RV heating systems

[spindrift]

While not a subject specific to HDTs, I do respect the collective wisdom here so I pose the following idea.  My wife and I are in the process of designing an RV where the primary heating and cooling will be accomplished through the use of a mini-split system.  The LG system requires 240V service.  The RV will have an onboard diesel generator capable of supplying 240V in a pinch.  I've had conversations with folks who report efficient heating using only the heat pump in the mini-split, even when temps dip into the high teens.

 

My ultimate goal is to minimize the use of propane in the RV and increase overall heating efficiency and flexibility.  My thought is to supplement the heat pump with a stand-alone CheapHeat system. Since this system doesn't require any gas hook-up, it can be installed virtually anywhere in the RV where there is available space, thereby providing maximum flexibility for the floor plan.  It's certainly much quieter than a propane furnace as well.  I have thought about diesel heat (Espar) since the RV will have a diesel tank but I'm no longer pursuing that idea because of cost (multiple heaters required for the length of the RV)

 

Any discussion of propane vs. electricity seems to always come down to a cost comparison.  Unless there's a HUGE reason to incorporate cost analysis, I'm going to let that issue slide for the moment.  Additionally, I don't envision that we will be parked in any one spot long enough to be concerned about a metered, 50A service.  We will have some solar. 

 

So there it is.  How much would I gain by having propane?

 

[SuiteSuccess]

Spin,

If this is the system you are referring to, we have it in our coach and love it.  Keeps trailer warm easily.  Note it can utilize 120.  We have not used one bottle of propane for heat since owning our coach.

https://www.rvcomfortsystems.com/add-on-system

[Danfreda1]

Carl I wish our cheap heat worked as good as yours and David’s. It’s been worked on more than once and doesn’t put out half the heat. I would not spend the money on the cheap heat if I were to buy another trailer. 
I might have it installed by a qualified cheat heat installer and may even have this on looked at by one. It’s a shame to burn through a 40 lb tank of propane every 3-4 days. 

[spindrift]

Yessir, that's the one, with a somewhat minor difference.  You can purchase a CheapHeat system as an adjunct to, or as a complete replacement for, a propane furnace.  I'm thinking if the mini-split is as good as advertised, and we're still in design, why not totally replace the propane with electric only CheapHeat

I should add that eventually,  we'll be fulltimers in this RV.

 

[spindrift]

5 minutes ago, Danfreda1 said:

Carl I wish our cheap heat worked as good as yours and David’s. It’s been worked on more than once and doesn’t put out half the heat. I would not spend the money on the cheap heat if I were to buy another trailer. 
I might have it installed by a qualified cheat heat installer and may even have this on looked at by one. It’s a shame to burn through a 40 lb tank of propane every 3-4 days. 

I don't get it.  That system is fairly idiot proof.  On the other hand...

[Danfreda1]

Exactly 

[Steve from SoCal]

I can't say how the 'cheap heat' works but, I am clearly in the no propane camp.    The 240 volt mini split should work on a 50 amp RV service just using the two conductors no neutral.    The 14-50 plug is 240 with the center tap neutral, just wire the mini to the two incomming legs. 

[lappir]

I'm going on 3 years with my LG and I have not had a LP Gas furnace hooked up until recently. (Yesterday in fact). The only reason I hooked the Gas back up is to have a backup for the electric heater I have in the water pump area. (It's the only area that has an issue with temps under 20 degrees.)

I have the low static flow with the Spacecraft ceiling ducting and a Wall mounted unit in the bed/living area. Don't really need the extra unit there and maybe some day will have it moved to the "Basement" to provide climate control for a potential large lithium battery bank. 

At 20 degrees outside temp the air coming from the farthest vent from the source was 80 degrees. I think last year it got to 12 for a couple days and I was nice and toasty as long as the power stayed on. I did purchase a generator large enough to power my rig just in case. Did find out it won't work on Propane at 12 degrees, at least with one of the small tanks. (the generator that is.)

