dmaceld said:
 I've been trying to find info on the ThermoFin plates, but  it doesn't exist on the web that I can find! Every page of  their website is under construction except the home page  and contact page. Their web site is currently worthless  except for their address and phone numbers."

I've been a technical sales associate at Radiant Engineering since January. I'm working on our new awesome website every day, and I put up a temporary website last week. The temp site has all of our ThermoFin info and brochures, as well as a request information form for specific questions and for brochure and sample requests. Comments and suggestions would be appreciated. Thanks! www.radiantengineering.com

Not sure what all the fuss is about re bending your own plates (fins I call them).

1. Buy a roll of aluminum flashing like that used for roofing
2. Cut pieces of it to the length you wish to work with. 36" worked well for me.
3. Use a router table and a cove bit to put a groove in the edge of a 4' piece of 4x4 lumber. Groove to be 1/16 deeper and wider than the pipe you are working with.
4. Determine spacing of pipe on the fin, either centered or 2 across. Mark all the pieces of flashing.
5. Using a 4' long scrap of the pipe, lay first piece of flashing on top of it and line up the marks.
6. Center the 4x4 groove on the flashing with these marks and use a hand sledge to hammer the flashing around the pipe and into the groove. Work back and forth along the length to ensure good bend around the pipe.

This is a bit of work to accomplish, but is far more economical than the cost of commercial made fins.

There you have it!

Mechanical design, material specification, production method and required tools, figure in "a bit of work" for man hours plus economics 101...fantastic!

Of course the output would be questionable and less than half of a proper ThermoFin, which is a "heavy" extruded aluminum heat transfer panel designed by a real engineer with real world experience. We don't leave home without them.

I can’t imagine any engineer ever getting involved with plates. It seems like the only folks who get involved with plates are the folks who sell them or install them. There must be good money to be had selling and installing plates to clueless customers who must have HR heating no matter how much it costs.

Let's see. Siggy is an engineer. And he goes over, even advocates, the use of aluminum plates in "THE BOOK" you are so fond of regurgitating. I refer you to a link, here:

thttp://static.squarespace.com/static/50de4c94e4b0a05702aac0fb/t/511a6e48e4b0735b6626ef38/1360686664633/PlatelessInRadiantville.pdfhe pdf

Imagine.

I am beginning to suspect you are a shill for the forced air industry.

"Let's see. Siggy is an engineer. And he goes over, even advocates, the use of aluminum plates in "THE BOOK" you are so fond of regurgitating"

Too Funny, I love it!!

No, John doesn’t like plates either. He just explains that plates are necessary if you place PEX below wood in order to get any significant heat transfer. He then provides the data and method to show how lousy plate systems perform compared to slab systems. I reckon John felt the need to do this because there are apparently folks who place PEX below wood without any plates at all and run supply temps in excess of 120F. I agree, it is hilarious…provided you are not the one who paid a premium for this level of heating performance!

here is a cost break down of a 1,000 square foot RHT floor panel system (our sandwich type system)
pipe needed on 8" pattern 1,500 '
turn bundles needed 2
Omega heat transfer plates 6 units 200'= 1,200'
5 outlet manifold
8 sheets of 3/4 plywood ripped to 6"
Values
pipe 1,500x.26' $390.00
Heat plates $810.00
RHT floor panel turns 2 units $300.00
RHT manifold SS $167.00
3/4 ply estimate $35.00 sheet x 8 $280.00
miss nails/staples $50.00
Total $1,997.00
OK, so we have less tha 2 dollars a square foot for a surface sandwich system, average install time 500 square feet per day 2 men. A 1,000 square foot square optimizes the install, real world is more involved. My point, cost is not so great, delivered water temps with this system can be 100 degrees or less, very efficient. Easy to apply in new or retro fit, has benefits that slabs do not, building floor is not stiff, diaphragm,the installer can take 1/2 the building commission it and come back for the rest later, on and on.. Read; I also like slabs, never said I did not.I am pointing out that the sandwich site built system has its place as a valid option. Dan

Okay, so the cost of just this sandwich built HR emitter [i.e., NOT including cost of the heat source, circulator(s), distribution plumbing and control system] might be $2,000 uninstalled and $3,000 to $4,000 installed. The cost of the equivalent concrete slab HR emitter might be $390 uninstalled (i.e., just the cost of the PEX if you are already pouring a slab for other reasons) and $600 to $800 installed. Delivered water temps with a slab HR emitter can be 85F or less. I will leave it to actual person considering their HR emitter options to ascertain whether the cost and performance differences between these options is significant to them.

I never said that a plate system was not an option. I just said that a plate system was a more expensive, lower performance HR floor heating option as compared to the slab option. I also said that it is the folks who sell plate system components and design/install these systems who largely market and advocate these plate systems. We don’t design/install plate systems, period. If we get a potential customer requesting a plate system, we just refer them elsewhere and wish them well with their project. Again, our focus is working with customers pursuing energy efficient new construction and NOT with remodeling old buildings where a sandwich built HR emitter may very well be the best option if you have a customer that insists on having HR floor heating and who doesn’t care about the cost (e.g., is opposed to going with a lower cost, higher performance, more versatile mini split cooling/heating system option).

