RE-DO NEAR BOILER PIPING FOR RADIANT SYSTEM

FIRE

Greetings to All and thank you in advance for any assistance you may be able to provide me in making an informed and educated choice.



I have an 8 zone all radiant heat system, installed 8.5 years ago.



It is a main boiler loop injection system, utilizing 8 taco circulators, a Tekmar 356 controller with outdoor temp and boiler return sensors.

The system is powered by a Buderus Logano 124x boiler and it is propane fed.



The near boiler piping is (in my view) pretty sloppily installed.(please see attached pics)



I am debating re doing the entire near boiler piping and scheme. as follows:



1. Use a Wilo variable flow rate pump and a Aquatrol controller.

2 Have all of the 8 manifolds re-done, with much straighter layouts and all the appurtenances required for accurate flow checking and proper velocities.



It s my UNEDUCATED impression( and that is why I need help), this will

reduce heat losses and unnecessary  boiler start ups due to

uncoordinated zone demands.



My basic question obviously is: <span style="text-decoration:underline;">is this all worth embarking on?</span>



I sincerely thank you for any help you can provide me...



Best Regards



Scott Kehagias

Mark Eatherton

I pitty the suckah...

that has to change a cartridge in one of those pumps :-(



I think you are on the right path, but before a final decision on design can be made, we're going to need to know the means and methods of distributing the heat. Staple up or tube in gypsum or tube in concrete, or all the above? How's it zoned?



ME

Paul Pollets

Re-pipe is worth it!

You could repipe this system using (1) variable speed pump and zone valves. You'd make the system smarter and eliminate 7 pumps, leaving the pump for the indirect DHW tank. There doesn't seem to be a mixing valve to control the radiant zones so we'll have to see what type of heat emitters are in place. 



I'm always surprised to see why the installer didn't use the Buderus R2107 control that's made for the appliance?? With the mixing valve card it does a high temp zone, a mixed temp zone and the DHWTank.

meplumber

What a mess!

It is almost a moral imperative to repipe that mess.

I agree with Paul.  A single circ with zone valves.  I recommend a Delta P circ (Grundfos Alpha or Wilo, etc.)  Mixing Valve is a must.  A four way mixing valve is recommended due to the cast iron block of the G124.  The 2107 with mixing card and a properly setup curve with do wonders for this place.

I don't know that it will do much for heat loss but you will decrease your flow rate significantly.

Good Luck.

FIRE

RESPONSES..THANK YOU

First & foremost:

Than you for your answers and input.



1. System distribution as follows:

   1st floor (4 zones 1,600sq ft all tile & slate) all 1/2" pex in

gypkreet.



  

2nd floor(3 zones 1,100sq ft 2 zones cherry floors, 1 zone tile) all

3/8"    

   tubing in  foil covered wood floor panels 3/8" pex.



    Basement(1 zone 1,600) . 1/2" pex in concrete slab not usually      

    running, set at 58F.



2.  Design calcs resulted in operating temp of 141F at 0F outside temp.



3.  Buderus controller was not used, because the installer could not figure

    it  out. Design engineer came up with current design using tekmar 356.



4. There is mixing circulator in mail loop(center bottom  in center pic.)



My main concern was fuel efficiency in running my system.

I am definitely going with the Wilo Stratus and an Aquatrol.



Now in regards to the mixing valve...I need to discuss this as well with the installer, whom I hold in high regard, he seems to be right on and his work looks great...not like my wall mounted beefaroni layout.



Please keep up the AWESOME advice...



THANK YOU ALL!!



Scott



 

FIRE

2107 & waste

The 2107 is no longer an option,, gave it away to a buddy, thus the new set up using the Honeywell Aquatrol controlling the new Wilo pump & all new thermostats.



In regards to the heat losses, I was mainly concerned with the "wasted" heat through all of the spaghetti copper piping  &

also the wasted fuel on all the "uncoordinated" boiler restarts, when separate zones call for heat, as opposed to the Aquatrol coordinating zone actuation based on temp and memory.



Thank you Sirs.



Scott

CMadatMe

Time Out

Let;s start from scratch here from a design standpoint. I may be taking a liberty here but there is NO WAY you need 140 degrees at design based on the application and floor surface temps. If there is only one mix here then there is a problem.



