zone valves vs. zone pumps

Duane Chaffee

I'm not going to cut down Honeywell or W/R but if you haven't tried the new Automag UR zone valve, I strongly suggest you give it a shot. I've been using Automag for 25 years now and have had two failures (bad coils). The new UR valve is even better. I can't begin to say that about any other valve.

Tom Simensen

zone valves & zone circulators

Does any one know how many motorized valves are used each year in the USA as compared to circulators for zoning? Or do you know where I could find this information?

Rich Kontny

Zone valve comparison

I would think marketing at Erie Mfg here in Milwaukee or Taco out east could give you a fairly accurate estimate!

MP 1969

Gary Fereday

Post your results!

ZV's are less exp[ensive than ZP's. ZP's have are inheriantly more redundant! Is the public more "price" consicous, or "Safety" consicous? bigugh

eleft_4

bigugh ? zone valves vs. zone pumps

Please clarify safety conscious.... is there a problem with one or the other?


al

Gary Fereday

Poor use of words perhaps

If the pump fails on a ZV system your out of luck and perhaps the system or its building will freeze. If you lose a ZP on a system the other ZP's will stave off freezing. Just my humble opinion! bigugh

Gary Fereday

This is of course

residential. Large cpmmercial jobs have two or more pumps that push to ZV's. If one pump cannot handle (dies) the load the other pumps come on line to keep the system going. bigugh

Boilerpro

I'm moving form zone pumps to zone valves

When you start using outdoor reset, your pumps begin to urn all the time. While little Nrf's use only 45 to 90 watts, or 007s or brutes, start adding four or five zones of these together and your talking a .5kw draw times 24 hours times 30 days per month equals 360kw per month for a home. This is almost as much as my regular electric bill in the winter. All the fuel savings from reset is canceled by high electric usage. Using one large or two meduim size pumps with zones valves tends to be more efficientwhen the valves are almost always open due to reset.

Boilerpro

kevin

good point.....

What have you been swihcing to ? I have had good luck w/ the Honeywell....and terrible luck w/ the Taco's(571)
I do like the Taco zone valve controls and w/ the EXP version I have done outdoor reset with great sucess. kpc

Troy_3

Automag

If you haven't tried Automag zone valves yet,you should. Since I switched, I have been very happy. Honeywell can keep making those cheap mexican valves and I won't miss those problems. We used to use all circs just because zone valves only seemed to last about 15 months. Three years ago we started using automag zone valves for the same electrical responsibility reasons stated above and we will not look back. They are very reliable. Built well and the company is great. Oh ya and they are made in PA by Americans.

BillW@honeywell

Zone Valves

Troy,Honeywell's zone valves are made in Canada and the US, not in Mexico. What kind of problems were you having?

Troy_3

honeywell

the little plastic gear seems to be the weak link from what I remember. Keep in mind I haven't used one for at least 4 years. The gear strips and you get a click , click, click as the brass gear turned and failed to open the valve.

BillW@honeywell

Zone valves

The delrin gear was removed from the V8043E over 10 years ago. The drive train used since is all metal. It is possible that some delrin models may remain in service, but that problem is long gone. Have you tried the Sparco PowerTrack zone valves, or the Honeywell VC series? Ask your distributor about them next time you're in the store. I think you'll like them.

hr

Take a look at efficiencies

when using small pumps on small zones.

In this example it shows one- 85 watt pump (maybe a 15-42) moving water (60.7 lbs/ cubic foot) at 10 gpm and 10 feet of head (about the knee of the curve for a 15-42) Runs about 21% efficiency.

Take that same pump and put it on a small zone requiring maybe 1/2 gpm. I always scratch my head when I see a wall full of 85 watt pumps moving a total of 10 gpm, usually without circuit setters to bring them in line

If a single pump failure on a zone valve system is a concern, for 50 bucks or so leave a spare on the job. Better yet pipe a second pump into the circuit with ball valves isolation that could be switched over quickly. Similar to commercial jobs with standby pumps.

Formulas from Modern Hydronic Heating, John Siegenthaler.

Worse yet look at the amount of electrical energy (blower motor wattage) needed to move 100,000 BTU with a forced air heat source!

hot rod

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Boilerpro

Switching....

I am still trying some different models. I have used W/R on several applications because they have nearly no pressure drop. The size of the port is nearly the same as the pipe size it mounts to, so pump sizes can stay down to achieve the same flow. Also, with outdoor reset you probably don't want a valve that's constantly energized to stay in the open position....I would suspect the life would be relatively short on these. W/R is power open and then power close so life should be long in reset systems. I believe Erie and some others make power close type valves that would probably give longer life than thier power open counterparts and freeze ups due to a failed zone valve are very unlikely. The Erie's have a reasonable pressure drop for all sizes. The Honeywell's have an extremely high pressure drop in the larger sizes. It appears that all that changes from one size to the next is the sweat ends, the flow port appears to be the same size on the half inch as on the 1 inch. Be careful when sizing these, you may end up without enough flow.
In summary, I am probably going to stick with the W/R even if they are a little noisy, or maybe the Eries that are normally open, unless I or others here see problems.

