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      Can two showers connect to one Pipe HEX?

      Advice on designing-in 1no WWHRS Pipe HEX connected to 2no showers (residential and non-residential examples).

       

       

      Residential Example:

      Connecting 2no back-to-back or stacked 1st and/or 2nd floor showers (eg ensuite and shower over bath) is a fairly standard design to maximise SAP impact and minimise cost for residential applications.

      Quite simply, the waste from both the shower over bath and the ensuite shower can be sent to the WWHRS. The showers can then be connected and modelled as either System A, B or C in SAP.

      From a SAP-modelling point of view, having all showers present connected to WWHRS ensures that the impact of the WWHRS is maximised.

      Residential Example

      An example schematic outlining this design (1no Pipe HEX connected to 2no showers, as System B) can be seen below:

      There are a couple of general design considerations, that you should be aware of for residential WWHRS designs:

      1. The distance from each individual shower drain to the WWHRS unit should ideally be under 3.0m (this is guidance rather than a strict rule)
      2. If the installation is System A – then the maximum flow rate for both showers should not exceed 16l/min (ie 2no 8 l/min showers)
      3. If the installation is System B or C – then the maximum flow rate for both showers should not exceed 22-24 l/min (ie 2no 11-12 l/min showers)
      4. The linear length of the pipework from the WWHRS to the cold side of the shower TMV, should not exceed 4.75m in each case.
      5. All showers should be TMV showers for SAP compliance.

       

      Non-Residential Example (eg student accommodation or hotel)

      For non-residential applications, eg. student accommodation or hotel mid/high-rise projects where back-to-back or stacked shower rooms are located around centralised service risers, then the Pipe HEX usually represents the best value and heat recovery efficiency.

      If a centralised DHW plant is present, then the WWHRS units should be designed in as System B (preheated CWM to cold-side of shower TMV only)

      The examples below can be replicated from 1st floor and above. For ground floor showers consider the Recoup Pipe HEX Active or Easyfit+

      Non-Residential Example (eg student accommodation or hotel)

      For non-residential applications, the Pipe HEX can often be accommodated within a service riser or void. An example for back-to-back shower rooms can be seen below (Recoup Pipe HEX installed as System B):

      An example for stacked shower rooms can be seen below (Recoup Pipe HEX installed as System B):

      This 2:1 shower arrangement is common in many hotel and student accommodation projects. We can assist with tailored energy efficiency calculations for SBEM/DSM modelling.

      For further info on this type of design, see the case study here for The London Standard Hotel

      There are a couple of general design considerations, that you should be aware of for non-residential WWHRS designs:

      1. The distance from each individual shower drain to the WWHRS unit should ideally be under 3.0m (this is guidance rather than a strict rule)
      2. System A or C should only be considered if each room or shower has its' own DHW source (eg HIU or localised boiler/cylinder present)
      3. If the installation is System B – then the maximum flow rate for both showers should not exceed 22-24 l/min (ie 2no 11-12 l/min showers)
      4. The linear length of the pipework from the WWHRS to the cold side of the shower TMV, should not exceed 4.75m in each case.
      5. All showers should be TMV showers for SAP compliance.

       

      Note for developers where shower over bath is a customer-specified option:

      We have seen a few housetypes, where a single ensuite shower and family bathroom with bath ONLY are standard, and customers can specify an additional shower as an option.

      If you have housetypes which specify an ensuite shower only as the standard option (ie 1no Shower: ensuite and 1no bath: bath only, no shower over), but allow customers to specify a shower over bath as an upgrade option, then you should be aware that this option does have the potential to negatively impact your SAP score.

      There are design options we could look at with you that would allow for an additional shower to be added over bath, without necessarily impacting the benchmark SAP score, where back-to-back bathrooms are present.

      Contact: technical@recoup.co.uk to discuss this further.