zone valves and zone pumps in same system

cutter

I built my house back in 1985 and since then I added two more rooms. The heating is Hot Water and currently I have four zone valves controlling the heat. The new rooms have in floor heat and will need a pump for each room. I was also going to plumb in a unit heater for the garage and have a pump for that zone also. Will this work or should I do away with the zone valves and install pumps on the zones?

Paul48

Here's the problem........I just bought a new bumper for my truck, will it fit?

SWEI

Post a photo of the zone valves, pump, and associated piping along with a diagram if you can.

Short version: You probably want to use zone valves for the new areas and change the existing pump to a variable speed ECM one. Depending on where you live, there may even be a rebate for that.

John Mills_5

I'm not much of a wethead but seems to me you have different temp needs. The unit heater will need hotter water than the floor. If you have baseboard it will too. Need to address that issue as well.

pecmsg

And what are you doing to prevent the garage heater from freezing?

cutter

John Mills said:

I'm not much of a wethead but seems to me you have different temp needs. The unit heater will need hotter water than the floor. If you have baseboard it will too. Need to address that issue as well.

Mixing valves should address that need, I would think

cutter

pecmsg said:

And what are you doing to prevent the garage heater from freezing?

At present the garage is not completely insulated and sheet rocked. The ceiling is half done and the west wall is not insulated. when it is -20 outside the garage is above 20 or so. I do not plan on completing that zone until the garage is finished. And if it is I feel the heat loss from the house will keep it above freezing. The boiler room is directly behind the garage so that will help a lot. The garage shares a very small wall with the house.

cutter

SWEI said:

Post a photo of the zone valves, pump, and associated piping along with a diagram if you can.

Short version: You probably want to use zone valves for the new areas and change the existing pump to a variable speed ECM one. Depending on where you live, there may even be a rebate for that.

SWEI
About a year ago I posted a drawing of a system I wanted to build and was advised to use a Caleffi design. The drawing is what I came up with after reading through a lot of the Caleffi design journals. The design, figure 6-14 on page 29 of journal 10 does not show a load , My drawing shows what I think will work, but would like some professional suggestions or advise.
The two in-floor radiant zones have not been put in yet. the in-floor pex is in one of them now. The garage unit heater has been installed but never piped to the boiler. On the drawing I have the unit heater pump on the return side but it could be put on the supply side. I was using zone valves to distribute the heat to the four zones.. those zone valves are shot but I have bought new ones so I would like to use them. I was told by Caleffi that I would need a sub manifold to do that so this is what I came up with.

The largest zone currently in the house has a 14.94 foot head loss. That is based on what I can remember of how that zone was piped in by size and length of pipe and fittings used. Taco has a pump (0012) with the head but the GPM is high. There are a few things not on the drawing like mixing valves and balancing valves, back flow valves on the in-floor and unit heater zones or the purging valves. The electrical is not no the drawing but I think I have that figured out. Not sure on witch side of the separator to place the sensors but I thought the supply side. I saw on a caleffi drawing where they had a sensor on the load side.

I currently have oil as the back up boiler but eventually want to convert to natural gas. With this piping configuration it would be easy enough to swap out a boiler.
I am not sure the drawing I am trying to post will appear. might be two of them if it does.

Any thoughts or suggestions?

hot_rod

I think this is what you show? The zone valve "header" needs a pump of course. Unit heater pump could be on the upper header also, matches the first two.

cutter

Hot Rod
Yes that is what I show, What I was wanting to know is will that configuration work or is there a better way of doing this. The taco pump (0012) has the right head for the job but the GPM is high. One zone has almost 15 feet of head loss. Would this pump work or is there a better choice? I thought of using Caleffi series 132 balancing valves or the series 127 balancing valves on the return lines unless someone suggests a better choice. Do you have any suggestions or thoughts on this? Thanks

SWEI

cutter said:

The taco pump (0012) has the right head for the job but the GPM is high. One zone has almost 15 feet of head loss. Would this pump work or is there a better choice?

GPM and head are interrelated -- how many GPM is that 15 feet computed at? What are the heads and GPMs for the other zones?

hot_rod

Maybe a ECM variable speed pump for the one with the zone valves. You need the mx gpm and head to select that pump.

That's the beauty of hydraulic separation you can mix and match pumps.

Balancing is really a fine tuning mechanism, those zones off the VS pump could have 127's added once you know the flows.

cutter

SWEI said:

cutter said:

The taco pump (0012) has the right head for the job but the GPM is high. One zone has almost 15 feet of head loss. Would this pump work or is there a better choice?

GPM and head are interrelated -- how many GPM is that 15 feet computed at? What are the heads and GPMs for the other zones?

