Results 1 to 9 of 9

Thread: Too much flow?

  1. #1
    Join Date
    Feb 2005
    Posts
    41

    Question

    My system has 1 circulator (TACO 007-F5) on the return, pushing into the boiler.

    If FT.HD. = loop length * 0.06 and GPM=HPx2178/FTHD, here are GPM in each of my loops using TACO 007-F5, 1/25hp, 3250rpm vs TACO 0011-F4, 1/8hp, 3250rpm:

    ZoneX: FTHD, gpm(1/25hp), gpm(1/8hp)

    Zone1: 10.8, 8.1, 25.2
    Zone2: 9.0, 9.7, 30.3
    Zone3: 6.6, 13.2, 41.3
    Zone4: 7.2, 12.1, 37.8
    Zone5: 6.0, 14.2, 45.4

    Recommended flow thru the new boiler is 10gpm.
    Are those flows with the 0011 simply TOO high?
    Most everyone suggests 1 circ/loop. Since it's rare that more than 2 zones call at one time, and zone 1 is easily the most active, what do you think of just adding another 007 on zone1?

  2. #2
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    67,910
    Yes, the 0011 would be too much.

    Did you allow for fittings in the loop.

    Just adding another 007 for zone 1 may work, but I don't remmember the original problem to give a better answer.

    You got too many threads going.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  3. #3
    Join Date
    Jan 2002
    Posts
    1,196
    What kind of radiation do you have Mark?

  4. #4
    Join Date
    Feb 2005
    Posts
    41
    beenthere: Original problem was the BANGing boiler. You may have seen that the mfr has agreed to replace it. During all of that, we discussed the possibility of low flow being the culprit. Don't know if low flow was the cause for the BANG, but after looking at it, most everyone agrees that flow thru the system is not adequate.

    hydronicsman: all baseboard, plus 2 undercabinet radiotor+fan units. Original bb is 1.25" cast iron. Zones 4&5 are new with 3/4" copper.

    Here are the details per zone:

    Installed radiation:
    Zone1, 60’ of bb (x600BTUH max radiated capacity = 36000), 120’ of pipe excluding bb, serving 850sqft to be heated
    Zone2, 60’ bb (36000 max radiated), 90’ pipe, 600sqft
    Zone3, 60’ bb (36000 max radiated), 50’ pipe, 400sqft
    Zone4, 30’ bb (18000 max radiated), 90’ pipe, 300sqft
    Zone5, 30’ bb (18000 max radiated), 50’ pipe, 220sqft

    House Totals: 240’bb (144000 max radiated), 400’ pipe, 2400sqft, approx 23 gal in pipe & radiators plus 6 gal in boiler.

  5. #5
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    67,910
    Cograts on the replacement boiler.

    Ok, now you are using the wrong flow rate for the 007, I think your using theroretic.

    Taco chart says.
    007 at 10 ft hd. is 3.5 gpm
    007 at 9 ft hd. is 5 gpm
    007 at 6 ft hd. is 13.5 gpm
    007 at 7 ft hd. is 12 gpm

    A 008 would be a better choice for your first and second zones, at 8 gpm or 0010 at 10 gpm.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  6. #6
    Join Date
    Feb 2005
    Posts
    41

    Thumbs up

    The 008! I can't tell you how many times I looked at that chart, but the 008 didn't jump out at me.

    It sounds like the 1 circ/zone is the "best" solution. I think I'll go that route.

    Thanks for the help.

  7. #7
    Join Date
    Feb 2005
    Posts
    41
    OK...
    just to be sure...
    now that I'm using the charts correctly...

    If I stick with 1 circ, here are the gpm generated by a TACO 0011 on each zone:

    Zone1: 10.8 FTHD, 22gpm
    Zone2: 9.0, 23
    Zone3: 6.6, 24.5
    Zone4: 7.2, 24
    Zone5: 6.0, 25

    (Remember, typically, only 1 zone calls at a time, but it's rare that more than 2 call at a time. Zone1 is easily the most active. Recommended flow thru G124/25 is 10gpm.)

    Are these flow rates simply too high?

  8. #8
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    67,910
    Yep, you'll get noise, might not pick up heat from the boiler, or get enough out of the baseboard.

    You might get condensation in the boiler also.


    Over sizing a circ is just about as bad as under sizing.

    Use a 008, or 0010, even a 0010 is alittle high, but ok.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  9. #9
    Join Date
    Feb 2005
    Posts
    41
    008 it is.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event