Some of the more astute readers of the last post – or really the more astute viewers of the photos – might have noticed that the plumbing changed in the photos of the loft flooring install from what the plumbing looked like when we initially installed it.
We had gone back and forth between wondering if we needed to install 3/4 inch piping at all in the tiny house (versus using 1/2 inch tubing for all the plumbing lines), as is commonly done in normal sizes houses before the final split of the piping to its destination terminus at a single appliance. In such a small space, with minimal water fixtures, it seemed like 3/4 inch lines might be overkill and unnecessary. We finally decided that it would probably be best to go with the 3/4 inch tubing, both to follow the norm and in case the 9 foot rise the water would have to take up and over the ceiling might require a greater volume of water to maintain pressure. So, that’s what we installed….. And then, our new water heater arrived in the mail…
Those little input and output nodes, yeah, they’re for 1/2 inch plumbing tubes… d’oh! Our water heater is made for RVs, and apparently RVs typically only have 1/2 inch water lines. So, we had to go back and remove all the 3/4 inch tubing and make everything 1/2 inch. If only we’d decided on the 1/2 inch from the get-go, or ordered the water heater before we started installing the plumbing pipes. Ah well, hindsight is 20/20. We had lots of 1/2 inch blue tubing, but not enough 1/2 inch red tubing and although the blue tubing is typical run for cold water lines, instead of buying more 1/2 inch red tubing (the red indicates a hot water line) to replace the 3/4 inch tubing, we just used the blue tubing and wrapped it in red tape to signify a hot water line. There’s no difference in the make up of the tubing between the two colors, it’s just indicative of the water temp.
Not exciting to have to spend time redoing something, but it happens. Can’t say we were in the mindset to remember to take photos of that revision.
But, all of our work on the plumbing wasn’t just redo, we did also make some forward progress by working on the elements prepping for install of our water heater.
Our water heater is a Precision Temp RV-550 NSP EC, which is a floor-venting tankless water heater made for RVs. Along with some really helpful information from someone who’s been using this water heater in a tiny house, the Tiny House Giant Journey blog has a link and coupon code to purchase the Precision Temp RV-550 NSP at a discount, which we took advantage of.
One of the major benefits of a floor-venting water heater is that it vents both the exhaust and any water if it were to malfunction through the floor, instead of making a huge puddle on the floor. It’s also nice not to have another hole in the wall, reducing potential for leaks during rain, and is more aesthetic with no vent on the exterior wall. It did mean we had to cut a hole in our floor – a few holes to be exact. Along with the hole for the venting exhaust and the hole for water overflow, the water heater also requires a hole in the floor for air intake. And, it uses gas to heat the water, so the gas line will come up through the floor.
The manufacturer of the water heater didn’t really provide any information about dealing with a hole in your floor (RV or tiny house) nor what to use to extend the venting pipe through the floor and out to the side of the trailer. So, as any good tech-using soul would do, we “Googled” it. We came across a couple great videos on installing the Precision Temp RV-550 NSP EC in a tiny house (which did appear to be connected to Precision Temp, but we never found linked to from their website). We also figured out to go to an auto parts store and buy tail pipe material to use for the exhaust pipe for the venting of the water heater. Just some more tiny house specific conundrums to puzzle through.
I was at work when Eli drilled the hole for the gas line and installed the connectors to hook the gas up to the water heater, so only a photo of the finished product. We also put the tubing in the wall that will plumb water to our outdoor spigot.
We won’t actually do the final installation of the water heater until closer to the final stages of the build so it’s not in the way for other construction. But, good to have most of the job complete!
Most RV’s have a grated aluminum on the side to let air in and out. The water heater is in an enclosed space. If you ever winterize, water heaters are just drained, do not put pink anti-freeze in the water heater. You should have shut-off valves to turn for water entering and exiting the water heater. Will you have a clean water holding tank on Halle Hygge?
In answer to the question about water pressure remember when you use a hose and want to squirt more water pressure you put your thumb or a finger on the end to increase the pressure to make the outlet narrower. A 3/4 inch tubing will give you more volume but a 1/2 inch tubing will give you more pressure. (Just trying to help you understand, not being sarcastic).
Love, Dad
Thanks for the RV system info and winterizing suggestions. At this point, we are not planning to have a clean water tank. Might be something we install down the line so we can go off-grid, but for now that will be a post-build addition. As for the water pressure, ah, you are right. I didn’t just mean the water pressure, but also the functional flow. We were concerned that the plumbing pipes (or tubing really since it’s PEX and not copper piping) being too small would compound a reduced functional flow with the water pressure reduction from the rise over the ceiling to create poor “water pressure” at the showerhead and bathroom sink. But, alas, a moot concern as the water heater we bought dictated we use 1/2 inch tubing! So, that’s what we had to use and the functional flow and water pressure will be what they will be! We’ll have to do our best to dictate the water pressure at its source.