Boilerpro

Boilerpro

Hey HR

> when using small pumps on small zones.

>

> In this

> example it shows one- 85 watt pump (maybe a

> 15-42) moving water (60.7 lbs/ cubic foot) at 10

> gpm and 10 feet of head (about the knee of the

> curve for a 15-42) Runs about 21%

> efficiency.

>

> Take that same pump and put it on

> a small zone requiring maybe 1/2 gpm. I always

> scratch my head when I see a wall full of 85 watt

> pumps moving a total of 10 gpm, usually without

> circuit setters to bring them in line

>

> If a

> single pump failure on a zone valve system is a

> concern, for 50 bucks or so leave a spare on the

> job. Better yet pipe a second pump into the

> circuit with ball valves isolation that could be

> switched over quickly. Similar to commercial

> jobs with standby pumps.

>

> Formulas from Modern

> Hydronic Heating, John Siegenthaler.

>

> Worse yet

> look at the amount of electrical energy (blower

> motor wattage) needed to move 100,000 BTU with a

> forced air heat source!

>

> hot rod

>

> _A

> HREF="http://www.heatinghelp.com/getListed.cfm?id=

> 144&Step=30"_To Learn More About This Contractor,

> Click Here to Visit Their Ad in "Find A

> Contractor"_/A_

eleft_4

Bill @ Honeywell

Bill,

What is your correct e mail address




al

Boilerpro

Hey HR....

Add a check valve to that setup and size each pump for half the load, then run the pumps together and viola...built in backup. Could even put in a couple of flow switches so if either pump goes down, an alarm will ring. Otherwise, with this setup, most of the time I bet nobody will know one pumpis out until it gets real cold.

Boilerpro

BillW@honeywell

e-mail

Bill.Wolfe@honeywell.com

Steve Ebels

A point missed here S Ebels

Or at least not mentioned yet. When using a ZV system, you have to size your pump to the total required flow rate. Say for example home X needs 8 gpm and the longest pipe run has a head of 10'. Home X is divided into 7 zones each with its own personal ZV attending it. You pull out your trusty Grundfos/Taco/B&G reference book and see that a 15-42 Brute hits the target flow and head right on the nose. So you put it on. The customer calls back a few weeks later and says on mild days his system makes noise. Like a whining or whooshing sound. OOOPPPPPSS! you forgot to install a pressure bypass or differential pressure bypass or whatever you choose to call it. That pump works fine as long as it's on its curve but what happens to flow velocity when only one or two zones are calling. Maybe those 2 zones only have a head of like 3 ft. and the little Grunt is pouring everything it has into those zones and your flow rate just went way past what it should be. SSSSSSOOOOOOOOOOOOOOOO the point is, if you're using ZV's a PBV is mandatory. At least on my installations.

JMHO as always

BTW It was son Andrew's birthday and as I write this, I'm eating a piece of homemade chocolate cake with homemade chocolate frosting with homemade whipped cream on top of that!!!

Jealous?? You should be (G)

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Boilerpro

Yes, this is true, however,

> Or at least not mentioned yet. When using a ZV

> system, you have to size your pump to the total

> required flow rate. Say for example home X needs

> 8 gpm and the longest pipe run has a head of 10'.

> Home X is divided into 7 zones each with its own

> personal ZV attending it. You pull out your

> trusty Grundfos/Taco/B&G reference book and see

> that a 15-42 Brute hits the target flow and head

> right on the nose. So you put it on. The customer

> calls back a few weeks later and says on mild

> days his system makes noise. Like a whining or

> whooshing sound. OOOPPPPPSS! you forgot to

> install a pressure bypass or differential

> pressure bypass or whatever you choose to call

> it. That pump works fine as long as it's on its

> curve but what happens to flow velocity when only

> one or two zones are calling. Maybe those 2 zones

> only have a head of like 3 ft. and the little

> Grunt is pouring everything it has into those

> zones and your flow rate just went way past what

> it should be. SSSSSSOOOOOOOOOOOOOOOO the point

> is, if you're using ZV's a PBV is mandatory. At

> least on my installations.

>

> JMHO as always

> BTW It was son Andrew's birthday and as I write

> this, I'm eating a piece of homemade chocolate

> cake with homemade chocolate frosting with

> homemade whipped cream on top of that!!!

