Zone valves vs circulators

Discussion in 'Radiant Heating and Cooling' started by BenWoj42, Jan 19, 2015.

  1. BenWoj42

    BenWoj42 Member

    Ever Since we've bought our new house, we've been remodeling and have only been using one zone out of the 4 to heat our house. Now that we're getting closer to finishing the house, I've been thinking about how I'm going to control my zones.

    I've read that a constant circulation (variable speeds) in the zones is a great way to keep your temperatures constant, but a lot of set ups I've seen are zoned and only circulate when called. What is the ideal set-up for geothermal zones? Multiple variable circulators which means a constant draw on electricity, or one circulator with multiple zone valves which only cycles when called?
  2. urthbuoy

    urthbuoy Well-Known Member Industry Professional Forum Leader

    No to constant circulation.

    And from then on, it depends on your zones' flow requirements.
  3. docjenser

    docjenser Well-Known Member Industry Professional Forum Leader

    We use kind of a hybrid solution.

    Outdoor reset, lower supply temps on warmer days, single variable speed DC inverter driven pump (Wilo), constant pressure, variable flow, zone valves. Almost constant circulation, thus the floors stay very evenly warm, and the pumping is very efficient. Pump shuts off when no zone is calling.
    I question the efficiency of multiple constant speed circulators, unless it is a very efficient micro pump.
    Here is an example:
  4. pfer10

    pfer10 Member

    Doc when you say the pump shuts off when no zone is calling does the pump do this automatically according to high pressure or you have external controls do it?
  5. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    The control system can use either input to stop running the pump(s).
  6. AMI Contracting

    AMI Contracting A nice Van Morrison song Industry Professional Forum Leader

    many circulators are slaved to an end switch on a zone valve.
  7. pfer10

    pfer10 Member

    Okay I was looking at one of ECM circulators and I noticed it had a shutoff pressure. Since it had the brains to determine the pressure in the system I thought that maybe in a multiple zoned system it would detect that all zones were closed and then shutoff. I guess then there would be no way to detect that it was open again.
  8. BenWoj42

    BenWoj42 Member

    The circulator I purchased is suppose to be able to adjust its speed based on pressure. So if zone one was open and circulating, if another zone opens up it's suppose to sense the pressure difference and adjust for more power. I'd assume it would work the same way when no zones are open. As soon as a zone opens up, the circulator would sense the pressure change and start up.
  9. Mark Custis

    Mark Custis Not soon. Industry Professional Forum Leader

    That is the plan. It eliminates the need for a differential by pass valve.

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