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After years of research, preparation and several design changes we are getting ready to build that ‘dream’ (sure) home.
Building a raised ranch (approx. 1450 sq.ft) with an unfinished basement. For heating seriously considering in-floor radiant in the basement with baseboard radiant on the main level. Gas is not currently available with no committment as to when it will be. Likely will use an oil-fired boiler and integrate domestic hot water. Really want to stay away from ducted forced air systems from an allergen/contaminant standpoint as well as trying to maintain a ‘finished’ ceiling look in the basement by using 2×6 T&G decking on the main level in place of plywood.
Anyone can share their experience going through this decision process? What worked? What didn’t? Is baseboard heating really effective? Heat pumps?
…yada yada yada… can you tell I am swimming in a sea of confusion?
Replies
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I have radiant heat throughout my 2 story home plus finished basement and have absolutely no regrets after 8 yrs. It's great. Rather than elaborating on all it's virtues, I'd like to emphasize how good it is in a basement floor. Lately I've read many posts here about the pitfalls of finished basement spaces and how they always end up being damp, musty and unhealthy. My basement is one of the most comfortable places in the house because of the warm and cozy slab underfoot.
*Somewhere (in this forum, I think) somebody mentioned that radiant floor heat is not a good idea for on or below grade applications. It seems it may encourage termites to thrive...
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I don't know, but could imagine termites liking warm soils under a radiant slab basement. But I'm in Kasilof, Alaska. Termites, if there were any in the state, would have to travel trough frozen ground to get to that warm soil. But there aren't any termites for the same reason we have no fleas and no ticks. Unfortunately, the mosquitos do survive the winter somehow. It's -26F out right now and I'm barefoot and comfy in the radiant-floored basement. The air temperatures are uniform from floor to ceiling and nothing mildews.
Swalwell: One of the many things I like about radiant floor heating is that a low temperature fluid is used. Because your "boiler" or water heater operates at a lower temperature, it is more efficient. The scary thing is what if a pipe breaks within the slab. It can be found by ear or stethoscope and fixed after jack hammering a hole in the slab. I like the approach of putting in two parallel loops and having the option of cutting one off if there is a problem. Also, don't scrimp on steel, sub-base compaction, or proper concrete placment (not too wet, vibrate it, keep it moist as it cures for a week). -David
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I live in lower NY State and have never heard of termites at that depth under a basement floor. Mine is 8 feet below grade, even if I had a walk out basement on one side the footers would still have to be 42 " below grade. If there is no buried debris, that's a long way to travel. Enough of that. I' m renovating my own home now and can't put enough of radiant heat in. It's in the entry, kitchen, mudroom. bathrooms and the sunroom. You don't state where you are located, so I can't tell what kind of heating load you have. Like Dave mentioned, the lower the water temperature saves fuel, however unless you use a non-condensing boiler the savings won't be as great. Design and planning is the most important issue. Poor design of loop lengths and patterns can cripple the system. I used european style panel radiators for the rest of my house with individual non-electric thermostatic valves. You can adjust each room regardless of the main thermostat. The whole system runs on an outdoor reset control. You can e-mail me for the particulars.
P.S.Your baseboard sections of the house will pale in comparison to the radiant.
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I have an on-going interest in hydronic
floor-heating, in the short term for a small shop
and/or studio, later for a retirement home. I've
gotten prices on most components, and the thing
that strikes me is the really high cost of
manifolds. What gives? Seems like you could make
'em up using copper pipe and T's, or am I missing
something?
One design I've seen calls for incoming cold water
to circulate through the floor loops on its way to
heater, so that water in the loops doesn't
stagnate during the summer. At first it seems
somewhat counter-intuitive, and that you could
accomplish the same thing with valves....then I
remember that I always forget what a bad memory I
have. Also, new water has to be heated
sometime/someway, anyway.
I'm wondering, also, about the cast iron vs.
bronze pump debate. Is there some reason to pay
extra for bronze if you don't have any steel in
your system? And what's the expansion tank for?
