Physically adding chemicals for a hydronic system

Discussion in 'HVAC Heating & Cooling' started by alternety, Oct 27, 2013.

  1. alternety

    alternety Like an engineer

    Apr 2, 2006
    I need to add a bunch of antifreeze to my system (around 25gal). What do you guys use to add stuff to a system? Without getting a lot of air in there.

    Clearly I need to release water as I add the chemical. So I have to find a place where the additive won't go straight out the drain. Given my layout, that is a challenge.

    I don't think gravity will work out for the feed. I am thinking maybe plumbing something together using a small fountain pump with a tank and a hose connector. I can isolate the primary loops and buffer tank from upstairs so I will probably have about 6' of head with a drain opened (with a control valve to regulate flow rate). I need to see what I can find for a pump. Any suggestions.

    Should I be doing something else?
  2. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Sep 2, 2004
    Retired Systems engineer for defense industry.
    New England
    When the plumbers filled my system (this was awhile ago, things got rearranged and no longer have a need for antifreeze), they put a hose on the suction side of the pump (they had installed a drain valve there), and just stuck that hose into a bottle of the antifreeze and opened the valve with the pump sucked it right in. Shut it off as the bottle emptied, put a new bottle in place, open the valve until done. If you'd drained enough of the system to make room for the antifreeze, you wouldn't be throwing it away.

    I only saw this once, and may have missed an important step, but that's the basics of what I saw.

    Hopefully, somebody that does this on a regular basis can provide more detailed steps.
  3. Sponsor

    Sponsor Paid Advertisement

  4. alternety

    alternety Like an engineer

    Apr 2, 2006
    That is a good idea. I will go contemplate my system. I need to open it up anyway to replace some parts (the damn antifreeze again) and add a couple of controls to better allow me to isolate parts of the system when I need to. So it would be no big deal to add some extra pieces while I am at it.
Similar Threads: Physically adding
Forum Title Date
HVAC Heating & Cooling Adding new radiant heat zones to existing system Feb 21, 2015
HVAC Heating & Cooling Adding Zone valves to Honeywell Aquastat L8148J Mar 6, 2014
HVAC Heating & Cooling Adding AC to existing baseboard heated home Oct 23, 2013
HVAC Heating & Cooling adding zone control to system Sep 29, 2013
HVAC Heating & Cooling Adding an air return Aug 21, 2013

Share This Page