So,
Math is your friend, yes mine to.
A carpenter and helper can install 500 feet a day average with a lay out (printed map of the pipe).
Assume they run $50.00 per hour for the pair, 8 hours / $400.00/ $800.00 installs 1,000 square feet
On a slab if you are stapling to the foam 2 men 2,500 square feet per day, tying to wire mat or rebar less like 1,000 square feet.
Do not forget the insulation at $1.00+ a square foot, typically only required in a heated slab (at least in the fine state of Washington).
No doubt slab is less cost, better heat mass but we have multi million dollar multi story homes where the solution for a slab on every floor is not a option.
Our systems can preform perfectly in these applications at very low delivered water temps similar to slab.
Same is true for the modest 2 story home.
Some homes will only have a slab in the basement.
It is not wise to rule out so many great options with hydronic heat, ceilings, walls, topping pours, radiators, sandwich and more.
This is one of the greatest things about water based heat. zoning, versatility, invisible.
So, as I said, I like slabs have some in my house, as well as topping pours.
Have no issues with heat pumps have one going in a house I am building currently(air movement, filtering, heat & cool), same house has a radiant floor 1 1/2" concrete topping (just cant get away from the stuff), and 5,000 watt PV system to off set the utility.
All good .
All about options, solutions and more.
Dan

Hey Dan;
One question on your numbers: How do you get to 8 sheets? I get a number more like 23.

Also, a couple of comments:

I used OSB, much cheaper, and added construction adhesive to avoid those squeaks. As far as cost both systems require a manifold, so that is a wash, as is most of the tubing, the slab might let you run slightly cooler, but you are still going to need the pitch to avoid striping.

Anyway, I did one of your RHT systems DIY, it is working great.

True Dave, the $167 manifold should NOT have been included in the comparison...good catch! I also wondered how Dan got 8 sheets and thought perhaps 31 sheets (i.e., 1000 square feet divided by 32 square feet per sheet) minus the area occupied by the PEX would have been required. However, I am not familiar with this RHT system at all and I just trusted and used all of Dan's numbers as he provided them for the comparison. If 23 sheets is the right number, that would further increase the sandwich built HR emitter cost by $525 (i.e., 23 – 8 or 15 additional sheets times $35/sheet).

Dan, I thought you said “500 square feet per day 2 men”. So it would take 2 men 2 days to accomplish 1000 square feet. So 2 men x 2 days x 8 hours/day x $50/hour is $1,600 in labor for the sandwich built HR emitter install. So total installed cost for the sandwich built HR emitter is $1,997 + $1,600 - $167 or $3,430 total (or perhaps $3,430 + $525 or $3,955 total if 23 sheets are required). Agreed, it’s all about options and to each their own...and we also like the fact that HR heating can be easily zoned, is invisible, is quiet, and is draft free too!

Posted By sailawayrb on 31 Jul 2014 01:26 AM

Dan, I thought you said “500 square feet per day 2 men”. So it would take 2 men 2 days to accomplish 1000 square feet. So 2 men x 2 days x 8 hours/day x $50/hour is $1,600 in labor...

He said it was $50/hr for the pair, not per each worker.  That would be 16 hours x $50/hr = $800.

Good catch Arkie6, I now see where Dan also said that too. I normally think of an hourly rate as being per person and NOT the rate for the number of people accomplishing the work. Okay, so Dan is thinking that the average hourly rate for this carpentry team is $25/hour. So 2 men x 2 days x 8 hours/day x $25/hour =$800. So total installed cost for the sandwich built HR emitter is $1,997 + $800 - $167 or $2,630 total (or perhaps $2,630 + $525 or $3,155 total if 23 sheets are required).

Amazing how much she has to say about something she has never done, and would never do!

Perhaps she read about it, in "The Book"? Or had tea with "John" where he imparted his decades of real-world experience in a instant?

If you don't agree with her, you are a hack, a fraud, unlicensed moron and worse; your customers are ignorant, gullible, and most egregiously; effete!

Correct my error on ply
Should be 216 ft2 gap and peri tier turns
784 ft2 ply or 24.5 sheets
Keep in mind this is a square room model
This area would install fast a day perhaps 2workers
In a home with odd rooms hall ways... 500 ft2 day is a good time value
Dan

Correct my error on ply
Should be 216 ft2 gap and peri tier turns
784 ft2 ply or 24.5 sheets
Keep in mind this is a square room model
This area would install fast a day perhaps 2workers
In a home with odd rooms hall ways... 500 ft2 day is a good time value
Dan

Amazing how much you have to say Badger about stuff that you do and clearly know little about! I never said if you don't agree with me any of that and if any of that truly applies to you, there is little I can do about it anyhow. You are free to operate and treat your customers as you please.

Thanks Dan for clearing up the sheet count issue.

As I recall, plates spaced for ~100% coverage have nearly the same heat transfer as a thick slab (with the same covering). A thin slab should be less, although tube spacing has an effect. And the low thermal mass (faster response) and lower weight have different values in different situations. Just to be provocative - Siggy makes it clear that he doesn't like high mass emitters. Even worse is trying to combine them with direct gain passive solar (read the link).

For the record my RHT system set me back ~$1.54/ft^2, with my wife and I supplying the labor. This was inclusive of manifolds and tubing. I will note that we installed it during the crash, so materials were cheaper than now. Dan's suggestion of $2/ft^2 before labor is probably sound.

In my area I think it would be at best difficult to get a slab poured, I know of flatwork that is going begging. Most of the experienced trades headed to the Dakotas to roughneck during the crash, and construction around here has seen significant recovery.

As to why I went with the low mass system the house is ICF with a CCSF roof, so fairly well insulated. I was concerned that a high mass emitter would complicate the control strategy. The low mass emitter gave me a type one loop that I could compensate by varying water temperature, with the 95 degree water I'm running slightly overdamped with a bang-bang control, so very comfortable with no overshoots. My GSHP is also running very efficiently with the moderately low water temperature. I also find that my legs get tired when I'm on a concrete floor all day, just less impact on wood. Anyway, these were my reasons, someone else could easily have different priorities and come up with different trade offs.