Not sure what this winter will have in store for me. I'm in Norman, OK at least till after January 10th. 

 

Rod

[NeverEasy]

1 hour ago, Danfreda1 said:

Carl I wish our cheap heat worked as good as yours and David’s. It’s been worked on more than once and doesn’t put out half the heat. I

Danfreda1, I would like to examine your system remotely from here.  If you are willing to answer some questions, I might be able to help you.

1. What is your system wattage? different wattage ratings, 1,800, 3,750 and 5,000 watts

2, Is the voltage suppled 120V or 220V?

3. What amp breaker is being used?

4. What AWG wiring is used from breaker panel (load center or aux load center) to Cheap Heat?

5. Approximately how many feet of wire is used from breaker panel to the Cheap Heater?

6. What is the path for voltage from the shore power connection to the Cheap Heater?   Example: Power arrives at the 50-amp trailer shore power plug, travels to the trailer main load center, a breaker then feeds an aux load center and then a breaker feeds the Cheap Heater.

Are you comfortable using volt/ohm meter?

[SuiteSuccess]

Spin,

My vote is for the add on system and keep the propane furnace as a “just in case”.  Doesn’t mean you will need it but speaking from experience, we were caught in Amarillo, TX in an ice storm and 19*.  No electricity, no water, and no stand alone generator.   Now my coach has a propane generator, but it would eat up a couple of 40# propane bottles pretty quickly.  Thank heavens for my backup propane furnace and some well prepared good friends who were camping with us and provided two Honda gas gens and 5 gallons of water (more if we needed).

Edited November 29, 2023 by SuiteSuccess

[palmeris]

Spin

We had very similar concerns as yours as we are in the process of a design build as well. Our research and input from many has led us to an all electric / diesel trailer to eliminate propane completely.  Going with two 240 volt mini splits with heat pumps ,diesel water heater, and heat exchangers for the underbelly. Also a 10k 240 volt diesel generator, 4k of solar, 30kwh of battery. We will also be living in it full time, wintering in south Florida with 50 amp metered service. Induction cooktop, convection microwave inside, no oven, electric black stone for outside.  

No back up for the heat, but back ups for the power to run it. Now my concern is the rate of consumption of the diesel fuel for the trailer devices, but figure will always have fuel on hand that can be transfer from truck to trailer if need be.

 

 

 

[lappir]

33 minutes ago, palmeris said:

Spin

We had very similar concerns as yours as we are in the process of a design build as well. Our research and input from many has led us to an all electric / diesel trailer to eliminate propane completely.  Going with two 240 volt mini splits with heat pumps ,diesel water heater, and heat exchangers for the underbelly. Also a 10k 240 volt diesel generator, 4k of solar, 30kwh of battery. We will also be living in it full time, wintering in south Florida with 50 amp metered service. Induction cooktop, convection microwave inside, no oven, electric black stone for outside.  

No back up for the heat, but back ups for the power to run it. Now my concern is the rate of consumption of the diesel fuel for the trailer devices, but figure will always have fuel on hand that can be transfer from truck to trailer if need be.

 

 

 

I'd like to hear of the amount of diesel that's used with the big generators and water heaters. I'd refrain from transferring from the truck unless it was an emergency. You should be able to fill the trailer tank with non taxed dyed fuel at a much less price than the road diesel. 

Did you do two ODU's with their own IDU? What type, cassette or the wall mount?

 

Rod

[palmeris]

Hadnt thought about the red dye non taxed fuel, thats a good point. My thought was to fill trailer at the  stop when fueling the truck, and only have to transfer if we are parked for extended periods like 6 months in florida for the winter. Do they have  untaxed offroad typically at the loves, pilot, TA etc?

Current design is single ODU with 2 cassettes,  ceiling ducted. diesel fuel consumption rate unknown at this point which is a slight concern, my understanding is 2 fuel tanks 1 for genny 1 for heat. We think heat will be used more than genny

[NeverEasy]

Carl, do you know the wattage of your Cheap Heater?

