Since this article is long and picture-heavy, I've published our travel update with pictures in a separate post. A link at the bottom of this post will take you to that article.
Our 16’ Casita now has a permanent heater powered by propane and electric.
I hope I can accurately express how amazing it is to be able to say that. Toward that end, here are a few facts:
Our 16-footer didn't come with a furnace.
You can buy a furnace and have it installed, but they are considered noisy by many.
Buddy and Wave heaters are dangerous: Mr 78sqft almost passed out twice trying to use them. When you give them enough oxygen (which means opening windows all the way, especially at higher elevations), the effect of the heater is negated in our small Casita.
There is a good heater out there you can install, but the current price tag of approximately $800 is not doable for us.
Our heating methods till now
Pre-heater installation method of staying warm: Fuel up and start the Powerhorse Portable Inverter generator at 8 pm or so. Set small ceramic space heater’s thermostat so it keeps the camper about 65-70 degreesF. Wake up around 2 am or 3 and refuel 1-gallon generator gas tank.
Alternatively (if there are close neighbors and it’s going to be above freezing), run the generator and heater full blast until about 10 pm and dress warmly for bed. In the morning, wake up to a cold camper, put cold clothes on, and build a campfire ASAP. Note that this was hubby’s preferred method, pre-wife. He calls it “toughing it out”. Wifey is somewhat tough but appreciates a warm space to retreat to during the cold days. She also gives a big 'yes!' vote for anything which would eliminate the midnight refueling hassle. Hubbies should be able to enjoy good sleep!
Over on Casitaforum.com (requires free registration to view forums), the idea of plumbing an auxiliary heater to the hot water tank has been discussed in depth. (Search for article titled "Water heater as boiler for heating the Casita".) One person tried it, was successful, but abandoned the system after he found water leaks (even after draining everything).
Dennis was sure this could be an ideal solution for our heating conundrum. We're full-timers; therefore the pipes won't be left unused long-term in cold temperatures.
We knew we would need 2 main components; a heater and a water pump. We began looking at auxiliary heaters and chose this auxiliary cab heater:
It has 2 electric fans and 3 blower openings coming off it. We liked the idea of being able to run ducting from two of the vents while letting the third circulate heated air in the under-bed compartment (where there are several water lines). The variable fan-speed switch was attractive, too. We ordered our AH545 from an Ebay seller.
We decided to buy and install a cheap water pump for testing purposes. We ordered this SurgeFlo to that end. If everything worked as it should, we planned to switch it out for a better American-made machine.
A few challenges
Let me side track here to tell you a bit about the challenges of working on your camper while living on the road. There’s no alternative sleeping area (see above disassembled bed piled in our dinette). If your work takes longer than a day you have to be able to find a stopping point so you can reassemble the bed and sleep in it. There’s no fully-equipped garage to pull the trailer into. Whatever tools you’re carrying are what you’ve got. Free campsites aren’t typically near large home supply box stores; we literally did most of the work in Lowe’s and Home Depot’s parking lots. (We even spent one night at Lowe’s. I actually slept well - yay! blackout curtains. It was fairly quiet all night, too, since they close in the evening.)
As with any project requiring small parts, you need a parts supply store. Ideally, that store has all the fittings and pipe you need to do the project all in one material. Real-world: you go in, see what they have, compare it to what you need to do, and use what they've got. You'll see in our pictures both braided water hose and CPVC piping. We used threaded brass and plastic fittings as well as push-to-connect brass and plastic. And instead of buying more white thread tape, we used the yellow gas thread tape we had on hand. We saved where we could.
Okay, side trip over. Let’s get to the project and the pictures! Please bear in mind I am not a technical manual writer. Descriptions will not be in tech-ese.
We originally thought to install the heater under one of the bench seats; but once we removed the bedding and Dennis began looking at his work space, including water line and wiring placement, it was clear it would need to go in the center of the back floor, between the two seats. (I should note here that this works for us because we keep the bed/diner in sleeping mode all the time.)
The first cut is the hardest! This is the hot water line coming off the heater on its way to the sink. A T-fitting will go here, routing to the new pump then the heater.
We’ll lose about half the under-bed storage space (what we refer to as the basement). Remember that slide-out drawer Dennis made which holds two plastic storage tubs? One of those tubs has to go, and the drawer rails have to be shortened. Note in this picture the extremely versatile cutting tool Dennis carries with him: a Ryobi 5.5amp angle grinder. (It will feature heavily in this project and the radiator fan shroud build.)
Here’s a sketchy view of the pre-existing water pump with the wiring and plumbing. This is all housed beside the hot water heater in one of the bench seats. Incidentally, this pump quit working about 2 weeks previous, so we bought a new 12V Shurflo to replace it (while we've got the bed torn apart, better do everything at once.)
Diagrams and more diagrams:
The first of many fittings:
A delicate but necessary process I call "milking" the hot water tank:
There was enough sediment in the tank that we needed to help it drain with a siphon hand pump.
