radiant slad heat


  #1  
Old 12-08-08, 01:18 PM
B
Member
Thread Starter
Join Date: Dec 2008
Location: Northeastern, MN
Posts: 160
Upvotes: 0
Received 0 Upvotes on 0 Posts
radiant slad heat

Just found this site. Lots of good advice to be found here.

I have a DIY house I build from plans, It's 2100 sqf with 800 sqf garage. All built slab on grade with 2" insulation under it and 2 1/2" on the edge, or side of the 2' thick drop footing.
I have lived in this house for 2yrs now, this will be the 3rd winter. And I dont have the heating system set up the way it should be yet. It's kind of a tempary setup I did for speed and cost during construction. And now I think its time to start to plumb, zone and wire it the right way.

I have 3 manifolds HeatLink brand 1 for garage w/3 loops 2 for house 1 w/4 loops and 1 w/6 loops... 1/2" pex in slab

The Boiler a Peerless Pinnacale 93% condensing 88,000 BTU.
Boiler is located in the garage and the manifolds are in the house. 40 ft of 1" pex connects the two.

First this I want feed back on is the way I have the two pumps set up. Pump #1 a GrundFos Type UP26-99f is mounted just before and pumping directly in to the 3 manifolds. Pump # 2 a GrundFos Type 15-42 is mounted on the return line just before it goes back in to the boiler. With these two pumps at different GPM is this wrong ? The bigger 26-99 pump gets alot warmer than the smaller 15-42, after they have been running.

Thank in advance, Buzz
 
  #2  
Old 12-08-08, 05:56 PM
X
Member
Join Date: Nov 2005
Location: USA
Posts: 2,338
Upvotes: 0
Received 0 Upvotes on 0 Posts
It's wrong if the system is not piped primary/secondary. Otherwise, you have pumps in series and that ain't right, at least for the application as you've described it.

If it's primary/secondary, then the pump for the boiler loop should be sized to provide the flow rate specified by the manufacturer.

The pump for the distribution loops should be sized for the head loss and temperature drop of the system as designed.
 
  #3  
Old 12-08-08, 07:20 PM
B
Member
Thread Starter
Join Date: Dec 2008
Location: Northeastern, MN
Posts: 160
Upvotes: 0
Received 0 Upvotes on 0 Posts
Xiphias, Thanks for the reply. Yes, the pumps are in series. One should be removed ? The primary/secondary you talked of. Would that be if I had a mixing valve it would be primary loop? And secondary would be from mixing valve to manifold pump ? Head loss ? Don't know. Temperature drop Boiler water temp goes in manifold at 110 and comes out of slab about 80-85. I'll give you a little more information on the in floor loops, maybe for head loss. Manifold #1 garage 850 ft 3 loops 1/2" pex #2 house 1124 ft 4 loops 1/2" pex #3 house 1516 ft 6 loops 1/2" pex 3490 ft total 1/2" pex With that many feet of pex that's why I added the bigger 32 GPM pump. System Design ? I had a heat loss done, thats all design I've had done. Any more help would be great, Thanks Again, Buzz
 
  #4  
Old 12-08-08, 07:35 PM
X
Member
Join Date: Nov 2005
Location: USA
Posts: 2,338
Upvotes: 0
Received 0 Upvotes on 0 Posts
Here's the I&O manual for the Pinnacle

http://peerlessboilers.com/DesktopMo...hod=attachment

(I think that'll work. If not, go to peerlessboilers.com and go to the tech section and find the manual.)

The installation shows how to pipe primary/secondary, and it provides a guide for sizing the boiler loop circulator.

To figure the head of the radiant circuits, use Taco's TD10 "Selecting Circulators." taco-hvac.com.

The Pinnacle is a re-badged HTProducts Munchkin. They also have some excellent piping diagrams.
 
  #5  
Old 12-09-08, 05:07 PM
B
Member
Thread Starter
Join Date: Dec 2008
Location: Northeastern, MN
Posts: 160
Upvotes: 0
Received 0 Upvotes on 0 Posts
re;

I found my Installation & Operation Manual. My boiler has a flow rate of 6.4 (gpm), with a pressure drop of 5.0 (ft).

So dose it mean that my primary loop at my boiler should have this size pump ? The pump I have installed now in return line now has a 0-15 (gpm). Its the Grundfos up15-42f. Would this be to many gpm. Or would a pump like the up15-10f with a 0-8 (gpm) be better ? Why are these pump rated at Zero to____ gpm ? Does it mean they would run at, say 4 gpm if they were restricted ?


