Zone Valve Fighting!

Justin Topel

I was wondering what your preference is in regards to location of zone valves? It seems that piping preferences can vary by region just like zoning with circulators or zone valves. I have seen valves placed on the supply and sometimes on the return. Where do you like to place them and why? The guys who say on the supply side point to heat migration into the zones that are not open. Does that much heat really migrate without circulation? The ones who place them on the return tell me that the pumps can cause problems with certain zone valves and their closing mechanisms. Does it really matter a whole lot? Just curious where others place them and why. I ask way too many questions of others to which I get the response "That's the way I was taught. I'm not really sure why its that way, but it seems to work for me just fine. People who do any different are just goofy." I smile and say thanks for the info. So which side of "goofy" do you prefer and why? Thanks

Mister T

don_205

I have

I have to agree with the guys that said put them on the supply.You can do away with the flow check.

And yes the heat will migrate out of the boiler without a flow check.Think gravity.

I find the reason for most zone valve problem are due to not having a differential by-pass valve in the system.


We have the same issue on geo system with well water and
lots of zone.You can walk all over the place and see bladder tank thru out,and yet the pipe still shake and bangs every time the valve closes.

Justin Topel

Thanks Don

Besides the heat migration, is there any other benefit to the particular placement of the valves? Any other opinions out there? Thanks

Mister T

billtwocase

Them's fightin words

All's posts like this do is pit one man against another in the end. My theory is if it works for you, do it. If it doesn't work, lesson learned. peace

Justin Topel

NO fighting meant!

The post name was just a joke. I am not trying to cause any fights yet I want to see if there is any reason to do it a different way. I know that so many people have various reasons as to their preferences. I am trying to see if there is a good argument for either way. I like to know the reasons behind the design. There are many things that are done just because, and there are reasons because it works best. I didn't mean any offense and do want to see any sort of fight, just want to hopefully learn something I didn't know I needed to learn yet :-). Peace to you as well.

Mister T

Mark Eatherton

I disagree Bill...

It's questions like this that cause people to think outside the box and question what it is that they do, and why. If you want to keep on doing the same ol' thing, that is your option, but I guarantee if you read all the posts placed on this thread, that you MAY learn something new, and might even apply it in the field...

Just because you've always done it that way don't make it right. Just because it works for you doesn't mean that there isn't a better way to do it.

Keep an open mind...

THIS is what the Wall is all about.

ME

billtwocase

oops

I do agree Mark, there is alot that can be learned, just had the tone of who knows more than another type of post. My mistake

Metro Man

zone valves

We always put them on the return side and let the loops take up any expansion issues when valves close. With the slow moving zone valves that we use it is not as much an issues as it used to be with the heavy spring older styles. We got a noise call from a system that we did not install and added a couple expansion tanks in strategic locations for an attempted quick fix but did not totally eliminate noise. A call into caleffi (zone valve type) and they recommended cutting a piece out of the coiled spring. Not scientific but it worked..... learn something everyday. I was worried about ghost flows through valves but so far so good. Radiant/BB/hydronic is low press. compared to what valves can handle so it makes sense.

As far a heat migration I think heat could migrate either way (supply or return) if left unchecked. Low temp mod cons probably not as bad as a cast but all depends on how all is Plum Ed

my 2c

Metro Man

billtwocase

pumping away

No offense takin Justin. I prefer to pump away. If there are zone valves, preferably Honeywell, I like thems on the return, obviously only if it is not a mono-flow, then they have to be on the supply. I only find banging noises, etc, when on a return if someone was nice enough to plumb them in backwards, especially taco. I find the cooler temps agree with the "O" rings, and other rubber material holds up alittle longer when return located. Just my findings, but I'm sure others will disagree or agree, but I do defer to Mark E. If it flows, he knows. Read his posts on here if you hunger for knowledge. peace

J.C.A._3

.....

