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Ultra-Fin

Rich_10
Rich_10 Member Posts: 6
Has anyone ever heard of or used Ultra-Fil Radiant Floor Heating System before? I'm a heating contractor from Vermont and always used climate panel and quick trac. I have no experience with this system.

Thank you,
Rich

Comments

  • Bob_31
    Bob_31 Member Posts: 7
    ultra fin

    Rich I am building a new 2500sqft colonial in central NY. I am looking at this system from a DIY point, I have prices to do the whole job and as you know very expense do to the labor intensity. There is a system that I saw locally installed but has not yet been used. We are starting to build the end of APRIL. If you find anymore out good or bad can you let me know. Thanks BOB in NY
  • Nron_9
    Nron_9 Member Posts: 237
    ultra fin

    Have yet to see an ultra fin system working but I will soon we are looking at installing a boiler for a customer who has installed the piping him self with the local reps help , there suppose to put out 20 btus per sq/ft which is a little shy for our climate I will post and let you guys know how it works when were finished
  • Justin Gavin
    Justin Gavin Member Posts: 129
    Ultra-Fin

    We have used Ultra-Fin on several jobs and continue to offer it on almost every bid. The stuff works really well for heating and floor warming.

    Couple of points to consider.

    1. To save on labor take 2 of the fins and screw together one side to create a "clam-shell". Place them in a box. You save alot of time and labor doing this prep work.

    2. I have tried regular pex and pex aluminum pex. I found the regular pex easier to pull through holes and to get in tight joists. The downfall is you might here ticking noises when the system heats up due to the expansion and contraction of the fins touching the pex aluminum. But the plus side is that that regular pex seems to transfer the heat quicker to the fins making it more responsive. We are sticking to using the pex aluminum for now just to be careful of noise issues. Also as you may or may not know the pex aluminum holds its form better which is important on return bends.

    3. Spacing, we found that the spacing is pretty important. Depending on the insulation of the band joists we usually start 6-8" From the wall and keep the outside wall loops a little tighter than recommended CYA. And when you get in tight spaces we have used baseboard element in the loops. We also do this in small confined areas (.5 baths, Coat Closets, to keep boots warm etc).

    4. From a pricing standpoint it beats the pants of Gypcrete, its more responsive than gypcrete allowing you to use a setback schedule.

    5. On a majority of our bids we offer Hydro-Air system, Infloor in the basement & garage, spot floor warming on tile areas using floor sensors and seperate stats. When doing this you might consider putting in a 3 way mixing valve to temper the floor warming temperature so that you don't overshoot rooms.

    6. When we do a system like this we always try to bid with a variable speed air handler with electronic air filter, This keeps the dust and air movement down as much as possible.

    7. This system gives customers an affordable system with options galore.

    8. We always offer the option of a complete home Ultra-Finned with a high velocity AC system with a second stage HW coil for second stage heat (often times needed for our climate) We sell a few of these a year but most people go for the Air Handler and Ultra-Fin.

    9. All in all we like it as an affordable option to gypcrete. I also like it better compared to staple up personally speaking.

    Good luck and if you have any more questions in particular feel free to shoot me an e-mail and I will help you the best I can.

    JG

  • Bob_31
    Bob_31 Member Posts: 7
    ultra fin

    Ron you speak of it putting out 20btu/hr and that it is a little shy for your area.1) What area are you in? 2)How can you increase the btu output so that your heating is working correctly and not undersized. I live in central NY and we start building in May, Also does it matter if you use a pinpoint boiler or a three pass like a Buderus for this system. Thanks Bob
  • Nron_9
    Nron_9 Member Posts: 237
    Bob ultra fin

    the boiler doesn’t matter except in the wallet over the long hall ,but our design for heating is usually more than 20 btu's +++ for every square foot of floor space to heat our homes here in Canada , I wanted to know if the heat output matched what the brochures said and if there are any problems with floor temp . does the heat affect the joist system the guys in Calgary don’t like the idea of running 180 F water through the new TGI plywood they feel the heat will affect the glue in the joists
  • Mark_33
    Mark_33 Member Posts: 5
    edited September 2018
    Ultra-Fin Experience

    Rich,

    I've been promoting Ultra-Fin for 3 years. I rep them in W.PA and WV. I have over 80,000 fins out there working better than any other joisted floor system I've used since 1988. I have had nothing but excellent results. The only drawback that you will incurr will be how much flooring material you try to put on top of it. Too much carpet still doesn't work on this or any other system.