*Jim: You can definitely site-build manifolds. Prefabricated ones may be stronger than sweated joints and allow you to save a little time in securing all those pipes to the wall. Or not. They also save a little time in assembly, but I agree, they seem spendy.That flow of cold water would give you a little free heat (maybe a 25% savings if boosted from 50F to 70F) and a very little free air conditioning.Bronze versus cast iron: go with bronze if you've got copper piping. You could use dielectric unions to isolate the copper piping from a cast iron pump, but that's 2 unions per pump plus installation time.The expansion tank is to accomodate the thermal expansion and contraction of water as the system cycles. Vitally important in a closed system which can get to really high pressures with small temperature changes. Note that with most pressure regulators you create a closed system. The system fills itself with water when needed but the water can't go backwards through the pressure regulator. Hopeful the P+T valve would blow before a pipe or pump splits. -David
*Jim,I have installed a radiant system and like it.I build my manifolds as you state. As for using all non-iron components its to do with oxygen infusing into non-metal tubing such as pex etc. I used Lars-teledyne unit and no-iron so as to not have the oxygen cause major problems. I don't use all the fancy controls that all want to sell and haven't observed any difference except saving as much as $1000. Only details that were finicky were threaded joints and plastic to metal joints leaking. Asked every plumber I knew for answers before finally getting the science of expansion, vibration dissimlar materials and solutions basically understood enough to control these beasty little seaps.In your post.... I don't understand how the water flush for summer thing works, say in when the system is making heat.Please email or post 800 number of company so I can haaave them send me a copy of this detail.Thanks,jack : )PS Radiant cellar slabs are the way to go if one really wants the space to be habitable. Poly should be used between soil and concrete to slow the capillary influx of moisture. I think this is the basics, the experts can tell you more.Regards' Jack : )
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Does anyone have experience installing a
single-zone radiant floor system using a standard
hot water heater? What are this issues to
consider? It seems like this would be
cost-effective for a small ho
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Osman,
Haven't done it yet but am planning a similar retrofit for my own home. Water heater will have to sized, for me probably a big unit.
Water heaters produce the right temperature water,are quick installs, reasonably priced and easy to vent, that's why I like the idea.
K,
My present home was purchased for it's location not it's heat source that's for sure...It's an electric backup heat pump/
b "forced drafty-chilly air"
system.
b Never never never
can anyone convince me these "electric utility" convince us their "energy saving" heavily subsidized over-marketed and chain-hyped propaganda you know what I'm trying to say....I think they suck, pardon my French. Heat pumps and their less than warm comfy feel are for warmer climates than I live in that only need the occasional shot of assisted heat and even then I just don't like them and neither do my customers. There so heavily marketed that you will find people that are contrary to me, that's not my problem...Oh well.
Fuel will be burned, water will circulate in my home eventually or this H*ll
b will
freeze over.
A shepherd without flock is a free man indeed,
Jack : )
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Swalwell:Some 10 years ago I installed a radiant slab in a 3300 sq.ft. log home. We absolutely loved it and plan one for our retirement home.It was very simple: one continuous loop of 3/4" "clearcore" ( should use PEX now ) and an insulated holding tank. One Grunfos pump and that was it. you can't beat the comfort of radiant heat. Period.It's great.
*I'm thinking of using a combination hot water baseboard and raidient heat in my new house. I've been looking at a boiler system made by Energy Kinetics in Lebanon, NJ. Anyone have any experience with this unit or other suggestions?
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I am in the process on designing a system with radiant floors on the first floor, baseboard on the second floor, combined with domestic water using a high efficiency / high output water heater (Polaris unit). Check out the following article for details. http://www.jlconline.com (them go into the magazine section under "browse articles", under "energy & HVAC". The article "Using water heaters for radiant floors" is an excellent article. I think this will be a cheaper and more efficient system than using a boiler.
