Heating using the hot water tank.

[MtnDon]

..... next to the last minute change of plans.... Change of direction and destination. Third party involvement on the other route got snafued. Now we are headed to Vermillion Cliffs National Monument on the AZ UT state line. Not as cold there but that was not the reason for the switch. The heater should still get a test.

[lrrowe]

Bob
I am well aware we are subject to a recall by the manufacture at any moment. From the time I started feeling bad (under the trailer) to actually dieing on the table at Toledo Hospital was about 20 minutes. I woke up with burn marks where they shocked me nine times. I was camping two months later on the north shore of Lake Superior.

I have not had that level of near death experience, but I have had my share of scares. And now everyday is a new day with great experiences ahead of me. And your photos drive that point home. Great views. That area is on my list of places to visit one day....when I get to visit my old campus in East Lansing.

[lrrowe]

..... next to the last minute change of plans.... Change of direction and destination. Third party involvement on the other route got snafued. Now we are headed to Vermillion Cliffs National Monument on the AZ UT state line. Not as cold there but that was not the reason for the switch. The heater should still get a test.

Any test will be a good one. I am starting my next experiment in addition to following yours and Shadow Catcher's lead. Since I have a raised and insulated floor, I have lifted my top plywood sheet and am cutting runs for potable Pex lines into the foam. Using aluminum sheeting over the EPS, there will be 100' of this tubing running hot water from the water heater.
Will this be practical, I do not know, but given I am doing it for under $75, then it is something I just have to do and see what the results are.

After all, I have installed the same in my house and I plan on trying to install solar heated water to the mix next year.

[MtnDon]

We were warm enough that most nights the heat never came on till about 0530 or 0600. I had it set for 66 F. Last night was colder, a low of 35 F and the heat came on earlier; not sure when but it ran about 0400. I think I have the ideal place for the temperature sensor now. That may need more testing / tuning but is easy enough to change with the remote sensor. I think we can call this a success for the seasons we will be using it.


If at some future point I want more heat I might get one of the 4 fan computer CPU cooler radiators. There are not many that are pressure tested to RV water pressures though so the choice is limited. Not sure I want to take a chance with a non pressure tested unit or one that is only tested to 15 PSI like most are.

[lrrowe]

Thanks for the report MtnDon. I guess I will go back and read up on your temp sensor now. I am making slow progress with my tubing in the floor. All the routing for the tubing is complete and I hope to add the tubing over the weekend if I do not get too tied up with Easter weekend company.

[Wolfgang92025]

MtnDon.

Maybe I missed it, but what are you using for a temp sensor ?

Thanks
Wolfgang

[MtnDon]

Wolfgang, it is one like this. I didn't buy it from thosefolks but it is the same thing. For some reason the ebay purchase history page is not bringing up all the items it should. The seller I used had them available in 12 VDC as well as AC types and in degrees F and C.

The probe is on a wire that can be shortened; place the probe where you want and the unit someplace easy to read.

[MtnDon]

Here's the way ours is mounted....



I ended up with the temp sensor right by the controller. I guess I could have used a std RV furnace wall thermostat.

[lrrowe]

I will have to think sensors out. I will have two heat sources. One almost Like MtnDon's and for that I could use either this one or a RV one like MtnDon mentions. And then I have a back-up (or full time, we will see) radiant infloor system running off the same water heater. For that one, I will use the one like shown here and put the probe in the floor as I do in my house. To answer any questions why do this, (have the floor system) as I mentioned in earlier posts, it is to both experiment and prove something to me and on the chance it really works and is effective/practical just privies another solution to the issue of heating a CT. I will not get my tubes in this week so I cannot take pics now and post because I am focused this week and caring for my wife and getting her to surgery this Friday for heart valve replacement.

[lrrowe]

Wolfgang, it is one like this. I didn't buy it from thosefolks but it is the same thing. For some reason the ebay purchase history page is not bringing up all the items it should. The seller I used had them available in 12 VDC as well as AC types and in degrees F and C.

The probe is on a wire that can be shortened; place the probe where you want and the unit someplace easy to read.

Just ordered mine.

[daveesl77]

I think I have read all the posts in this thread, so please forgive me if this has been asked and answered...

