Reply
 
Thread Tools Display Modes
 
Old 12-10-2010, 07:37 PM   #1
zim
Mini-Skoolie
 
zim's Avatar
 
Join Date: Jun 2010
Location: Dover, FL
Posts: 59
Year: 82
Coachwork: Thomas
Chassis: TransitLiner
Engine: Cummins 5.9l
Rated Cap: 72
Radiant Floor Heating Reference

A buddy of mine sent me a very nicely done .pdf with clear diagrams and discussion about the various types of plumbed radiant floor heating systems. I thought about posting it here, but since it's covered by copyright, I'll post the link to page where it resides. Visit http://www.radiantcompany.com/details/ and download their installation manual. Other links on the left of the page contain a wealth of info.

I'm not affiliated with them in any way, just wanted to share something I found useful.
__________________
Project Blog @ TechnoVardo.com
zim is offline   Reply With Quote
Old 12-14-2010, 01:29 PM   #2
Bus Crazy
 
Stuff's Avatar
 
Join Date: Apr 2010
Location: Estevan, Saskatchewan, Canada
Posts: 1,485
Year: 1990
Coachwork: Goshen
Chassis: Ford
Engine: 7.3
Rated Cap: 25
Send a message via AIM to Stuff Send a message via MSN to Stuff
Re: Radiant Floor Heating Reference

that would be awesome in a bus or an rv but would require skirting and no boondocking to have it work!
__________________
1990 E-350 Goshen Coach - 7.3L Diesel ---> http://www.skoolie.net/forum/viewtopic.php?f=36&t=5756

My Youtube channel - https://www.youtube.com/user/thestuffz
Stuff is offline   Reply With Quote
Old 12-14-2010, 05:36 PM   #3
Bus Crazy
 
somewhereinusa's Avatar
 
Join Date: Nov 2010
Location: Andrews,Indiana
Posts: 1,636
Year: 1991
Coachwork: Bluebird
Chassis: AARE
Engine: 3116 Cat 250hp
Rated Cap: Her, me and Molly
Re: Radiant Floor Heating Reference

Thanks that will be helpful, I'm in the planning stages and want to use radiant heat.
somewhereinusa is offline   Reply With Quote
Old 12-15-2010, 10:44 AM   #4
zim
Mini-Skoolie
 
zim's Avatar
 
Join Date: Jun 2010
Location: Dover, FL
Posts: 59
Year: 82
Coachwork: Thomas
Chassis: TransitLiner
Engine: Cummins 5.9l
Rated Cap: 72
Re: Radiant Floor Heating Reference

Quote:
Originally Posted by Stuff
that would be awesome in a bus or an rv but would require skirting and no boondocking to have it work!
I live in the south and really don't plan on moving around all that much... certainly no boondocking. I don't think skirting would be an absolute requirement as heat rises, though I'm considering it anyway for cosmetic purposes. Also, I will put the tubes in on top of the foam board I'm already laying down. I had also planned on painting a silver stripe on the floor beneath the heated area to help reflect heat upwards.

Attached Images
File Type: png floor2.png (559.9 KB, 719 views)
__________________
Project Blog @ TechnoVardo.com
zim is offline   Reply With Quote
Old 12-16-2010, 09:10 AM   #5
zim
Mini-Skoolie
 
zim's Avatar
 
Join Date: Jun 2010
Location: Dover, FL
Posts: 59
Year: 82
Coachwork: Thomas
Chassis: TransitLiner
Engine: Cummins 5.9l
Rated Cap: 72
Re: Radiant Floor Heating Reference

Quote:
Originally Posted by Smitty
zim- Won't all the water just squirt out the ends of the pipes?
That's my self washing floor system... patent pending

Quote:
Originally Posted by Smitty
What effect will the plywood constantly rubbing on the sides of the PEX (from road vibration) have over time? What's your plan for freeze protection?
PEX, aka Cross-linked Polyethylene, is some pretty tough stuff. As tubing, it has a life expectancy of about 50 years and the plastic itself is used in artificial joints as a wear-resistant material. I plan to route 3/4" channels into the plywood after it is screwed down, which the tubing should fit into quite snugly. I know the plywood is only 3/4" deep, but screwing it thoroughly to the 1x4's should hold everything down quite nicely after the channels are cut. Also, the entire run will be one continuous piece. 4 runs of 30' and all the turns to hook up to the water heater should easily come off a 200' roll (about $80) in one piece.

