Bumblebee Flow Rate?

jt3

Gentlemen,

TT Solo 110 w/2 heating zones (baseboard) and an AMTROL 41 gal indirect. Heating zones have a HEC2 Bumblebee and a Taco Delta T circulator, both initially set to 20 degree Delta T.  Due to short cycling last year added a 30 gallon electric hot water tank as a buffer tank.  Once the Bumblebee got past the initial power on cycle it was settling down to an 11 watt draw and showing 6.8 gpm flow rate.  In an attempt to reduce the flow rate and reduce slow the mixing in the buffer tank, I reset the Delta T to 30 degrees on both zone circulators.  Bumblebee still shows 11 watts and 6.8 gpm flow rate.  I don't have a way to accurately measure the temperature on the supply and return pipes but shouldn't the flow rate have shown some drop with a change in the Delta T setting?



Thanks

Gordy

flow rate accuracy

I would use temps to see what you have sometimes the BB, and Alpha pumps are not the most accurate at what the gpm read out is, and what is actually happening.

jt3

Thanks Gordy

Will have to get something that will take an accurate temperature reading.



Jim

hot_rod

downstream of the circ

consider the 132 Quicksetter. It becomes your isolation valve, flow setter and adjustment, and temperature gauge. A little more cost compared to and iso-valve flange, but perfect for dialing in, or confirming flow rates, troubleshooting, and pump replacements.



I have been adding them to all my circs, including this Alpha drainback circ to watch how the flow rate ramps up and down during fill and siphon established modes.



A no-lead version for balancing DHW recirc risers is about ready.

ced48

Those Flow Rate

readings form the Bee are not accurate, I have fond them to be not even close-

SWEI

Alpha drainback circ

How closely is the Alpha GPM display tracking the meter?

hot_rod

way off

I beginning to think the flow rate indicators should not be on any of these circs. My experience shows them to be very inaccurate, also.



Maybe turn that readout into temperature, or something that can be measured more accurately. Or a Sirius radio station



If installers are using these readouts to assure performance, or troubleshoot, that could be a problem.



Currently my Alpha DB circ is reading 4 gpm, flowmeter reading 9 gpm

Bumblebee reading 12.8, flowmeter reading 6.5

Both are in fixed speed modes, moving plain water.



Now granted there is some accuracy tolerance in the flowmeter also, this is not a lab quality device.



The pump curves confirm the flow rate to be close to what the flowmeters are showing, but way off from the display.



I'd like to run these tests with lab instruments attached in actual installations.



I know exactly the piping circuit these circs are attached to, so I can run some numbers and see how close the flowmeters are to what theHDS program calculates. I'd bet the flowmeters are closer to the truth

SWEI

Interesting -- thanks

Looks like Wilo may have been smart not to offer a GPM reading on the Stratos.  They do show feet of head, but I haven't had a chance to check their math.

hot_rod

Same with the B&G Vario

no display on the one I have. I thought that would be in the "minus column" but knowing the readings are so fickle on the other brands, maybe not.



I have an Armstrong Compass ECM on my radiant. Right now, in Auto function is seems believable 4 gpm, @ 13W. I really like the electrical junction box on this circ. they supply a rubber cord strain relief and a 1/2 threaded connector for condiut or flex connections.

Paul48

Begs The Question

What else is not accurately displayed then? Is the watts display, just probable, and not actual?

Gordy

When they came out with gpm display

I was wondering how they could accurately come up with the logic for that mode. To many variables.

hot_rod

still more pros

then cons. I like the low energy consumption, and the amazing starting torque. That torque alone solves a lot of heating season start up, stuck rotor, calls, and probably goes un-noticed. A few service calls to free up a stuck circ pays the additional ECM cost.I've always wished for a simple indicator light on all circs. , The digital displays sounded better yet, but not if it tell lies At least you know when they are powered.To hit the next Euro efficiency level I suspect they will tighten tolerances in the pump even more, for less fluid "slippage". So that starting torque will be a critical feature knowing how crummy system fluids are in American hydronic systems.

SWEI

Circulator J-boxes

have certainly received their share of swear words from me over the years.  Bravo to Armstrong for recognizing that.



I heard a some complaints a few years back from wholesalers about the Stratos clearances being tighter than those on the Alpha, which presented some issues for clueless retrofitters.

SWEI

Starting torque

and auto-exercise were both big wins.  Of course, someone actually has to RTFM if they want the auto-exercise to work.