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Bus Discussion => Bus Topics ( click here for quick start! ) => Topic started by: Cary and Don on March 29, 2008, 12:31:23 PM

Title: Hydronic floor heating
Post by: Cary and Don on March 29, 2008, 12:31:23 PM
We plan on using floor heating.  We came across the pans for 3/8" hose real cheap and the 1/2" tubing cheap.  The question is should we buy pans for 1/2" hose or 3/8" tubing for our pans and use the 1/2" tubing for our fresh water plumbing.  Is 3/8" tubing big enough to heat our kitchen and bathroom floor?

Don and Cary
GMC4107
Neoplan AN340
Title: Re: Hydronic floor heating
Post by: Nick Badame Refrig/ACC on March 29, 2008, 03:10:13 PM
Hi Don,

Use the 1/2" to not restrict flow. The more flow you have the more even heating you will have.

The only draw back with in floor radiant is Slooow to get up to temp and Slooow to cool off. If that don't bother you,

then you will be very happy with it.

Good Luck
Nick-
Title: Re: Hydronic floor heating
Post by: Sojourner on March 29, 2008, 06:35:23 PM
As what Nick said.
Bus wall is about 1/3 thickness at what residential home is, so to compemsate the lack of good insulation of a residential home, is to add more lines of hoses on lower half of bus's wall.

Craig (gumpydog.com) has a very good site to answer your questions.
http://www.gumpydog.com/bus/MC9_WIP/HVAC/House_HVAC/House_Heating/Hydronic_Heating_System/hydronic_heating_system.htm

FWIW

Sojourn for Christ, Jerry
Title: Re: Hydronic floor heating
Post by: Cary and Don on March 29, 2008, 08:16:32 PM
Thanks for the link to Gumpydog.  That is a great site.  I think all of us inexperienced can spend a few hours reading the whole site.

We are going to have electric heaters, the hydronic heat, and maybe a couple small diesel blower heaters up front.  That way we can use which ever is the cheapest depending on where we are. We don't have any floor heat now, and those tile floors are coooold in the morning.  If your are going to put in one loop, might as well do a full system.

Don and Cary
GMC4107
Neoplan AN340
Title: Re: Hydronic floor heating
Post by: pvcces on March 29, 2008, 09:42:14 PM
Don and Carey, a small heat pump will give you the ability to heat or cool your bus from the same piece of equipment. A small residential unit can give good bang for the buck with no increase in electricity use. You should be able to install a one ton unit pretty easily; you want a low ambient, low current model. If you want to really be able to handle cold weather, then go for 1 1/2 tons, instead.

The energy cost should be way below anything else that you can do.

Tom Caffrey
Title: Re: Hydronic floor heating
Post by: TomC on March 29, 2008, 10:22:00 PM
Something to consider- for insulation, after stripping the walls down I screwed in 1x2 fir strips horizontally at about 12" spacing to both make the wall thicker and to have a base to screw my wall and ceiling coverings to.  This made for 2.25" of sprayed foam.
To heat my bus I have one 35,000btu propane Atwood furnace.  I have four outlets evenly spaced from about 6ft back from the drivers seat to the bedroom in back.  For heat in the bathroom I have a house type electric wall heater that does a great job.  Here's my point- my Atwood furnace, in the 8 years it has been in and I've been using it, has required zero maintenance up and beyond a once a year cleaning before the heating season after summer.  Do you think an extremely complicated hydronic heating system like what Gumpydog has with all the ball valves to control flow, the hydronic electric heat exchanger, Diesel fired boiler to power the water heat, can say that the system only required you to adjust the simple thermostat to turn it on and off with immediate heating results, either on or off?  Also, this single 35,000btu heater has worked well down to 15 degrees (the coldest I've been in and was windy to boot) and heats the bus just fine. If you have doubts about if one 35,000btu propane furnace will heat your bus then install two-it will still be ALOT of money less then the hydronic heat without all those heating water lines, valves, etc.  Personally, the thought of springing a leak under the floor after all your cabinets and appliances are in just would scare me off from doing a system like that.  Good Luck, TomC
Title: Re: Hydronic floor heating
Post by: gumpy on March 30, 2008, 09:08:11 AM
I heard you can't put hydronic floor heat in a bus!  ???
Title: Re: Hydronic floor heating
Post by: TomCat on March 30, 2008, 10:09:09 AM
Not having any bays under my coach, I knew I was going to need some form of floor heat to keep it tolerable during the often harsh Colorado winters.

I opted for NuHeat electric mats under my Italian tile flooring in the kitchen and bath, in two of their standard sizes.