As for freezing, I've been using PEX in the current bus for about 3 years now and I've not had any flow problems. Of course, we only get a half a dozen hard freezes over a winter, but it still drops below freezing for a week or so when it does. When asking tradesmen for some advice, I was told that the stuff could handle a freeze without bursting because of it's elasticity, though the joints might be a problem. On this bus, I'm not worried about freezing because hot water will be flowing through the loop when it's cold out. I will also have the connections to the loop outside the bus, just in case one decides to spring a leak.

Some folks use a closed loop system with anti-freeze, but I want to keep it simple.
__________________
Project Blog @ TechnoVardo.com
zim is offline   Reply With Quote
Old 12-16-2010, 02:59 PM   #6
zim
Mini-Skoolie
 
zim's Avatar
 
Join Date: Jun 2010
Location: Dover, FL
Posts: 59
Year: 82
Coachwork: Thomas
Chassis: TransitLiner
Engine: Cummins 5.9l
Rated Cap: 72
Re: Radiant Floor Heating Reference

Quote:
Originally Posted by Smitty
I have an artificial knee, and it's no better than the one they sawed-out. You mentioned 4-30' runs, does that mean you're zoning 4-different areas?
One zone, ~120' of tubing run up and back and up and back.


Quote:
Originally Posted by Smitty
I understand about the ability to resist bursting when frozen, but what happens when if it freezes, and leaves you with no heat (because water flow has been blocked)? Once the thermostat is satisfied, flow will stop, and the opportunity to freeze prevents itself, especially with hot water.
I guess that's a possibility, but the design of the open loop systems keeps everything flowing with no stagnant water in the tubes. Just leaving the thermostat at 40 degrees year round should kick on the idle heat before the system can freeze. I could see a temp sensor on the loop that kicks in a circulating pump if it becomes a problem, but I'm optimistically confident that won't be an issue in Tampa.

Quote:
Originally Posted by Smitty
I think I'd fill the system with glycol, just to be on the safe side. Won't you're system be a closed loop? What are you using as a boiler (heat source)?
I'm going with the open loop system as described in the link in the original post. They describe a system that uses a tankless heater and from what I've read, it's a lot more energy efficient than a closed loop system due to losses at the heat exchanger (if using one boiler for house water and heat) or running two heaters (one for each). I plan on using an electric tankless heater with a good bit of overhead capacity, 220v and probably about 2.5GPM. I have a low flow shower head, and even with the radiant floor loop, it shouldn't have to work too hard nor draw it's full rated current. I still have an brand new 6 gal 110v tanked heater that can be used for a closed system if I'm not happy with the results. I'd just need to close up the loop on the tankless side and connect it to the tanked heater. It can fit nicely suspended beneath the bus and I could switch to anti-freeze in that if I find myself living in a higher latitude.

Quote:
Originally Posted by Smitty
To satisfy my own curiosity, what led you to decide on this type heating system? I mean I've said before I couldn't justify it (floor radiant) in a bus (for such a small, and mobile floor space), so I'm just curios about the advantages you saw over other various ways to heat your bus.
That's a fair question. Living in Tampa, my heating needs are minimal compared to a lot of other full timers and I got tired of storing space heaters in the warm months, having them crap out when I needed them, or constantly blowing breakers, etc. A wood stove would be really nice, but it would just take up space the other 10 months of the year and I'm not fond of cutting wood or hauling it around in my little car. I don't want to deal with propane or LPG because I'm always a tiny bit paranoid about leaks and fire, and again, there's the transportation of fuel involved. I know myself well enough to know that I'm lazy and forgetful and I might go several days without heat before I remember to stop and buy gas. Finally, I don't like the efficiency numbers and prices on roof units that provide heat as well. I also want one system to heat the whole bus without having to run duct work.