    One of the biggest advantages of Ultra-Fin is the output. The McDuff's had the product tested independently with phenomenal results. With water temperature at 180F, the room at 72F, and a floor temperature of 85F, the system can crank out 41.6 BTUs/SqFt. Being the skeptic that I am, and thinking about the simple formula of
    floor temp. - room temp. X 2 = BTU/Sq.Ft.Output, the test result didn't add up. After further investigation of the test procedings I realized there were no walls mentioned on the test floor. They built a model 4' wide and 10' long, 3-16"O.C. bays with 3/4" Plywood on top, Ultra-Fins @ 30" spacing, and NO Walls to hold the heat in that space. The test area, or room, was obviously larger than the floor heating sample. Consequently, the test sample was heating more than 40 sq.ft..

    I have never designed joist floor systems for more than 25 BTU/SqFt. Not with Aluminum Plates, Staple-up Systems, or Hanging Systems. There are limitations of output because of direct contact issues with the first two systems, (you got to use tempering valves), and output capability issues with the Hanging Systems, (PEX just isn't the best radiator out there). Ultra-Fin dismisses my former paranoia. As long as the floor covering is kept to a low R-value, I don't hesitate to venture above that 25 BTU/SqFt range when the "AUST" is low, like when a lot of glass is present in an area.

    I don't hear much anymore about "AUST" factors. If you aren't familiar with that term, it stands for Average Unheated Surface Temperature. When you have a lot of glass in a room, the glass gets way down in the 50'sF range when it's cold outside. As the cold air drops off the glass and across the floor, the floor heat is wiped away before it hits the 85 degree "No-No" Range the Wood Floor Manufacturers dictate. In other words, the floor can crank out 41.6 BTU/SqFt without harming wood floors. I don't believe that happens with the other joist systems. You have to go to way more expensive systems like Thin Slabs or ThermalBoard.

    Ultra-Fin saves you serious money in copper distribution piping. You can actually homerun all zones to one central manifold location in the basement. That is because you can heat up to a 500SqFt area with 250' of 1/2" PEX.(Suspended systems require 3-250'loops for the same area). That includes 50' of leader to get you to the manifold. Most zones are less than 500SqFt, but even with a 1000SqFt zone, you only add one more Zone Valve. The cost of that zone valve is way less than piping to a remote 6-loop manifold location.

    You save money again by eliminating Thermostatic Mixing Valves. The system is much like baseboard in that you pipe it directly to the boiler. Whether the water is 160F or 180F, it heats the fins that are suspended 2"-3" below the bottom of the subfloor, which heat the air in the joist space, which EVENLY heat the wood floor above without harming them. A true Win! Win!

    The installation is pretty simple too. Ultra-Fin offers a 15 minute video that shows you how. They would have made it longer but they couldn't think of anything else they could possibly tell you. You pop a chalkline 12"-15" from the rim joist, drill 1" holes 3" below the subfloor, go in 30" more and do the same thing, then sew the tubing through the holes. There are a few tricks that make you more proficient at the process, shown in their installation book. Next, you rivot the first row of holes together at your bench, then slide the pair over the tubing and rivot the fins together. My distributors have pneumatic rivot guns available to their customers or they sell them for approximately $85.00. You really need to have the pneumatic rivot gun. It makes life much easier.

    If you have any questions, let me know.

    Good Luck!
    Mark

  • Nron_9
    Nron_9 Member Posts: 237
    ultra fin

    mark any homes in canada i live in the calgary region of alberta and we get teps as low as -35C though not for long ,but we still need to be warm enen on the colest day of the year
  • Kevin_in_Denver_2
    Kevin_in_Denver_2 Member Posts: 588
    Ultra-Fin Recommended heat output

    Although the system was measured at 41 btu/ft2/hr, I talked to Matt at the factory who said you should use 20-25 when designing a system.
    Superinsulated Passive solar house, Buderus in floor backup heat by Mark Eatherton, 3KW grid-tied PV system, various solar thermal experiments
  • Mark Eatherton1
    Mark Eatherton1 Member Posts: 2,542
    Spoken...

    like a true rep. I have some questions for you Mark. How is it that this product delivers more btu/square foot/hour than its surface to air capacity can deliver?

    Was this a cold start figure, or a stable condition steady state situation?

    I've seen the product, and have in fact tested it in radiant wall applications. I found that when the air in the cavity get raised, that the convective output pretty much drops off, and the only thing left is the radiant component.

