Raidiant ceiling

big willy

I have a coustomer who wants raidiant floor heating in a three story house. This is fine in the slab on the first floor and as staple up for the second. however the staple up for the third floor is not enough to heat the space. my figures tell me I need about 45kbtu for the third floor (windows all the way around. With the avalible square footage an 85 deg. floor gives 40kbtu. close but not enough. The last thing I want is to be the guy who almost made the system right. With this in mind I proposed a few small fan convectors in the kickspace under the bookshelvs on the walls. they didnt like this idea. I am going tomorrow to talk to them about raidiant ceiling to meet the load on the cold days. i want to make the ceiling a second stage on a zone valve and do just the perimeter of the area. This is not somthing I have done before and I really dont want to use the aluminum plates that wirsbo sells. So if you have seen this done or have done it or even if you have driven buy a house that has it INPUT. Thank you all. Nothing like having other professonels to bounce things off of.

ALH_4

radiant

How about the U-Fin plates Radiant Engineering sells?

Here's a photo of a radiant wall with U-Fin.

Matt Undy

Just a coupel ideas

Is the cabinetry existing or is it new construction/renovation?

What about hiding some fin tube radiation in the cabinetry somewhere or using some flat panel radiant baseboard in the toe kick of the bookshelves?

big willy

nice

It look like the studs are just noched and the plates are set and tube is cliped in. I have to check but that might work my only concern is that the are using a lot of tubular steel to build the house. but if the plates were parallel to the tube joists that would still work thanks.

big willy

no bueno

the home owner wants invisible and quite and a gold toilet so the toe kick heaters got the ax. but thanks for the input.

Dale

ceiling/wall

I guess the first idea would be to add some to the walls as the other post suggested. However I really like radiant ceilings if the money is there, the ones I've seen run at about 110 F surface temp so the system temp primary loop would need to supply 140 or so instead of the 110 you might be able to design for in the rest of the house. With all the glass and being close to the correct load with the floor you might only need tube on the perimeters. I would bounce this design off the tubing supplier,if you use wirsbo/uponor I'm sure they would have a good opinion.

Unknown

it works

Light plates, pex-al-pex, and wirsbo recommends a max 120 water temp (though that depends on ceiling height).

picture of how we do it is attached. works great. picture is of a radiant system being installed for sole and primary heat.

jp_2

attaching drywall?

Rob, how do you attach the drywall there? seems too close for comfort, do you the ceiling drywall?

Unknown

You have a piece of 1x3 strapping every 16" o.c.... that's a standard strapping detail for this area whether you heat the ceiling or not... plus a second run of strapping offset a bit.

Drywall screws right to the strapping, against the plates. Only one side of the plate is stapled so the drywall can make the plate "conform" before drywall screws potentially lock the plate in place. Obviously you need to insulate over the assembly before that happens

Only one hit so far... on a 180 bend, never seen one on a straight run... and with PAP you can push the bends up away from the drywall to protect them a bit.

a 3" wide strip gives the drywallers plenty of space to hit with their screws before they worry about pipe. and until the last piece of DW goes up in a row, the strapping and tubing is visible.

Brian_19

Radiant

I use Wirsbo joist track for wall and ceiling. I use it as the primary heat in second floor bedrooms. I use wall heat in bathrooms as a supplement to floor heat.

big willy

The best part

is that you guys make me look smarter than i really am. I know this is possible but in my area hydronic anything is uncommon so this kind of info is hard to come by. The internet is the best thing since sliced bread. Thanks for the info god bless.


PS. Its really od the way the thread builds seams that the order of the posts gets kind of screwy.





AND IM DONE

Rob Blair

Big Willy

Here is a picture of Rehau's Raupanel used on a wall. No reason it couldn't be used on the ceiling too.

Rob

Unknown

I see a lot of posts here about using extruded plates in walls and ceilings.

guys, you're only fighting a piece of drywall. There is no reason to double, triple or quadruple your material costs to drop your water temps with ceilings... you're already running under 120 and that's with 40 BTUs/sq ft!

If this is just supplemental heat, extruded aluminum of any kind is serious overkill.