For my situation, it just seemed like a cheap and easy way to go (see the comment about about laziness). The cost is about $200 added to the existing plumbing system and I like the fact that it's invisible and unobtrusive. In short, it looked like something fun to tinker with. It might turn out to be folly, but at least I'll know, eh?
Attached Images
File Type: png heating loop.png (7.1 KB, 697 views)
__________________
Project Blog @ TechnoVardo.com
zim is offline   Reply With Quote
Old 12-16-2010, 03:13 PM   #7
Bus Geek
 
lornaschinske's Avatar
 
Join Date: Jun 2004
Location: Roswell, NM
Posts: 3,587
Year: 1986
Coachwork: BlueBird
Chassis: 40 ft All American FE
Engine: 8.2LTA Fuel Pincher DD V8
Rated Cap: 89
Re: Radiant Floor Heating Reference

We had considered this type of floor for the Eagle combined with toekick heat exchangers. I do not think we will be doing a liquid heat one for the skoolie, but I may install an electric floor since I like to be barefoot year round (if God had meant for me to wear shoes, I would have been born with them on!). My original plan was to use PEX, of course, filled with an Eco Friendly antifreeze. They make a super light mortar mix (we've used it when installing floors in custom built showers). Last time we bought some was at a tile store down in Albany GA. I don't remember the name of it but it came in some very lightweight bags. That was what I had planned on using with a plastic mesh embedded in the mortar mix. THINGS CHANGE! Since we spend most of our time in campgrounds hooked up to facilities, I would like to include the electric radiant heat mats. I would have to talk David into it (David is a "shoe" person... what do you expect from a Yankee?). But first, I will go thru a winter with just the insulated floors first.

Electric floor heat
http://quietwalk.com/quietwarmth/index.html from Lowes
http://www.suntouch.com/ from Home Depot
__________________
This post is my opinion. It is not intended to influence anyone's judgment nor do I advocate anyone do what I propose.
Fulltime since 2006
The goal of life is living in agreement with nature. Zeno (335BC-264BC)
http://lorndavi.wordpress.com/blog/
http://i570.photobucket.com/albums/s...ps0340a6ff.jpg
lornaschinske is offline   Reply With Quote
Old 12-16-2010, 04:27 PM   #8
zim
Mini-Skoolie
 
zim's Avatar
 
Join Date: Jun 2010
Location: Dover, FL
Posts: 59
Year: 82
Coachwork: Thomas
Chassis: TransitLiner
Engine: Cummins 5.9l
Rated Cap: 72
Re: Radiant Floor Heating Reference

Quote:
Originally Posted by lornaschinske
I do not think we will be doing a liquid heat one for the skoolie, but I may install an electric floor since I like to be barefoot year round.
That was another reason for wanting the heat on the floor. My daughter and I both despise shoes and she complains about the cold floor more than anything. I considered electric, but by the numbers I had available, PEX was about a third the cost. The QuietWarmth stuff is cheaper than what I was looking at, so it's definitely worth doing up the numbers again. The electric has the appeal of being able to section the bus off in thirds with three of those 1.5 x 10 strips. I'd be curious as to how well they heat the space, though... at 1.1 amps, they only draw ~130 watts each. Even the 3 x 10 strips are under 300 watts and put the price back up to almost $800 to do the whole length of the bus. Of course, I don't know how well the water is going to work, either
__________________
Project Blog @ TechnoVardo.com
zim is offline   Reply With Quote
Old 12-17-2010, 05:38 PM   #9
zim
Mini-Skoolie
 
zim's Avatar
 
Join Date: Jun 2010
Location: Dover, FL
Posts: 59
Year: 82
Coachwork: Thomas
Chassis: TransitLiner
Engine: Cummins 5.9l
Rated Cap: 72
Re: Radiant Floor Heating Reference

Quote:
Originally Posted by Smitty
I looked at the link, but not interested enough to download it (my aircard/data restrictions), but generally a "closed loop" system recirculates the same water, an "open loop" (like say ground water heat pump) takes water from one source, and discharges it into another (like 2 wells for instance). Explain the difference (cliff-notes) between the 2 in your application please. Are you pulling from one water tank, and dumping into another? What could be the possible advantage to this (if that's the case)?
For someone not interested enough to read the material, you sure have a lot of questions! It's explained in the download, but I'll regurgitate my understanding of the tech. A closed loop is, as you say, completely isolated from the house water, either using it's own heater or a heat exchanger from the main hot water heater. An 'open loop' (kind of an oxymoron if you ask me) runs all the house hot water through the floor. It is, in essence, like adding a couple of hundred feet of tubing between the faucet and the heater. Then, near that faucet is a one way valve that lets the floor output feed back into the heater input when house hot water is not being used. I believe this is the 'open' part of 'open loop'. The one way valve and pump keeps things going in the right direction when a water faucet is opened.

