Wilo ECM pumps for primary loop

Uni R_2

Para 38 iirc

Big Will

Do what was drawn

A job that we are starting soon was drawn entirely by a mech. engineer. ________ Oh goody. ________
Any way they specified Wilo Stratos pumps for everything. Sounds great really. My only thought was for the boiler loop.
It seem to me since the munchkin boilers that they specified work best with a constant water volume through he heat exchanger that a properly sized Grundfoss pump would do just as well. Since modulation is not necessary. However I do know that the variable motors in furnace use less power even when running at a constant speed.

Note: I am trying to talk them into using the Knight instead of the Munchkin just better in my opinion but not the point at all.

Constantin

Hmmm...

The only benefit I see here with a Stratos is the inherently-higher efficiency of the motor vs. PSC-types out there. I wonder if Laing or others make a permanent-magnet motor at a single-speed setpoint that achieves the same thing (potentially at a lower cost and potentially at a higher energy efficiency because they don't need the electronics).

You can achieve the constant water flow simply by setting the Δhead to the right setting. However, I'd research about some of the setback features, etc. in this pump to make sure that if they can auto-enable that they are turned OFF. In other words, dumb the pump down to the point where it delivers a specific amount of flow.

Could the pump be made smarter? Sure, but you'd have to have an interface on the Munchkin and the pump that would allow them to connect and ramp as needed. Then, things could really get interesting.

Hopefully, one day, more solar hot water and boiler manufacturers selling stuff into the US market will allow customers to embrace the benefits of varying flow through the system. A standardized interface would help a lot, i.e. idiot-proof plug combos, etc. In the meantime, we'll likely continue to see proprietary solutions

Unknown

If electrical rates are high enough, ECM pumps can have payback even in a constant flow app.

it can draw 45 watts to do what 90 watts does in another pump. at 100% on duty cycle (close, if you're using reset?), that's about 32 kwH/month difference, or about $3/month per ten cents/kwh. With a six month heating season, that's $1.80/year for every penny a kwh you pay for electricity.

in many areas that won't achieve payback quickly. But in some it will.

Big Will

NRT Rob

We talked about a unique indirect water heater for a reverse cycle chiller system a while ago. The job did not pan out. However in northern radiant and residential hydronics is still a **** industry. Most distributors sell hydronics as a second. Although not as bad with hte economic changes. The point is when I went looking for someone to quote the Wilo pumps for this job the only dealer in norther California that was responsive was a agricultural pump supplier. He quoted for the job but has no idea what we are doing with the pumps or why. So the point is do you sell the Wilo line? If so we need to talk in the near future. Also a line card from you might be helpful. Most of the stuff I purchase is coming from the east coast anyway.

Uni R_2

Hate to be a cynic...

"If electrical rates are high enough, ECM pumps can have payback even in a constant flow app."

To truly evaluate that, you would need to know how long the electronic guts are going to last and these products are just coming onto the market now.

A 90 watt pumping running 24-7 200 days a year is only about $100 at $0.25/KWH which is about double the rate here. So $50 a year savings might take 5 years to cover the difference in cost.

For here, to break even, it would take twice as long - cheaper electrical. Will the guts go 10 years?

Not saying anything bad, just saying that the lifespans right now are unknown.

Unknown

that's about $100 more than the cost difference I'm seeing... and a 3 year payback would certainly seem to be worthwhile. Even 5 years is pretty safe.

but you're right, we don't know lifespan. If these pumps die in less than 10 though, they are definitely dogs.

Uni R_2

In Canada...

It's about $315 vs $75.

Unknown

I was a little off in my last estimate (more like $50 difference) Still, in the end we'd be quibbling over a year or two either way. In constant flow residential apps they won't be taking over soon. But electricity may change that in the upcoming years. Knocking out a bypass on variable flow systems, and its associated fittings really makes the economics nice though.. If you think they will last.

ECM pumping isn't new and I'm willing to bet they will last though I am interested in the magnetic issues I have heard murmurs about... and I can understand being less optimistic for sure.

Nathan_6

Wilo as primary

The wilo can also operate in a deltaP-T when you have the IR module to program it this way. So that way the pumps speed can vary with the boiler load saving even more money in the long run. As you water temp drops say due to outdoor rest you might not need to flow 20 degree delta T across the boiler so the pump slows down increasing the delta T across the boiler.

Call the factory and ask to talk to Steve Thompson he is the Vice President of - Technical & Training Services and he will be more then happy to help you out and maybe even point you in the direction of a rep in your area that deals with the heating aspect wilo pumps

Best of luck

Constantin

You're right...

a ΔT application may be exactly what the doctor ordered to make a Munchkin even more energy efficient. However, I'd worry less about getting Wilo to educate me on how to make the physical connections and worry more about the implications re: warranty from HTP. You're essentially creating a new boiler here.

CC.Rob_15

costs

Electricity here is $0.22/kWh. I can see the two 007s on my constant circ system in the winter elec bills. Just those two are responsible for 65-70 kWh/mo, which is around 15% of our total monthly usage.

They are, however, rock-solid reliable and should last a very long time.

One alternative would be to go with some nice Belimo ZVs and an ECM. Payback on the installed cost would probably be around 5 yr. Not bad.

Another would be simple swap of both circs for ECMs, in which case payback is more like 3 yr.

But any breakdown in ZV or ECM and the cost savings go out the window. (And the embedded energy of the whole operation goes way up compared to just keeping the 007s.)

Just some thoughts.

Unknown

you're right to consider that, though we have just established with triangle tube that as far as the prestige is concerned, all they care about is staying below something like a 40 degree dt.

that's not really a 'new boiler'. from the boiler's point of view not much new is happening here.

optimizing your dt for a given situation might require some more brains, and I still wonder about minimum velocities but I'm not getting any indications that the boiler engineers care (or, any flow that guarantees proper dt operation also exceeds any minimum velocity requirement for "heat exchanger bubble scrubbing"). As long as delta T is in the acceptable tolerance, of course.