Thanks again, Buzz
 
  #6  
Old 12-10-08, 10:45 AM
B
Member
Thread Starter
Join Date: Dec 2008
Location: Northeastern, MN
Posts: 160
Upvotes: 0
Received 0 Upvotes on 0 Posts
head loss

How do I do a head loss ?

Would it be better to use 1 pump and zone valves for secondary, or go with 3 pumps for the zones ?
 
  #7  
Old 12-22-08, 10:08 PM
B
Member
Thread Starter
Join Date: Dec 2008
Location: Northeastern, MN
Posts: 160
Upvotes: 0
Received 0 Upvotes on 0 Posts
Does anyone have any answers for me ? Or advice.

Thanks, Buzz
 
  #8  
Old 12-23-08, 05:12 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 19,710
Upvotes: 0
Received 8 Upvotes on 6 Posts
I dunno answers... maybe...

You are correct that as the pump is restricted, it will pump less water. That's exactly what the pump curve charts show.

So, let's say you want to pump 6.4 GPM at 5' of head... find a pump where these numbers tend to intersect... usually better to pump a bit more than a bit less, if none are exact. You usually want a pump with a 'flatter' curve, rather than a 'steep' one.

I would plan on using one of the recommended pumps in the I&O manual.

Head loss... straight pipe or tubing has X number of feet of head per X (usually 100) feet of pipe at a given flow rate. Each 'fitting' has a head that is expressed in feet (of straight pipe). You need to add all these numbers up, and come up with a number called TEL (Total Equivalent Length) of pipe. Then you multiply that with the spec for the tubing to come up with total head.

In parallel circuits, you typically would use only the most restrictive of the circuits for pump selection purposes. This is because if you can pump the most restrictive, you can pump the others...

Me, I would probably go with the zone valves and one pump, just from an electricity saving angle... but others like pumps ... it's like chocolate and vanilla ... your choice.

Are you currently running full temp water to the radiant manifolds? Radiant is usually run at lower temps ... you probably need mixing valves and pumps ... look at the way the radiant panels are shown in the Peerless manual ...

Your end result piping diagram is going to look like a combination of elements from several of the diagrams in that manual.
 

Last edited by NJT; 12-23-08 at 05:32 PM.
  #9  
Old 01-01-09, 09:37 AM
B
Member
Thread Starter
Join Date: Dec 2008
Location: Northeastern, MN
Posts: 160
Upvotes: 0
Received 0 Upvotes on 0 Posts
pump sizing

I've been looking at Taco TD-10 selecting circulators, as Xiphias said to. Trying to figure ft of head. Boiler Loop was easy, because of All piping same size 1 1/4". But have a little me difficulty doing the primary loop.
The 90' of 1" pex I got the head figured out, and all the 1" copper piping to the manifolds. That is about 13.3 ft of head.
But how do you do the 3 manifolds of 1/2" pex ?

Do I Just do the manifold with the most Loops ? That would be 522 ft of head !

Or do I just do the longest loop on the manifold ? That would be about 35.2 ft of head.

NJ Trooper asked if I was running full temp water through manifolds...... NO ..... Aquastat on boiler is set for 125* and thats about the only higher I can get the temp up the way the boiler and piping is set up now.
Thats why I need to Replumb and pump my system. So on them cold nights say -10* to -30* I could maybe put 130*-140* water through the slab for the heat loss at those cold temps.

Thanks for any help, Buzz

HAPPY NEW YEAR,Beer 4U2
 
  #10  
Old 01-01-09, 11:47 AM
X
Member
Join Date: Nov 2005
Location: USA
Posts: 2,338
Upvotes: 0
Received 0 Upvotes on 0 Posts
3 loops of 1/2" pex, 1/2" dia, each 200 ft long, coming off the same manifold will flow about 1.2 gpm each, at 125F supply temp. The total would be 3.7 gpm at a head of 10.1 ft. That's with a Taco 007.

If you had 5 loops, you'd probably be around 1.1 gpm in each loop and the total head would be under 10 ft.

BTW, at these parameters, each loop would give about 4800 BTU/hr assuming 1.5" concrete slab and 6" tube spacing.
 
  #11  
Old 01-01-09, 02:21 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 19,710
Upvotes: 0
Received 8 Upvotes on 6 Posts
If I'm following this correctly, you guys are ADDING the head in parallel loops?

Not correct.

Let's use a simple example... Two parallel loops, one with a head of 10 ft, and one with a head of 5 feet. Individually that is...

Put them in parallel.

Would the resultant TOTAL head be 15 ft? No, it wouldn't. It would be LESS THAN 5 FT.