Quote:
Originally Posted by Smitty
How did you determine the amount of piping needed (length of the loop)? I mean how many btu did you determine it required, at what design temp to heat the interior of your bus, and how many btu/foot does your system provide with the input (btu) of the boiler you plan to use?
I've been working on 45 BTU/ft2, a number I got talking to an engineer at the company mentioned in the link. Spacing is determined by the bend radius of the tubing (Eight times the diameter) and length is determined by the area and spacing. I did shoot a little low with 120' and I'll need to increase the heated area with another 60' of tubing, but that should get me up to around 5000 BTU, which is what my existing heater puts out. As a side note, I looked at the stuffs Lorna posted and called up one of the companies to talk to an engineer. He said their electric technology was about 10~15 BTU/ft2 and that he doubted very seriously that their product would suffice as a single heat source.

Quote:
Originally Posted by Smitty
On the freezing thing....if it's below freezing, and you're set at 40* on your t-stat, what's to prevent freeze-up between cycles? Especially if you'd go out of state to a colder area? Same with selling a bus with a system like this (not that you ever plan to sell, or visit where below freezing temps are common....but plans change....lol, look where I'm at ) A temp sensor would only sense the temp of a specific point in the system loop, what if it freezes elsewhere, like a cold spot that's just right for the wind or temps to catch? What happens if your boiler just fails? You can toss some space heaters in the bus, but what is the time-limit of repairing the boiler, or draining the system completely before it freezes?
Leaving a faucet drip will allow no standing water in the system, which is what I do now if there's a deep freeze coming. Otherwise, I could leave the circulating pump running and just control temp at the heat source. From what I remembered from houses I've lived in with hydronic heating is, the cycle is pretty short. As for all the rest, I could die tomorrow, too, and wouldn't that be a big change of plans? I find it easier to adapt than predict.

Quote:
Originally Posted by Smitty
Always found it odd that homeowners were "afraid" of gas (natural or LP), but not of electricity, something I used to run into a lot. Wiring can short just as easily as pipe fittings can leak. What will you cook with? Do you have a gen with the capacity to power your heating system, and if so, won't you be required to buy/transport fuel for it as well (like you say you'll avoid by not using LP)?
I'd say 'uncomfortable' more than 'afraid' in my case. I've been a continuously licensed ham (W1BMW) since 1976, worked as a bench tech and tower jockey, spent a few years installing CCTV, fire suppression & control systems in jails and prisons, as well as spent two years traveling with the SeaWorld blimp as her in-flight electrician (I maintained the advertising display). I'm not saying I know all there is to know about electricity, but I've spent most of my life getting comfortable with it. I have only installed one gas appliance, so while I THINK I could handle a good gas setup, I KNOW the quality of my electrical work.

I cook with a countertop convection oven, a dual element cooktop, a rice maker, and a microwave, all electric. I eat a lot of steamed veggies and will occasionally toss something on the grill outside (which is gas, and often empty). I've never gone hungry from not having a generator or an LP stove. If I ever do put a generator in, I'll find a small marine diesel unit and pull fuel from the bus tank. They show up on craigslist around here pretty regularly for under $500. If it runs one air-conditioner, the fridge and my computer system when a hurricane takes out shore power, I'd be OK with that.

Quote:
Originally Posted by Smitty
What will you use for a pump for the heating system? I don't see how you could install this system for $200, since the boiler (tankless) would eat a large portion of that, and the pump the largest portion of the remainder, then add the piping, fittings, and valves to isolate/service/etc.
We have miscommunicated. What I wrote was, it was only $200 ADDED to the hot water system I'm already putting in. Yes, I'm already spending more than that on the tankless heater and such, but those items are already in the plumbing budget. I'm saying this is how much more I'll have to spend to add hydronic heat. The tubing is $80 for a 200' roll and I'll be using the existing 12v circulating pump left over when I pulled out the built-in heating. I calculated about another $80 on fittings and check and drain valves. Figure in $40 for the stuff I didn't plan on, and I come up with $200 over what I'd be spending if I didn't put in the floor loop.