    I have no doubt that they do in fact put out some heat, the question is how much?

    And what about the cost of operation. Given the opportunity to operate a system at a substantially lower temperature (140 or less) I'd opt for something that doesn't require 180 degree F temperatures. But, thats just me...

    Nice job of representation on your part though.

    Will there EVER be a set of testing standards against which all products can be rated??? I'm holding my breath.

    ME

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  • John Madden
    John Madden Member Posts: 19
    Ultra Fin

    I have done three homes in our area (north western VT) the latest being a 3000 sq.ft. 2 story home for my son. The basement poured floor, and the garage, are done with pex piping embeded. The living areas (first and second floors) are done with Ultra Fins. I used a buffer tank with a reset control and a manually adjusted tempering valve for the supply water to the poured floor zones. That way tank temperature is governed by outside ambient temperature and the temperatre to the poured areas is constant. We had several periods where the outdoor temperature dipped into the negative 20'sF and had no trouble maintaining a very comfortable 68° indoor temperature. This with a building under construction! The highest system operating temperature recorded was 154°F.

    It is a fact which MUST be remembered that if there is a huge R factor for floor coverings that no matter the distribution method you won't "meet the need"!!

    As with any system there are "trade-offs" some of which may not show up right away. In our particular experiences we have an average heat loss of 28 BTUh/sq.ft. at design (we use -30°F) or a delta T of 100°F.
  • Mark_33
    Mark_33 Member Posts: 5
    Ultra-Fin Output

    > like a true rep. I have some questions for you

    > Mark. How is it that this product delivers more

    > btu/square foot/hour than its surface to air

    > capacity can deliver?

    >

    > Was this a cold start

    > figure, or a stable condition steady state

    > situation?

    >

    > I've seen the product, and have in

    > fact tested it in radiant wall applications. I

    > found that when the air in the cavity get raised,

    > that the convective output pretty much drops off,

    > and the only thing left is the radiant

    > component.

    >

    > I have no doubt that they do in

    > fact put out some heat, the question is how

    > much?

    >

    > And what about the cost of operation.

    > Given the opportunity to operate a system at a

    > substantially lower temperature (140 or less) I'd

    > opt for something that doesn't require 180 degree

    > F temperatures. But, thats just me...

    >

    > Nice job

    > of representation on your part though.

    >

    > Will

    > there EVER be a set of testing standards against

    > which all products can be rated??? I'm holding my

    > breath.

    >

    > ME

    >

    > _A

    > HREF="http://www.heatinghelp.com/getListed.cfm?id=

    > 88&Step=30"_To Learn More About This

    > Professional, Click Here to Visit Their Ad in

    > "Find A Professional"_/A_



  • Mark_33
    Mark_33 Member Posts: 5
    Ultra-Fin Output

    Mark,

    You sound bitter!

    I already explained the surface to air dynamics. I'm not Mr. Science, but I know I can put out 50+ Btu/Sq.Ft. in a sun room concrete floor without taking the floor over 80F. I know that might be unusual for a Rep to take that much interest in jobs, but then again I'm an unusual Rep. I still consider myself a student of RFH even though I've been doing it since 1988. I don't know it all, and I am a skeptic just like you, so I try stuff first before getting excited about it, like I am about Ultra-Fin. The fact remains that the fins work really well. I have over 87,000 of them out there at last count. They all work! I still limit my designs to approx. 25-30 BTUH/SF, depending on floor coverings and other factors.

    I'm suprised that you tried them in a wall system. McDuffCo doesn't reccommend them in that aplication because the product is designed to heat the air in a dead air space, and then the warm air heats the subfloor surface. You must remember, warm air rises, therefore it will tend to favor the high side of the wall. Hanging tubes through wall studs doesn't work well either, but aluminum plates against the drywall does. The method of heat transfer all depends on the application. Sometimes radiation, sometimes conduction, sometimes convection, and a lot of times a combination of all three.

    I hope this helps! Hey Mark, light'n up a little bit.


    I'm not sure why you are so upset about such a good product. What's wrong with running PEX at 180F? ASTM F876/F877 rating says it's O.K. even @ 80PSI. What's wrong with eliminating the need of a tempering valve? A boiler reset control is all you need if you want some additional energy savings.

