Need a 1500' long loop fix

Tim Doran_2

HR,
Send me the particulars and I can calculate the output at various water temperatures and flows. SQFT covered, spacing, slab depth, desired room set point, floor covering, etc.

Tim D.

hot_rod

Maybe

ME's idea to change flow direction every 20 minutes or so would help a lot. Siggy suggested a 4 way to reverse direction. Does this look do-able?

Though I would try to mount a zone valve motor assenbly to the 4 way to move it from position to position. Or maybe just a slow rpm motor and let it rotate constantly?

Any other ideas?

How about a pump to move 1.3 gpm at 79' of head!! to give me a 40 degree delta T.

Or .8 gpm at 38' of head at a 60 degree delta T. A Grundfos 26-120 fits close to that. Thanks John Sweaney at Watts Radiant for the streeeeched calcs!

Gary Hayden

Fixing 1500 ft loop

Hotrod

Any chance that you can dig out under slab at perimeter and patch in distribution lines from below that go back to a new manifold to break the circuits into 4 - all depends on layout pattern and access from below. Use a drill system like used by utility cable layers to go under streets to go from edge of slab where connection is to below manifold location. All sounds like a bunch of work, but the system will be right when done. Possibly run larger pipe from below manifold to perimeter and tee off to smaller pipes as in floor circuit. I guess I need more details on panel design? I am not encouraging anyone to crawl under the slab however and if it is a basement location, a lot of digging!

Mark Eatherton1

I've used that successfully...

numerous times, unfortunately. I used an inexpensive ESBE four way with a matching motor, and a programmable reversing relay from WW Graingers. You can play with the variable time factor and get it optimized.

How did you end up with this one???

I'd post the number from Graingers, but its at work, and I'm not:-)

ME

Andy N._3

I think the four way would be a great way to do it if they made an actuator that would move back and forth position to position. I believe a motor that would turn constantly would only be in the proper position to move the water one direction or the other for a very short time. most of the time it would be "in between" the position you wanted it. What if you tried this arrangement of Normally open and normally closed valves? then you could use a nice digital time clock to program in "on" and "off" times. I think it would give much more flexibility as well as more affordability.

Just my opinion,
Andy N.

John Ruhnke1

Two pumps in a row......

Hot Rod,

How about two Taco 009's pumped in a row or in series. One right after another. The 009 kicks ****. It has the strongest push at the lowest flow. Two in a row doubles the head. I think you will get 60-70 feet of head from this.

JR

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Radiant Wizard

What's the subject here?

I must have missed the original post. Can someone fill me in. Thanks

[Deleted User]

1500 foot long radiant floor loop

and how to overcome it short of jackhammer surgery...

ME

Radiant Wizard

What is the Heat Loss

for the room or building? You might be able to get about 3 btu's per sqft if your lucky out of the radiant. That will be about .90 gpm @ 46ft head. That's with a 10 degree Delta-T. With a 20 degree Delta-T it'getting 5 btu's per sqft it would be .75gpm @ 33ft head and at 6 btu's per sq with a 20 degree Delta-T you would be back at .90 gpm @ 46ft head. A Taco 009 will give you about 33 ft of head @ 1gpm thous allowing you to get about 7,500 btus. Take what you can and add supplmental heat.

hydronicsmike

Wow.

Great ideas.

If you ever try one of the suggestions, please fill us in how it worked for you.

I like the 4-way idea in particular. How do you overcome the delay in actuator response, or do you use quick diverting valves? Or does it even matter (flow in both directions as the valve actuates)?

The idea of using two zone valves, one NO and the other NC, sounds also very good and promising. I guess they'd have to be full port, wouldn't they?

Mike

Art Pittaway

What dia. tube is it??

If you have 3/4", and pictures of the install, maybe you could you find a spot in the middle of the run close to a wall and make it (2) 3/4" X 750 ft loops. That could be made to work without a multi stage pump. It's a long shot but with out the whole picture...? Also guys, don't forget that water is an abrasive and when the velocity and P/D get high enough it eats through things, and pex isn't immune.
Art

hot_rod

Thanks for tips

The job is a finished basement, including carpet and pad. No pictures or documantation available. The builder installed the system and claims he does these all the time and they work fine. I know of one other that is in litigation currently.

I hope to come up with a fix to get some output. Currently the system has a water heater, 1/2" pex, and a 15-42 Grundfos.

The calculated load is 25,041 BTUs/hr about 10 BTUs per square foot, 104 supply. I figure with carpet I could run a much higher supply temperature and handle a 40- 50 degree delta T. I may try a 130 supply, still safe for carpet and pad. At a 50 degree delta tee I should see a 80 return temperature. I think the reversing valve will help a lot.

I am building a reverser and will show the final product. Probably throw a couple of the new 15- 100 Grundfos, (low gpm high head) in series, at it for a start.

