Thermofin v. Thinfin

Unknown

Size the radiators for 120 or 125 SWT and a 10 deg dt to keep size down, and skip the mixing block.

alang

Thermofin v. Thinfin

I'm a DIYer designing my underfloor system for my main floor (heated space underneath). It is basically one combined space (entry, living room, dinning room, kitchen, family room) with the same flooring throughout. Using Watts RadiantWorks software I came up with 11K BTU/hr for the entire space (Seattle, 21*F design day) but some areas have higher heat loss due to windows, skylights, and a french door. I was planning on using 1/2" pex and Thinfin C throughout. RadiantWorks came up with 118*F supply, 1.1 gpm at a 20*F dT. Should I use the thicker Thermofin as a way of doing banding? Should I just make sure that my loops are per "room" and use a nice manifold with balancing valves instead?

When should you do a 10*F dT instead of 20*F?

In general when would you use Thremofin over Thinfin?

For the remainder of the system I was planning on:
RadiantWorks calced total house heating load of 21K BTU/hr
Panel radiators (all homerun with thermostatic valve) in the finished walk-out basement (3 bedrooms, 2 bathrooms, laundry room)
TT Prestige Solo 60 using it's outdoor reset to control the radiator supply.
Taco RMB using it's outdoor reset to control the lower temp radiant floor.
Smart 40 (or 50) indirect hot water tank.


Since the Taco RMB has the radiant loop circulator built in does it easily allow you to change from 20*F dT to 10*dT?

Thanks for your help.

Chris

CMadatMe

Joist Heating

In general I use Wirsbo Joist Trak and always 3/8" tubing..Alot easier to pull and you don't get more btu's out of 1/2" just 50' more loop length..

I always loop each room seperately. I also always determine my zoning based on solar gain and layout with the exception of my kitchens which are always on their own zone and with a floor sensor. I don't like on/off radiant systems they tend to chase the day. I'd rather always have some type of floor temp running that way when the big heat tab in the sky falls I'm not dead cold. As far as delta T goes. Generally all joist appliacations run between a 15 and 20 degree delta t. Only time 10 is in slab applications.

Andrew Hagen_4

Thinfin

Thinfin is good for most applications. Thermofin gives a little extra, and may have slightly better contact with the subfloor because it his a little more rigid than Thinfin. Thermofin is also 1/2" wider than Thinfin.

In practice, the only difference is slightly lower fluid temperatures to provide the same amount of heating. if you are looking for the absolute best dry system available, Thermofin is the product.

I wouldn't worry much about your delta-T other than for pipe and pump sizing. The delta-T is continuously changing during operation depending on the heat load. I would design for a 20°F delta-T.

Thinfin and Thermofin are both available in 1/2" and 3/8". I would use 1/2" because I prefer to have as few loops as possible.