Hydronic Heating a 13 Footer

[Kurt & Ann K.]

I wonder if it would be possible to insulate under the floor. How to protect it from road damage is my question. Maybe a thin sheet of plastic or aluminum glued to sheet foam insulation?
Could the tanks be freeze protected also? Would road clearance be compromised or would the insulation all be above the axle and not prove to be a problem?
Are there other considerations?
Kurt & Ann K.

[Brian B-P]

I wonder if it would be possible to insulate under the floor...

I have been thinking about under-floor insulation, even without in-floor heating. I think it is an entirely reasonable idea, at least in my 17-foot Boler

...How to protect it from road damage is my question. Maybe a thin sheet of plastic or aluminum glued to sheet foam insulation?

The fiberglass sheet material used as the outer surface of "fiberglass" stick-built trailers is available in sheets in various thicknesses and finishes (e.g. with or without gelcoat). A common brand name is "Filon". I have considered getting some of this (perhaps as scrap from an RV repair or manufacturing operation) for this application.

Off-road and rally competition vehicles routinely use relatively thick sheets of solid plastic as rock guards, but that would be too heavy for the large areas involved. Newer conventional trailers use thin plastic - perhaps composite such as fiberglass - underbody covers for aerodynamics; maybe that would work well.

My current thinking is to use polystyrene foam insulation (Styrofoam®), glue it in place, and use screws through the foam and just into the floor to hold the cover sheet. I have not tried this yet. An alternative would be some sort of brackets from the frame rails, but I would rather not weld on the rails or drive self-tapping screws into them.

...Could the tanks be freeze protected also? Would road clearance be compromised or would the insulation all be above the axle and not prove to be a problem? ...

This depends on specific trailer construction; however, in my Boler B1700 the frame is a pair of 4" high box rails, and the flat floor runs across the top. In the areas without water tanks, there is space for 4 inches of insulation before it would hang lower than the frame.

The tanks in my trailer protrude significantly below the frame rails, and it would be necessary to raise the trailer to provide room to significantly insulate them. I have seen photos of trailers with foam insulation apparently sprayed on the tanks, but this looks neither tidy nor durable to me.

[b]Bigfoot is proud of their winter-worthy insulation design, and uses 1.5" foam in their walls. I wonder if and how they insulate their floors and tanks?

[Steve L.]

My Pelonis and my two 100 watt heated floor mats keeps me in stocking feet in really cold weather and take up virtually no space.

When I looked at this in the past, it was with an eye towards low 12v usage for rustic camping i.e. without shore power. Otherwise I wouldn't have had an urge to go that way.

I had thought to put the car heater core behind the current furnace grate removing the furnace carefully for inclusion if I ever sold the trailer.

A muffin fan or two for air movement is easy enough, but a low current water pump to circulate water is harder to find. Counting on convection to move the water didn’t seem efficient. But still, banging the radiator for heat might prove nostalgic.

I don’t drink the water that comes out of the water heater but still, water that’s been through a heater core seemed, in the end, an unattractive idea. Lead free solder not withstanding. I mean, all my water comes out of pipes so I don't know what my hang up is, but even so. In a bigger trailer, a second dedicated heater in a closed loop seemed more advisable.

And in the end, the need to rustic camp in freezing weather went away somewhere. Go figure. I rustic camp because I rarely plan far ahead enough to make reservations and regular campgrounds fill up quickly. Any winter camping, even with shore power, is pretty isolated camping so the need to rustic camp just isn’t there.

And so, the only attraction would be any gee-whiz factor or inherent advantage. In the end, I didn’t see enough of either so I moved on. Interesting discussion though.

[Lee Washburn]

Here is the link for the hot water heater. http://www.ducktec.com./itm00211.htm I did call a local supplier yesterday, & he said this model ran on 220, not 110 as stated in the ad on the net. This heater should be a 110 unit for campground power, & it should be confirmed before buying.

Rob, do you have any links for low power fans, & pumps?

hay how about a wood stove some copper pipe a water tank on the roof. alonge with some wood storage in a box on the back. another 900lbs wont hurt any thing WILL it or may be we should just do what i did in mexico cabo in 1960 we were sleeping in tha back of DOC'S truck with one of the kids blankets i got so cold i went to the air plane started the engine turned on the cabin heat and sleep like a baby. at day brake we flew south to zwat it was warmer on the main land & fishing was much better. surfing on that trip was no to good so fishing was our thing. O what we wont go through to go fishing.
LEE

[Rob S.]

Sorry I have been MIA between snow, vacation and computer nonsense. I want to clear up one thing for all out there who depend on AC power for their rigs. We all camp with our rigs in different ways and places. All too often suggestions are to just plug in for appliances, heating, cooling, fans and lights, etc. Since I spend about 95% of my time untethered my goal is to find 12v batt/solar, LP or alternative solutions that do not depend on the power company.

One of the biggest concerns for a radiant floor type heating system would be the slow response time. In houses radiant floor systems maintain a comfortable level but are slow to respond to sudden needs to increase or decrease the temp. I also thing that by the time you insulated the entire floor under to minimize heat loss you could come up with alternatives for less work and money.

Back when this topic started I did a bit of research came up with a few things. Sharing the concern for possible lead based solders, I found on ebay a couple of different times relatively in expensive stainless steel exchangers with muffin fans already attached. Pictured below is a double but my first search I also found singles of the same type. This one is listed as a "buy it now" for $32 US. If one were still concerned about water quality I would suggest that you build one out of standard copper fin and tube radiator from Home depot or Lowes. In fact if you were to encase several back and fourth loops in a box that was open on the top and bottom you would likely not need the fans and have created a convection type heater. The trade offs are small sixe you need the fan, larger area you don't.

For a pump, I was thinking along the lines of a generic automotive solid-state fuel pump. Facet has one that draws about an 1 amp 37 gal and hour at 4-5 psi. Found this on ebay for about $40 New. Not sure how safe it is for potable water yet but I am checking on that. Basically we need to find a 12v very low amp draw pump that will handle the heat of the water and be safe.

The last bit I wonder about is run out of water...run out of heat. You would always have to make sure you had enough water in the system. Also has anyone run their water heater in the winter time? You always see the bypass kits for cold weather.

Well that's my two cents worth.

Rob

[Roger H]

Water heaters work just fine in cold weather. The bypass kits are for winterizing so you don't have to fill your water heater with anti-freeze. Of course you'll need to winterize your water floor heating system when you're not using it!

Roger

[Darwin Maring]

Up North they sell a perculator heater (Tank Heater) that attaches to the car water system. It boils water and makes a poping noise as the water is moved from the heater to the system.

You might want to look in www.jcw.com for a block heater. Item # ZX540036R

http://www.jcwhitney.com/autoparts/Product...t=engine+heater