  • Mark_33
    Mark_33 Member Posts: 5


    Ron,
    Every system has it's limits. If the heatloss is greater than 30 BTUH/SF, I look at supplemental heat sources.
    Mark
  • ALH_3
    ALH_3 Member Posts: 151
    high temp

    Two drawbacks I see. Perforating the joists and having to run at high temperatures, the latter being the biggest drawback. Ultra Fin eliminates the possibility of using a condensing boiler. Ultra Fin might work, but at what cost? With rising fuel costs, systems like these make less sense.

    As far as 50 btu/ft^2/h goes, the only way to increase a temperature limited radiant floor's steady-state output is to decrease the temperature of the room. I doubt most people would be comfortable in a 55ºF room.
  • Radiant Wizard
    Radiant Wizard Member Posts: 159
    Ultra-Fin

    I too was interested in the product so I decided to go to the horses mouth for some questions. So I spoke with Malcom MacDuff (President of the Company) and I have come up with some things that trouble me.

    1.You must use 180 degree water and zone each room. All this does is bring us back to bang, bang operation. Outdoor reset is not an option.

    2. They require floor surface temp to be 85 degrees. I don't know about you but with my designs with traditional radiant heating floor temps never need above 80 degrees. Seems like your at the max with Ultra Fin. Good chance screwing up a floor.

    3. You need the entire bay. Proper insulation and spacing are crucial.

    4. Here is the most important problem. SLOW RESPONSE TIME. According to the manufacturer it takes 45 minutes to and hour for the floor to come up to temp. This is where that bang, bang operation can get you into trouble especially with a room with solar gain.

    These are just a few things that bother me with the system. I really believe it's catered more to the DIY than the professional but like any product it has a place.

  • hr
    hr Member Posts: 6,106
    Concerns about 180° near engineered wood members

    The TJI folks have contacted Larry Drake with issues where pex has been stapled against the upper cord of wood "I beam" type of joists.

    Apparantly at elevated temperatures the laminate starts to delam and caused bumps in the floor as the wood swells and lifts the subfloor right at the point of tube attachment. Something about the moisture being driven out of the laminate, caused by high temperatures at "tube attachment points" along the member.

    I would think the same effect could be possible where the 180° tube passes through, and contacts the laminate, at holes in TJI type of materials. Maybe an insulator at EVERY hole should be mandatory. We all know how that works out in the field :)

    I think the radiant industry needs to work with the Forest Resource labs and engineered wood product manufactures to get some actual data on this topic. Seems like problems and complaints along this line end up at the TJI manufactures desk, often unbeknownst to the radiant industry. We certainly don't want the engineered lumber folks denouncing radiant, due to this installation problems, do we?

    These specfic problems have been cases where a staple up (suspended tube type application) have had the pex fastened to the sides of TJI's at that upper cord. In this case the pex tube actually contacts the laminate. The theory is the high temperature drives all remaining moisture from the wood and causes the glues to fail and allows the delam. From what I have been told. I would imagine the same effect would be noticed when pex, or rubber is stapled in contact with "ply" type of wood, and run at high, 180-ish, temperatures. Which is not uncommon when radiant systems fail to perform at design, or below, days!

    Time to build another test assembly in my shop! Plenty of scrap TJI pieces on job sites around here :)

    I'm still a big proponent of low temperature radiant applications. To much potential for problems with high temperatures. Including pex lifespan, fitting stress, expansion noise and wear points, etc, etc.

    Personally that 140-150°F number seems like a safe "high limit" number for hydronic radiant.

    It also conviently fits "condensing" temperature equipment :)

    160° and up temperatures conviently "fit" baseboard, panel and cast iron radiators, and air handlers. Maybe that's where it should be left :)

    hot rod

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  • Nron_9
    Nron_9 Member Posts: 237


    In Europe the new boiler max is 167 F that is the boiler max high limit for heating systems now they say for every 3* you drop boiler temp you get 1% energy savings now per house thats not a lot but per town it is large enough to make sence why wait untill we have acid rain here to decide that we should do somthing about it when we can learn from others , and then make changes to apply to our particular regins to make things work best
  • David_5
    David_5 Member Posts: 250
    High temps and plywood

    Roof sheathing is plywood and certainly gets hotter than 100 degrees in the summer. I have never heard of problems in that situation.

    David
  • John Abbott
    John Abbott Member Posts: 355
    Good point.......

    David,

    I would hazard a guess even here in the northeast that under black shingles the plywood and TJI rafters are over 160 degreesI know I have measured air temps as high as 140 while installing a Spacepak system In a Police Station last summer.

