Engineered wood flooring max temp?

[Woodfarmer1]

I have engineered hickory flooring 3/8 on top of 5/8 plywood, my pex is in the joist cavity which is 12" wide x 16" deep, not affixed to the underside of the sub floor. I am running 120* water through the pex, and just can't seem to get more than 75* on the flooring temp. Do I dare increase the temp to the pex

 

[Fred61]

I don't have engineered flooring although I have installed it for others. I have a mix of flooring in my house. Brazillian cherry, ceramic and laminate. I'm running 140 degree water with no ill effects. I wouldn't hesitate to run up to 140 with engineered. It would be different if your tubing was in-floor instead of under floor.

 

[PassionForFire&Water]

Did you use the Aluminum Heat Transfer plates on the PEX in the joist cavity?
Is the floor joist cavity insulated and do you have an air gap where the PEX is attached?
1 or 2 PEX runs per floor joist cavity?
How long is each PEX run?

(broken link removed to http://www.radiantprofessionalsalliance.org/Pages/SystemDesigns.aspx)

 

[Woodfarmer1]

No aluminum plates
3 1/2 inch pink
1 run per joist space and I'm only guessing here that each run is 100' out and back there are a total of six for 1500 sf and one in the loft of 200sf

 

[arbutus]

I have engineered hickory flooring 3/8 on top of 5/8 plywood, my pex is in the joist cavity which is 12" wide x 16" deep, not affixed to the underside of the sub floor. I am running 120* water through the pex, and just can't seem to get more than 75* on the flooring temp. Do I dare increase the temp to the pex

The Uponor Complete Design Assistance Manual and Zurn Radiant Design Manual will have charts that show the required water temperature. 145°F is considered to be the upper limit for wood floors, but your engineered hickory may have a different upper limit. Call the manufacturer if you can't find this information on the installation directions.

Is the insulation faced? Is the space below heated at all?

 

[PassionForFire&Water]

What floor temps did you design for?

I just think that without these Aluminum Heat Transfer Plates you will not be able to "suck" the heat out of the water in the PEX tubing enough.
You can not fool the physics behind the system.

Try with 140F and see what happens

 

[Vizsla]

It's supposed to be two runs per 16oc joist space with Al transfer plates. Your fixing a problem with a bad bandaid, ie hotter temps because of poor transfer. 140 is too much, even 120 is too much. It can be done with 90-100 deg using the uponor or stadler viega floor systems. 100' are some short loops too. I run barley does 5"-6" wide with the plates.
With 1 run it makes for uneven heat as well. You would almost need fin tube 6" below floor with the radiant aluminum Vee plates. That was a way they used to do it long ago, not very common tho.

 

[stee6043]

As stated above, everything I've read would suggest your setup isn't adequate regardless of water temp. There are cheap ways (roof flashing, foil insulation, etc) to accomplish the heat transfer you want. Do a little more digging and find the answers to the real question you should be asking - why isn't my system working at 120. Not "how high can I go". I think you'll be far happier if you fix the problem directly...

 

[TimfromPittsburgh]

I have Karns engineered wood floor with radiant infloor heating in one room. The instructions provided by Karns state that the temperature at the top surface of the engineered floor must not exceed 85 degrees F. I would expect the manufacturer of your engineered floor would have some similar guidance for radiant heating applications.

 

[JP11]

I have mine 8" on center. stapled to subfloor. No plates. Inch of air space then 2" foil faced foam.

I'm running 140, maybe a bit above. Have laminate and tile everywhere. Seems to work fine. Been 5 years, no ill effects.

JP

 

[flyingcow]

ONLY IN MY KITCHEN(25% of my first floor space)---Throw my 2 cents in. i have staple up Wirsbo with aluminum plates. Each bay has a loop up and back. 1 1/4 inch of subfloor with ceramic tile on top. It is insulated underneath with 4 inch of F/G. I keep my water temp at about 125/130. In january to feb i turn it up to 140. FYI, this is not my main heat, just creature comfort. If my wifes tootsies are comfy....so am I.