Circulator pumps vs zone valves

Hey_Obie

Trying to redesign my oil hot water bioler system (30 years old). I currently have one zone (1 1/4 piping with monoflo/venturi fittings) and I want to break it into three zones so I can control the heat better in the winter and be able to add programmable thermostats.  I also am adding a heat exchanger zone into my heatpump which services an addition that was built 15 years ago (hate the emergency electric heat backup - not cheap either).

I was going to control the zones with zone valves and someone asked why I am not using circulator pumps. I thought zones valves were less expensive and quieter and didn't need a flo control valve.  But I think circulators is a better design.

So two questions:

Zone valves vs circulator pumps?

What circulator would you use that is fairly priced and fits on a 3/4 copper pipe?

Thank you,

Obie

Wayco Wayne_2

Zone valves

are my choice lately. A while back I bought an energy monitoring device for my house. (TED The Energy Detective) It has current sensing loops around the electric lines feeding the breaker box. I have a real time electric monitor sitting next to me. (When the kids leave something on that uses electricity such as their curling irons I run upstairs and terrorize them. I have a heating system that uses all circulators. I was JUST sitting here wishing I had zone valves instead because of the electricity I'm watching being used. I also have a zone that uses hydro coil back up to a heat pump. It works great. I vote for zone valves with a variable speed circ with an ECM motor. That's what I give my customers these days. WW

Mark Eatherton

Watts up your btu??

In this day of energy awareness, every watt is accounted for.



My vote in new construction is non electric thermostatic control valves, and ECM circ's.



In retrofits, ECM circs and low wattage zone valves.



The claim of pump redundancy for back up is lame.



The days of walls full of pumps are on their way out.



my $.02 kwh worth:-)



ME

Charlie from wmass

Guess I am lame

I have had much better luck with pumps on systems. Ones I install and ones I repair. I would love to go non electric but alas it is not my money I am  spending. I agree that an ECM pump and TRV's would be the best. I will continue instaling pumps for the sake of simple to trouble shoot and repair systems. I would like to know why I can not find Taco 005 pumps. I would like a smaller Delta T pump for the multi pump systems.

Mark Eatherton

Lame use of the word lame...

I should have used the term "inappropriate" in light of energy conservation.



Not wanting to offend.



I find your comment about it not being your money curious as well though. The consumer is looking to you for guidance to the most efficient system,no?



I look at the parasitic costs as being MINE, even though they are not, and I try and get them as low as I can, because , you're right, it's NOT your money. It's THEIRS, and depending on the design, you might be spending their money without their knowledge!



The world is a constantly changing place, and so is hydronics.



ME

Charlie from wmass

the savings in energy may not out way the added costs

I have not crunched the numbers but I would like to see what the return rate is for the more efficient pumping methods. The load for pumps is so low to start with in most resonably zoned  systems. I am not talking the systems with 12 pumps for 2,000 square feet of home. I have a system like this person is describing I am meeting with tommorrow. I would very much like for them to take the system to thermostatic valves and an ECM pump a tri fire boiler and an outdoor reset control. The current boiler is 3 times the size the home requires and runs for a tankless heater. To say I can cut the oil bil in half would not be stretching the facts. But to cut the electric bill in half as far as what is used by the heating system would amount to saving maybe 1000 watts a month? even if it were 2000 watts how much money is that?

NRT_Rob

ballpark the cost this way.

100 watt circulator. Constant Circulation. 72,000 watts/month (720 hours x 100 watts).



0.10/kwh = $7.20/month, per pump of operation. I used these numbers for easy ballpark.



0.20 kwh/month, double it. 0.15, add half, etc.



Using Reset on/off control, I'd guess 75% run time.



50 watt circulator? Half it.



for a typical 15-58 on a reset system it's about $5/month, per pump. That can pay for any extra cost in the initial install pretty quick in most cases. if you have a six month heating season, that's $30/year, per pump.

Hey_Obie

No one likes a small orifice

I thought it was catchy. No wife comments please.



I like the efficiency and simplicty of one pump. I think the system design is more critical with the zone valves.



But the new ECM pumps definitely resolve some of the negatives about zone valves (banging)



But what I don't like is the size of the orifice inside the zone valves. I have b&g 3/4" zone valves and the hole inside doesn't look like it will carry 3/4" of water. I guess it must, but it sure looks small.

NRT_Rob

there is a number that helps with this

it's call a Cv value. all zone valves have them.

Dave Yates (GrandPAH)

my cost savings

Former 10-zone 11-circ system (10 @ 87-watts + 1 @ 180-watts)



Now 2-Alpha ECM (2-temp system) with 10-Caleffi 3-watt ZV



Savings for this year's transfer of heating from boiler-to-zones (not yet completed) will be around $450.00. Projected out 20-years with an annual 5% increase in costs for power after factoring in next year's 35% increase due to deregulation shows I will have saved more than $20K.



If I'd installed this for a customer, the installed cost would have been $3,485.00. Their first year (at 11-cents a kWh) return on investment would be 13%. Next year, following deregulation, the ROI will be 17%. And, that's for a retro-fit job. Do this from scratch & the ROI gets much fatter.



ECM technology is here to stay.

Mark Eatherton

And it is CRITICAL to a function called fluid flow control.

My good friend Robert Bean puts on a seminar through the RPA about this, and your conception is a common misconception.



More flow is not necessarily better.



Without these restrictive orifices, the fluid has a tendency to continually change flow through a large port, and cause issues with balanced flow. Just because the hole is not the same diameter as the pipe does not mean it will not flow properly.



Just like reducing a pipe size to get in or out of a component. Just because you use a 3/4" X 1/2" reducing coupling does not mean the system is only going to see the 1/2" pipe size for its whole length. Oh sure, it is a restriction, but it is not the whole developed length.



The reason I mention the 3/4 X 1/2 coupling, is because in most cases (residential hydronics) a 1/2" Z.V. is more than adequate. But, to the untrained eye, it "LOOKS wrong" so, consequently, it is not done.



Pressure drop through a control valve is critical, and should represent roughly 1/3 (if memory serves me correctly ) of the pressure drop through the circuit as a whole. If I am wrong, hopefully RB will see it and correct me :-)



ME

Hey_Obie

Thanks ME

I thought I had the wrong zone valves. So I think I am OK. It sure takes a while to learn this sport.