cirulator advice please
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cirulator advice please
i am going to put in a new pump to replace the old and leaking and noisy B&G 100. My choices are the taco 007 and the 008. i have a 3/4" copper baseboard hot water system, 4 zones, with the longest loop having an effective length of about 350 feet. by my calcualtions, at a flow of 4 gpm, the head is 13; at 3.5 gpm it is 10. any thoughts on the 007 vs the 008? i assume i can use the current flanges with either pump? is that correct?
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i am going to put in a new pump to replace the old and leaking and noisy B&G 100. My choices are the taco 007 and the 008. i have a 3/4" copper baseboard hot water system, 4 zones, with the longest loop having an effective length of about 350 feet. by my calcualtions, at a flow of 4 gpm, the head is 13; at 3.5 gpm it is 10. any thoughts on the 007 vs the 008? i assume i can use the current flanges with either pump? is that correct?
What doesnt look right with your calcuations i=s
Head 13 =4 gpm
Head 10=3.5 gpm
As your system friction head resistance to flow decreases your gpm will increase. this is backwards from what you stated.
H1/H2 = (W1/W2)2 ........... 2 is suppose to mean squared
H= head in FT
W=GPM
Personally i would stick with the B/G pump If its a ball bearing design switching to a sleeve bearing for less noise.
B&G is a good pump, what kind of noise is it making sound like marbles? or more squeaky?
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Rebuild kits are available for B&G 3-piece pumps.
If your choice is to replace your pump, and the 100 was performing satisfactorily, pick a replacement with a pump curve close to the 100.
As far as flange compatibility - yes, that's a definite maybe! Check the pump dimensions available on the pump manufacturers' websites.
If your choice is to replace your pump, and the 100 was performing satisfactorily, pick a replacement with a pump curve close to the 100.
As far as flange compatibility - yes, that's a definite maybe! Check the pump dimensions available on the pump manufacturers' websites.
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sorry. my post was way too confusing.
the old B&G was installed, years ago, for only 3 heating zones [and i remote water heater]. I got rid of the wter heater andreplaced it with a 4th zone, which has the longest effective length of all [350 feet]. the B&G can handle a head of 8 at a flow of 4 gpm or less [flat curve]. this pump is now delivering only about 1 1/2 gpm in the longest zone. time to replace!!
if i want a flow of 4 gpm with the current zones, i need a pump that can handle a head of 11. the 007 cannot do this, although it can possibly handle a head of 9 at 4 gpm. the 008 can definitely do the job, but uses more energy. i do think the 007, at a flow of 3.5 gpm, can handle a head of 8.6.
so, do i get a pump slightly undersized or slightly oversized, since my design specs at 4 gpm fall between the two pumps?? is it ok to settle for 3 to 3.5 gpm flow [which is what the 007 will do]??
the old B&G was installed, years ago, for only 3 heating zones [and i remote water heater]. I got rid of the wter heater andreplaced it with a 4th zone, which has the longest effective length of all [350 feet]. the B&G can handle a head of 8 at a flow of 4 gpm or less [flat curve]. this pump is now delivering only about 1 1/2 gpm in the longest zone. time to replace!!
if i want a flow of 4 gpm with the current zones, i need a pump that can handle a head of 11. the 007 cannot do this, although it can possibly handle a head of 9 at 4 gpm. the 008 can definitely do the job, but uses more energy. i do think the 007, at a flow of 3.5 gpm, can handle a head of 8.6.
so, do i get a pump slightly undersized or slightly oversized, since my design specs at 4 gpm fall between the two pumps?? is it ok to settle for 3 to 3.5 gpm flow [which is what the 007 will do]??
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Personally If would use the existing Pump as a tool to figure out what your new system head would be for selecting a pump . Increase in gpm is a increase in velocity which increases system resistance. I will make up some numbers assume that your system head now 6 FT head= 1.5 gpm
using the formula i stated before you can predict what your new head requirements are at your new GPM of 4.
select a pump on these values as mentioned as flat as possible with the highest effiecency rating.
