Sandwich method

singh

Thanks Rob.
I will relay the info to Tim.
Yea, I talked to wirsbo and they told me the same thing with QT vs. sandwich outputs.
I noticed the other day at the big box, that sill barrier foam
rolls has some R value, maybe that below infill,and very thin,what do you think.
I will keep you up to date and will post some pics, look forward to working with your plates;).
Email directly if you want.

singh

I have an upcoming job with all radiant in log home.
Heat loss was originally figured using Wirsbo QT, however
H.O decided he can do it himself,I will install multicor tubing, boiler etc..

My questions are:

He plans on using OSB, anyone see any problems with the adhesives used in that or should he go with plywood?

Should output be the same or close,now that plates will be on top,rather than aluminum on bottom of QT?

Second floor will have carpet and no insulation underneath,as this is a log home and the 1x4 t&g subfloor is the exposed ceiling below.I'm concerned with the subfloor seperating because higher temps. needed and the second floor zones becoming a radiant ceiling below, and making the bedrooms uncomfortable.At best should I insist on the bubble wrap. Sleepers and foam board not an option.

Heat source will be GB142 and will have reset.

Thanks in advance.

Unknown

Sandwich has better output than quik trak, if you use a plate with a decent grip on the pipe (good contact area).

That second floor problem is a good one. Bubble wrap isn't worth it, might as well just add another 1/2" of plywood for all the good it will do. At least you have the additional infill material working as additional insulation as opposed to quik trak! If you can, increase the thickness of the infill material there to 1" or more and it will help, and keep the carpet thin thin thin. If that is not acceptable, then the HO needs to not put carpet up there.

I'm guessing he doesn't have flat ceilings up there. If he does, might want to look at that (radiant ceiling) as an option.

singh

Nope,ceiling is out and walls are logs also so no wall panels either.
Rob, I believe plates are coming from you??
I knew sandwich has better output , but can't find and info as to how much exactly compared to QT or climate panels.
The T&G ceiling has me worried,its like hardwood floors but reverse,I hate to see big gaps from below forming,no matter what floor covering above.
Thanks.

RoosterBoy

howdy Singh

i will tell you a story about heat loss on a log cabin i did last year and my thinkingh the home owner would go with vynil it didnt happen instead he has super thick fbacker pad and two inch carpet ) we put insulation 2" foam under the floor ,luckily i stopped by and asked about fuel useage and the like....the long and short of it is i ended up putting in 11,000 btu of baseboard to bring the place up off 65 in a mere 45 below zero day. the plates are doing all they can to distribute the heat evenly buh you be careful ....any time Things change theres inevitably something in there for us seeing as you are using the buderus heater what about seeing if he would go for some pannel rads *~/:) they are dialable

Unknown

Ah, this is nervegna? We actually have a contractor that does sandwich methods like this; he straps out the floor and uses rigid foam in between the strapping, with the plates stapled to either piece of strapping over open space with the rigid foam under the pipe and plate. No contact there though.. for the life of me, I can't understand how he doesn't get noise, but he doesn't.

For sandwich... there aren't any good output charts or anything available. I guess the people making charts would rather sell you quik trak In our experience, it runs a good 5-10 degrees cooler than quik trak.. but that's rough, very rough estimation. It's good enough to design around at least.

I wouldn't worry about the ceiling.. temperature should be fairly low up there, and load should be low.. if you're doing outdoor reset especially, you should be fine.

It does sound like Tim needs to ditch the carpet in this case though.

Michael_6

Have NRT get Raupanel for the second level. This will take care of the downward loss and give you double the output.

Unknown

That wouldn't take care of downward loss.. you then have direct conduction to the subfloor from the aluminum, and you also have direct radiant to the subfloor from the aluminum. The sandwich has the infill layer in addition to the subfloor providing downward resistance.

Raupanel definitely kicks ****.. it's also three times the cost of sandwich if you aren't charging for labor. That narrows if you're a contractor charging time to install it, but it's hard to justify for most DIY installers.

PM_2

Beware of heat loss

Beware of the heat loss from log homes. It will change (for the worse) over the next few years as the as the logs acclimate themselves to their new orientation, temps, and loads. In many cases, the heat loss will be higher than an average quality stick built house with blown in cellulose. Most milled log home mfg's are snake oil salesmen when it comes to heat loss data.

Plan on supplimental heat just about everywhere.