*David & Jack,Thanks, and I just got back from a long weekend in LA. Now I know where the expression "Been to Hell and Gone" comes from.Of course using bronze to copper makes more sense! What was I thinking?! But to belabor the expansion tank question a bit....how does the radiant heat system, using a water heater vs. boiler, differ from any other "normal" hot water supply system, except for having a (much) longer run of pipes? So why would you need a pressure regulator, either? Or an anti back-flow valve?Jack, the system layout is from radiantec.com. They just have incoming cold water routed through PEX in floor, on its way back to heater. As David pointed out (I think), you might even get a bit of cooling effect during the summer.One other possibly silly question: if you're going to pour a new slab, and are putting down either total or perimeter foam, won't gophers see this as a golden opportunity for condomania? And pretty soon displace your foam? (We have a pretty big gopherproblem here in n. central CA.)
*Jim: No reason for the expansion tank, unless there's a pressure regulator (or other valve functioning as a check valve). And no reason for a pressure regulator in most situations. But in standard hot-water baseboards, those fin-tube pipes are pretty thin-walled. The system are operated at 15 or 30 psi, hence the pressure regulator. I've also worked in a few towns where night time pressures (low demand) in the lowest parts of town could exceed 100 psi and occasionally cause the P+T on the water heater to blow off. We'd warn the customers and take extra care in directing the P+T discharge, but another solution would be a pressure regulator and an expansion tank.Don't know about gophers in foam, but a family of them screwed me on a toxic waste site treatment system (in the CA central vallley). They set up housekeeping inside my PVC discharge pipe and their bodies blocked the flow badly. Of course, they drowned in the process, but it cost another $600 to find the problem and dig up their carcasses.
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I have been researching radiant floor heat and have compiled information from Radiantec, Stadler, Applied Radiant, Heatway and local HVAC contractors. My question, to anyone who has experience, what major mistakes are possible if I were to install this system myself (with spousal help, of course)? We will have a plumber install the boiler and other "hard" connections.
Also, what are your opinions on mounting the PEX under the floor or stapling the tube to the subfloor and having the gypcrete(?) poured over it? (What type of contractor does this???) We will have hardwood floors, tile, and carpet.
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Jean: Glad you survived that 2x6 posting and the resulting brew-haha.
Biggest possible mistakes (not sure if I can come with 10 like AJ always does):
Flexible floors and cracking gypcrete.
Hitting the tubing with a nail or screw.
Letting the water get too hot in the gypcrete and thermally expanding it too much.
Therefore, my recommendation, especially for DIY-ers, is to mount the PEX under the floor rather than trying to build a stiff enough floor and find a contractor to do the gypcrete floor properly.
For many other decisions, I'd split houses into two cases: Well insulated - then you can go with a low output water heater (like a standard water heater) and you don't have to worry about high efficiency too much because you won't be using much energy.
Not-so-well-insulated or a retrofit - you'll need more heat and it will pay to get a higher efficiency heater. Unfortunately, you'll also need the radiant floor to heat more per square foot (i.e. resulting in a higher floor temperature). Others have posted about wood floors expanding and contracting (due to temperature, but especially changing humidity), and at some point, the floors are uncomfortably warm (if a 50's style house is heated in winter months).
Other things to consider:
Keep your loops about the same length so flow will be balanced from one loop to another. And about the same piping/square foot (typically one linear foot/square foot) so different areas of the floor will be heated evenly.