    John
  • hr
    hr Member Posts: 6,106
    This report

    documents some actual roof temperatures. Notice, however the time that the roof plywood actually was at 160°F.

    http://www.fpl.fs.fed.us/documnts/fplrp/fplrp543.pdf

    I suspect a radiant floor system running 24/7 on a design day would be more stressful than an intermitent roof temperature load.

    As I understood the problem with hot pipes stapled to the TJI cord was the unevenness of the heat. The attachment points that saw the elevated temperatures were the problem area. Ripples in the subfloor could be felt over the spots where the tube contacted, and dried, and caused the seperation of the top cord.

    Plywood and engineered lumber manufactures acknowledge the strength degredation caused by high temperatures and have tables that indicate the loss of strength at various temperatures. This could be more of a problem in a loaded floor joist than a plywood roof that really doesn't see loading like a floor of floor joist. probably wouldn't see snow loading at 160 F temperatures onn a plywood roof.

    Anyways, I'm just passing along observations and concerns of the manufactures. I'm not nitpicking the the UF product, just the challanges with high temperature wood exposure in general.

    I sure wouldn't want to have to fix a bunch of delamed floor joist in one of my customers homes :) Especially if my radiant heat system caused the problem! Would you?

    hot rod

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  • John Abbott
    John Abbott Member Posts: 355
    I.....

    Printed that report and read it good information thank you.I do have one question though the tests were done on a 3/12 pitch which I believe would limit exposure to the sun until it was high in the sky.Here in the NE and I suspect anywhere else there is significant snowfall and severe cold that a pitch that flat is unheard of.My question is would a 12/12 pitch with a SW exposure generate temps higher than in this test?I am not nitpicking the test I am just trying to get some data to apply to our field and even a" guesstimate" would be welcome.

    John
  • Mi39ke_2
    Mi39ke_2 Member Posts: 61
    Elevator going down...

    In my market, the Ultra Fin is being gobbled up by the novice hydronic distributors and they in turn are regurgitating it into manna from heaven for the na
  • jerry scharf_2
    jerry scharf_2 Member Posts: 414
    The 12/12 should be cooler

    The amount of solar radiation per sqft drops as the angle shifts from perpendicular to the sun rays. If you swag the summer peak solar collection angle in the low 20 degrees (solar rays in the high 60s), the 16 degree roof would get hotter than a 45 degree roof.

    jerry
  • Mark Eatherton1
    Mark Eatherton1 Member Posts: 2,542
    Bitter???

    Sorry if I came across as bitter. Rather, I was TRYING to come across as a skeptic. I just dislike false, unproveable numbers in a public forumn. Thats all. I agreed that they do work, they have to. But to what degree?

    You never answered my questions about the state at which it supposedly delivered all the btu's. Was this during a cold start up, or after 4 hours of continuous energy input. The fact that you have so many out in the field measn nothing to me really. There are a lot of staple up systems out there too...

    Trust me Mark, you'll know when I'm bitter:-)

    Are you telling me that air is an excellent transporter of heat? Are you telling me that these things can create convective currents in a stagnant, hot, closed quarter environment?

    Show me some numbers that make sense, and I'll copitulate.



    TTFN

    ME

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  • Mike T., Swampeast MO
    Mike T., Swampeast MO Member Posts: 6,928
    Help me understand this test please...

    "One of the biggest advantages of Ultra-Fin is the output. The McDuff's had the product tested independently with phenomenal results. With water temperature at 180F, the room at 72F, and a floor temperature of 85F, the system can crank out 41.6 BTUs/SqFt. Being the skeptic that I am, and thinking about the simple formula of floor temp. - room temp. X 2 = BTU/Sq.Ft.Output, the test result didn't add up. After further investigation of the test procedings I realized there were no walls mentioned on the test floor. They built a model 4' wide and 10' long, 3-16"O.C. bays with 3/4" Plywood on top, Ultra-Fins @ 30" spacing, and NO Walls to hold the heat in that space. The test area, or room, was obviously larger than the floor heating sample. Consequently, the test sample was heating more than 40 sq.ft."

    It sounds as though this floor construction was put into a space at 72° and the "output" is determined by flow and delta-t. That will determine the amount of heat being liberated by the tube and the Ultra-fin, but not the amount of heat being delivered to the space by the floor surface.

    Unless this construction was sunk into a depression, it had sides (or at least I hope it had sides). Say they're 10" high. That adds another 20 square feet (10" * 28'), and output per square foot is a more realistic 27.73 btu/hr.