Let's say you have two pieces of 1/2" pipe the same length. In parallel, the net result would be the same as one LARGER piece of pipe, equal to roughly the same cross-sectional area of the two smaller pipes... with a resultant smaller head.

There is an electrical analogy ... RESISTORS (Xiphias loves when I use resistors as analogy! ) Two resistors in parallel will always have a lower total resistance than the lowest of the two. Piping head works the same way.

[edit: The electrical analogy is LINEAR, but the hydraulic reality is most definitely NOT... where two resistors of the same resistance would present as HALF as much, two loops of piping would be less than the highest, but not as low as half...]

So, bottom line is that you always size the pump for the single highest head loop. If you can pump that loop, you can pump the others. And, as the other zones open and close, the pump will adjust the flow according to the pump curve.
 

Last edited by NJT; 01-03-09 at 08:57 PM.
  #12  
Old 01-02-09, 06:12 AM
X
Member
Join Date: Nov 2005
Location: USA
Posts: 2,338
Upvotes: 0
Received 0 Upvotes on 0 Posts
Originally Posted by NJ Trooper
If I'm following this correctly, you guys are ADDING the head in parallel loops?
Umm, not me. I'm using hydronic design software....

Read my post carefully, Troop, and you will see that it follows what you describe.
 
  #13  
Old 01-02-09, 07:44 AM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 19,710
Upvotes: 0
Received 8 Upvotes on 6 Posts
Yeah, my bad... I think that's what buzz is doing though... sorry .
 
  #14  
Old 01-03-09, 06:16 PM
B
Member
Thread Starter
Join Date: Dec 2008
Location: Northeastern, MN
Posts: 160
Upvotes: 0
Received 0 Upvotes on 0 Posts
So what would be the head on say 300 ft. 1/2" pex ?
 
  #15  
Old 01-03-09, 07:59 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 19,710
Upvotes: 0
Received 8 Upvotes on 6 Posts
On page 14 of this PDF file

Manual of Modern Hydronics

there is a chart that gives head per 100 feet for a range of tubing sizes and flow rates.

1/2" XPA is said to have around 2.5' head per 100 feet at 1.5 GPM. So, 300 feet is 7.5' head. Somewhat higher for standard pex (smaller I.D). You should consult the charts from the manufacturer of your tubing though, but it's gonna be 'close enough' most likely.

Are you saying that the longest single loop running off any one of the manifolds is 300' ?
 
  #16  
Old 01-03-09, 08:12 PM
B
Member
Thread Starter
Join Date: Dec 2008
Location: Northeastern, MN
Posts: 160
Upvotes: 0
Received 0 Upvotes on 0 Posts
Yes, 300', but is filled with 50/50 anti freeze. I think that will add sum head.
And what you guys were saying is the head will be less with 6 loops X 300' ?
 
  #17  
Old 01-03-09, 08:53 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 19,710
Upvotes: 0
Received 8 Upvotes on 6 Posts
The anti-freeze will probably affect the head somewhat, but moreso it's ability to move the heat... not sure the exact amount, but the output does go down from what you could get with water.

Let's say that you have six 300' loops of 1/2" tubing, each loop wants 1.5 GPM of flow. Each loop by itself is say 7.5' head.

The total flow in the manifold wants to be 7.5 GPM. You will need to feed that manifold with 1" tubing.

Xiph can tell ya for sure, but I _THINK_ you are probably looking at only 2-3' Head TOTAL for said manifold. His numbers were a lot higher than that, based on what the software said... so that's why I'm not sure...
 
  #18  
Old 01-03-09, 09:46 PM
B
Member
Thread Starter
Join Date: Dec 2008
Location: Northeastern, MN
Posts: 160
Upvotes: 0
Received 0 Upvotes on 0 Posts
Yes feeding manifold with 1" pex. But what happens if one more manifold calls for heat, or the garage manifold calls for heat also. Do you think the 1" pex would be enough ? Or would I be better off investing in 1-1/4" pex?
 
  #19  
Old 01-08-09, 07:48 PM
B
Member
Thread Starter
Join Date: Dec 2008
Location: Northeastern, MN
Posts: 160
Upvotes: 0
Received 0 Upvotes on 0 Posts
I e-mailed Taco and told them the lengths of the pex loops per manifolds. They told me to use a Taco 007 circ. per manifold.
I also asked them what controllers they would recommend.
They suggested using ..... Taco SR503-1EXP and a PC700-2 outdoor reset control.

What do you guys think about these controllers? Have you had any feedback or discussion on them ?

How about the 007 circ., would It be better to 007ifc ? Or dont I need flow control on a primary/secondary?

