radiant heating

jerri · 02-10-2005, 11:26 AM

I am installing radiant heating in my stream all is going well except the price.
I hear that airstream will be doing this in the future does anyone know.

Over59 · 02-10-2005, 03:58 PM

Do tell us more details.

malconium · 02-10-2005, 07:55 PM

Jerri,

I will also be installing radiant heating in my 1973 when I get to that point. What approach are you thinking of taking? I would love to compare notes with someone else who doesn't think that I am nuts for going this route.

I am intending to use reflective foil on top of the sub-floor and add 1x2 strips length wise at 6" O.C. I will add aluminum fins on top of that with 1/2 plastic tubing snapped into place. Check out the following thread for some more information and especially my post #10 where I have included a diagram of what I am doing:

http://www.airforums.com/forum...ad.php?t=15229

There are of course a lot more details to the whole thing that I would be happy to discuss if you would like.

By the way - welcome to the forums. There is a lot of information available here on most any AS topic. Radiant heating is not covered in nearly as much detail as many other topics though. Where are you located? Tell us some more about your AS and what you have in mind.

Malcolm

pamelake · 02-21-2005, 01:57 AM

Jerri and Malcolm...please keep us posted on you progress. I am very interested in doing this in my '74 Tradewind. What kind/brand of radiant did you choose? Pam

rseagle · 02-21-2005, 04:08 AM

I for one, being a "Boondocker" would like to see Airstream introduce a safe, efficient radiant heater similar to the Panel Ray Heater of the '50s. It vents the CO gases to the atmoshere and exchanges the heat to the interior of the trailer. See attached:

http://www.vintageairstream.com/arch...6BubbleOH.html

I know modern versions are used to heat garages, barns, etc.

The furnace fan in our trailer just eats up too much valuable battery power to consistantly use during cold weather outings, without recharging with a generator every day.

I also have a catalytic heater, but I wouldn't feel safe using it while sleeping.

What type of radiant heater are you retrofitting with?

Xray · 02-21-2005, 05:42 AM

I wholeheartedly agree with Bob and he makes a good point but forgets one that is important to us - noise. Those darn modern furnaces are noisy.

Do you all think the radiant systems being contemplated here will use less battery than the furnaces in use now? From my own experience in houses I've owned with radiant hot water systems, they aren't really more energy efficient than, say, forced air though I prefer them for all the other reasons. I notice a pretty big spike in electric costs during the winter months when the radiant systems are chugging along and the circulation system is under constant load.

I'd like to know what other options there are too. I read all the warnings on the catalytic heaters and get scared off.

Ideas?

rseagle · 02-21-2005, 07:19 AM

I wonder if an infra-red tube heater such as the one attached could be fitted into an Airstream.

http://www.reverberray.com/products/ls.html

mandolindave · 02-21-2005, 07:50 AM

I read somewhere about a guy who made a heater out of a water heater,
a car radiator, and a fantastic fan. He said it was much more efficient than a furnace.

Leipper · 02-21-2005, 11:34 AM

that 'guy' might be
http://www.solarhaven.org/HPArticle.htm

This is a hydronic system with a forced air mechanism. Passive systems, such as it appears some folks are suggesting in this thread, would be a bit more work and might be a problem in reduced headroom - an inch or two lower ceiling (raised floor) could make a significant difference for a tall person in an RV. The passive systems will stil need a water pump or two and will use battery.

The other problem to consider is winterizing and, perhaps, the isolation between the heating fluid and the main water supply.

A typical RV water heater is about 15k BTU/hr. This would probably need a fairly high duty cycle in sub freezing weather and might not be enough for outside temperatures below 20F.

malconium · 02-21-2005, 12:26 PM

My hope is that an electric pump that is sufficient to move water around through the tubing will not be any more energy hungery than a fan that blows around the hot air. I have not yet decided on a pump and would like to find one that is as quiet as possible. I also intend to mount the pump somewhere away from the bedroom. The most logical location for my AS is under the kitchen sink. Does anyone have some suggestions on quiet 12 volt pumps?

The approach that I am planning to take will cost me only 3/4" of extra ceiling height. Take a look at the diagram I pointed to a little earlier in this post.