Chet

[rickeieio]

Dyed fuel may not be worth the effort.  Right now, I can buy taxed fuel at Costco for nearly a dollar less than I can buy dyed fuel locally.  And then there's the convenience factor.  How much is it worth to go out of the way to save pennies on red fuel?

Besides spending big bucks on a coach and the latest and greatest systems, while trying to pinch pennies on fuel doesn't make sense.

Tom, I'd go with the more expensive diesel fired furnace just because you'll have fuel.  It's likely more efficient to run a furnace than to run a genny to make electric to make heat.  All that heat the genny makes is wasted.

[spindrift]

37 minutes ago, rickeieio said:

Dyed fuel may not be worth the effort.  Right now, I can buy taxed fuel at Costco for nearly a dollar less than I can buy dyed fuel locally.  And then there's the convenience factor.  How much is it worth to go out of the way to save pennies on red fuel?

Besides spending big bucks on a coach and the latest and greatest systems, while trying to pinch pennies on fuel doesn't make sense.

Tom, I'd go with the more expensive diesel fired furnace just because you'll have fuel.  It's likely more efficient to run a furnace than to run a genny to make electric to make heat.  All that heat the genny makes is wasted.

Diesel heat as a standalone; replacing both propane AND the CheapHeat system?  In the expense column, it may be a wash.

[rickeieio]

23 minutes ago, spindrift said:

Diesel heat as a standalone; replacing both propane AND the CheapHeat system?  In the expense column, it may be a wash.

That's where I was thinking.  You'll likely not spend enough time in really cold places to need a lot of heat other than what your split can provide with some solar.  Small space heaters are handy, and can warm just the area where you need it.

Packaging of the diesel furnace v. Cheap Heat may be a factor, but I doubt it.  Eliminating the propane furnace AND the tank is a plus too.  Spending other peoples money is sure easy.........

[spindrift]

14 minutes ago, rickeieio said:

 Spending other peoples money is sure easy.........

There's no place like this place for that.

[SuiteSuccess]

3 hours ago, NeverEasy said:

Carl, do you know the wattage of your Cheap Heater?

Chet

5000.  So it would pull 20 amps correct if on 240?

[NeverEasy]

Thanks, Carl.  Yes, that is correct. Wanted to compare it to Danfred1's as he is pulling 24-26 amps. I think he is correct in thinking he has an air flow problem.

Edited November 29, 2023 by NeverEasy
Wrong user

[Phil D]

8 hours ago, palmeris said:

Hadnt thought about the red dye non taxed fuel, thats a good point. My thought was to fill trailer at the  stop when fueling the truck, and only have to transfer if we are parked for extended periods like 6 months in florida for the winter. Do they have  untaxed offroad typically at the loves, pilot, TA etc?

Truck stops typically have dyed fuel for the hundreds of refrigerated semi-trailers that pass through every day.  That's usually the easiest place to find it.

[palmeris]

So the 2nd pump on passenger side is the refer pump correct,  is it only dyed fuel and cannot be used in trucks 2nd tank legally?

[spindrift]

2 hours ago, palmeris said:

So the 2nd pump on passenger side is the refer pump correct,  is it only dyed fuel and cannot be used in trucks 2nd tank legally?

No, the fuel tank on a reefer trailer is on the trailer itself.  The right side, tractor tank is simply an additional tank that normally feeds the primary (left side) fuel tank.

[palmeris]

Thank you . So untaxed is another pump handle at driver side fuel island. ⛽️ 

[spindrift]

12 minutes ago, palmeris said:

Thank you . So untaxed is another pump handle at driver side fuel island. ⛽️ 

Not exactly.  The pump requires you to specify reefer or tractor fuel when selecting fuel.  The reefer fuel taxes are refunded to the company/owner operator so it's basically untaxed.  However, the fuel comes out of the same hose/tank and is not dyed.  The same is true for any fuel used for your APU.

Edited November 30, 2023 by spindrift