This is really interesting using the Rv water heater for cabin heat and it makes perfect sense. Has anyone done this using an on-demand type heater? My thought is that if you had a secondary pump system, on a recirculating flow line, you would then use the thermostat to activate a relay which would in turn activate the pump. Water flowing then tells the heater to fire up. As you guys note on a tank type system, if you do a closed loop, then the feed water temp will keep rising. This would also happen with the on-demand, but I think much faster. With my little 5L, it raises the incoming water about 30-50 deg F at 3/4 heat/flow rate in 10 seconds. You could then put a high temp shut down in the circuit to cut out the burner ignition once the water got to say 150 degrees or so. It wouldn't be a pressurized system, just a free flowing pump dumping heated water back into a storage unit.

Circuit would be 1) Storage Tank - 2) secondary pump - 3) Heater core - 4) return to tank with high temp cut off on igniter, but not the pump. Thermostat turns off pump and igniter.

So, is this viable or am I missing something. I ask because I already have the on-demand and will happily add the heater system if it looks doable. Unfortunately, can't really test much on the cabin temp rise now, as it is 90 in Florida.

dave

[MtnDon]

I think it should work. Just a matter of working out the controls. One of the temperature controllers I used should work fine. They have the ability to program the hi - lo temperature differential settings from 1 to 25 degrees,IIRC.

Not sure if you mean to include a small storage tank in the water heater to radiator system. A small tank would likely reduce the on-off burner cycling.

There would be pressure in the system if only because of the expansion of heated water. If this was a part of the regular water system that would also mean the heating loop would be pressurized. That should not present any issues.



Does the heater burner in your water heater make much noise when activated? I've heard some on demand heaters that have quite a roar. Our water heater is well insulated on the inside and the trailer walls are also well insulated. I can still hear the burner fire up when it is night time quiet. It is not bothersome, quiet quiet actually. But that was a concern I had. Ours is actually quieter than the traditional forced air RV furnace was in our old class C RV. The most noise comes from the fans used to move air.

[Shadow Catcher]

Dave, one thing to remember is that this is very much experimental and open to the ideas of all of us. I am doing the wiring on my thermostat and borrowed an idea on where to mount the thermocouple from Don.
My original idea involved an external boiler which could still be made to work.
I do not see a problem with what you have in mind, but some one else might.

[Socal Tom]

I think I have read all the posts in this thread, so please forgive me if this has been asked and answered...

This is really interesting using the Rv water heater for cabin heat and it makes perfect sense. Has anyone done this using an on-demand type heater? My thought is that if you had a secondary pump system, on a recirculating flow line, you would then use the thermostat to activate a relay which would in turn activate the pump. Water flowing then tells the heater to fire up. As you guys note on a tank type system, if you do a closed loop, then the feed water temp will keep rising. This would also happen with the on-demand, but I think much faster. With my little 5L, it raises the incoming water about 30-50 deg F at 3/4 heat/flow rate in 10 seconds. You could then put a high temp shut down in the circuit to cut out the burner ignition once the water got to say 150 degrees or so. It wouldn't be a pressurized system, just a free flowing pump dumping heated water back into a storage unit.

Circuit would be 1) Storage Tank - 2) secondary pump - 3) Heater core - 4) return to tank with high temp cut off on igniter, but not the pump. Thermostat turns off pump and igniter.

So, is this viable or am I missing something. I ask because I already have the on-demand and will happily add the heater system if it looks doable. Unfortunately, can't really test much on the cabin temp rise now, as it is 90 in Florida.

dave

I'm missing how this is really different from the current system? The HW heater heats the water based on the demand ( low temp). The pump and fans are activiated by the thermostat in the cabin. When the temp falls in the HW heater then it turns on and raises the temp back above the cutoff.
Tom

[Socal Tom]

I think this method makes perfect sense if you already have a hot water heater. If you don't, or lack the space to add one another option would be a RV type furnace. They can be picked up used, and if you install the 4 inch ducts like Compass Rose has, you can put the heater in an box and set it out side the RD. Run the ducts to the inside and have the thermostat inside. It just takes a 12V supply and a hose to the propane tank, and could work just like the "hacked Frigedaire" but for heating instead of cooling. I've seen used RV furnaces go for $100 or so.
Tom