Many of these systems are installed with one pump and multiple electric valves to control which zones are getting heat. I like multiple pumps, each wired through their own thermostats. Not much more in materials, same installation, and, if one pump fails, you still have heat. You can also use smaller pumps so that if only a one zone needs heat, only 1/40hp is used, not 1/25 hp or more. Happy heating. -David
*Jean,David's entire post is my experience also....(Wow Dave)Some additional thoughts; Carpet is an insulator...I use baseboard heat in addition or instead of radiant in these areas. Tile areas, are perfect for radiant, and as for hardwood floors....well you better know it's moisture content and the sub floors moisture content along with room size and non-heating season temperature and humidity levels that are going to be allowed. In a home that I laid hardwood flooring a recent check, the floor looked like it did the day I finished it. The homeowners prefer ac in warm weather, humidify in cold, and I believe that's why it still looks perfect.I've mentioned this before....radiant heat is not able to be adjusted minute by minute with instant changes in comfort such as forced hot air, which is what I recommend to my second home/camp customers. I do recommend all bathrooms have radiant floor heat, with the only drawback being is getting the "bathroom hog" to let in the next user.Lastly, the most comfortable home I have ever stepped foot into was heated from the full foundation's slab, up. The slab was heated by ducting warm air through it but it could just as well been warm water. There was no space from the walk out foundation level to the third floor crows nest drawing room that was too warm, too cold, drafty, etc. Very very nice but not a $50/sqft home, closer to $100/sqft if GCed.Jack : )
*Thought I'd posted this but since the conversion it isn't here so I'll try again.Back in the 50's and early 60's radiant heating was all the rage with many systems put in. Then after some time, about 10 - 15 years they started having leaks, blockages, etc. The repair methods were to find the leak, jack hammer out the floor, repair then reconstruct the floor and finishing. All in all an expensive process. So most of them were abandoned in place in favor of baseboard radiators.With this background: What is different now that would make the new radiant systems better? Or, is this vulnerability to high maintenance costs after a few years just something that is accepted to get the comfort they provide?
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I'ver heard some people say you need to insulate with rigid foam between joists below the subfloor of a suspened slab (1-1/2 inch of gypcrete/concrete over 3/4" decking) and some say it's not necessary if the lower floors are heated. What's the concensus here?
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Fred,
There are many ways to deal with problems of "old."
In slabs for example, tubing can be sleeved where it crosses expansion joints so as to protect tubing from being damaged....Much has been learned and there are tricks of the trade like anything else.
Jack : )
*Jack:The systems I'm refering to had sleeves, expansion joints in the plumbing, and some even were put in races to minimize effect of cement product on the tubing. You know radiant heating has been around since the Romans, I'm told since I'm not THAT old, but in modern housing it seems to come and go in its' popularity.It is popular for awhile. Then stories about the high maintenance and repair costs come to the forefront and popularity wanes. And the cycle continues.As for me, I like radiant heating in principle but am concerned about whether the historic problems have been solved.By the way; the last time someone said: Trust me, I know the tricks of the trade."; he was reaching for my billfold with the other hand.
*Fred,I like radiant.I like warmed cellar slabs.I like Fred L's understanding of moisture and what to do about it.I have installed Radiant pex/aluminum fin style under sub floor. It is working, maintenance free, and the customers rave about it year after year. They are both retired, and have lived in several homes with every heat system ever invented.Lastly, I am not looking for you to trust me about tricks, and am not too fond of your inference about your wallet and what happens with it with whom. b I mostly post to share my experiences and to learn about present day building techniques that are above average in all aspects.b Happily and successfully using and installing radiant floor and non-radiant floor heating systems,Jack : )
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Thanks again for all the advise! Yes, I survived all the advise for the 2x6 framing (and obviously adventured for more!!)
This probably won't be the last post of questions from me. You guys (and gals) are a great source of information!! And often entertaining--JoAnn Liebler?!?
*I am looking for infomatrion on water heaters using fuel oil as a heating sourse for a radiant system.
*Fred, I agree with Jack. I have radiant heat on three floors and I love it. The only thing I would add is that there are new tubing materials that make unlikely the kind of failures you describe. The tubing I went with has been installed in exterior entrance sidewalks with seasonal movement here in Anchorage, AK. for nearly 30 yrs. I was told it can stretch 1000% before breaking. Improvements have been made in the oxygen permeability of plastic tubing to control system corrosion, but in my case I use a stainless steel heat exchanger that isolates all the radiant zones from the boiler and any ferrous materials. It's been working well for 10 yrs. now and got a pretty hard workout this winter with a wicked "La Nina" cold snap, temps. down to -40 F. Comfortable and not worried in AK, Greg
*Your in the wrong BB for radiant heat info. Try the Wet Head Graffiti Wall or http://www.Dan Holohans.com and click on "the Wall".