The bath floor heater uses 110w when on full (only when outdoor temps are under 20*f), and is usually only on halfway. The kitchen mat uses 200w when on full, but it usually stays on half as well.

The regulators (thermostats) run on a 15 minute cycle, and the higher you have them set, the longer during the 15 minutes the mats remain on.

They are pretty quick to heat the floors, but I never noticed how long the floors take to cool off once the heater is shut down.

If properly installed and tested, NuHeat will warranty their mats for 20 years.

Jay
87 SaftLiner

Jay
87 SaftLiner
Title: Re: Hydronic floor heating
Post by: Cary and Don on March 30, 2008, 06:06:15 PM
We have had the propane argument.  I hate gas, all gas,  I cook on electric.  Don thinks gas is a good idea.  It smells, the cook top take up a lot of counter, you have to add the big old tank. Please don't get him started on this one again.

The electric mats sound interesting.  We might add that.  We are just trying to have options.  The main reason we are looking at the hydronic floor heating is so we can keep the floors warm at night without running the generator.  I have heard that the burner can be maitenance intensive.

We don't want the problem we have now.  Heat strips in the Coleman, useless, one good toe kick heater, and a oil radiator space heater.  We have stayed bearable warm in the teens, but not what I would call comfortable.

Cary
GMC4107
Neoplan AN340
Title: Re: Hydronic floor heating
Post by: Dreamscape on March 30, 2008, 06:20:16 PM
Cary,

Talk to Craig "Gumpy". I saw his hydronic system today and he knows what he's doing. He sad they stay toasty warm when the temps are sub-zero. If it was me I would probably head south, I hate cold! ;)

Paul
Title: Re: Hydronic floor heating
Post by: TomC on March 30, 2008, 10:28:40 PM
Cary-  I too hate propane-I've seen through my truck driving experiences many motorhomes burn to the ground with propane leaks.  But I succumbed to propane because of the massive cost at creating a hydronic system and the upkeep that I didn't want to get involved with.  With my two 10 gal electric water heaters, the only propane I have is the stove and the furnace which are right next to each other with the propane tank (20 gal) that is directly beneath.  I have an electric solenoid valve on the tank with a switch inside to keep the propane turned off when not needed, and a CO/gas sensor at the floor since propane sinks.  In the nearly 10 years it has been in, no problems with either the propane tank, stove or furnace.  I highly recommend you reconsider the use of propane instead of saddling yourself with the constant maintenance and adjusting necessary with a hydronic heating system.  Course I'm sure you'll do what you want though.  Good Luck, TomC
Title: Re: Hydronic floor heating
Post by: JohnEd on March 30, 2008, 11:13:00 PM
I read a post here recently where a Knut installed floor heat with his Wabasto.  Did it according to the book.  Floor had HOT spots right above the water line that were so hot he had to tear up the floor and install metal shields directly above the tubing to spread the heat.

Might want to search for that one and get ahold of the poster.

TomC has some powerful points.  If I have the money I will install hydronic so I can use the bus system for defrost while stopped and run the front heater instead of installing toe kicks in the front.  I want the engine heat feature and hot water generation.  Efficiency is a big issue for me.  I have propane heat and I can't fault it for reliability and efficiency.  My propane water heater just eats gas, however.

Good luck,

John
Title: Re: Hydronic floor heating
Post by: WEC4104 on March 31, 2008, 05:16:39 AM
Okay, stupid question time...   For hydronic systems, is there anti-freeze in the liquid that is pumped through the system, or do you drain it when the bus is stored in cold weather?
Title: Re: Hydronic floor heating
Post by: Nick Badame Refrig/ACC on March 31, 2008, 08:53:35 AM
Hi Wayne,

Yes, automotive antifreeze or heating glycol will work fine.

If you choose water, then yes, yao may have to drain it.

Nick-
Title: Re: Hydronic floor heating
Post by: gumpy on March 31, 2008, 04:09:10 PM
Quote from: TomC on March 30, 2008, 10:28:40 PM
... instead of saddling yourself with the constant maintenance and adjusting necessary with a hydronic heating system.  Course I'm sure you'll do what you want though. 

I sure wish someone would fill me in on just what all this "constant maintenance and adjusting necessary" stuff is.

I must be doing something wrong. All I do is set the thermostat.

Well, maybe someday someone will educate me.  ::)
Title: Re: Hydronic floor heating
Post by: Brian Diehl on March 31, 2008, 04:21:10 PM
I don't get the "constant maintenance" part either.  My unit has worked marvelously!  Love that Webasto!
Title: Re: Hydronic floor heating
Post by: Dreamscape on March 31, 2008, 05:06:55 PM
I saw Craig's and Brian's systems. If I had it to do over, that's the way to go. What a great way to stay warm.