If the guy that install this is the guy that saids you needed 140 degree water the install is self should flag you to have a new loss and radiant design done before you decide on anything. The Aquatrol which is a nice control still may not give you what you need. The last thing you want to do is make the same mistake twice.

FIRE

design data

I see your point, but please see the attached data.



Yes the installer was using the data shown, as per his supplier.

Additionally the installer did not accurately follow the pipe diagram.



I am ripping everything out except the boiler and dhwh and restarting from scratch, using The Wilo and Aquatrol. The NEW INSTALLER will re do everything and not necessarily base the temp data on the previous design.



Precisely why I need this great input.



Thank you



Scott

NRT_Rob

well

you've got injection mixing. too many pumps, so you can fix electrical usage, but honestly you're not likely to do much to your fuel efficiency here by repiping that you couldn't do with just a boiler reset control and no repipe.



I would repipe the manifolds... $30+ in electricity/mo in savings there, easy.



Of course, it's ugly, and having a nice mechanical area might help with resale or something.

FIRE

repipe

"you've got injection mixing. too many pumps, so you can fix electrical

usage, but honestly you're not likely to do much to your fuel efficiency

here by repiping that you couldn't do with just a boiler reset control

and no repipe."

Adding the Wilo pump does eliminate the extra pumps, but doesn't the Aquatrol's coordination of zone supply based on history of previous demands, eliminate boiler extra restarts?

I was under the impression(maybe mistaken) that aspect saves on fuel.

Also the need for higher temperatures would be lower due the smaller flows and velocities of the new variable speed pump. Wouldn't that save boiler firing duration  as well? 



"I would repipe the manifolds... $30+ in electricity/mo in savings there, easy."

Agreed, and I guess all the loop piping as well...thus complete re pipe.



"Of course, it's ugly, and having a nice mechanical area might help with resale or something."

Efficiency and durability is my main concern.



Thank you very much for your input.



Scott

NRT_Rob

I'm not that familiar

with the aquatrol: zone sync is nice for sure, but I would want boiler reset first. if it does both, great. but it shouldn't require a repipe to use boiler reset and zone sync, and you're already set up for mixing.

FIRE

boiler reset

"with the aquatrol: zone sync is nice for sure, but I would want boiler

reset first. if it does both, great. but it shouldn't require a repipe

to use boiler reset and zone sync, and you're already set up for

mixing."

As per the Aquatrol specs, it does boiler reset.



In case I am misunderstanding, you are saying to use the same system design, but do the repipe, as needed. Re piping the manifolds, is the main project, so re piping the main loop and injection is not much more.



I hope I am understating your point.



Thank you very much for your advice Sir.



Scott

NRT_Rob

sure

that's as far as direct benefit is concerned. I don't know what the extra cost of repiping the rest is.. .if it's fairly cheap, might be worth doing.



but I'd say moving to zone valves and a delta-p pump... with or without major repipe on that side yes.



add the aquatrol, yes.



not sure much else would be truly helpful.

CMadatMe

Heat Loss

I'm a little confused over the loss. The Living Room is the only room in the house that has outside walls or windows? It's heat loss is 21K but a room that is only 20sqft or so less is like 7k...That is why the high water temps. Heat loss needs to be done properly...Water temps should be significantly less.

FIRE

LOSS

L.R.  is an open great room with glass window wall(18f high x 22ft wide).

Rest of rooms are 8' ceilings with normal windows.

It is a Lindal Cedar home.



Does this make the Heatloss calcs/temps accurate, or do you see a problem with the high temps.....everyone seems to say 141 is too high.



Thank you



SK

CMadatMe

Heat Loss/Design

I have no confidence in the heat loss you posted nor the radiant design. I would be starting from scratch.



I believe you would see that the water temp needed at design day would be less than 120 degrees. My strategy for piping would be...



Change the boiler aquastat to the Honeywell L7224U and add the WS8735S to reset the boiler. I would pipe the boiler pri/sec or low loss header and then use a Taco RMB for my radiant. KIS, keep it simple....The aquatrol utlitzing the zone feature really is no help for radiant.