Converting my 5th wheel camper to hydronic heat

Martiangod

im trying to convert my 5th wheel camper to hydronic heat,
running a espar 5 kw water fired boiler.
have 2 24 inch slantfin rads in goose neck and 2 24 inch slantfin rads in living space, also have a fan forced unit at entry door....noisey.
im on two levels. upper level good heats, lower level not bad. problem im having is coolant recovery. pulling off bottom of recovery tank, non pressurised, then spilling into top of non pressurized tank.
the espar diesel coolant heaterdoes an awesome job. it intakes and discharges on 5/8 lines. i split and do two loops of 1/2 inch. i want to close the loop. remove the spill tank. would a automotive overflow tank suffice?
i will also have an insullated aluminum tank coming my way, can i put a buffer tank on one loop with 1/2 inch fittings but still satisfy the system?

Martiangod

i know this is off the wall for the normal hydronic questions. but currently im running basically a flow through on my tank set up but the seams on tank are not standing up to heat...leaking, im not short cycling its just tank i have coming my way is an rv hotwater tank which has 1/2 inch fittings, if i do the tank on the discharge side of one 1/2 inch loop would i have problems. using this tank would give high preasre relief and i would gain a 120 volt heat element

neilc

and you'll be using an antifreeze,
correct?
the RV won't run or be heating all winter, right?

neilc

just like the domestic needs winterizing also , , ,

Larry Weingarten

Hi, Before getting into the design considerations, have you done a heat loss calculation or figured out what the heat loss from the camper is when it's cold outside? Everything you're trying to do needs to be based on that number. My experience with campers is that they lose heat very efficiently

Yours, Larry

Zman

Can you draw out how your system is piped including the elevation difference?
I have a Cirrus 820 slide in camper with the Aldes hot water system and it works really well. It is much smaller than a 5th wheel and heats very comfortable with either 1.8KW electric or the propane fuel source.
The system is unpressurized, open with the reservoir about 4' above the boiler and emitters.
https://nucamprv.com/blog/cirrus-and-the-alde-central-heating-system/

Martiangod

heat loss is astronomical om an rv.
my one draw back is the ekevation change, lower leg is below boiler, by about 8 inch, upper leg is about 19 inch above tank an boiler and currently drains back. system purges ok pumpm is internal in the espar heater, need head pressure to operate. trying to do this on the cheap. at 0 degrees, im maintaining 73 in gooseneck and 70 in lower deck, but once it frops below 0 im 65 up top and 63 on lower deck, antifreeze in system, 50 50 mix
when i get my tank, a reporposed rv hot water heater, im aiming it to be highest point in system.

Martiangod

this is an experiment at best on my own rig, hydronics are coming to rvs and im a 40 plus year rv tech trying to get my head above hot water before this becomes mainstream

Martiangod

Zman said:

Can you draw out how your system is piped including the elevation difference?
I have a Cirrus 820 slide in camper with the Aldes hot water system and it works really well. It is much smaller than a 5th wheel and heats very comfortable with either 1.8KW electric or the propane fuel source.
The system is unpressurized, open with the reservoir about 4' above the boiler and emitters.
https://nucamprv.com/blog/cirrus-and-the-alde-central-heating-system/

been trying to learn what i can reading online about the Alde system in cirrus campers

Martiangod

basically, have tank 6 inches above diesel boiler which has 5/8 intake and outlet, im running 5/8 to a tee that reduces to half inch for upper leg and half inch for lower leg, upper leg had 2 24 in slatfin 30 rads, lower leg has 2 24 inch slantfin 30 rads and a fan forced 14000 btu water to air heat exchanger. 12 feet of 1.5 inch feed and return fed though in floor heat duct to rear of coach which does give some radiant off the floor. discharge currently is 2 1/2 inch legs teed to 5/8 dumping back into tank
im hopeing space limiting have new tank above upper loop, no drainback.
its not really a buffer tank setup as it will be on the discharge side on the system, but will be a 6 gallon storage of hot water.
Right now it is 24 degrees outside and 72 up and 70 down
at 0 out i drop to 68 64

Erin Holohan Haskell

@Martiangod, I've moved your post to the Main Wall. Thanks.

Zman

Specs for RV components can be hard to come by. Knowing the boiler circ performance curve, the pressure rating (if any) of the boiler and the head loss of the boiler would be helpful. If it is to stay an open system, the reservoir needs to be at the highest point.