Installing hydronic heat

[brians1969]

Being a full-timer in New England means heat (or the lack of it) is important to us. Like everyone else, I have the usual Suburban hot air furnace. It works reasonably well. It is also noisy and loves to drink propane! For reference, in 10 degree weather, I'll go through a 20 lb. cylinder in slightly under 2 days.  Now I know that some of the newer high end motorhomes have hydronic (hot water) heat. these are insanely expensive...doesn't fit in with my classic motorhome-low dollar approach.

So about two months ago I started to collect parts.  Got the atwood water heater from a dealer that pulled it out of a customers camper. It had frozen and ruptured the tank. Fortunately a friend of mine does aluminum welding and he welded back up!
Got the heater core/fan unit off ebay.  Got the circulating pump of ebay, too. It is quiet, low draw model.

I connected everything up last week.  After getting all the air bled out, it worked! It's too soon to tell how well it works as it is still warm. I may need another radiator. I'll keep everyone posted as it gets colder.
brian

[Oz]

Very inventive!  I remember, as a kid, most of ouir homes had baseboard hot water heat.  I'll always remember the ticking of the fins in the baseboard units when they warmed and cooled.  Also the gurgling, which meant the line needed bled.  But what I remember most is that it was always a cozy warmth, not dry, like hot air heat and the heat continued to emanate from the registers well after the furnace had shut off, unlike hot air systems.  Do let us know how this works for you as we get into the colder months!

[salplmb]

i have thought of this for a long time and would really be interested in how it works out. i would think this would be a way more efficient way to heat.
thanks for sharing your experiences with us.
sal

[JDxeper]

A google resulted in two links the one posted and this one

ftp://sunsite.unc.edu/pub/academic/environment/alternative-energy/energy-resources/homepower-magazine/archives/26/26p53.txt

I could not get the other one to work.

[salplmb]

thanks,
that link worked for text only. dont know if there was any pics.
thanks again.
sal

[DaveVA78Chieftain]

Explorer 7 did not work for me either but Firefox did.  So, I printd it to a PDF and posted it at http://www.mediafire.com/download.php?hm3zix3jekt8sso

Neat idea and does not seem difficult at all.  Might be worth looking at a lot closer.

Enjoy
Dave

[brians1969]

I plan on posting more comments as it gets colder.  My total investment is about $350 so far. $150 for the water heater, $70 for the circulating pump, $25 for the heater/fan,  and the balance for switches, relays, wire, hose, etc.

I may need to add another radiator. I have just the one by the dinette and am concerned that the back area by the bathroom may need something. But we'll see.

[DaveVA78Chieftain]

Great.  Let us know how this works out.  I am currious about propane usage and such.  The article does express BTU's but you never know how it will work out.  Air circulation throughout the rig will be important for this.  With 2" foam insulation panels under the floor and strech plastic window covering in my rig, it can still get chilly in the dead of winter even with the furnace running.

Good Luck,
Dave

[dgapilot]

I think the page they want is here
http://www.solarhaven.org/RadiantHeatingInstallations.htm
It talks about installing PEX in a mobile home. I don't know how this would work on a mobile home since there is a myraid of tanks and such under the floor of my coach. They also added R13 insulation under the floor, again, hard to do for something rolling down the road. I have seen radiant heat systems installed between the sub floor and finished floor but you need to add a layer of 3/4 plywood and route traces for the pex to go through. We still  have the problem of insulation under the floor, as thet could be a significant heat loss area. I'm considering putting electric hadiant heat in my floor when I tear out my carpeting. Take a look here
http://www.thermosoft.com/radiant-floor-heat/
To do this, I would have to upgrade my electric to a 50 amp service which would allow me to run the floor at 240 VAC using the 2 50 amp legs. Heat mat would run about $800, an upgraded power panel, wiring, and thermostats. Would make a nice installation, I just don't know how efficient it would be as the specs only show about 1800W for the size I would be doing.

I have lots more projects before I get to this, so something better may show up by then.

[brians1969]

No dga, although it's a great article that isn't the one. I think he did the camper hydronic system first.  Perhaps that was the inspiration for the house project.

[dgapilot]

After I posted yesterday, I read the text link on the RV using a heater core as the heat exchanger. Didn't see any pictures, but sounds like a good idea. I was thinking, an old school bus rear heater might make a good heat exchanger for this type system. Might be able to pick one up cheap at the junk yard. Should already have a blower motor (not sure abour efficiency of it though), and alt=ready has en enclosure.