*Radiant heating is second only to motherhood and apple pie!! I installed a very simply system in a log home in Montana years ago and it is still going strong without problems.I'm planning on it for my retirement home, also in cold country.Like anything it is only as good as the designer and installer. The radiant panel assn. can give you some useful info.@ http://www.rpa-info.com
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The Energy Kinetics boiler is expensive and hard to clean. Buderus is my current choice.
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I would like to know if anyone knows much about
polybutylene in radiant floor systems. Specifically, will glycol damage polybutylene, and will glycol inhibit scaling, bacteria, and fungal growth.
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A glycol mix will preclude the growth of flora and fauna. Like 30 or 50%. Very low concentrations are edible by bacteria. Read the label on your Good Seansoning's salad dressing - propylene gylcol added as an emulsifier. (NOT ethylene gylcol - a cup of that will kill you).
Glycol implies a closed system so no scale. You get scale when lots of water flows through the system and each gallon leaves a few minerals behind. Don't know for sure about compatibility with PB.
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Has anyone had any experience with Radiantec ,Good , bad, pro , con ??? They recommended PXC over PEX for a large slab ,,, I thought PEX was top of the line ????
*Richard, check out the 97 per cent effecent gas or LP stainless steel boilers made by Heat Transfer Products, Inc in East Freetown, MA. that will heat your domestic hot water also. I have installed them and they are wonderful effecent and trouble free. I have had to replace one ignitor and it was/is warranted for 10 years.Neil
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Neil,
Do you have a website for HTP? It looks like a good choice for my jobs that aren't oil.
Ron
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Ron,
Heat Transfer Products:http://www.htri-net.com/ also known at Voyager or Superstor. 120 Braley Road, East Freetown, MA 02717 508 763-8071 or 1 800-323-9651. The units are 316L stainless steel construction. Less than 1/2 degree per hour heat loss. The self diagonstic electronic control features digital readout of water temperature set point and differential temperature range 70 to 180. Zero clearance to any combustible surface/can be installed in any closet. If you need any help, please E-mail. High output for any commercial or home application. You just do not run out of hot water for normal installations and you have high 90 percent efficiency that dramatically reduces operating costs. One would think I had stock in this company, but I do not, it is just a good product.
Neil Glass
Neil Glass
*Hello Jean,You can install the heating system yourself. Mounting PEX under the floor is certinaly doable. Using gypcrete on top of the subfloor is the best route, you get more heat transfer with lower temperature water. Gypcrete is less labor intensive.Under the floor is a bitch, it is last choice, but will work.Neil Glass
*Ron,Do not know of HTTP, their address is 120 Braley Road, East Freetown, MA 02717 1 800 323-9651. The heate is a "Voyager". Internal gas fired. 1/2 degree heat loss per hour. Compare heat loss with a cast iron boiler and flue.Neil
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After years of research, preparation and several design changes we are getting ready to build that 'dream' (sure) home.
Building a raised ranch (approx. 1450 sq.ft) with an unfinished basement. For heating seriously considering in-floor radiant in the basement with baseboard radiant on the main level. Gas is not currently available with no committment as to when it will be. Likely will use an oil-fired boiler and integrate domestic hot water. Really want to stay away from ducted forced air systems from an allergen/contaminant standpoint as well as trying to maintain a 'finished' ceiling look in the basement by using 2x6 T&G decking on the main level in place of plywood.
Anyone can share their experience going through this decision process? What worked? What didn't? Is baseboard heating really effective? Heat pumps?
...yada yada yada... can you tell I am swimming in a sea of confusion?