I need to find this contractor and give him some design info to read over! If this homeowner ends up in court also, maybe the contractor could be required to show his design and calcs He moved here from Alaska recently. I suspect he may have left a trail of these long loopers behind him in the great north also!

hot rod

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Mark Eatherton1

6A855

That the WW Grainger part number for the TDR programmable relay. Only bummer is that it requires 120 volts for the brains.Also need 6X156 11 pin base socket.

ME

Terry_4

HR

what part of Alaska is he from? Are you talking General Contractor or P&H? I know of a guy who is no longer around here that would be very capable of doing something like this. It's not a good idea to mention names here, but I might know some background info. e-mail me if you'd like.

Terry

hot_rod

Hey ME

what did you use for an operator that allowed you to reverse direction and had a 1/4 stroke. I am looking atb a louver motor from Graingers.

hot rod

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David Van Wickler_3

Heat Timer

and I have been working on a reversing control for some time. It would talk to a three wire motor and be capable of programming length of time between cycles, position reset after call for heat is satisfied.

I called Heat-Timer because TAco has been using primary secondary pumping strategies in commercial applications in both heating and cooling. In cooling, the temperature differentials are much tighter, with significant latent losses if the chill water temperature isn't maintained.

The question is what is the average water temperature required and what is the flow rate?

If this is a "please help me I'll pay you anything" then install one or two pressure guages (0-15) and measure the differential to find out the flow - just be sure to lower the system pressure to 8 or so.

You will need to figure out the supply/return temperature and knowing the flowrate determine the velocity. Velocity is time/distance. So with the velocity you'll know how to set up the reversing function timing.

Another method is to locate the loops and cut the concrete.

David Van Wickler_3

Heat Timer

and I have been working on a reversing control for some time. It would talk to a three wire motor and be capable of programming length of time between cycles, position reset after call for heat is satisfied.

I called Heat-Timer because TAco has been using primary secondary pumping strategies in commercial applications in both heating and cooling. In cooling, the temperature differentials are much tighter, with significant latent losses if the chill water temperature isn't maintained.

The question is what is the average water temperature required and what is the flow rate?

If this is a "please help me I'll pay you anything" then install one or two pressure guages (0-15) and measure the differential to find out the flow - just be sure to lower the system pressure to 8 or so.

You will need to figure out the supply/return temperature and knowing the flowrate determine the velocity. Velocity is time/distance. So with the velocity you'll know how to set up the reversing function timing.

Another method is to locate the loops and cut the concrete.

Mike T., Swampeast MO

Not ME but...

...Danfoss ESBE series 60. Fixed 90° limit switches, reversible, 24vac with either 3-point or "floating" control depending on model.

Operation time seems a bit high, 1.7 minutes, but lots of torque at 45 in/lbs.

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

ESBE series 80 has adjustable limit switches and various operation speeds. Type 81 does 90° in 10 seconds @ 60 hz, but torque is rather low at 25 in/lbs. Series 82S bumps the torque up to 90 in/lbs with corresponding increase in operation time, 45 seconds.

All of these models seem available in either 3-point or floating control as well.

Mike T., Swampeast MO

One of my weird ideas...

...I'm sort of guessing that you have to resort to the directional reversal because the layout is undocumented and you have no idea where to find the "middle" to split the loop.

Perhaps you could hook up the system, run it and "follow" the heat with a IR thermometer? If lucky it may work and it may be in a "good" place to make a small hole in the slab and still wind up with an accessible service-access point.

Mike T., Swampeast MO

Muphy's Law

Both of those operators can be had with auxilliary contacts than can be used for "proving". For piece of mind I think you could use an adjustable delay electronic relay (probably delay on make) to light a "trouble" light if/when the valve "sticks" or motor dies.

hot_rod

Here's what I have so far

I tried an Erie ZV motor first, then tried this Louver motor. Seems to have more fizz (torque)

A fairly simple mount to the 4 way valve with some modifications to the supplied brackets. It powers open, spring return.

Should be a fairly inexpensive cure. If it works

Just kidding about the 1 HP Burkes, sort of!

hot rod

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RichW

1500 foot loop

Circulator 1 runs continuously. The 4-way valve is power on and spring return- it cycles the water back and forth through the 1500' loop. The easiest control for the 4-way valve is a timer motor/switch. This eliminates the need for a computer controller to keep track of the remaining time on the last cycle. When the call for heat ends the timer motor is switched off and the 3-way valve sends water to the inlet of the circulator.

RichW

1500 foot loop

Circulator 1 runs continuously. The 4-way valve is power on and spring return- it cycles the water back and forth through the 1500' loop. The easiest control for the 4-way valve is a timer motor/switch. This eliminates the need for a computer controller to keep track of the remaining time on the last cycle. When the call for heat ends the timer motor is switched off and the 3-way valve sends water to the inlet of the circulator.

Richard Miller_2

I just got back from Alaska...

...and I piped the entire system in 1,000' loops. Since it is so far north I figured it would work.








JUST KIDDING! REALAX!

[Deleted User]

According to Siggys new soft ware...

this circuit will deliver 17,000 BTUH at .54 GPM with a 007 circulator.

Only problem is, it occurs in the first 20% of the circuit!

This software is GREAT!!

ME