[Equest-users] VRV Special case: is it worth modeling?

Thu Oct 14 11:36:30 PDT 2010

I know that it id not a good idea to do without looking into it more, but after 
reading through the literature, specifically the new features document, I felt 
ok doing it. The document specifically lists an air cooled condenser as being an 
acceptable option.  I was, and still am skeptical of it, but 
the documentation clearly states that it is a valid option. 

________________________________
From: Carol Gardner <cmg750 at gmail.com>
To: Eddie Corwin <ecorwin at altanova-energy.com>
Cc: equest-users at lists.onebuilding.org
Sent: Thu, October 14, 2010 2:30:57 PM
Subject: Re: [Equest-users] VRV Special case: is it worth modeling?

Eddie,

You should not mix air source heat pump data entries with WS/GS heat pump 
entries. eQUEST will let you do many things you shouldn't and this would fall in 
that category. Hard to say what the impact is but safe to assume it's not good. 
If you disagree with the output look elsewhere.

Carol

On Thu, Oct 14, 2010 at 10:41 AM, Eddie Corwin <ecorwin at altanova-energy.com> 
wrote:

Omar, attached is an example .inp file (when opening, make sure you are viewing
>INP files, and not PD2 files only)
>
>You need to change your system to PVVT, then go throughput an setup the proper
>inputs (fan power, schedules, condenser type...). There is  one issue that I 
ran
>into, and that is the following:
>
>On the first tab, labeled "Basics", there is an option that says "WL/GS Heat
>Pump" I selected YES (because selecting NO gave me unrealistically high
>results), even though it is an air-to-air heat pump.  After reading through the
>literature, this does seem to be a proper selection, as long as
>your condenser is set to air-cooled. After that, just make sure you have the
>proper curves (Daikin can provide you curves for their unit).
>
>Let me know if you run into more problems, but don't be afraid to dive right 
in.
>
>-Eddie
>
>
>
>________________________________
>From: Omar Katanani <omar at ecoconsulting.net>
>To: Eddie Corwin <ecorwin at altanova-energy.com>;
>
>Gary.Schrader at buildings.schneider-electric.com
>Sent: Thu, October 14, 2010 12:14:36 PM
>Subject: RE: [Equest-users] VRV Special case: is it worth modeling?
>
>
>Thanks a lot guys!
>
>The EER of the VRV is 10 (I had read it wrong).
>COP= EER / 3.412
>EQUEST asks for Elec. Input Ratio (inverse of COP). So I assume the EIRis
>3.412/10 = 0.3412… correct?
>
>As for modeling the VRV:
>Can you please detail to me how to extract the performance curves from
>Residential VVT and how/where to input them? I don’t have heating in my VRV
>system (zones served are elec rooms & UPSrooms)? I have attached my file in 
this
>email. Would it be possible to help me by roughly inputting data into 1 of the 
4
>zones (I called the systems: VRV-1, VRV-2, VRV-3, and VRV-4)?
>
>If any of you helps me with this I can submit my simulation results and report
>by mid-next week, and this would be awesome and I’ll be grateful!
>
>I know each one of us is busy, but Eddie gave me the impression that it would
>take a couple of minutes to fill the inputs! If you think that would take more
>time, I would much appreciate it if you detail to me what should I do as much 
as
>possible!
>
>Many thanks again,
>
>Omar
>___________________________
>Omar Katanani
>Sustainable Design Engineer
>Email: omar at ecoconsulting.net
>
>EcoConsulting (Lebanon)
>NahasBuilding, 4th floor
>
>4 St-Maron Street/ Georges Haddad Avenue
>Postal Code: 2028 5806 SAIFI
>Beirut, Lebanon
>Tel:          +961 (0) 1 971 266
>Mobile:    +961 (0) 3 045 045
>
>EcoConsulting (UK) Ltd
>28 Marshalsea Road
>London, SE1 1HF
>Tel:  +44 (0) 207 939 0989
>Fax:  +44 (0) 207 939 0981
>Website: www.ecoconsulting.net
>
>
>-----Original Message-----
>From: equest-users-bounces at lists.onebuilding.org
>
>[mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Eddie Corwin
>Sent: 14 October 2010 18:28
>To: equest-users at lists.onebuilding.org
>
>Subject: Re: [Equest-users] VRV Special case: is it worth modeling?
>
>
>For the most part, I agree with Gary.  I believe that you will also find
>significant savings from part-load performance from the VRV system.  VRV
>systems operate more efficiency at part-load, especially when compares to a
