Results 1 to 5 of 5
  1. #1
    Join Date
    Apr 2007
    Location
    Ireland
    Posts
    40
    Rep Power
    0

    Two stage lift using UFH



    Some years ago I seen a new build home fitted with a GSHP which heated a large UFH area in a residential property.
    The hot water was provided with an unvented cylinder that had a separate smaller heat pump integrated with the cylinder.

    The collector for this heat pump was the UFH circuit.
    Do systems like this require the main heat pump to operate in tandem with the hot water heat pump?
    So that the system is providing a 2 stage temperature lift to the hot water cylinder?

    Also could anyone name any companies using this method?
    Many Thanks.



  2. #2
    Join Date
    May 2012
    Location
    England
    Age
    53
    Posts
    1,220
    Rep Power
    28

    Re: Two stage lift using UFH

    .

    If i have understood you, the hot water cylinders collector (evap)
    is piped into the floor where the Ground Sourced Heatpump, heats?

    I have never seen that done but could think it would help with the
    higher water temps required in the cylinder, trouble is, the critical temp??

    What refrigerant was inside it? I think that would be a very big factor
    in whether it would work efficiently or not.

    As for the main heatpump working or not?? think what temp the floor would
    be if it was not, low 20's maybe high teens? Could it be a form of cooling
    when the main heating is off in the summer?

    Condensation would be a hugh factor in this and dew point temps would have
    to be closely controled for it to work.

    I have never seen it so I can't coment on who would do it.

    Regards

    Rob

    .
    Last edited by Rob White; 27-12-2016 at 01:46 AM.
    .. ... -. .----. - / -- --- .-. ... . / -.-. --- -.. . / --. --- --- -..

  3. #3
    Join Date
    Apr 2007
    Location
    Ireland
    Posts
    40
    Rep Power
    0

    Re: Two stage lift using UFH


  4. #4
    Join Date
    Apr 2007
    Location
    Ireland
    Posts
    40
    Rep Power
    0

    Re: Two stage lift using UFH

    The layout is schematic 13.4 that I seen installed. Except without the buffer tank and radiators.
    http://www.hautec-waermepumpen.eu/de...S%202014-1.pdf

    This system has been running now for 9 year now without issue.

    What are the servicing procedures for both set ups?
    Many Thanks.
    Last edited by Solair; 27-12-2016 at 04:58 PM.

  5. #5
    Join Date
    Feb 2014
    Location
    UK
    Posts
    26
    Rep Power
    0

    Re: Two stage lift using UFH

    Both heat pumps need to be running.

    The DHW cylinder heat pump is using the RETURN flow from the ufh to the heating HP as its heat source.

    The UFH system isn't the collector for the DHW heat pump, it's the return flow to the main heat pump that is, so effectively the DHW heat pump has a 'warm source' making it more efficient.

    It does mean that the main heating pump will be working harder / longer, and that both heat pumps are needed to be running when the DHW heat pump is. However the DHW heat pump should be highly efficient.

    Having said that, in hot climates, with careful control, the DHW cylinder could effectively be acting deliberately to cool without any heat input from the heating heat pump. - Dew point and condensation are critical when using ufh to cool the house in the summer.
    Last edited by Worcester; 24-02-2017 at 05:03 PM.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •