zone valves or circulators??

Matt L.

I plan to add separate zones to my present gas fired hot water boiler, a simple closed loop system, what would be the most efficient method?? to use zone valves or add individual circulators?? the elements used are standing cast iron radiators, installing everything myself as I did the boiler and new piping, time and money are not that important, I would like technical advice please thanks!!

Nick_16

My thoughts

I think it is up to the person installing it. I think using zone pumps is a waste of energy and more expensive than zone valves. I think it also depends on each zone's needs. Ex: Some radiant zones and some baseboard with much different head pressures. This is just what I learned.

lchmb

one other thought

I admit I am a fan of circulator's....with that said, I would also want to check your water. If you have heavy mineral's you may have issue's down the road with zone valves. Circulator's seem to fair better in this situation....

Robert O'Connor_7

Matt..

Circulators are my first choice. Robert O'Connor/NJ

hr

Depends on the load

if you are talking a few gpm, typically the current circ has enough room to handle that. I lean towards zone valves for small, say below 7gpm add ons. Kinda foolish to run an 80 watt circ for one small zone and throttle away most of the head.

It's kind of a Ford vs Chevy topic here

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Ron Schroeder_3

I prefer a mix. With an indirect DHW tank, I ALWAYS put it on it's own circ. Next, I usually split the house into two groups of zones with 1/2 of the zones on one circ and the other half on an other circ. This gives redundancy if one circ fails. With the proper isolation valves, you can quickly move one of the heating circs to the DHW if it's circ fails (at zero degrees on Sunday on a holiday weekend with company over).

For zone valves, I prefer the low wattage ones like the Taco ESP or the 2 or 3 watt thermal ones like Danfoss etc.

Ron

Sweet_2

Z.V or Circs

Depending on number of zones and gpm required. I think circs will give you more control over your heating system as a whole .With that said if your system is relatively small ZV are a user friendly zone controller. If it were me and I wanted total control of my heating system, circs would get the call.

hr

If you circ pump every zone

are you using circuit setters to dial them in, or is every one just running "wherever" on it's curve?

Some running off the bottom of the curve at @ 10% efficiency, some running off the top of the curve... Ocassionally one at the knee of the curve

Use a pump overlay curve some time to see where you are actually running on the curve, you're in for a surprise.

Use 6 zone circ to move 100,00 always strikes me as odd. Near 500 watt current draw to move 100K. Starting to sound like a forced air system, power consumption wise

Heating guys generally throw a 007 or Brute on any and every zone regardless of gpm or pressure drop requirement

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Jerry Boulanger_2

An interesting discussion

Most electric zone valves for heating are normally open, meaning that they consume power when they are closed. If you measure the wattage on small circulators, it goes down slightly when they are throttled. If the pump is matched to the branch requirements with an electronic speed control (dimmer switch), the wattage drops dramatically. I have a demonstration board with four branches on it circulated by a small SLC pump. With the system unbalanced, the pump draws about 77 watts. If I balance the system to the design flow (5.7 Usgpm)using flow limiting valves, the pump draws about 70 watts. If I then 'trim' the pump with the speed control to match the system (still pumping 5.7 USgpm), the pump draws about 30 watts. There are some losses in the speed controller, but still a significant drop.

hr

Jerry

I disagree with your ZV statement. I know of only one ZV that is normally open, thats the "head scratching" Automag.

Honeywell, Erie Caleffi, WR, Taco, B&G, take your pick, are all power to open. This includes the motorized and heat pill type. Which brands are you thinking about that need power to stay closed?

As far as controlling motor speed with a dimmer, doesn't a dimmer shed the current with those heat sinks? Seems if the motor is showing less consumption, then the dimmer is just turning the rest to heat?

VS speed controls work differently then dimmer (resistors) by chopping the wave somehow. tekmar VS controls don't give off heat like a dimmer switch does.

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Mike T., Swampeast MO

Since You're Considering Options

Don't forget thermostatic radiator valves (TRVs).

Many makers and decades of proven, reliable performance. They're sort of like variable zone valves for each radiator so you get complete zoning in each and every room.

They're self-contained and non-electric. A surprisingly large system can be supplied with a single surprisingly small circulator.

Cast iron radiators utterly love them. Combined with constant circulation the radiators just get warmer as it gets colder outside. The radiators will rarely (if ever) be truly hot--instead they're cozy warm--utterly perfect when coming in from the great cold outdoors.

Provided your standing iron is rather oversized (most are) and you use an outdoor reset curve with a bit of "headroom" you'll find extremely rapid (for a hydronic system) setback recovery.

Cost is from "bargain" to "moderate" depending on your definition and the number of zones you've planned using other means.

Jerry Boulanger_2

Hot Rod

Normally open valves are popular up here (Saskatchewan). These valves are open in the de-energized position and are powered closed. Examples - Honeywell V8043D1064 and Erie VT2xxxAx2, where the 2 indicates spring return normally open. If the valve is closed, the actuator is powered.

Re: the speed control, I'm not sure what the losses are in the one I'm using, but it's not a light dimmer (resistive load), it's a speed control for a fan motor (inductive load). The voltage and the current both take a dive when the speed is reduced, but my meters are on the load side of the control. The next time I fire it up, I'm going to move my meters to the line side of the switch to see what the real impact is.

hr

Jerry, why

the powered close ZVs. Seems they would consume power all summer long, and if a motor failed would the end switch be "made" and keep the pump or boiler running? Just trying to see the reasoning behind powered shut ZVs?

Maybe we can talk this over at the Western Hydronics meet in April, do you attend? I'm thinking, like every year , that I need to check out the Western Canada Hydronics scene.

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Weezbo

Western Canada may not have seen the caleffi and taco ZV .

Speed drives are good things.i like speed drives.speed drives are good.rheostats er they not Zackly same animals.let me ask how west in Canada? Yellow Knife ? white horse direction? i noticed That there arent any people on a buddies site for that area ,and considered maybe advertizing to do a little bit of work fromm time to time.i am a little bit further West as it were....

Jerry Boulanger_2

I guess the

theory is that if the power fails (transformer burnout) or the actuator goes, the heat will still be on. In a total power failure with a millivolt boiler, you might even get some gravity flow. Also, with a valve that failed open, the flow would prevent lines from freezing. They do consume power all summer long unless you turn off the power to them.

Yes, I will be at the Foothills Conference in Edmonton (with my demo unit)in April. In fact, I am one of the speakers. It's a good show, and I would look forward to meeting you there.

Weezbo, Saskatchewan is directly north of Montana and North Dakota. I live in Regina, about 120 miles due north of the 49th parallel and Plentywood, Montana.

Weezbo

I stopped there for food one day At a Chinese place....

My Canadian relatives used to live north east of you and i was thinking the way down the Alkan how beautiful Canada is looking these days.....oh the speed limits thru the place are scary...i was trying to go 110 buh really 104mph is about max in my comfort range...specially on the windier parts of the road..;)North Pole to Montana in a day and a 1/4..after work...

Ron Schroeder_3

Normally open zone valves makes sense energy wize if the call for heat is more than 50% of the time like it should be with outdoor reset. Have the warm weather shut down disable the zone valve power and then you have power savings in the summer.

Makes sense, just never seen it here on the east coast.

Ron