Of course, I would get that in writing ahead of time regardless.

Nathan_6

Mod Con Delta T

If you look at the Lochinvar knight boiler the manufacture gives you a delta T range from 20 to 40 degrees depending on boiler size. They even tell you the required flow rate and head to achieve those delta T's. What they don't tell you is why they let the boiler operate across such a large Delta T. The reason so you can save money on the pump size and electricity cost to operate the pump if your designed system can operate at the 40 degree delta T. You need to run at the lower delta T of 20 if you have mostly High temp zones so the boiler doesn't short cycle on the high limit. but if you are in reset or running a low temp radiant slab or snow melt go ahead and run the boiler down to 40 degrees Delta T it don't care.

This really comes into play on the bigger commercial jobs running the 500 plus XL boilers. Look at the price difference between a pump that will give you the 20 degree Delta T and the one that only has to deliver 35degree Delta T.

I called and asked Lochinvar about this very subject last month as we have a parking Lot snowmelt job that requires two 500 xls. But the max system design temp is 110 degrees.
So I called to see what reason behind the different boiler delta T's because to operate the 500XL @ 20 degrees it takes a pump capable of 23ft/hd and 46gpm were as to operate at the 35 degree delta T it only takes 10ft/hd and 26Gpm. IE a smaller and less expensive pump. Needless to say we are setting the system up with all wilo Stratos pumps

So Really you are not making a new boiler you are still operating it with in the manufactures specifications you are just taking advantage of technology to make the whole system more efficient.

Nathan_6

Interface module

The wilo Stratos does have a interface module that allows it to operate on an external 0-10v signal. So if some one wanted to play around a bit you could tap into say the boilers modulation signal and vairy the pump according to that signal or maybe if you were using a Tekmar control to control the boilers modulation you could run that signal to the pump as well. (don't know for sure just thinking out loud) So when the boiler was at 20% the pump would operate at X speed but when the boiler ramped up for a higher temp demand so would the pump.

The future looks bright for smart pumps and boiler controls.

Uni R_2

Simply need...

Small set curve simple ECM pumps. For DHW loops, monoflo, a lot of radiant circuits a fixed low is fine.

How low of a wattage pump could do the same curve as a 007 or 15-58 on speed 2? With ECM maybe 25 or lower? That would be simpler and better in many applications.

No reason a modcon couldn't have a 2 stage primary pump system with 2 parallel pumps with builtin FCs. One side or the other or both could be energized by the "boiler" controller depending on fan speed and pump run time. Only one pump for normal low output and a secondary pump when the boiler needs more flow. The second could be variable if you wanted to go the extra mile.
Tekmar?

scott markle_2

patriot supply

Will,

if your looking for an online vendor try Patriot supply.

Constantin

There is no doubt in my mind that it can be done...

I simply wanted to caution folk to consult with manufacturers of equipment first. Mod cons in particular have some very expensove replacement parts. I wouldn't want to be on the wrong end of a warranty claim!

For all you know, manufacturers are already trying the same stuff right now and would love to have a couple of beta test sites.

Kevin Koenig_4

ECM Pumps

At Last! A reasonably priced ECM circulator that is ideally suited for these applications. ITT recently purchased this company and will be introducing this circulator to the US market very soon. This is a pretty impressive little pump! http://www.lainginc.com/pdf/E10brochure_web.pdf

DanHolohan

Kevin,

you should also mention that you work for the B&G rep and that you're not a contractor who installs the product. Thanks.

Big Will

I have never used Lang

Other than hot water resurc. line pumps. Reliable ? I like the Taco Line but prefer the Grundfoss.

Supply House Rick

Kevin you just got smacked!!!

By the master

Constantin

Hey Kevin,

Whenever B&G/Laing gets around to posting an I&O manual on their website for this pump, can you send me a copy? The Brochure is cute but it doesn't get into the details of how these pumps are set up and how they can be controlled.

Constantin

Cool...

... I assume you are referring to the Honeywell controller? I'd be surprised if most controllers couldn't do this sort of thing... heck, even my $18 Arduino kit has something like 5 analog inputs/outputs, and that's before using any kind of multiplexing rig.

For me, it's more of a question of how mere mortals enable it and whether they are allowed to enable it with a manufacturer's blessing.

Kevin Koenig_4

Kevin the\" CNY B&G Rep\"

So Sorry Master. I will edit my "author" to indicate that I am a Rep and no longer a contractor.
I Just wanted to give your readers a heads up on what is coming down the pipe. The spherical rotor pump design has been around since the mid 70's and has proven itself to be very reliable and extreemly effecient device. Laings exposure in the US market has been mainly in the DHW recirc market but in Europe they are better known in the heating industry. It will be a while before an english version of the O&M manual is available but for anyone that is fluent in German here is a link where you can download the O&M in german.. Kevin.. http://www.laing.de/eng/products/pumps/heating_pumps/

CC.Rob_15

Ach du lieber!

Sehr gut! Danke schon!

The English section of the I&O is on pages 14-19. Not a lot to it, but it's readable.

Kal Row

use the wilo set for constatnt speed..

i posted this before:
to illustrate what ecm motors do for you - i have two little head motor magnets that i pulled out of a crashed hard disk - and i challenge people to pull them apart - you need two vise-grips to do it - that's the kind of force the permanent magnet rotor in an ecm pump brings to the table - small circulators go from 80watts to 15-35watts instantly and have way more starting torque

so even though you dont need variable speed - the life cycle electric savings make it worthwhile