One of the real beauties of ceiling heat with lightweight plates is that it's cheap.. very cheap (16" o.c.), very fast to install, and still low temp!

jp_2

How light weight?

i like the idea of ceiling heat in certain areas.

how thick are the plates you use? are you sure you even need them? we've all talked about how useless thin plates are on the floor .

are you talking supplimental heat or full heating here?

Unknown

our plates are 11/1000th of an inch thick.. flashing grade, really.

I can't imagine what kind of hit the output would take without conduction to the drywall... or how you'd hold the pipe to the drywall without plates. But am I SURE? no. I'm *pretty sure*, but I haven't done the higher end math you'd need to do to figure that out.

Light plates aren't useless in the floor anyway... they are just so severely outclassed by heavy plates to the point that the choices are typically Suspended for Economy or Extruded for performance. They are definitely an improvement over staple up naked or suspended tube though.

In a ceiling though we can't rely on joist air stratification or convection to provide any heat... it must be radiant and conduction only, since you're transmitting heat downward.

ALH_4

thicknesses

Just for reference:

Thinfin U/Thinfin C is 0.050" thick

Thermofin C is 0.0625" thick

I forget Joist Track exactly, but I think it's very close to the thickness of Thermofin.

Radiant Side Track is 0.040" thick

Installation difficulty seems like it would be high with the Side Track. Anyone used it?

Steven Gronski

Heat emmission plates

I have done rooms with supplemental heat in the ceilings and Wirsbo/Uponor makes a single groove or double groove heat emmission plates that are perfect for wall and ceiling applications with no cutting or notching of the joists or studs,the numbers are A5055001,A5075002,A5073752 etc. You may be able to find out more about these plates at wirsbo.com

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

Bernie Riddle_2

Why don't you guys look into Vieg's climate panel. It can be installed on the ceiling

VIEGA'S the BEST

Unknown

You get half the output at three times the price. Exaggerated, maybe, but that's a poor choice IMHO.

big willy

no panels

I talked to a guy today who put raidiant ceiling in his home. He used tube with no plates and put reflectave faced insulation behind it. with 140 deg water it heats the space just fine. The boiler has to run at that temp to serve other loads in the house anyway so I wont be reducing its effeciancy any. WHAT SAY YOU GOOD SIRS?

Joe_75

I have radiant walls and ceilings in my bhome without plates, only foil faced insul. They work fine, but I have wondered if plates would be better. I have installed radiant walls in the foam block/ oncrete walls (Poly Steel) wiothout anything and have had good results. For a customer I have and would use plates just for piece of mind.

Unknown

I would think reaction would be slower, and you'd be operating it as a bang-bang system, which I'm not a real fan of. I prefer more continuous operation... not necessarily true continuous, but at least reset to low temps, so you don't ever have to worry about cooking their heads! Modulated output, to some degree at least.

So the short answer is, I wouldn't do it that way. Could it work? Sure, but I wouldn't trust it for a client's house, at least not without verifying surface temperatures on the ceiling first!

big willy

keep in mind

This is a second stage. There will be radiant in the floor as well. The load is high because there are windows all the way around and its on a ridge by the ocean so high winds are a factor. The floor would put out enough heat to meet 75% load at 85deg surface temps. If I run raidiant around the perimiter of the ceiling it would give me the extra 25% for the bad days.

ALH_4

2nd stage

I like Rob's omega plate with pex-al-pex plan as a second stage. The pex-al-pex will help reduce the possibility of expansion noise.

If it was the primary heat, I like Thinfin-U. The photo I posted above heats a bedroom on an upper level. At first I was a little nervous depending on what kind of furniture gets placed against that wall, but the numbers said it should work, and it works well at radiant floor temperatures. The owner is particularly exacting, and he would certainly have let me know if his daughter's bedroom did not heat well. He was very opposed to the look of a panel radiator. It was part of a major remodel project, and it would have been very difficult to add more heated area.

Thinfin-U has significantly less aluminum (less expensive) in it than original extruded plates. I like the U-channel beacuse you can install the tube after the plate. The limitation with extruded plate thickness is at least partially based on the extruding company. Thinner shapes require more pressure to extrude and uniformity along a 4ft or 8ft length is difficult to guarantee, particularly as the plates get wider.