A pressure differential bypass IS your friend in the absense of am ECM circ. Learn it...Live it, Love it! Chris

Justin Topel

No harm

I understand that there are some who seem to just start an argument on the Wall. I never want to be one who ever promotes one. Its like I tell my lovely wife, if what I say can be taken either good or bad, please choose the good. I strive to never hurt or offend anyone. I am a solar contractor who has partnered up with a hydronics contractor and ask a lot of questions. Sometimes I get an answer, sometimes I don't. I really, REALLY would like to learn things the right way. I want to give the customers the best information, products, and service I can. As a kid I always was the annoying one who asked the teachers why. I was never really satisfied until I saw the thing working in my head. I didn't fault them or become angry, just sought elsewhere for the answers. I never like the answers that I got that said others who differ from their design were just stupid. I thought..man there must be a lot of stupid people out there or they might be the smart ones instead. I try with my guys to help them completely understand why we do things a certain way and then allow them to question or suggest something different. I'll tell you sometimes they can really surprise me and teach me something new when I understand a lot more than they do in regards to the system. I encourage them to see it in their mind and that promotes employees who are able to think for themselves or help me troubleshoot something that is not right. It has been really beneficial to me. That is one of the reasons I really like the Wall. It helps me see how others think. How they see the picture could be a whole lot better than I do. Again no harm done and have a GREAT weekend.

Mister T

billtwocase

Thanks Justin

wish you the best on your venture. This is the place to get answers in all forms. Lots of knowledge can be had in here. I can come of wrong at times myself. I guess it's a human thing lol. peace

Mark Eatherton

Old school versus new school and it Depends!

Justin,

The Old School (Honeywell V8043) way was to apply them to the return. This was to give a longer life to the motor windings, seals etc. It was also a good idea to put them on the return to keep them from bypassing due to excess head pressure generated by the pump.

The New School way is to use slow acting valves (almost ALL manufacturers) and then apply pressure activated bypasses to avoid over pressuring the valve and causing valve bypass. I say this is akin to driving your car with the accelerator pedal to the metal and your other foot on the brake, or slipping the clutch if it's a manual transmission. Not the most prudent use of pumping energy, but it keeps valve from banging and bypassing.

As for location, with most newer systems being run on an outdoor reset, it really doesn't matter whether they're on the supply or the return.

The Ultra New School way is to use a variable speed pump, can the PAB, and use non electric zone valves which are proportional in control, resulting in the maximum use of energy. delivering the utmost in efficiency and comfort.

Now, what about port size. Do you prefer full port zone valves, or restricted port zone valves, and when and where and why?

Anyone who knows Robert Bean knows the answer to this question :-)

So, as with any hydronic heating question, the only correct answer is "It depends!"

ME

Indysteamer

pressure activated bypass

Mark- Could you explain more about "pressure activated bypasses?" Specifically what you use to do this as far as products and piping strategies. Also, if anyone has any pictures that would show some good examples I would be very grateful.

Thank you in advance!!

Mark Eatherton

PAB information....

Indy,

A pressure activated bypass is an adjustable pressure relief valve who's outlet is piped back in to the system. It can be installed directly around a pump, or between the supply and return main. I have on rare occasion, installed it on the supply main at a remote RFH manifold location that was the "reference" zone. In this application, if a bunch of the zone valves were calling, there would be no flow in the reference zone, which would cool down, and cause the ODR to increase the water temp, thereby satisfying the other zones, causing them to shut down, and then causing the reference zone to then see flow and heat and satisfy the need for heat. Worked pretty nifty.

In normal cases, when most or all zones are satisfied, the pump is extremely oversized at that point in time, and the PAB bypasses excess pump head (pressure) to make sure that the flow through the active zones are not excessive, or if all zones are satisfied, that the pump is not dead headed.

If used with zone valves that call for the pump, then it is acting like a governor to the pump.

If used with non electric valves, it keeps the pump from dead heading because there is no interface in logic between the non electric valves and the pump. The pump is started based on outdoor temperatures. It still acts as a governor to the pump, but more importantly keeps the pump from dead heading.

Manufacturers include Caleffi, Honeywell Braukmann, Oventrop, Danfoss and I may have missed some that others will chime in on.

If you are using a variable speed pump, i.e. Grundfos Alpha or Wilo Stratos or Ecos, YOU DO NOT WANT TO HAVE ONE IN THE SYSTEM!! It will confuse the living crap out of the poor pump....

Hope this helps.

ME