As far as the efficiency of radiant heating systems in the floors I think it is a generally accepted fact that they are more efficient. This is especially true for poorly insulated spaces since more of the heat is transferred directly to the people by radiant energy rather than by warm air. I can try to dig up some of the facts if anyone is interested in the proofs. I suppose that it would also be possible to run a tube through the holding tanks to help keep them from freezing up.

Radiant heating systems in concrete slabs are routinely used in many parts of the world to keep sidewalks, driveways, parking lots and even some parts of roads such as near intersections de-iced. I think this makes it pretty plain that a system can be designed to put out as much heat as a person needs for a given situation.

For winterizing it should not be any more dificult to drain the water out (pump it out?) than for the rest of the water system. It might also not be a bad idea to leave the heat on a low setting to keep things from freezing up. In my case winterizing is not such a big issue since it does not get below freezing nearly as much as some parts of the country.

A radiant system can be designed so that the heating water is not seperate from the other water system. Take a look at the information at the following site for some information about the approach:

http://www.radiantcompany.com/

Click on "System Types" at the upper left and then on "The Open System" on the next page. The key is to allow fresh water from the external connection to regularly pass through the radiant heating tubes so that nothing has a chance to get stagnant.

By the way I have done some research on radiant systems and have concluded that a single loop of tubing would be sufficient for my 31' AS. My total floor area is somewhere in the range of 200 square feet.

I am sorry that I am not a little closer to starting the radiant heating installation than I am. Right now I am concentrating on getting insulation in my walls and putting the inner skins back on. I now have the inner skins and end caps back in place at both ends of the AS. I can start putting the insulation in between now. I will be happy to give more details as they unfold but some of the information will simply have to wait until I actually get started with the process.

Malcolm

rseagle · 02-21-2005, 02:31 PM

I mentioned the Panel Ray Heater earlier. It was used in the Airstreams in the 'Fifties.

I'm curious how that heater works? What type of BTU ratings did they have.
Can any of the Vintage Airstreamers help with this?

I could be wrong, but I don't think they used electricity (AC). I believe that DC systems weren't introduced until the Sixties.

A true electric-less, vented to the atmosphere, quiet, efficient radiant heater would be very desirable for "Boondocking". I'm surprised nothing is currently available in RVs these days. Is anyone aware of anything?

sfixx · 02-21-2005, 04:04 PM

Quote:

Originally Posted by rseagle

A true electric-less, vented to the atmosphere, quiet, efficient radiant heater would be very desirable for "Boondocking".... Is anyone aware of anything?

I was reading more about the Olympian heaters. Theoretically they meet all your requirements because they don't require "venting to the atmosphere" because they do not make CO. They do require a vent open to provide make-up air to replace the oxygen used during combustion. I would love to hear from someone with Olympian heater experience.

Thanks,

Steve

mandolindave · 02-21-2005, 04:44 PM

Excuse my half witted post...But I did remember the "guy" saying
that he only needed a low volume water pump for his heating system.
A higher efficientcy fan and the low volume pump used a lot less
electricity than the furnace blower did.
The problem I see with a hot water heating system is the water.
I don't want water in my trailer in the winter. But a heater is fun
to have in the winter. Couldn't you just fill the system with antifreeze?

rseagle · 02-21-2005, 05:56 PM

Right! CO is the result of incomplete combustion. Supply air is needed to provide complete combustion and CO2. So, while the catalytic heaters like the Olympian, SportCat, Mr. Heater Buddy, etc. don't theoretically need venting for CO2 (even thought that will kill you too), ashyxiation due to lack of oxygen is why we need to open windows with these type of heaters. It's a double edge sword.

I also found out that the Panel Ray heaters need interior supply air to combust, even though the CO2 is vented thru the roof vent. See attached text info and photo examples:

http://www.vintageairstream.com/forsale_wanted.html

If a newer design concept used outside supply air, say, from under the trailer to a vertical Panel Ray style heater with a roof vent, then the need to open a window would be unnecessary. The combusted gases would always be isolated in the stack from the interior of the trailer, yet the radiant heat exchange through a series of fins would transfer the heat into the trailer. No electricity either. It would be nive to have a pzio-electric igniter though.