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Injection Loop Size

Patrick_3
Patrick_3 Member Posts: 20
in THE MAIN WALL
Goodmorning Gentlemen,
I have been reading up on the injection system and I think I have it on paper and ready to begin building up, but would like a second opinion. System will have a total of 5 radiant zones and 2 high temp zones.
Radiant zones are designed with 20 delta T and 105* supply.
Zone 1 (garage) 1.5gpm, 3.4 head, 15100 btu
Zone 2 (main fl) 1.6gpm, .9 head, 16269 btu
Zone 3 (master) .7gpm, 1.2 head, 6631 btu
Zone 4 (bed rm) .6gpm, .7 head, 6139 btu
Zone 5 (basemt) .8gpm, 1.4 head, 8330 btu

Zone 6 Indirect water heater
Zone 7 20ft baseboard

Using design procedure from tekmar manual:
Boiler supply temp (Tb)= 180*
System supply temp (Ts)= 105*
Tb-Ts = 75*

System flow rate = 60,000btu @ 20delta T = 6gpm
Flow ratio = .20
Injection flow rate (6gpm x .20)= 1.2gpm

According to the desing table my injection loop could be made up of 1/2" copper, taco 007 circulator and a globe valve to throttle flow.
Looking for a little assurance before I begin, thanks, Patrick.
Was hoping to meet up with some of you at the ISH convention, but due to employees not wanting to work (I guess sitting at home pays better than $15.00/hr) I had to cancel my trip.

Comments

  • KCA_2
    KCA_2 Member Posts: 308
    Yep!!


    Seems right to me..

    And I sympothize about your employees..

    KCA :-)
    :-) Ken
  • [Deleted User]
    [Deleted User] Posts: 0
    i did the calculation at 1.5 gpm

    the max for half inch pipe, it would provide a blended temperature of about 112 degrees useing the full gpm. so you will be less, as you already figured out,,your correct as far as i can figure with pencil/paper.
  • hr
    hr Member Posts: 6,106
    About right

    What's a few 1/10's between friends! At that flow rate, and zip for pressure drop, shop for a smaller pump or you will end up throttling away most of that 007. Seems silly to throttle a 10 gpm pump down to 1.2 gpm! A 003 would be plenty, less electrical consumption and less throttle needed.

    I'm going to these small balance valves with the little flow indicators for the balance valve. You get a nice fine adjustment, (needle valve) and some pressure drop to help that pump :)

    You could probably inject enough through a 3/8" lines and run the pump up curve even further.

    I'm also installing the pump on the return side these days so it runs in 105 degree temperatures instead of 180. Not a big deal, but why not. The throttle valve goes on the high temperature supply riser.

    I'd throttle those employees a bit while your at it :0

    hot rod


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  • TJ
    TJ Member Posts: 18
    Who makes that valve?

    HR who makes that valve?
  • Patrick_3
    Patrick_3 Member Posts: 20
    Thanks

    for being there when a guy needs a second. I will check on the 003 pump and the balance valve. Once again I thank you and best too all!! Patrick
  • hr
    hr Member Posts: 6,106
    The valve

    is available from Watts Radiant, Flowguard. I believe it is a Dumser which is now a Watts company. Oventrop may have a similar valve also. There are a bunch of these out there this is the first I have seen with the little window.

    hot rod

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  • hr
    hr Member Posts: 6,106
    ISTEC

    at www.istec-corp.com also shows that same valve.

    hot rod

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  • tombig
    tombig Member Posts: 291
    Fell Off My Seat

    I'm a contractor and I have been absorbing the wealth of knowledge that you 'regulars' bring to this site. Thanks,sincerely. I've had a few chuckles but hotrod's comment about throttling at the end of a very concise and thorough response made me laugh so hard I fell off my chair.
  • frank s
    frank s Member Posts: 64
    stinking employees!!!!

    Can your employee's actually afford a home making 15.00 an hour???? I'd take the money saved from not going on your trip and spread it out amongst the men! I guess they know they can never be fired....seeing how slaves have to be sold
  • Patrick_3
    Patrick_3 Member Posts: 20
    Helper

    > Can your employee's actually afford a home making

    > 15.00 an hour???? I'd take the money saved from

    > not going on your trip and spread it out amongst

    > the men! I guess they know they can never be

    > fired....seeing how slaves have to be sold



  • Patrick_3
    Patrick_3 Member Posts: 20
    Frank

    What do you pay for helpers. These are first and second year aprentice, no hvac schooling except what I pay to send them to and spend to train them. It hasn't been 15yrs since I left the farm milking twice a day and throwing hay for 8hrs in between for $3.00/hr no overtime pay either. Oh yea, vacation? holicay pay? right!! Journey pay is $25.00/hr. With out knowing what I've done for these guys I believe your attitude is out of line!! Patrick
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