DIY Home Improvement Forum banner

radiant heating floor system/PEX/water heater

5K views 12 replies 6 participants last post by  YerDugliness 
#1 · (Edited)
I was wondering, I live in a 50+ year old home with all wood sub-floor and an outdated terribly inefficient baseboard hot water heat system (old noisy iron pipes and a 50 year old boiler that burns gas like it's going out of style) I'm trying to find out if it would be feasible to install a radiant hear floor system that receives the hot water from my natural gas water heater (we rented a home for about 2 years with a hot water radiant system in the concrete slab and it was never cold). Most of the current floors are hardwood floors other than ceramic tile in the den, kitchen and two small bathrooms. I have access to all the floors/joists/etc. from beneath due to a full unfinished basement that has no insulation(yet). Most of the systems I come across appear to require installation during initial construction, is there a retrofit system that can be added later? I'd like to use one of the pex systems for ease of installation by my husband and myself. (I have done a good bit of basic plumbing-my most recent job was building large koi ponds with custom filtration/refill/drain systems) any ideas?
 
#2 ·
No offense to you or your husband but this is not a very DIY friendly project. The design of the system is pretty critical. Perhaps if you had help with that part, it would become a bit easier. There is A LOT to consider....most likely more info than you can get from just a few posts here. Here are a few links to look at. You'll need to consider layout, manifolds, controls, zones, mixers, insulation and a heat source. Take your time and don't be afraid to get some professional help for certain parts of this.

http://www.radiantmax.com/r-underfloor.html

http://www.infloor.com/radianttrak.html

http://www.blueridgecompany.com/

good luck!
 
#3 · (Edited)
Thanks for the quick reply. The main system I've come across that peaked my interest is geared towards a do-it-yourself approach (for the basic systems at least) : http://www.radiantec.com/index.php

This is why I posted here. We already have a high efficiency natural gas hot water heater (which appears to be the preferred heating source). Also, where I live (a very small southern town) there are currently no local HVAC contractors specializing or even thinking about radiant heat systems, the few I talked to said they would have to do some major research before even giving me a quote or just take a swing at figuring it out (which is NOT what I want to hear a professional say). Every place down here pushes heat pumps :( I grew up in a electric heat pump heated home, it was never warm unless you cranked it way up (shooting the heating costs through the roof) and I've heard the same from most everyone I know that has one. My husband also has bad dust allergies and an air duct system wreaks havoc on his health. My only hope with a professional is to find some one willing to drive from out of town and not charge me an arm and a leg (we are a young couple on a tight budget with our first child on the way, so reasonable cost is very important )
 
#4 ·
I'm not suggesting you need to spend a lot of money. Figure your budget out and set aside some of it for professional advice. I'm fairly sure you could send your floor plans to some of these online companies and they could design your system for you, spec'ing out the appropriate materials. THAT'S your biggest hurdle.
If your local HVAC guys would need to research it, surely you will too! Spend some time looking that the links and don't be afraid to ask the manufacturers questions too. Heck, you may even find a company that will design your system for free if you buy their materials. No guarantees but I've seen it done before.

Good luck!
 
#5 ·
Thanks. Yeah, I know it's going to be a long road ahead to get this figured out...along with LOTS and LOTS of research :) Good thing I like research, seriously. I hope some good luck does stay with me throughout this project :yes: thank you again for the replies and the well-wishes!
 
#6 ·
I own a 100 year old home in SW KS and would like to fit it with radiant heat from under the subflooring. I, too, have access from the basement. My problem is that about 40 years ago my mother had another floor installed over the subflooring (which appears when viewed from below to be tongue and groove) and the nails used to secure the (probably) particle board went all the way through the floor and hang down into the basement by about 1/2".

Right now I'm in the scheming/dreaming stage, but I don't want to have to remove the floor that was installed 40 years ago--there was some good reason the second layer was installed but as my mom is now dead I'll never know what it was. If this is going to be an impossible barrier (other than taking a bad-ass tool and clipping off all those nail tips protruding through the subfloor), I want to quit dreaming about it right now!!!!

Anyone have any experience with this sort of problem? Any suggestions or ideas would be greatly appreciated!!

Thanks!

Doug
 
#8 · (Edited)
I do not mean to be negative, but water heaters are not allowed by code to be used as boilers. I installed a pump and coil in my return air duct as a separate zone, only to find out it was illegal, and had to be removed in order to get my AC inspected.

It has to do with the UL rating, and safety testing for the UL rating does not cover it being used as a whole house heating device, or a substitute for a boiler.

I was upset, but thats the law, at least here. My ex-father in law has been heating his house for years with an "on demand" water heater, and it works great, but, that doesnt make it legal, and will come back to haunt him when they go to sell the house.

What I really find interesting is that in European countries, they have already dealt with the fuel cost issue, and some of thier technology is so far advanced from ours here in the states, its almost shameful. Visit some overseas HVAC sites, and get some ideas. Personaly, Im waiting for fuel cell technology to get here.
 
#10 ·
To the person with the protruding nails: Smack them flat with a hammer.
To the person wanting a Hydronic system:
If you are handy and resourceful, there isnt any reason why you could not install a hydronic underfloor system as long as it has been engineered and sized right.
Call Watts Radiant 800-276-2419 for some help and guidance on the initial sizing/specs.
I would strongly suggest using Onix tube rather than Pex for an underfloor installation. Its a bit more expensive than pex, but requires no heat transfer plates and is faster and easier to install, so cost wise its either cheaper or a wash in the end.
Small dedicated boilers and on demand water heaters are not too expensive and may be used for smaller systems.
:thumbsup:
 
#11 · (Edited)
Now you're talkin'!!

To the person with the protruding nails: Smack them flat with a hammer.
I would strongly suggest using Onix tube rather than Pex for an underfloor installation. Its a bit more expensive than pex, but requires no heat transfer plates and is faster and easier to install, so cost wise its either cheaper or a wash in the end.
Small dedicated boilers and on demand water heaters are not too expensive and may be used for smaller systems.
:thumbsup:
Where can I learn more about this Onix tubing {edit--found it with a Google search}? I'm just about ready to invest in the connection tools and guess I ought to find out more about this stuff {edit-gosh, what, no expensive crimpers or expanders, just simple hand tools????}. This sounds like just the system I have in mind for that old SW KS vacation/project/retirement home! I just went to great expense to install 200 amp underground service into the house as well as an electric whole-house HWOD unit. I've often wondered if one of the smaller 120-V HWOD units could be pressed into service to keep a small reservoir of recirculating water warm. Since the efficiency of the HWOD units is dependent on the temperature of the incoming water, it seems to me that once you got it up to temp it wouldn't take that much to keep it warm enough for an under-floor radiant system.

I am the poster with the nails, knock 'em down I shall :thumbup: (maybe, that is....read on).

Sure wanna say thanks for the tip about this Onix tubing! The thought of not having to fuss with heat exchangers is exciting! That was my issue with the nails all along--too many nails sticking down too far to get a heat transfer plate into good contact with the subflooring's underside. Heck, I may even be able to leave most of the nails sticking down--they might provide a good stop-barrier for the underside insulation.

Thanks, again!

Dugly
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top