Got 2 questions for the experts!!!!!

Tim Gibbins

1.Would like to hear some feedback re:Ultra-Fin. Can it really produce the BTU's they claim? Doesn't the higher water temp. defeat the cost savings of low temp. radiant?
2.How do you calculate the water temp. at the end of a baseboard loop w/180 degree entering, 600btu per foot fin tube at approx. 4-6gpm?

Thanks in advance, you guys are always very helpful, TG

By the way, my father always told me X is an unknown quantity and a spurt is a drip under pressure! (expert)

Jed_2

Question 2

I suggest you get hold of "Modern Hydronic Heating" by John Siegenthaler, P.E. See Chapter 8, Pg 210. There is a whole sequence of repeated calculations, based on published baseboard output ratings(derate IBR heating effect), SWT, gpm, and effective Lenghth of the baseboard setting. Hydronics Design Toolkit Software will do this for you, based on your input value scenarios.

Jed

Unknown

Thanks Jed

> I suggest you get hold of "Modern Hydronic

> Heating" by John Siegenthaler, P.E. See Chapter

> 8, Pg 210. There is a whole sequence of repeated

> calculations, based on published baseboard output

> ratings(derate IBR heating effect), SWT, gpm, and

> effective Lenghth of the baseboard setting.

> Hydronics Design Toolkit Software will do this

> for you, based on your input value

> scenarios.

>

> Jed

gib

Thanks Jed

I have that book SOMEWHERE

Mike Kraft

Tim

Your curious about Ultra Fin.Me too:) This is a recent"radiant floor" product.It confuses me as it seems to confuse you.This reflects in .........

? #1.Doesn't the higher water temp. defeat the cost savings of low temp.

One thing we need to observe is radiant floor is used for its ability to offer humans the most comfort in a heating emitter.It heats objects .......not the air.Non convective.It can be a very pricey install depending on a country mile of options.So lower water temps(the lowest) in my book accounts for a well planned and efficient system.So I agree with you 180* seems a bit stupid.

? #2.How do you calculate the water temp. at the end of a baseboard loop w/180 degree entering, 600btu per foot fin tube at approx. 4-6gpm?


This depends.:).......Lets assume you are using 3/4" finned tube element.Rated @ 600*/linial ft.@ 180*F.

You would need to reference a manufacturers cut on the flow ratings.But for this scenerio stay with 4GPM.....6GPM would give you some harmonics and eventually some errosion leaks.Thats just a bit to fast.

So now you want to know what the water temp will be @ the end.You get to pick that number:)Thats called Delta T....On resy HWBB jobs typically we use a 20* Delta T.This is a # that is needed to obtain your flow rate.20 is a good number because it is a reasonable drop and a convienient number in the equation......simple math.

So you will divide the heatload(BTU/HR) by 8.3(weight of A gallon of water)x60(min in an hour) x your Delta Tee = flow rate.If you multiply all these #'s we get 9,960....round up to 10,000.So you can divide your BTU load by 10K and this gives you your flow rate.You can design with whatever drop you like.It will effect the lengths of the emitters the further down the "loop" you go.

OK?........cheese

Tim Gibbins

Thanks Cheese

Here's the situation, Master bath remo.,HO wants radiant under tile in bathroon. No problem, bedroom has 17' of 3/4 baseboard already, HO says put it on the same zone (HO also seems to be running out of capital on this job) and tie it in at the end of the baseboard loop "it will be cooled down enough". I would prefer to just add a low temp zone, but OK we will mix it down at the radiant manifold, he says "NO too much unnecessary expense"!! I know the temp. at the end of the baseboard loop is going to VARY with the load and convection... I have seen the Euopeans put a thermostatic zone valve on the supply and on the return of panel rads or towel warmers then feed the bathroom floor with the cooled down water, I wonder if that could work here?

Thanks for the formula in the above post, the HOST of this site taught me that in 1992 and I use it daily. I wonder if the answer to my question is answered in one of Dan's books?
I moved not to long ago and cannot find the right box, maybe he and John Siegenthaler will get to sell me some new books.

Happy Trails, Gib

Mark Eatherton1

Why not...

radiant walls? Probably more square feet of wall available than floor or ceiling anyway....

Just thinking outside of the box here.

Welcome to the Wall Gib!!

ME

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

Tim Gibbins

Maaaaaaaan thats a great idea!!!

Too bad the tube is already down with lightweight gyp. The wall wouldn't care about the highter temps. I like your out of the box thinking, what do you think of my thermostatic zone valve thought.

gib

Mark Eatherton1

TRV's and HWBBH

Gib, if the HWBB is in series and controlled by a zone valve you don't want to use a non electric thermostatic radiator valve. It could shut the series circut off before the regular thermostat is satisfied.

Energee makes a 3 way non electric thermostatic bypass valve that would work in your application. The only potential problem I see would be if the bath room needs heat, but the master zone doesn't.

But, as Mick Jagger said, "You can't always get what ya want."

Got a hundred or so friends coming over for my and my wifes 10 annviersary party. Gotta run! 15 gallons of green chili to cook.

ME

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

steve gates

you can

borrow mine. always handy here in the ofice.