ECM circulator worth it?

super_snop

Hello all. My boiler has been a work in progress. Basically fixing up the whole system. I plan to replace my old thermodynamics boiler next season with a weil mclain wgo-3. Right now I have copper fin tube throughout my 2200 sqr ft. Home with 2 zones piped with a separate circ on each. Planning on switching over to a zone valve setup utilizing the taco sentry valves and one circulator. I was originally going to just put one 007 circ on there but the ecm circulators have caught my eye. Any major advantages to running a grundfos alpha 2 or a taco VT2218? Also, what mode would be the best for my setup if I go with a variable speed circ?

STEVEusaPA

Don't put a wgo in. Use an EK if you need domestic hot water, or a triple pass with a small indirect. If you don't need domestic hot water, still an EK or any triple pass.
Not enough info to comment on the circs, but any circ that uses less energy is better.

super_snop

No domestic water. I’m beginning to look into the tripple pass boilers

Big Ed_4

Baseboard is basically a stupid system , Cheap series system ,I would stay with the two circulators . Replacing them with zone valves will be a step below . Panal radiator , home run with TRV's on each , yes Alpha . Keep a simple system simple

hot_rod

A bit of energy savings wuith an ECM motor. Best feature, properly applied is the Delta P which will change pump output based on the load(s). Even with two zones you will see some benefit.

EdTheHeaterMan

Changing from a circulator on 3/4" pipe to a zone valve on 3/4" pipe might be a problem. I said might be!

Some zone valves may restrict flow in the 3/4" loop from 4 GPM to 3 GPM. What that means is that if you have more than 45 or 50 feet of radiator element (the fins) you may see insufficient heating during the coldest days of the winter. You may not notice the problem for most of the year because you don't need full capacity when you don't have full design temperature.

This is my go-to text for teaching this concept.
http://media.blueridgecompany.com/documents/ZoningMadeEasy.pdf

Look at page 17 at the bottom "How to size the valves and the circulator", and continues on page 18.

But it is a good text to read from beginning to end for a more complete understanding of your system.

hot_rod

Pumps or valves. It really comes down to personal preference, assume you have a 60,000 BTU/hr load at design. Split into two equal zones at 30,000, so 3 gpm per zone. A single circ should easily handle that 6 gpm requirement.
One ECM around 45W at design, and modulating below that for a single zone.
With two of the PSC type fixed speed circs, like a 007 around 160W, and probably running way at the bottom, least efficient part of the curve, I'd guess running at 15% wire to water efficiency.
In either case a 24V transformer would be required to power stats and relay box.
I think some areas have rebates to upgrade the circs.

dsireusa.org shows all the various state incentive programs.

EBEBRATT-Ed

@EdTheHeaterMan

Your right about the zone valves. I put in a 1" Honeywell with a Cv 3.5 and the water didn't move so well (dummy me) I realized what the problem was and put in a Taco the Cv is 7 (maybe it was 7.5)

Robert_25

I installed an ECM circulator a few years ago and have been very pleased with the reduced pipe expansion noise.  I suspect my zones were overpumped before. 

Take a look at the Taco 007E circulator.  You could put one on each zone and still have energy savings compared to your current setup.  

super_snop

This is basically going to turn into an overhaul of my entire system. I would like to keep it as simple as possible. After reading the book “pumping away” I will be pumping away from the boiler. A 007 on each zone just sounds ridiculously overkill from my research. Thats the only reason I have been looking into the ecm circs and switching to zone valves. I would use a taco zone control and power the single circ off of my hydrostat 3250 plus this way I can maintain the 120 degree holdoff safety feature. 

Big Ed_4

Pumping away from the expansion tank on the supply with a air scoop is pumping away .

If you want the ECM and zone valve all you need is a proper size transformer to power valves , I would recommend adding a fuse or instal one with a circuit breaker . No need for a zone control . But simplifies wiring .

Install the valves furthest from pump , which would be on the return .

The end switches will tie into TT on the Hydrostat which will power the ECM . Some ECMs need to be powered all the time to learn .
With zone valve you changing to a single parallel system . Which one loop will favor until satisfied . I would reverse return piping to help equalize pressure drop ..