Fixing a poorly installed radiant system in a 9200sf house

Unknown

Hi Sam,

That would be interesting, but is fairly unnecessary. These things are pretty well documented already.

Personally, I would skip reflectix and go with an R13 rigid, blown or fiberglass if the basement is fully heated, R19-30 if not. I don't trust reflectivity in joists long-term to maintain its benefit.. but it does work at first, for sure. I certainly wouldn't use only reflectix though.

I have designed all kinds of staple ups under various subfloors, it's just a matter of adjusting for great R-values. a 1/2" of plywood isn't much to worry about, and I don't think if you used cement board that the tile guys would be very happy.. lots are insisting on 1-1/8" subfloors under tile backers these days. Then again, people did less for a long time...

Now if you are not planning to demo the basement ceiling, then the additional cost of the quik trak may not be so additional and the output may be adequate. But if you're going to demo anyway, it would be quite silly to install quik trak over this, less silly if your tubing won't fit an extruded plate.

Sam_17

Fixing a poorly installed radiant system in a 9200sf house

OK guys, grab a coffee this is gonna be a long one....

5 Years ago I bought a 9200 sf home that was built in 1991. The home was built very cheaply, corners were cut everywhere, but the price was right and it has loads of potential. It was our intention to renovate in stages over the next decade. The first winter was a real shocker, we really couldn't get the house upto comfortable temperatures on most of the main floor, that and it was costing about $1000 a month in natural gas just to get what we were getting.

Now before I go any further I should probably describe the house. The House is 9200 sf on 3 levels. The main level is about 3300 sf with ceilings heights of 18' in 50% of the area, 9' in 30% of the area and 12' in the remaining 20% of the area. The top floor rooms have 9' ceilings and the basement (walk out) has 12' ceilings. The house has over 100 windows. I am located in Vancouver BC. The predominant floor covering is carpet, with hardwood in about 50% of the main floor.

The existing heating system was the sadest looking thing you had ever seen in your life. A small 120k btu cast iron boiler, 1 little grundfos pump for the enitre house. The install looked like it was done by an aprentice just out of highschool. The expansion tank wasn't even mounted right. The entire system is run in poly b, below joist staple-up, about 1-2" below subfloor. NO insulation. (The basement stays a nice temperature) The system is broken into 9 zones, basement has 2 giant loops that use baseboard heaters.

Needless to say we used a lot of electric space heaters for the first few years.

2 years ago we started our first major renovation phase.

In this renovation we completely rebuilt the mechanical room, and completely rebuilt the boiler system. Because of the poly b system we switched over to components that would not be an issue. 2 SS Triangle Tube prestige Condensing Boilers (110k btu each) (Had heat loss done on the house and determined 200k btu was required) 1 SS 80 gal Aeroso dual coil quick recovery tank for domestic hot water. Tekmar boiler control, 10 bronze taco distribution pumps etc. Because of the poly b we have set the MAX heating loop temp to 160F. One thing to note, we are on well so the is no clorine in our water. Things are better with the new system but not great.

--------------------

To give you an better idea here is a snapshot of my current operating conditions (right now):

Outside Temp: 37 F
Supply Temp (tekmar) 140 F
Return Temp: 123 F - All main floor zones on and the master suite (800sf)
Delta T: 17 F

To maintain the above, the Tekmar is running 1 boiler at 67% or 73700 BTU.

Mainfloor air temps range from 72 F to 68 F depending on the room, location etc.

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I know our biggest problem is the carpet, and this is something we plan on getting rid of in our next renovation phase. And this is where my question lies:

It is our intention to change the flooring on the entire main floor to travertine (stone). This right there will be great improvement over the carpet because of the thermal mass and lack of insulating foam that the carpet underlay has. Though is this improvement enough?

Now because we are going to stone we will need to build up the subfloor with atleast and additional 1/2" plywood. How much does this degrade the heat transfer? and will it just end up a trade off for the carpet?

Two options have come to mind:

1) Build up the subfloor with Wirsbo Quik Trak instead and run all new 5/16 lines. This would be a lot of work, and due to the long runs we would probably need many more loops. This seems like it would be a lot of work.. but logically it seems like it would be a HUGE leap forward in the efficiency of the system.

2) Build up the subfloor with stardard plywood and lay the travertine and then wait until we are on the basement stage of our renovation. When we do the basement I would open up the ceilings, and use an extruded aluminum material like Wirsbo Joint Track Panels, then insulate with reflectex. I am not sure if the poly b is an exact fit for these tracks.

What do you guys think?

Is is worth doing either of the above? Or will the switch to a stone floor alone, even with the double subfloor make a marked difference?

Any better ideas?

Sorry for the long post, I just want to paint a clear picture for everyone. Thanks for your time..

Weezbo

Hello Sam, you have a lot of things to consider....

do you have a ventilation system of some sort?

what i mean by that is an HRV or forced air with secondary heating and cooling, make up air for appliances within your home ,some bathroom fans or large kitchen exhaust vent hoods, anything other than doors and windows ?