SWEI, I am not sure how to do the calculation for a GPM, the 15 foot of head could be a GPM of 8. One of the other two zones has a 5.28 foot of head and the other has a 6.713 foot of head and that GPM could be 4 each. The fourth zone is a in-floor zone of 3/4 copper that was installed before pex came into north America, or became widely known. I no longer use that zone and should just cap it off.

cutter

hot rod said:

Maybe a ECM variable speed pump for the one with the zone valves. You need the mx gpm and head to select that pump.

That's the beauty of hydraulic separation you can mix and match pumps.

Balancing is really a fine tuning mechanism, those zones off the VS pump could have 127's added once you know the flows.

Hot Rod, I assume the mx in your reply means maximum. I am not sure how to calculate the gpm flow. From reading in the Califfe journals the flow could be around 4 gpm for my two 3/4 inch zones. That large head loss zone I have starts out as one inch copper then branches into two 3/4 inch copper pipes, Before it returns to the boiler the two 3/4 pipes return to a one inch copper pipe. The one that starts out at one inch could be 8 gpm.

I was thinking the 132 series balancing valve could be used to get the 15 to 20 degree temperature drop. and once you had that you would have the gpm flow. Or should the series loop design have a lesser temperature drop.

This house has the series loop system in it. I did not know there was any other system design. If I knew then what I know now I would have put in the 2 pipe reverse return system in the main floor. The basement would have had two zones of the series loop instead of one long series loop.

This house has always been warm in the winter. Maybe not heated efficiently, or maybe the most economically. When I plumb in the two new in-floor zones and the unit heater, I would like to do it right, and maybe improve it some if possible. Any help on this would be appreciated, thanks

cutter

Hot Rod and SWEI Could we go back to this. I should have done step one for Taco circulator sizing. Here are my head losses and flows for this manifold. all calculations done for 180 degree water.

Living room kitchen and dining
Head loss is 13.699
flow is 3.924 gpm

Upstairs bed rooms
head loss is .93
flow is 1.1875 gpm This may need to be speed-ed up to move air to an air separator.

basement
head loss is 3.109
flow is 2.185 gpm

The fourth zone will not be used.

I read where the middle third of the pump curve is what the pump is based on. The middle third of the taco 0012 is 15 to 30 gpm and the entire zone valved area requires 6.89gpm. Would the Taco work or is there a better choice. The ECM variable speed pump cost 2 1/2 times what a fixed speed cost. To size a variable speed pump do you need the total of all zones head and total gpm?
Any suggestions?

SWEI

The head disparity between those zones is going to make balancing a bit of a challenge. Is there any way to repipe or rearrange things to reduce the head loss on on that main zone?

Properly calculating parallel hydraulic resistance requires some math.

We use ECM pumps in 95+% of our designs now, because they increase comfort and reduce noise in addition to saving energy.

cutter

SWEI said:

The head disparity between those zones is going to make balancing a bit of a challenge. Is there any way to repipe or rearrange things to reduce the head loss on on that main zone?

Properly calculating parallel hydraulic resistance requires some math.

We use ECM pumps in 95+% of our designs now, because they increase comfort and reduce noise in addition to saving energy.

The piping is covered up with the ceiling of a finished basement so that would be a big and messy job to do that. There is two bathrooms that could have been taken away from that large zone and put on that bedroom zone, that would have helped some.
" Is there any way to repipe or rearrange things to reduce the head loss on on that main zone?" It is not an impossible task but extremely difficult.

The guy that designed this should have done the math then. I think it is a bit late for that now. What's there is there and I would like to try and correct what I have the best way.

Do you have a suggestion for a ECM pump or maybe a suggestion for a manufacture?

cutter

Hatterasguy said:

SWEI said:

Properly calculating parallel hydraulic resistance requires some math.

............and iteration.

Iteration | Definition of iteration by Merriam-Webster
www.merriam-webster.com/dictionary/iteration
Merriam‑Webster
Definition of ITERATION. 1. : the action or a process of iterating or repeating: as. a : a procedure in which repetition of a sequence of operations yields results successively closer to a desired result.

How is that done after the job has been installed.

cutter

SWEI, would a solution be to put that large zone on a pump of it's own?

hot_rod

I'd be inclined to try a pump like the Grundfos Alpha and dial it into the best speed. I doubt that 13' is accurate. Without knowing or determining the actual pressure drop with accurate gauges and calculations it a best guess at this point.

Dedicated zone pumps, with a wide adjustability would be my suggestion.

The B&G Vario circ is another good option I think it has about nine fixed speed settings and it is an ECM circ.

I'd rather see you get the pump sized as close as possible and dial in the speed as opposed to balancing as a balance valve with that much throttling, if in fact you head assumption is correct, is a large parasitic device.

