Aluminum distribution Plates?

WarrenPFJr

What is the latest thought on Aluminum distribution plates? I am trying to determine what is the best way to go in terms of getting the most from my dollar. It seems like there are several thicknesses to choose from and theories on the spacing of these plates. I plan to install between 2x10 flr joists, 16" O.C. with 3/4 ply sub floor, coverings will be 3/4 hardwood in some areas and slate tile in others. This will be over a basement that i hope to finish someday soon so did not plan on insulating the joists. It would seem like the thicker the Aluminum the better it will transfer so this would be a no brainer if i had an infinite bank account but at some point the Aluminum thickness and efficiency must level out right? How about opinions on the bubble foil? Any thoughts from you pros.?

bill_105

Currently...

there  is a good chat on the main wall about this. ME came up with an interesting comparison on different methods.

And Alan showed a product with just a little twist of same old stuff. It has a video.

There is one thing for sure when using this product though, I'm going with installation crew number 2 !

kcopp

the extruded....

plates are by far the best option for staple up. The thin stamped plates where better than nothing are so-so. Yes they are not cheap.... but are good. Bubble foil.... by itself is junk. You are better off going w/ the best/thickest fiberglass/batt (or the like) insulation you can find. Go w/ at least r-19.

WarrenPFJr

Thanks for the feedback guys.

Bill- Definitely crew #2. I never even considered the fin type and plan to look into that option a bit more. The post is referring to the Ultra-thin type product on pex right? not necessarily baseboard type copper fin run with copper pipe in the bays of the floor joists?



kcopp- Insulating the bays is still recommended if i plan on using the space below? The floor joists are 2 x 10 so i could potentially insulate with R30 or R38C if insulation is the recommendation. I just thought it wouldn't be needed if i plan to use the space below (basement with pex in concrete). The heat will rise for the most part right? Or is it beneficial to isolate your zones (at least between floors) as much as possible?

Rich_L

Insulate!

Best to insulate between the floors to keep the heat going where you want it. I assume your thermostat for the main floor is on that level and you would be heating both levels with no control for the basement with out insulation. R-19 is plenty and don't push it tight to the tubes. Leave an inch or two between the underside of the floor and the insulation.



BTW heat does not rise, hot air does. Radiant heat travels in all directions. If unrestricted from above it will heat the lower level floor just like the sun shining (also radiant heat) on it.  

NRT_Rob

insulation under radiant

R10 between heat floors, R20 over a cool space, R30 over a cold space. minimum, and don't forget the all important rim joists!



a room by room heat load calculation should decide whether you need plates or not. You either need heavy gauge aluminum or you don't really need plates, as far as I'm concerned, in a joist situation, and 90% of systems or more should really use the heavy gauge aluminum.



lightweights can be better than nothing in a joist but you need a GOOD lightweight with good tubing contact, not something hammered out with a block of wood.

kcopp

Heat does not rise....!

Hot air rises. Heat goes to cold. That is a misnomer. Gotta insulate. AND the insulation when using the extruded plates goes right up against the plate. NO air space.

WarrenPFJr

I'm starting to get it.

The pex and plates will be in the joist bays between the basement and the 1st floor. The first floor will have 3 different zones and controls. The basement will be an additional zone with its own Tstat. About half of the basement will be finished in the future while the other half will be used as storage. I only ran pex in the concrete to the portion i plan to finish. So if I am reading you guys correctly the pex and plates in the joist bays over the future finished basement should get R19, while bays over storage should get R30. I have quite a bit of the foil/bubble wrap left over from a different project that i figured i would use-up since i have it- Whats the best use for this stuff?



And to throw another bit to the equation I have a large, high output fireplace on the first floor that I am hoping to use as my primary heat, especially for the open second floor. The radiant system is just to keep things comfortable and something to rely on when Im too old to split wood. I have this fireplace set up to dump excess heat into the basement if things get too toasty on the first floor. If I insulate the heck out of the joist bays will this dumped air heat eventually work its way back up? I'm curious to see how the radiant will mix with the use of a fireplace.

kcopp

put a floor....

sensor in the area around the fireplace 10 feet of so away. That way the floor can heat up and anticipate when the fireplace is on. Tekmar 511 is a choice.

NRT_Rob

for the foil/bubble wrap

you could throw it away, or you could put the time and effort into installing it under any joist radiant areas... but ignoring it from an R-value perspective and just getting a "little extra" out of it.



the fireplace will crank up, radiant will turn off. I second the idea of using floor sensing to avoid cold floors in that case. this is not a high mass radiant so as the fireplace dies out the radiant should just pick back up seamlessly.



make sure you zone the areas that will get fireplace heat by themselves though!

SWEI

Leave an inch or two?

Why would you do this?



Foam or wet spray cellulose (complete contact with both plate and surrounding subfloor) is the best bet here.