The new whole-camper pump is installed:
Dennis needed to cut a small access hole to reach the water lines just behind the hot water tank:
This next picture is not our water heater, but shows the T-junction Dennis had to access inside that little square:
He wanted to make sure that the hot water returning from the auxiliary heater to the hot water tank would not get mixed with the cold water supply to the bathroom. To that end, he cut the pipe just past the T and plugged it. Then he created a cold water supply extension off of the whole-camper water pump and connected it to the cold water supply going to the bathroom.
Pump now plumbed to heater:
The heater is mounted to the aluminum angle using 4 screws across its front.
Dennis thought we might need a way to isolate the system (for instance, when taking a shower or using the sink) so he placed a valve in easy reach. (The rest of the story: The valve ended up being damaged - it let water through at any position. The store didn't have another at the right price, so Dennis just stuck a connector in the two hoses. No problems so far. We have a big, apparently unnecessary loop of water hose under our bed. )
Here's the plumbed system, pre-wiring.
It was very exciting to be at a point where we could install the switches!!!
They're right by the bed, just under the switch for the whole-camper water pump. The dial is for the fan speed, and the toggle turns the heater water pump on and off.
After wiring, Dennis put the ductwork on. We bought 3 in x 8 ft semi-rigid duct from Lowe's and tightened them down with hose clamps.
A labeled diagram of the plumbing (Red and blue arrows indicate water temperature and direction of water flow):
1. Hot water (HW) supply to auxiliary heater (AH) (tapped into the HW line going to the sink with a T-junction).
2. Cheap pump to supply AH.
3. Auxiliary heater
4. Cold water (CW) line from RV's freshwater tank to whole-camper water pump.
5. Now-excess water hose (leading to that isolating valve we thought we would need but apparently don't).
And a view of where the whole-RV pump is housed:
1. HW return from AH
2. HW line from HW tank to kitchen sink and AH.
3. CW supply line from freshwater tank to whole-camper pump.
4. CW supply from pump to HW tank (blue down arrow), and sink and bathroom (blue up arrow).
5. AH return dumps into CW supply to HW tank. (All that excess hose is between 4 & 5.)
Dennis put R13 pink insulation on the floor and against the back wall of the whole under-bed area. It was basically like putting a puzzle together, especially on the whole-camper pump side:
Freshwater tank side:
And in the middle:
Figuring out the plumbing was definitely complicated. There could very well be ways of simplifying it, but this is what we came up with. Given all the factors - the space we were working in, the supplies at the stores closest to us, and how we use our camper - this system works well for us.
The originial whole-camper water pump that quit working on us turned out to be fine. Dennis hooked it up to the van battery to test it, and it started right up. Sometimes motors need boosts, apparently? This worked out well for us. The cheap pump was exTREMEly noisy and vibratious (made-up word!), in an unpleasant, bed-rattling sort of way. So we reinstalled the original (also a well-made ShurFlo) water pump and switched the new ShurFlo over to the auxiliary heater. Much, much quieter. (We're still getting used to it, but it is a HUGE improvement. The insulation helped immensely, I'll have to say.)
The back of the camper right by the big back window stays cooler and drafty (by necessity, there are weep holes open to the air which let condensation drain off the windows). We have a hazy plan of using that third blower opening to duct a vent behind the bed into the sleeping area. (We think a shop vac extension may work well for this.)
Either we'll update this article with a parts and cost list, or we'll add one to the thread over at Casitaforum.
The important thing: does it work?
Findings and some data
First thing we tested: no leaks!
As far as the heating aspect goes: It consistently makes a 30 to 40 degree (F) difference in outside versus inside temperature. It kept the camper around 65degF the first night we used it (no insulation). Outside temperature when we woke up was 28degF. We've had several nights with lows in the 20s since we began using it. 65 degrees is comfortable and acceptable.
The two fans are powerful! We find we like closing our bathroom curtain (we removed the door) to keep more heat in the main living area. You can feel the air current all the way to the bathroom.
The system uses anywhere from 13-18% of our solar battery bank (four T105 6-volt deep-cycle batteries) a night. Including laptops and microwave usage, we use about 20% of our reserve per day. Usually we can recover that in one day of the (two 160 watt) solar panels charging the batteries. Since our refrigerator only stays cold on electric at the moment (a future project, whee), we've been powering it with the generator in the evening and using the space heater meanwhile. When the generator shuts off between 2 and 4 am, Dennis reaches down and flips the new heater on. This reduces nightly battery drain.
We're still collecting data on propane usage.
We are extremely happy with this set-up so far. We're farther north earlier than Dennis has ever come any other year, and the heater is what made it possible. We haven't elminated generator usage, but we have elminated the need for Dennis to get up, get dressed, and go outside twice in the night.
Soon I'll share our radiator fans installation and fan shroud build. Meanwhile, click on this sentence to read our travel update. You might want to fix a hot drink to enjoy while you read!