[DaveVA78Chieftain]

The dash heater in a motorhome could also be used.  Water was supplied by chassis engine.   They also had the fan built in.

Water heaters come in several flavors.  For the heat supply there is LP gas, electric and engine heat models.  I see no reason why the engine heat circuit in a HWH (with that option) could not be used for routing the plumbing.  Used alone, the tank would be filled with water and sealed.  Another option would be to use the tank water for one circuit and the engine circuit for another circuit.

Using a DSI model HWH would solve the pilot blowout problem.    Then again, pilot blowout would typically be a moving RV issue, so by using a HWH with the engine heat option would solve the problem as the heat source would be the chassis engine rather than LP gas.

Ahh, choices, always choices!  Well, what did you expect?  It is an RV and they have more choices than .... 

Dave

[brians1969]

Yeah, I'm using an Evans heater. Evans makes auxillary heater units for buses and they made them for our motorhomes too. Heater core and fan all in a compact box. I added a temperature sensor onto the inlet pipe, so the fan doesn't start running until the heater gets to 113 degrees.

I also have the electronic ignition on the heater. It also has the 110 volt heater option!

[Cakeman2253]

Lets see if this link works. I went to there site.

http://www.solarhaven.org/Hydronic.htm

If not here is the main page and you can find it.

http://www.solarhaven.org/SolarHavenMainPage.htm

Very interesting. Would be nice to know how it works in a MH.

[DaveVA78Chieftain]

It don't work in IE, broke, caput.  Thats why I made the PDF and made it available to all in post 12 (http://www.classicwinnebagos.com/forum/index.php?topic=5704.msg20851#msg20851).

A side note
Hydronic heating is not an unkown commodity in the RV/Boating world.  A larger modern Winnebago cousin,  the 2003 40ft Ultimate Freedom, has the diesel fired Hurrican II Hydronic system (http://www.itrheat.com/hydronic.html).  Rather than using a water heater as the heat souce, there is a diesel fired boiler that is the heat source.  It provides heat to the water heater, heat register/blower, and cold start for diesel engine.

Dave

[brians1969]

Dave do you know how much that system costs?  I was a little curious. I heard somewhere they are pretty pricey.

[DaveVA78Chieftain]

Converting british pounds to US $ from http://www.calcuttboats.com/hurricane.html

A SCH25 base boiler unit is $3600
A narrow boat installation kit (pump, fittings, etc.): $825 or
a sum totoal of at least $4425 (shipping to not included)

Not to mention you have to install a diesel fuel tank.    W%

You have to remember that those who purchase yachts and RV's for greater than $200,000 don't really worry about tossing around several grand for creature comforts.  Those that make systems like this also know that   Hm?

Dave

[Froggy1936]

I have a question. Why the fancy word (description) Hydronic  When it is just a hot water heating syestem ?  Mabey to get the rich to use it !  Frank

[brians1969]

Wow Dave! That's expensive! But you're right, 200k for a motorhome, what's a few more thousand?

Froggy, my guess is to avoid confusion with the other hot water heating system in your house/rv.  That is your "domestic" hot water system.

[DaveVA78Chieftain]

Frank you know you have to be politically and socially correct these days   W%  Besides you have to call it something so you can apply for the patent rights.
But I do agree with your thought!

Definition of Hydronic:
of, relating to, or being a system of heating or cooling that involves transfer of heat by a circulating fluid (as water or vapor) in a closed system of pipes.
First know use of the word is around 1946

Background information and use of systems designed around the "hydronic" principle: http://en.wikipedia.org/wiki/Underfloor_heating


Yes, that does mean the automotive style heater under the dashboard is a hydronic space heating device.

Government nomenclature:  Space Heater, Hydronic, Air/Water

Dave

[DaveVA78Chieftain]

For those that want all they can find about existing Hydronic systems: http://www.rvtechlibrary.com/heatair/hydronic.htm

Aqua-Hot (formally Hydro-Hot) is big in the bus size RV market like Newmar or Tiffin.  And yes, the more complex you make things the more gremlins there are to find.  More $ = More Gremlins = More repair $   W%

Dave

[jkilbert]

interesting article. if i used mine more in the winter i think i'd have to do this.  and as far as the heater core...look for a junked ambulance, the rear heater/ac is an all in one unit with the fan and sometimes thermostat and fan controls mounted on it....even a vent panel