of the old water heater came to $2900, which is a lot of money, but after I saw how much work they put into it and how complex the additional solenoid kit install was, I think it was money well spent. I believe it also meets requirements for a 30% federal tax credit, which is $860 off what I will owe to the IRS.
The unit I got was the Rinnai V53e, which is their value line. It’s frankly more than I need in terms of capacity, but it’s the smallest in the line. So far I’m very happy with the unit. I’ve been using it for 3 weeks now and the biggest change I’ve noticed is that I can take very hot showers, even when it’s very cold out. Just today it was in the high 20’s and the water was hot enough I had to turn it down a fair bit. With the RV-500, at temperatures like today, I’d be taking a cold shower even when it was working full steam.
The unit’s pump and vent make more noise that I expected, but it’s not too loud. In a normal sized house I doubt you’d hear it. For me it’s mounted on the other side of the wall from my shower so you hear it’s thrumming.
The biggest win is that I get my under sink storage back and the dump valve kit is amazing. If I’m worried about the heater unit wearing down my batteries. I just flip a switch and the water is instantly dumped on the ground, problem solved.
- How do you plan to heat water in your tiny house?