And a question from my previous post. Do you think I will have enough flow or BTU though 1" pex , for secondary piping ? The primary piping is 1-1/4" copper.

Thanks, Buzz
 
  #20  
Old 01-08-09, 08:40 PM
X
Member
Join Date: Nov 2005
Location: USA
Posts: 2,338
Upvotes: 0
Received 0 Upvotes on 0 Posts
If the Pinnacle does not already have an outdoor reset package, then the PC-700 might do it. But I'm not sure how the boiler would modulate in that case. Not familiar with how that boiler is set up.

But on the simpler questions, yes, the 007s would be fine. Use flow checks in the isolation valves, or flow checks in the lines. Or use a 007-IFC, or if you want a different brand try the Grundfos 15-58 with IFC.

You'll need the SR relay (no need for the EXP version if not using the PC700) in any event.
 
  #21  
Old 01-08-09, 08:56 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 19,710
Upvotes: 0
Received 8 Upvotes on 6 Posts
(no need for the EXP version if not using the PC700)
Unless you were interested in the 'pump excercise' module.

I thought the Peerless Pinochle had a built in ODR ? I haven't looked that closely at it, but there was a thread recently that indicated that it did...
 
  #22  
Old 01-08-09, 09:53 PM
B
Member
Thread Starter
Join Date: Dec 2008
Location: Northeastern, MN
Posts: 160
Upvotes: 0
Received 0 Upvotes on 0 Posts
The newer Pinnacle have ODR, mine is 4 years old now.

What's a Pump excercise module ?

How about tekmar brand controllers and ODR ? What do they offer I could look into ?
 
  #23  
Old 01-09-09, 04:11 AM
X
Member
Join Date: Nov 2005
Location: USA
Posts: 2,338
Upvotes: 0
Received 0 Upvotes on 0 Posts
You need to call Pinnacle and ask. There is a tekmar modcon control that if needed would be very good.
 
  #24  
Old 01-09-09, 08:40 AM
X
Member
Join Date: Nov 2005
Location: USA
Posts: 2,338
Upvotes: 0
Received 0 Upvotes on 0 Posts
The Pinnacle is a rebadged HTProducts Munchkin. You could also ask Pinnacle whether the HTP Vision1 outdoor reset/control package could be used. It should.
 
  #25  
Old 01-09-09, 05:40 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 19,710
Upvotes: 0
Received 8 Upvotes on 6 Posts
Originally Posted by buzz_mn_58
What's a Pump excercise module ?
PC600 Series PowerPort Cards
 
  #26  
Old 01-10-09, 01:47 PM
B
Member
Thread Starter
Join Date: Dec 2008
Location: Northeastern, MN
Posts: 160
Upvotes: 0
Received 0 Upvotes on 0 Posts
I dont think any of them PC600 cards are anything I need.

I have a question about primary loop closely spaced tee's. Does it matter if the tee's are plumbed as followed ?

#1. Primary loop 1-1/4" copper. Use 1-1/4"X1-1/4"X1" tee.
Then stub out about 12" of 1" copper off this tee, then
adapt to 1" pex. for the secondary loop.

OR

#2. Primary loop 1-1/4" copper. Use 1-1/4"X1-1/4"X1-1/4"tee
Then stub out about 12" of 1-1/4" off this tee, then use
a 1-1/4X1" adapter then adapt to the 1" pex secondary.

My thinking on #2 is, If the 1" pex secondary doesn't flow enough BTU's I might change it to 1-1/4" pex. Then I wouldnt have to re-plumb my primary tee's. I only would have to remove the 1-1/4"X1" adapter. What you guy's think ?
 
  #27  
Old 01-11-09, 03:16 PM
B
Member
Thread Starter
Join Date: Dec 2008
Location: Northeastern, MN
Posts: 160
Upvotes: 0
Received 0 Upvotes on 0 Posts
Any opinions on my last post ?
 
  #28  
Old 01-11-09, 03:47 PM
X
Member
Join Date: Nov 2005
Location: USA
Posts: 2,338
Upvotes: 0
Received 0 Upvotes on 0 Posts
1". 1" can carry a lot of BTUs at a 20F dT. 80k BTU/hr @ 8 gpm.
 

Last edited by xiphias; 01-11-09 at 06:19 PM.
  #29  
Old 01-11-09, 05:01 PM
NJT's Avatar
NJT
NJT is offline
Member
Join Date: Oct 2006
Location: USA
Posts: 19,710
Upvotes: 0
Received 8 Upvotes on 6 Posts
Aren't the side ports (bulls) of the tees in CST setup always supposed to be at least one pipe size smaller than the RUN of the primary loop? I can't recall having seen them the same size...