> Jealous?? You should be (G)

>

> _A

> HREF="http://www.heatinghelp.com/getListed.cfm?id=

> 175&Step=30"_To Learn More About This Contractor,

> Click Here to Visit Their Ad in "Find A

> Contractor"_/A_

Boilerpro

Yes, this is true, however,

With zone valves it is much better to use a flat curve pump (ie. B&G series 100, 2 inch NFI, or maybe the new NRF-33) instead of a steep curve pump such as the Grundfos, NRF-22 and most of the maintenace free pumps. If only one zone is calling for heat it just backs down the flow curve, but develops only a little more head. If you are using outdoor reset, most of the time multiple zones are open, so this is unlikely to be a problem. Remember, with zone valves, finding the right pump is more than just looking at peak design flow and head. It is no different than designing a good system, peak design is only one of several conditons at which a system should work well.

Biolerpro

Steve Ebels

If you don't

Design for max flow and head, what do you design for BP??

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Rich Corcoran_3

There are ggoodarguments on both sides.....

I will say I have always preferred to use pumps (especially now that they'll help put my kids though college!)

You need to look at the system and make decisions - you can't treat them all the same. There are many options today - circs, circs with integrated check valves, multi-speed circs,as well as zone valves. Choosing the right pump for a zone makes the system work as it designed. In the case of a zone valve job, the pump needs to be sized for total flow at the highest head that exixts in the zones -so it will be oversized unless the full load is present. I agree with Mr. Ebels - you should really use a differential bypass valve for these types of applications.

eleft_4

Email

Bill,

just got your auto reply.....Have A nice vacation


al

hr

You would have the exact same

issue if you lined up a dozen of thr exact same size zone pump on all different GPM and pressure drop zones, wouldn't you. Unless you are installing flow setters and checking the settings those row of pumps are running all over the curves.

I agree with the PAV, although copper baseboard has been installed for years without them and performs fine.
Probably because flat curve B&G 100 used to be the norm.

I suspect the latest assortment of flat curve wet rotor pumps on the market are to help address this., and the injection pump requirements. Am I close Rich?

hot rod

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Boilerpro

Design points I use

Obviously, I start at making sure the system can met design conditions. However, I also look at the system at two other conditions. One is the typical day load, or the baseload design point... typically about about 20 to 25 F outdoors average temp and building occuppied. Since this accounts for the majority of the system operation, I believe it is very important to be sure that the system will operate at highest efficiency and comfort at this point. On constant supply temp systems with zone valves this means that much smaller pump output is needed. Sizing one pump to carry this load and then only kicking in a larger pump during very heavy loads would save an enormous amount of energy. If you take into account piping that is sized for peak load (say 100gpm), but on a typical day you only need to run 50 gpm through the same piping, you can imagine how small the horsepower requirement becomes since the pressure drop becomes so low.
When looking at boiler capacity, I do the same thing if I can use multiple boilers. For both these, If you begin to look at internal gains from people, lights, and solar, the heating load drops even more than the warmer outdoor temp suggests. In strutures like apartment buildings, offices, and churches, the typical day load probably is only about 1/3 the peak load. Since I do alot of church work, I've found this is almost always the case, so I usually install a lead boiler about 1/3 peak design and one or two additional boilers to make up the rest. I haven't done this with pumps yet but on a system without reset or only partial reset, I bet the typical day pump horsepwer needed is only 1/6 that of design. I did look at this once at my local High School. I think peak load was about 3million, typical day about, 800,000,Peak load pump size, 20 hp, typical day pump size about 3 hp.

The other design condition I check is the real light load periods...will I have problems with short cycling, will the system respond efficiently to take the chill off. Just some of my own thoughts.

Boilerpro

corey

Those multi-speed circs...

Rich,
What about using just one multi-speed [or variable-speed] circulator combined with zone valves? This seems to offer many of the advantages of both approaches, and no need for a differential bypass valve.
One expected advantage would be less electricity consumed.
Not particularly mainstream, but I understand you are selling these in the states now.
What are the disadvantages to such a design?

Boilerpro

With outdoor reset, however,

pump is at or near full load the whole heating season, because all the zone valves are open almost all the time... hence, it makes more sense to use one or two larger more efficient pumps than several smaller less efficient ( and usually greatly oversized due to limited selection at smaller capacities) pumps for each zone. Say on the multispeed Brute and others, can these be directly wired to provide multiple speeds when in operation. Ie. A small zone kicks in and only runs the pump at low speed, then a big zone kicks in and powers the pump to run at high speed? What do have in the way of flat curve pumps in the maintenance free category..those similiar to the series 100, 2 inch NFI... in equal or lower pumping capacities?

Boilerpro