Would you happen to have any existing radiators ? would you consider New Age radiators like Myson or Buderus to be something you could "live with"? i just bumped a post about some 3/4 kitec.and one on competively price rads...take a look at that Sam...

would abandoning the base board ( probably the only part of the system you think 'at least works') be ok with you?

i happen to like your idea of insulating the main floor/ basement ceiling.

i also like your idea for stone floor as it seems a much more healthy choice for your environment...although i do have a question that lingers about in a murky corner that raced forward and is now begging for attention:)....just what do you mean by Sub- floor, in the existing area of the main floor? 3/4 OSB?

say for instance you opened up the ceiling and "took a look" "tukaluk" just to see what you might see and it was slightly less than your wildest imagination could have allowed, you passed out from lack of oxygen to the brain and nearly died...would removing the "radiant system " be just too much to handle ?



Thank you


there is something that makes me wonder,.....do you have sub station (manifolds with by passes) ? or are you having a large number of pipes tied together in the boiler room?

Chris_82

Just two points

Yes, obviously the pex flooring (quik trak) or any of the similar products work well in 5/16, 3/8, etc., you don't need 1/2, and then stone will work, its not all that much "extra work." But if you’re concerned about price, it goes up quickly. We did a sort of under floor renovation for someone that wanted a warm floor over a mural, plaster vaulted ceiling, in other words no access from below! We first placed foam and blocked off the end spaces between the floor joists, (after ripping out the floor), a layer of insulation, and then we cut fire resistant foam board and jammed it between the floor joists, foaming any cracks. We placed Onix tubing on top of the foam board, one layer of 3/4 t & g plywood, one layer of 1/2 cement board and then tiled the floor. It took a long time. However the customer was very happy as we accomplished what others said couldn't be done. But walking on bare joists was a real pain. On lower floors, we used the 3/8 plates everywhere in each joist space and then 8" of insulation that was carefully placed, the stuff with the flimsy clear vb plastic covering, to reduce insulation dust. The upper floor worked better than the careful staple up floors. So it can be done but no-one will certify a project like this in advance. I don't see why careful application of insulation wouldn't work in your situation. Even if it is inefficient warm floors are a plus, and adding more radiation down the road is easy if needed. Many of the staple up jobs have been revisited 1 to 2 years later, mostly large oriental carpets, to add Runtal units, nice glorified radiators that come in designer colors, beautiful but pricy http://www.runtalnorthamerica.com/

These are some ideas of non-traditional installs, that we just gambled on, and worked well, and I'm sure this thread will get lots of attention in the next few days.
point one, we always tile over cement board.
two, we always use the aluminum plates underfloor. Gypcrete is nice but isn't always avalable.
Oh the run on about the upper floor ceiling thing was about not using reflectex, as an insulator on a staple up or plate up job.

bb_7

Option 1

Sam:

I would stay with the radiant. Call the ZCP guys about your controls... http://www.zcpinc.com/ They are a great resource, and will make your mechanical room look nice and clean, and take up less space.

Although it is most likely more expensive, I would take option #1. It seems like you want to do it right, and you have plenty of ceiling height to handle the extra space for the PEX.

Warm Regards,

bb

Paul Pollets

BC Help

Sam, I'd call Viessmann at (877) 853-3288 in Langley. Ask for Fred Meier. He can refer you to some expert help in the area.

To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"

jp_2

cutting corners

since the project went the cheap way, are you sure 1/2 plywood would be enough for the stone flooring?

go look around john bridges tile yout world site:

http://www.johnbridge.com/vbulletin/index.php

you can check out floor deflection there.

Sam_17

That would be 1/2 on top of the existing 3/4 plywood (NOT OSB) The joists are 2x12" on 12" centres

Unknown

If your existing pipe fits joist trak, joist trak, in that configuration, will perform AT LEAST as well as quik trak, properly insulated underneath (i.e. not just refletix, you want real R value under it).

For area using just a 3/4" subfloor, joist trak will OUTPERFORM quik trak. for a LOT less money and, in this case, less work too.

I'd test your pipe in a plate and see how well it fits. I'd check out Radiant Engineering's Thinfin or Thermofin plates as well, the thinfin is perhaps slightly better than joist trak, thermofin is the king of joist installs. Personally we usually use thinfin though.. it's usually quite enough.

Sam_17

Thanks for your feedback.

I was actually thinking of doing a test in a small area where I have access to the ceiling in the electrical room. I was thinking of trying different material and insulation methods then measuring the floor temp above in the mud room (which only has vinyl tiles right now) and seeing what type of results I get. Granted it will be hard to consistently maintain the testing conditions, though I think it would be interesting to see what if any differences I get.

What type of insulation do you recommend if reflectix alone isn't enough?

Have you ever done staple up installs where there is 3/4 + 1/2" subfloor? What if I were to use cement board instead of a 2nd layer of plywood?