Similar to driving with the accelerator to the floor and using the brake pedal to get the exact speed, or gpm in this case.

Steve Thompson (Taco)

Geez Hot Rod - you must be getting old man's memory. Once again I remind you here are more manufacturers of ECM circs (manual variable speed) than just Grundfos and ITT (Xylem).

hot_rod

Steve Thompson (Taco) said:

Geez Hot Rod - you must be getting old man's memory. Once again I remind you here are more manufacturers of ECM circs (manual variable speed) than just Grundfos and ITT (Xylem).

Duly noted Steve, I will be more aware and have been in the past to mention all the known ECM brands in posts.

I do, by the way acknowledge and show Taco in my trainings and you have seen Taco and their contributions to the industry noted in many of the Idronic issues. Do you do the same for Caleffi ?


Here is a slide I had in my present station in Alaska last week, over 100 folks attended the seminars.

cutter

Hatterasguy said:

cutter said:

I read where the middle third of the pump curve is what the pump is based on. The middle third of the taco 0012 is 15 to 30 gpm and the entire zone valved area requires 6.89gpm. Would the Taco work or is there a better choice. The ECM variable speed pump cost 2 1/2 times what a fixed speed cost. To size a variable speed pump do you need the total of all zones head and total gpm?
Any suggestions?

First of all, the headloss of over 13 seems excessive if you're going to maintain a flow rate that will give you a DT of 20. Most systems with 3/4" piping won't ever see such a headloss at the typical flow rates that a DT of 20 provides.

And, if you're looking for efficiency with three disparate zones, the DT pump is almost mandatory to vary the flow rate depending on which zone is open.

In your current situation, any pump is going to send all its flow to the two zones with the lower headloss when all zones call.

To fix that, you simply want to raise the headloss in the two zones with minimal loss to something closer to the headloss in the big zone. If you matched them all precisely, you'd get identical flow rates through each of them when all zones call. Now, this may not be desirable because one zone may have more radiation than another zone and you may want a bit more flow to one zone or another.

But, all of this is adjustable after the fact by the addition of simple globe valves and two pressure gauges, one before the circulator and one after the circulator.

You run each zone individually and note the pressure differential between the two gauges. Multiply by 2.3 to convert to feet of head. Adjust the globe valve to throttle the flow to increase the head and raise the differential across the circulator.

Perform this on the two tiny zones and you can balance them perfectly to the loss in the large zone. Note, however, that you may not want them perfectly balanced for the reasons noted above.

Be assured that the DT circulator is your best friend in this situation as it will vary speed depending on how many zones are calling and also by the SWT. Any fixed speed circ is just a crapshoot and will typically flow way too much and any headloss disparity becomes exaggerated.

Remember, you only need to flow 2 GPM to deliver 20,000 BTUH

Hatterasguy, I will do as you suggested and as Hot Rod said earlier. I will use a variable speed circulator. I did a little reading on them and they will use less electricity than a fixed speed circulator. I doubt they will ever save as much in electricity as the extra cost for one of them though.

Hopefully my head loss is not as much as I caculated. All the piping is covered up so I can not see what I did 30 years ago. The piping was all calculated from memory and the most likely way I could have ran the pipes. Those 6 monoflo Tee's did not help the head much either. 173.4 feet of head with those..

As for the iteration definition, reading the definition I knew that it was too late to make a correction. My response was worded poorly, I meant no harm.

cutter

hot rod said:

I'd be inclined to try a pump like the Grundfos Alpha and dial it into the best speed. I doubt that 13' is accurate. Without knowing or determining the actual pressure drop with accurate gauges and calculations it a best guess at this point.

Dedicated zone pumps, with a wide adjustability would be my suggestion.

The B&G Vario circ is another good option I think it has about nine fixed speed settings and it is an ECM circ.

I'd rather see you get the pump sized as close as possible and dial in the speed as opposed to balancing as a balance valve with that much throttling, if in fact you head assumption is correct, is a large parasitic device.

Similar to driving with the accelerator to the floor and using the brake pedal to get the exact speed, or gpm in this case.

Hot Rod, I got that 13 feet using the taco numbers for calculation and I was maybe a little off from that using the Caleffi numbers. I re-did the head loss after I did taco's step one and got the correct gpm. All the piping is covered up so I sort of guessed at how it was ran from 30 year old memory. I knew what rooms were on each zone and approximately how I got there. I wonder if I am off by a country mile on head because I currently have a series 100 bell and gossett and the house has always been warm. From memory a series 100 pumps a total head of 8 and a gpm of around 25.????????? (not asking for an answer, just not sure)

Dedicated zone pumps, with a wide adjustability would be my suggestion.
Are you suggesting pumps on all of the zones and doing away with zone valves? Or sizing that one variable speed pump as closely as possible?