I'm going to do something similar using our Proheat X45, only using that to feed some heat exchangers. So I guess it would be similar.  ;)

Paul
Title: Re: Hydronic floor heating
Post by: JackConrad on March 31, 2008, 05:34:03 PM
Maybe I have not used my ProHeat enough since installing it last fall. Only maintenence so far has been fillling the fuel tank and setting the thermostat.  Jack
Title: Re: Hydronic floor heating
Post by: rcbishop on March 31, 2008, 05:56:03 PM
...and if one has carpet over hydronic...well, the floor gets warm, but it takes a long time for "upstairs" to  warm up.  We have it in our home, embedded in concrete  with pad and carpet on top .....doubt seriously we would go thru the expense again IF carpeted. Under the tiled areas, it is fine but takes a few days (2-3)  to get up to speed, as Nick indicated. Very high propane bills when it is used, and we keep both  thermostats at 64 degrees............left it "off" this past winter.  Have had it for 10 years.

BTDT, FWIW  :D
RCB
Title: Re: Hydronic floor heating
Post by: sweeney153 on March 31, 2008, 06:24:04 PM
Quote from: rcbishop on March 31, 2008, 05:56:03 PM
...and if one has carpet over hydronic...well, the floor gets warm, but it takes a long time for "upstairs" to  warm up.  We have it in our home, embedded in concrete  with pad and carpet on top .....doubt seriously we would go thru the expense again IF carpeted. Under the tiled areas, it is fine but takes a few days (2-3)  to get up to speed, as Nick indicated. Very high propane bills when it is used, and we keep both  thermostats at 64 degrees............left it "off" this past winter.  Have had it for 10 years.

BTDT, FWIW  :D
RCB


I put it in my house when i built it 17 years ago and it's by far the best I have ever experienced. It's comfortable, even heat and very economical. I have tile, wood and carpet. If the floor gets hot the water is too hot. I am not that familiar with the bus systems thou I am planning to install it. The only problem I see is there my not be enough insulation for it to work correctly.
Title: Re: Hydronic floor heating
Post by: Stan on April 01, 2008, 05:19:04 AM
QuoteThe only problem I see is there my not be enough insulation for it to work correctly.

That hits the nail squarely on the head. For any heating system to work well in a bus, you have to reduce heat loss. You need less glass and more insulation.
Title: Re: Hydronic floor heating
Post by: hiwaycallin on April 01, 2008, 08:30:06 AM
Gumpy ... nice work and thanks for posting all the details. It seems pretty obvious that this type of system is best installed early in the conversion process. What about retrofitting an existing conversion? Obviously the floor needs to be redone, but do the cabinets, etc. need to come out too?
Title: Re: Hydronic floor heating
Post by: luvrbus on April 01, 2008, 08:40:45 AM
I don't what the problem with floor heat would be BlueBird had with the Primus hydronic system a mat that laid uder the floor about as thick as the NewHeat system and it worked great the ones I was around
Title: Re: Hydronic floor heating
Post by: Lee Bradley on April 02, 2008, 09:57:53 AM
Gumpy,
Thanks for sharing the details on putting in hydronic floor heating. I would never have thought of putting it in the walls and the aluminum sheeting and hard board saved me a bunch of do over. Just one question; I don't see any air bleeds. Is that a problem?
Title: Re: Hydronic floor heating
Post by: gumpy on April 02, 2008, 04:33:50 PM
Quote from: Lee Bradley on April 02, 2008, 09:57:53 AM
Gumpy,
Thanks for sharing the details on putting in hydronic floor heating. I would never have thought of putting it in the walls and the aluminum sheeting and hard board saved me a bunch of do over. Just one question; I don't see any air bleeds. Is that a problem?

Lee,

No air bleeds necessary. The pumps are on the supply side, not the return side, so the lines are pressurized. The suction and return are below the level of the coolant in the heater. The pumps push all the air out and it returns to the reservoir, where it is expelled through the pressure cap. Once all the air is out, it can't get back in the lines unless the level of the coolant drops below the suction or return lines. The lines also won't drain back to the reservoir, and there's no head pressure on the pumps. I did put some stub outs on the manifolds when I built them, to catch any air that might pass by them. I was going to add needle valves to them to bleed off the air, but haven't found a need for them.

I did put some bleeds in the engine compartment on the engine preheat lines, but only need them when filling the lines for the first time or when I've drained the engine for some reason.

craig