>chiller.  I just finished modeling a VRV system, and with the newest version of
>eQuest, it is not that difficult.  Simply use the PVVT system, and set the
>compressor to variable speed.  You will need a low-speed curve for both heating
>and cooling.  I took those curves from the ResidentialPVVT system.
>
>I also agree that a COP of 10 seems unreasonable, but I assumed that you meant
>an EER of 10
>
>-Eddie
>
>
>
>________________________________
>
>From:"Gary.Schrader at buildings.schneider-electric.com"
><Gary.Schrader at buildings.schneider-electric.com>
>To: omar at ecoconsulting.net; equest-users at lists.onebuilding.org
>Sent: Thu, October 14, 2010 11:10:43 AM
>Subject: Re: [Equest-users] VRV Special case: is it worth modeling?
>Omar,
>
>The only thing that would save you a significant amount of energy in my opinion
>would have been scheduling large VAV air handling and plant equipment that was
>originally serving them. I had a project where I took data closets off of the
>VAV units and put VRV units in the closets so that the VAV units no longer had
>to run 24/7. Scheduling these large VAV units had a significant savings impact.
>
>In your case, it sounds like you may have something similar but I would need
>clarification. You said that your closets (that you want to convert to VRV) are
>currently FCU. I assume that these FCUs are served by chilled water. By
>switching these closets over to VRV, are you able to now schedule the chiller
>off? If yes, I would assume that significant savings would result by not 
running
>a chiller (and pumping) 24/7, even with a high unloading capability and
>variable-speed pumping. (If you had low unloading capability and constant
>pumping, more savings would result)
>
>At face value, simply changing the efficiency of the cooling equipment isn’t
>enough to evaluate energy savings. If, however, you can significantly change 
the
>schedule of plant equipment because it is isolated from zones that require 24/7
>operation, savings could be significant and I would certainly recommend a 
model.
>
>Sidenote: 10 COP seems very, very high for even the best VRV equipment. I would
>check that value to ensure accuracy…
>
>Best luck,
>Gary
>
>_______________________________________________________________________________________________________________________
>
>
>Gary Schrader| Schneider Electric | Buildings Business | Energy Solutions |
>Engineer I
>Phone: +1 913 217 8068 | Fax: +1 913 469 0206
>Email: gary.schrader at buildings.schneider-electric.com | Site:
>www.schneider-electric.com/buildings | Address: 16011 College Boulevard, Suite
>212 , Lenexa , KS 66219 , USA
>
>*** Please consider the environment before printing this email.
>
>________________________________
>
>From:equest-users-bounces at lists.onebuilding.org
>[mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Omar Katanani
>Sent: Thursday, October 14, 2010 5:41 AM
>To: equest-users at lists.onebuilding.org
>Subject: [Equest-users] VRV Special case: is it worth modeling?
>
>
>Dear all,
>
>My school has some 200 zones including classrooms, storage rooms, offices...
>
>The HVAC system is a VAV one, with FCU for 17 offices/storage rooms.
>
>In the new updated design, 4 of these FCUs were replaced with a VRV system. I 
am
>about to model that:
>
>Do you think that these 4 small zones (electrical room (x 2), UPS room,
>telephone room) will significantly change the Space Cooling results (not that 
no
>heating is required)? I mean, these zones had FCUs and were conditioned. All
>that changed is that a VRV (COP=10) replaced the chiller (COP=5.4) for only 4
>zones!
>
>I would like to avoid the complexity of modeling VRVs if possible!
>
>Many thanks,
>Omar
>___________________________
>Omar Katanani
>Sustainable Design Engineer
>Email: omar at ecoconsulting.net
>
>EcoConsulting ( Lebanon )
>Nahas Building, 4th floor
>4 St-Maron Street / Georges Haddad Avenue
>Postal Code: 2028 5806 SAIFI
>Beirut, Lebanon
>Tel:          +961 (0) 1 971 266
>Mobile :    +961 (0) 3 045 045
>
>EcoConsulting ( UK ) Ltd
>28 Marshalsea Road
>London , SE1 1HF
>Tel:  +44 (0) 207 939 0989
>Fax:  +44 (0) 207 939 0981
>Website: www.ecoconsulting.net
>
>
>
>
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-- 
Carol Gardner PE