retro fit underfloor radiant heating??
Both my master bath and my kids bath have tile floors. While the air in the rooms is warm enough for our tastes, the tile floors are always cold and uncomfortable to walk/stand on barefooted when u get out of the shower. House, which is 6 years old, has typical forced air heating/cooling with properly sized units.
Both baths are on the main floor (1600sqft ranch) and are over 1600sqft unfinished basement (currenty in progress finishing off aprox 1100 sqft of the basement), with the master being over the finished part. Kids bath will be over un-finished storage/shop/mechincal area.
Are there any retro fit staple up type eletric radiant floor heating systems that are worth looking at/considering? I would like to take the chill out of the tile floors and like I said the actual air temp in the rooms are more that fine for us, so I am not looking to heat the whole room.
Is there any other things that I can do to warm the floors up? insulate the joist spaces under the bathrooms? anything else I am missing or failing to think of? I am not interested in tearing out the tile at this time as the basement is taking all my free time and funds, LOL, at this time.
Thanks in advance,
J-
Replies
I'll Bump you, so your post stays in the recent cat.
Try doing a search ( top right) I'm sure this has been
covered many times. Should be lots of info in old threads.
To warm some of our floors. Here's what I've decided to do:
I have an oil fired indirect water heater. Instead of installing a buffer tank and all the controls, I plan to circulate the DHW through a plate heat exchanger. The other side of the exchanger will inject into a header to be zoned for each room controlled by floor sensors. This will take three circulator pumps, several zone controls, a separate expansion tank and air eliminator. The DHW tank temperature won't have to raise because I just want to warm the floor, not heat the room.
I'm not sure how good the electric joist systems are, but I'd look hard at them here if you don't already have a hydronic heat source.
insulating is a big deal as well.
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cool thanks for the info guys. I do not have a hydronic heat source and it would seem to be overkill/not worth it to install for just two small rooms. I'll look into the staple up electric.
If anyone has had any experience with the staple up electric systems please let me know what you think.
As for insulation, I would think that merely finishing my basement, insulating the basement walls (which are poured concrete now) and having a ceiling between the basement and the floor joist will likely make a noticible difference. Figured I would do the radiant system while everything was open (i'm doing a drop ceiling in the basement so it could be done later, but more convient now).
Thanks
J-
Insulation will help some, but because tile is more dense than wood it will "suck" more of the heat out of you. Heat goes to cold, you can have two materials the same temperature, yet the tile will feel colder.
In cases where customers have HWBB and want to warm the floor of a bathroom or kitchen (not wood). I've strung sections of BB fin tube in series through the joist bays.
you want to insulate the floor directly. especially the joist ends, and rim joists.-------------------------------------
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Thanks for all the info guys. Did some research on line this weekend and it looks like the Watts Radiant HeatWave under floor mats are going to be the way I go. Looks to be pretty easy install and high quality.
Anyone have experience with these?
J-
You could use a tankless water heater, some pex tubing, one pump, expansion tank, and then you could have a mini closed loop system, under $1000. Or you could install a pump on your hot water tank to give youself instant hw at the master bath and use the return line to heat the tile floors. It would mean that you would need to have a way to drain the system in the months that you did not use it and insulate the floor very good so as not to run the meter too much NRT may have some input on this, I have been doing this in FL for the older homes that want to get rid of the chill in the tile.
GRI have been thinking about this for my master bath should of put in an electric mat under the tile Oh well hind sight is best. But I worry about the thickness of the floor, I have 1 1/8 OSB with 1/4 Durrock and tile, mortar set. Do you think too thick for good heat transfer?Wallyo
Rob might have more insight into elec mats than I do, but I would think that they would be similar to hydronic heat. The more mass the better, remember you could heat your 6" concrete basement floor with hydronic heat, the important thing is the rise and fall time, more mass=longer temp rise time. As I had stated, I have used the return loop of a HW recirculataing system to do master bath floors,, 3/4 ply, cement board and 1/2 marble, works fine.
I was thinking hydronic just worried about the 1 1/8 OSB.
See if NRTRob checks in again, but mass is what you want to use hydronic heat, more mass less cost to operate, except for the initial temp rise. I would use heat transfer plates and as Rob said, INSULATE. You need to keep the heat on the floor and not the crawl space and/or basement.
mass isn't really relevant; it's about conductivity. concrete is fairly conductive.. not so with wood.that said, 1-1/8" of wood will slow things down and make for higher water temps, but it should be doable. I would assume heavy plates should be used if hydronic, unless a load calc told me otherwise.-------------------------------------
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Thanks for the clarifacation on mass. But doesn't mass even in lower conductivity help in keeping the heat? I understand that it would take a higher temp and maybe a lower flow rate, but my thinking is that once you have 1 1/4" of wood up to temp it would hold it longer than 3/4" of subfloor. Yes?