    If the construction was highly insulated both around and below, then I'm having a very rough time understanding this output level unless it was the peak achieved as the construction was being heated. I guess there could be a big fan blowing across the surface ;0


    I'm not doubting the ability of the Ultra-fin to remove heat from the water, it just seems to be rated in an extremely misleading way and when that happens I tend to get highly skeptical.

    If you start making claiming like "50 btu/hr/sqft output" with floor surface and room air temperatures within generally accepted limits, people are going to think that they can actually deal with a 50 btu/hr/sqft loss from a "real" floor.

    That reminds me of the way audio amplifiers used to be rated when comparing "normal" home equipment with automotive equipment. Home audio was rated for a continuous output at very low distortion while automotive audio was rated for peak output at extremely high distortion. It does seem to me that Ultra-fin takes the "automotive" route when it comes to rating...
  • Mike T., Swampeast MO
    Mike T., Swampeast MO Member Posts: 6,928
    A.U.S.T.

    Understood--essentially another way of looking at M.R.T (mean radiant temperature).

    "When you have a lot of glass in a room, the glass gets way down in the 50'sF range when it's cold outside. As the cold air drops off the glass and across the floor, the floor heat is wiped away before it hits the 85 degree "No-No" Range the Wood Floor Manufacturers dictate. In other words, the floor can crank out 41.6 BTU/SqFt without harming wood floors. I don't believe that happens with the other joist systems. You have to go to way more expensive systems like Thin Slabs or ThermalBoard."

    Au contraire sir. I have two nearly identical baths both heated with copper in Thermofin under the floor. They share common supply/return manifolds and are constantly circulating with temperature dictated by simple mechanical reset. No control valves, no t-stats, no nothing. They have an identical tube layout, tube length and fin length. The only real difference is that one bath has two double hung windows and an exposed wall--the other is fully internal.

    At design conditions (with heat loss reduced by 20% for the efficient nature of radiant panel heat) the exposed bath floor has around these output characteristics:

    32 btu/hr/sqft* (ACTUAL size of heated portion--not the entire floor) @ 83° average surface temp @ 125° average** supply temp in a 74.8° room.

    The internal bath floor has these output characteristics:

    10 btu/hr/sqft* (ACTUAL size of heated portion--not the entire floor) @ 83.4° average surface temp @ 135° average** supply temp in a 75° room.

    ---------------------------------------------------

    *output can be significantly increased above these levels by fully opening the supply/return valves supplying the manifold--they are both only about 1/3 open.

    **supply temp 140° with 30° delta-t in the exposed bath; 10° delta-t in the unexposed; 20° average for both as flow through each should be essentially identical.

    ---------------------------------------------------

    Those radically different outputs still trouble me and I still don't quite understand, but I most sincerely believe it has MUCH to do with conduction. If this were a highly convective transfer system (like Ultra-fin), I most sincerely believe that the output characteristics would be VERY different.

    ---------------------------------------------------

    By no means does Ultra-Fin have some sort of "magical" characteristic that allows it to put out more heat from the actual panel when compared to other forms of heat transfer from the water. You merely have to change the conditions (AUST, MRT, etc.) of the space.

    One other thing. While the cool air from all of those windows moving across the floor will tend to draw a bit more convective output, the radiant output is changing with a 4x magnitude with difference in temperature between the floor and all of that glass.

  • Mike T., Swampeast MO
    Mike T., Swampeast MO Member Posts: 6,928
    Those output numbers & the difference

    Still really bother me. This is a highly dynamic system, but I've been lucky enough to have nearly steady outside temps right at design (8°) to take lots of measurements that should be quite accurate.

    I tried to make some comparisons between these and another bath in the house that has an electric radiant floor, but the numbers seemed to be "garbage". Unlike the radiant baths, the air temp yo-yo's and seems to bear zero relation to the temp of the spaces surrounding. (The radiant baths stay right at 5° above the average temp of the surrounding spaces regardless of inside or outside temp.)

    As the hydronic floors were intended for "floor warming" and supplemental heat is available (or unnecessary in the case of the internal bath), I never bothered to compute a heat loss for these spaces--until today.

    3x the output with the same panel construction; essentially identical layout and water flow; 2x difference in delta-t; nearly identical surface and air temps???? How can this be?

    If there is any "magic" here, it's the magic of proportional control, constant circulation, reset, and radiation--and none of those control methods seem to be options with the Ultra-Fin.

This discussion has been closed.