Quote:
Originally Posted by Smitty
Wouldn't a 6 gallon 110v water heater have a 1500w element in it? And you expect that to keep-up with 120' of piping (for anything more than just a couple degrees design temp) in anything close to freezing temps? Where are you getting these load calculations from? I'd be curious to see them. What is the temp rise rating (water in/water out) of your boiler (tankless) at 2.5GPH? Many I've seen would be less than 50*.
I plan on tankless. I mentioned the 6 gal tanked heater as something else to try. But, assuming the water comes out of the ground at a chilly 40 degrees, the first time it goes through the loop, the system might only bring it up a few degrees, sure. But as it continues to circulate, it will go up another few degrees... and so on. Over time, the only thing the heater will be doing is putting back in the heat lost through radiation or heat lost when people pull hot water from the faucet. Think of the flooring loop as a small storage system with the volume of whatever the tubing holds.

Quote:
Originally Posted by Smitty
I have the initial impression your design doesn't have the capacity (from say a 30* design temp, to 70* living space temp) to heat your bus, so all the questions I'm asking (again) are simply to satisfy my own curiosity.
Not quickly, of course not. But the looping handles that over time. It might take an hour or two to warm up, but with the insulated and (relatively) airtight space, I'm reasonably confident it will be OK for my needs. I think I detect a bit skepticism and am willing to admit you might be completely right. If I've under-designed, I can increase the heat source, selling off the old unit and buying another. I can try the tanked heater with antifreeze and experiment with a closed loop system. Or, if it's a total bust, I've spent $200 to gain actual data on radiant floor systems that I will document and share, potentially saving others from the same poor decision. I love you guys and I'm willing to take one for the team! You can even say 'I told ya so'!

Quote:
Originally Posted by Smitty
ETA: Hydronic systems are easily zoned, like you mentioned was a plus of the electric. It just requires zone valves and relays, as well as the additional thermostats.
Smitty
I am aware of that, as I had a 3 zone baseboard heating system in NJ. I added a 4th zone for the basement office. I can handle the plumbing, but I what can I say? I am a loyal friend of the electron. Besides, after finding out the electric only puts out 15BTU/ft2, it's moot.
__________________
Project Blog @ TechnoVardo.com
zim is offline   Reply With Quote
Old 12-18-2010, 02:31 PM   #10
Bus Geek
 
lornaschinske's Avatar
 
Join Date: Jun 2004
Location: Roswell, NM
Posts: 3,587
Year: 1986
Coachwork: BlueBird
Chassis: 40 ft All American FE
Engine: 8.2LTA Fuel Pincher DD V8
Rated Cap: 89
Re: Radiant Floor Heating Reference

Smitty, he is essentially building the same system that Aquahot installs in Class A's (but no radiant floor).

ZIM, down load the Aquahot manuals to get more info on the plumbing part of the setup. I had them send me info years ago (11/2001) and they sent me everything... which is bad to send to a DIYer (I understand that they don't do that anymore... gee, I wonder why???). They sent me all the parts lists, installation manuals, owners manuals, operation manuals and prices. I priced out everything and discovered that I could build a system identical to an Aquahot (the one that uses the Webasto DBW2010 Coolant Heater) for 65% LESS than what they would charge me. and that was all new parts... no scratch and dents, etc. At the time I was posting on the Busnuts forums... so I posted about what they sent me and the prices I came up with. It was several months after my posting that the info they sent out changed.
__________________
This post is my opinion. It is not intended to influence anyone's judgment nor do I advocate anyone do what I propose.
Fulltime since 2006
The goal of life is living in agreement with nature. Zeno (335BC-264BC)
http://lorndavi.wordpress.com/blog/
http://i570.photobucket.com/albums/s...ps0340a6ff.jpg
lornaschinske is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Hydronic Radiant Heating in a Bus nat_ster Heating, Cooling and Appliances 47 05-26-2016 11:37 AM
Radiant Floor Heating......feedback requested Shawn C Heating, Cooling and Appliances 14 12-30-2012 11:18 AM
Propane Heating - Radiant vs Blue Flame Stuff Heating, Cooling and Appliances 12 11-08-2012 05:19 PM
luxury in-floor heating TygerCub Conversion General Discussions 2 07-31-2009 10:07 PM
Radiant Floor Heating oldog12 Conversion General Discussions 8 08-24-2006 02:05 PM

» Virginia Campgrounds

Reviews provided by

Powered by vBadvanced CMPS v3.2.3

All times are GMT -5. The time now is 02:49 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2017, vBulletin Solutions, Inc.