H1= actual head ( you need to measure it ) 6
W1= actual gpm 1.4
H2 = New head ( this is what you find using the equation i mentioned previously and you need for selecting a pump.
W2= New gpm 4. ( 0r what ever you you flow requirements are. IF you size your 4 and you need 3.5 you can throttle your balancing valve to obtain your new flow rate. basically you are Increasing system head .
Inceased gpm = increased velocity which = increased frictional resistance to flow.
This way there is no guessing what kinda of system head you will have when you install a new pump, and you need to know what your new head is for selecting a pump.
Maybe overkill but this is what i would do in a commercial application. Takes the guess work out of it.
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using the formula i stated before you can predict what your new head requirements are at your new GPM of 4.
select a pump on these values as mentioned as flat as possible with the highest effiecency rating.
H1= actual head ( you need to measure it ) 6
W1= actual gpm 1.4
H2 = New head ( this is what you find using the equation i mentioned previously and you need for selecting a pump.
W2= New gpm 4. ( 0r what ever you you flow requirements are. IF you size your 4 and you need 3.5 you can throttle your balancing valve to obtain your new flow rate. basically you are Increasing system head .
Inceased gpm = increased velocity which = increased frictional resistance to flow.
This way there is no guessing what kinda of system head you will have when you install a new pump, and you need to know what your new head is for selecting a pump.
Maybe overkill but this is what i would do in a commercial application. Takes the guess work out of it.
---
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Forgot to mention when selecting a Pump take a look at your NPSH this is the point your pump will cavitate if it falls below this point. Lower the NPSH the better
NPSH= Net Positive Suction Head.
NPSH= Net Positive Suction Head.
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I'm interested in those multi-speed circulators. Perhaps a slight drawback might be that efficiency would be optimum at just one speed?
One advantage would be if you were unsure of the preferred gpm/head requirements for your system. Then, you could play around with the speeds.
Or, and this is interesting to me, what about switching speeds - based on the season, outdoor reset, etc.? For systems with zone valves, the speed could be changed depending upon the number of zones calling for heat?
The possibilities seem endless.
One advantage would be if you were unsure of the preferred gpm/head requirements for your system. Then, you could play around with the speeds.
Or, and this is interesting to me, what about switching speeds - based on the season, outdoor reset, etc.? For systems with zone valves, the speed could be changed depending upon the number of zones calling for heat?
The possibilities seem endless.
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I'm interested in those multi-speed circulators. Perhaps a slight drawback might be that efficiency would be optimum at just one speed?
One advantage would be if you were unsure of the preferred gpm/head requirements for your system. Then, you could play around with the speeds.
Or, and this is interesting to me, what about switching speeds - based on the season, outdoor reset, etc.? For systems with zone valves, the speed could be changed depending upon the number of zones calling for heat?
The possibilities seem endless.
One advantage would be if you were unsure of the preferred gpm/head requirements for your system. Then, you could play around with the speeds.
Or, and this is interesting to me, what about switching speeds - based on the season, outdoor reset, etc.? For systems with zone valves, the speed could be changed depending upon the number of zones calling for heat?
The possibilities seem endless.
I really don't think they lose much due to the speed changes, I am no pump engineer but I would imagine everything has be optimized.
#13
I'm interested in those multi-speed circulators. Perhaps a slight drawback might be that efficiency would be optimum at just one speed?
One advantage would be if you were unsure of the preferred gpm/head requirements for your system. Then, you could play around with the speeds.
Or, and this is interesting to me, what about switching speeds - based on the season, outdoor reset, etc.? For systems with zone valves, the speed could be changed depending upon the number of zones calling for heat?
The possibilities seem endless.
One advantage would be if you were unsure of the preferred gpm/head requirements for your system. Then, you could play around with the speeds.
Or, and this is interesting to me, what about switching speeds - based on the season, outdoor reset, etc.? For systems with zone valves, the speed could be changed depending upon the number of zones calling for heat?
The possibilities seem endless.