True, but there is another way to achieve the same effect; modulate your water temperature.That has other benefits such as faster response time, possibly.. better efficiency, possibly.. and a more even floor temp over time, among others.-------------------------------------
-=Northeast Radiant Technology=-
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Thanks for the input. There are very, very few things that you post that I have some small issue with and this is not one of them, sorry I did not get back to your response until today. Went to my Dad's for his 89th B-day, and yes I put a gun in his hand and take him Deer Hunting every year.
that's ok, I was late responding becoming a dad myself ;) Maybe someday my new daughter will do something crazy with me on my 89th birthday too heheh...-------------------------------------
-=Northeast Radiant Technology=-
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Good luck with that. I was thinking after my last post that out oldest son will be 69 on my 89th B-day, he may not even remember.
jjc155
Listen to NRT Rob. if you're going to heat the floor it would be pretty risky to do it with electric matts.. but by using a simple electric water heater and some hydronic tubing you can do it relatively safely. I use that system to heat my whole house. (5500 sq.ft. in Minnesota where we are in process of getting another six inches of snow as we speak)
couldnt find anywhere in his posts that NRT thought that they were risky, unless I missed it. Saw where he said that if I did not already have a hydronic source (which I do not) that "I should take a hard look" at the electric systems. I read into that, that he was implying that they may be the way to go in my case, but again I may be wrong. I definately did not pick up from him or anyone that these systems have any inherant high level of risk to them. I'm not looking to heat my whole house just warm the cold tile floor.
What would you think that the risks would be frenchy, for the electric joist space mats?
Thanks
J-
By reading your post I got the impression that you were looking for a "retro" between joist electric heating mat. I don't know of any , but then I am not an expert.
The warm floor electric mat you speak of are installed under the floor tiles, "on top of you floor joist/sub floor" So you would have to demo the floor tile, work that into your cost. Very comman and can be set up with a thermostat.
Grcourer is correct on making a floor warming system with a small elec. water heater and is on circ. that runs a staple up , "under the sub floor, between joist"
Check over on http://www.heatinghelp.com , on "the wall", a contributer, "Hotrod" has make such a beast and posted photos for the $$$ mentioned. Use a little Titan 2-3 gallon heater, circ, pex , ect... very cute!! Maybe something to look into.
If you can't get you answers here on BreakTime , you will on "the Wall"
Two best sites on the web.
Edited 4/1/2008 11:07 am ET by cameraman
you got me right. I'd strongly consider electric if I didn't already have a closed hydronic system to tie into for such a small area.-------------------------------------
-=Northeast Radiant Technology=-
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cool thanks NRT that what I was thinking.
here is a link to the system that I am likely gonna install. Its made by Watts radiant floor systems and it is the Heat Wave model. They have a staple up under floor model that looks very good.
http://www.wattsradiant.com/professional/heatweave.asp?s=hw-underfloor
Thanks
J-
I have put in those type of underfloor mats a few times(different brand), they have worked well, but as a vol fireman I have also seen a fire caused by them. Apparently a couple of years after they were installed , a plumber doing some work pushed the insulation up to run his pipes, making contact with the mats. This started a fire in the crawlspace which found its way to some un fireblocked openings then up to the attic and roof before the smoke detectors even sounded.
Even if it would cost a little more than the mats to do a small elecric WH and run hydronic in the floors, for the piece of mind, that is what I would do.
Excuse me for stating the obvious, but sometimes a nice rug is all that is needed.
"Excuse me for stating the obvious, but sometimes a nice rug is all that is needed."
And cover up all that expensive tile!
warm floor in bath
Put a more expensive Persian rug over the tiles :=)
no problem for the obvious. That is what we do in the girls bathroom, but even in there the rug does not cover enough (due to the shape of the room and not finding a rug that works, but I havent really looked much honestly).
In the master bath its the size that is the problem. The bathroom is 10x12 so the rug would be huge and the shape would not work well, at least in my mind.
J-
Spoken by a man who has never enjoyed warm tile floors in the morning when it is -20 outside.
I've enjoyed a warm rug when it's 20 below outside.
What is wanted is not the will to believe, but the will to find out, which is the exact opposite. --Bertrand Russell
I'm a bit germophobic and when I see a rug in a bathroom, I wonder how often it gets sanitized and washed. Gross! I prefer to step out onto my dirty clothes LOL! Bob's next test date: 12/10/07
I too would rather step on a pile of my clothes rather than a rug, I just want my pile of clothes to be warm from the radiant heated floor.
I lived in Northern Michigan so I know what you mean.I solved the cold floor problem by shutting off the heat in my bedroom. The only heat vent was in the bath and the heat had to pour over the floor first to get out to the bedroom. I also added several heats in the crawl space/basement. Most people I know shut all the heat out of their basements. I always poured the heat into them. I figured that heat rises and I wanted warm floors. My heat bills were the cheapest on the block and I didn't have to wear winter clothes all winter, so I think my theory was correct. Bob's next test date: 12/10/07
Having spent 11 years in N Mich and now 22 years in NE Fl, I find that there are many ways to save $ and stay comfortable in your home. I cut and stacked wood for 11 years and the wood heater was the primary heat unit. I have a fairly efficient A/C unit with closed cell foam and Astro-Foil insulation. The house was built in 1906 and has about 16" of crawl space, and a floor is 3/4" heart pine. I have a closed loop system for the floors that I use from about mid Dec to mid March. When the floor is running the heat pump is not. Here in Fl the A/C people love to put in electric heat coils (all undersized) I had the coils disconnected and only the cir fan in the air handler runs when the thermostat calls for heat, I have the RH set at 72-74 and the airhandler set at 76. works fine for me and the elec use has gone down about 5%.
If your heat bills were cheaper, there was more to the story in either your envelope or heating system.there is no getting around the fact that additional cold area (basement walls) will raise your energy costs over not having that additional cold area. the only question is how much it raises your bills (answer is: typically, not that much, but it will increase not decrease your fuel bill).-------------------------------------
-=Northeast Radiant Technology=-
Radiant Design, Consultation, Parts Supply
http://www.NRTradiant.com