Xiph, isn't there a paper on this that buzz can read? Was it at Taco? or one of the Tekmar essays?

I have to say first that I really haven't been following this thread very closely... and this may not apply... but here's the paper I was thinking of... worth a read in any case:

Mixing Methods and Sizing of Variable Speed Injection Pumps
 
  #30  
Old 01-19-09, 09:06 PM
B
Member
Thread Starter
Join Date: Dec 2008
Location: Northeastern, MN
Posts: 160
Upvotes: 0
Received 0 Upvotes on 0 Posts
P/S piping

What do you guys think would this work for my P/S piping ?

hope my picture is there for you to see, first time trying.

http://i308.photobucket.com/albums/k...2475/Plans.jpg
 
  #31  
Old 01-20-09, 07:46 PM
B
Member
Thread Starter
Join Date: Dec 2008
Location: Northeastern, MN
Posts: 160
Upvotes: 0
Received 0 Upvotes on 0 Posts
What do you moderators and plumbers think of my piping drawing I posted ? I want to get my Peerless Pinnacle boiler plumbed right before the next cold snap, this weekend. Any and all input would be great. You people have been loads of information for me, and lots of others. Thanks, Buzz
 
  #32  
Old 01-21-09, 04:32 AM
X
Member
Join Date: Nov 2005
Location: USA
Posts: 2,338
Upvotes: 0
Received 0 Upvotes on 0 Posts
Sure why not. Keeping in mind that I'm neither a plumber nor a moderator.

It is generally good practice to follow the manufacturer's installation instructions. Your diagram appears to do that. It is similar to Figure 3.4 in the Pinnacle I&O manual.

You don't need the little air vent on the elbow at the top of the primary loop.

Don't forget all the valves, drains and unions.
 
  #33  
Old 01-22-09, 06:56 AM
B
Member
Thread Starter
Join Date: Dec 2008
Location: Northeastern, MN
Posts: 160
Upvotes: 0
Received 0 Upvotes on 0 Posts
P/S piping

thanks for your reply, Xiph.

The reason I was putting the air vent on the elbow on primary, is because this will be the highest point of my system. What do you think ? Do I need it ?
 
  #34  
Old 01-22-09, 08:09 AM
X
Member
Join Date: Nov 2005
Location: USA
Posts: 2,338
Upvotes: 0
Received 0 Upvotes on 0 Posts
Originally Posted by xiphias
You don't need the little air vent on the elbow at the top of the primary loop.
Ummmmmmmmmmmmmmmmmmm. No.
 
  #35  
Old 01-22-09, 08:31 AM
O
Member
Join Date: Dec 2007
Location: A Galaxy From Afar
Posts: 337
Upvotes: 0
Received 0 Upvotes on 0 Posts
With that pipe being the highest point of the system an air scoop and vent wouldn't hurt.

Placing the vent on an elbow most likely won't do much. The water flow rate will be high and not allow the air (or most of the air) to flow up into the vent body.

Al.
 
  #36  
Old 03-03-10, 07:04 PM
B
Member
Thread Starter
Join Date: Dec 2008
Location: Northeastern, MN
Posts: 160
Upvotes: 0
Received 0 Upvotes on 0 Posts
0ne Year Later

It's been a little over a year now........And I move my boiler to another wall and plumbed it P/S with close spaced tees. Like the prev picture I posted.

I had my boiler shut down for 72 hrs. with no heat in the house. Good thing for warm weather, warm for northern MN.
The house only got down to 62*f. The slab holds it heat quite well.

Why is it I cant get the boiler to heat the water over 120* ?
It took 5 hrs to get it to 120*. I thought with the P/S piping that the water tempature would rise to what ever I set the aquastat to.

Thanks, Buzz
 
  #37  
Old 11-14-10, 02:27 PM
B
Member
Thread Starter
Join Date: Dec 2008
Location: Northeastern, MN
Posts: 160
Upvotes: 0
Received 0 Upvotes on 0 Posts
Still have questions.

water still not getting as hot as I would like it to get.

On boiler loop I have a taco 3-speed 00R set on number 1 the slowest setting. On the #1 setting I got the hottest water.

On secondary I have the Grundfos UP26-99 pumping into the three manifolds. With no zone valves.

Do you people think the 26-99 is the problem ?
Maybe moving the water to fast through the system ?
To much different flow through close spaced tees ?
Or is it to much with all three manifolds flowing at one time ?


I want to set it up like my picture I posted on bucket. With 3 00R's one for each manifold, but havnt done that yet.

What you guys think ?

Thanks, Buzz
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: