[Equest-users] Water to water geothermal heat pump / Radiators / No cooling / Natural ventilation

[Nick Patsos]

Bill thank you very much, I will look into it with the approach you
describe.

Regarding the temperature schedule for the GHX, is it possible to calculate
it somehow? Sure there is limitation to the energy that the ground can
receive from a closed circuit exchanger in comparison with the open loop
that can receive any amount.

The project is for LEED for Schools 2009 so it uses the 90.1-2007, no
heating only systems there.

Best regards

Nick Patsos
Mechanical Engineer


On 7 February 2014 16:53, Bishop, Bill <bbishop at pathfinder-ea.com> wrote:

>  Nick,
>
> You can use a chiller of TYPE = HEAT-PUMP to model W2W GSHP. You attach
> it/them to a CHW loop of TYPE = PIPE2 (a two-pipe loop) that provides
> either hot or cold water but never at the same time, and configure the
> switchover using the Operation and Controls tabs of the loop. You can also
> add condensing boiler(s) to the two-pipe loop and stage them with the W2W
> chiller(s) using Equipment Controls and Load Management in the loop
> Controls tab. The GSHP connection to the ground loop is via a LAKE/WELL CW
> loop, to which you can attach a GROUND-LOOP-HX of TYPE = LAKE/WELL. You
> have to specify the temperatures of the HX in the LOOP-TEMP-SCH (they are
> not calculated hourly like they are for the other GHX types) or eQUEST will
> default to the monthly ground temperatures from the weather file.
>
> I would look into the heating-only Systems 9/10 in 90.1-2010 for spaces
> with no cooling.
>
> Regards,
>
> Bill
>
>
>
> *William Bishop, PE, BEMP, BEAP, LEED AP **|** Pathfinder Engineers &
> Architects LLP*
>
> *Senior Energy Engineer*
>
> [image: webCertified_logo_colorRGB72DPI.jpg]
>
>
>
> 134 South Fitzhugh Street                 Rochester, NY 14608
>
> *T: (585) 698-1956*                        F: (585) 325-6005
>
> bbishop at pathfinder-ea.com <wbishop at pathfinder-ea.com>
> www.pathfinder-ea.com
>
> [image: earth for signature]Sustainability - the forest AND the trees.
>
>
>
> *From:* equest-users-bounces at lists.onebuilding.org [mailto:
> equest-users-bounces at lists.onebuilding.org] *On Behalf Of *Nick Patsos
> *Sent:* Friday, February 07, 2014 7:00 AM
> *To:* equest-users at lists.onebuilding.org
> *Subject:* [Equest-users] Water to water geothermal heat pump / Radiators
> / No cooling / Natural ventilation
>
>
>
> Hello all,
>
>
>
> I need your opinions on a very complex system that I have to model for
> LEED in eQuest.
>
>
>
> The system is a water to water geothermal heat pump capable of producing
> hot water for heating and in the summer season chilled water for cooling,
> not simultaneously.
>
>
>
> The hot water is to be used by low-temp radiators (no fans) in spaces or
> FCUs. In some spaces ERV ventilators provide fresh air (constant speed) /
> in some only natural ventilation is provided (significant issues there to
> be discussed in due time).
>
>
>
> There are spaces which have no heating/cooling by FCUs, only radiators
> (with ERVs or without).
>
>
>
> I have made a diagram to give a quick overview picture attached.
>
>
>
> The issues are as follows:
>
>
>
> 1) I tried modelling a Loop-to-loop heat pump system producing both hot
> and chilled water but I find significant consumption in cooling (coincident
> with heating) in the winter months which is highly unusual, thus very
> increased overall consumption in comparison with the baseline packaged VAV
> (PVAVS) system. Any alternatives ?
>
>
>
> 2) For the not cooled spaces I used baseboard heating and as system PVAVS
> cooling (due to the same as baseline cooling condition), I don't know if
> this is the correct approach. For the fan power of PVAVS do I have to use
> the same as baseline kW/cfm ? What about when the system is in heating when
> only baseboards should work (no fans) ? How 's this to be modeled ? Any
> ideas?
>
>
>
> 3) For the geothermal loop, I have a ground loop heat exchanger, now
> modelled as Lake/Well (due to limitations of the Loop to Loop heat pump)
> but in reality it will be a straight pipe closed circuit loop. I remember
> reading about creating a custom temp. schedule to model the exchanger, is
> it possible ?
>
>
>
> 4) Something more obvious than the above but still unsure, is PVAVS in
> eQuest the way to model Packaged VAV with Reheat as in 90.1 ?
>
>
>
> 5) Has anyone successfully tried the Shermad-Grimsrud method for natural
> ventilation in eQuest ?
>
>
>
> As you see, it is really messed up, mostly due to the water-to-water heat
> pump. I know that I'm asking lots of questions in different topics at once.
> Ideas in any of the topics are greatly appreciated.
>
>
>
> Nikos Patsos
>
> Mechanical Engineer
>
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