[Equest-users] Water side economizer

John Aulbach jra_sac at yahoo.com
Sat Nov 7 18:41:46 PST 2015


As always Nick, you are the "straw that stirs the eQuest drink (Reggie, Reggie !!). But remember one thing..I have no chiller, just a massive water cooled package unit. And this is Los Angeles.. 


     On Saturday, November 7, 2015 5:43 PM, Nicholas Caton <ncaton at catonenergy.com> wrote:
   

 #yiv8318395501 #yiv8318395501 -- _filtered #yiv8318395501 {font-family:Helvetica;panose-1:2 11 6 4 2 2 2 2 2 4;} _filtered #yiv8318395501 {panose-1:2 2 6 9 4 2 5 8 3 4;} _filtered #yiv8318395501 {font-family:SimSun;panose-1:2 1 6 0 3 1 1 1 1 1;} _filtered #yiv8318395501 {panose-1:2 4 5 3 5 4 6 3 2 4;} _filtered #yiv8318395501 {font-family:Calibri;panose-1:2 15 5 2 2 2 4 3 2 4;} _filtered #yiv8318395501 {font-family:Verdana;panose-1:2 11 6 4 3 5 4 4 2 4;} _filtered #yiv8318395501 {panose-1:2 2 6 9 4 2 5 8 3 4;} _filtered #yiv8318395501 {panose-1:2 1 6 0 3 1 1 1 1 1;}#yiv8318395501 #yiv8318395501 p.yiv8318395501MsoNormal, #yiv8318395501 li.yiv8318395501MsoNormal, #yiv8318395501 div.yiv8318395501MsoNormal {margin:0in;margin-bottom:.0001pt;font-size:12.0pt;}#yiv8318395501 a:link, #yiv8318395501 span.yiv8318395501MsoHyperlink {color:blue;text-decoration:underline;}#yiv8318395501 a:visited, #yiv8318395501 span.yiv8318395501MsoHyperlinkFollowed {color:purple;text-decoration:underline;}#yiv8318395501 p.yiv8318395501MsoListParagraph, #yiv8318395501 li.yiv8318395501MsoListParagraph, #yiv8318395501 div.yiv8318395501MsoListParagraph {margin-top:0in;margin-right:0in;margin-bottom:0in;margin-left:.5in;margin-bottom:.0001pt;font-size:12.0pt;font-family:SimSun;}#yiv8318395501 p.yiv8318395501msobodytext, #yiv8318395501 li.yiv8318395501msobodytext, #yiv8318395501 div.yiv8318395501msobodytext {margin-right:0in;margin-left:0in;font-size:12.0pt;}#yiv8318395501 p.yiv8318395501msonormal, #yiv8318395501 li.yiv8318395501msonormal, #yiv8318395501 div.yiv8318395501msonormal {margin-right:0in;margin-left:0in;font-size:12.0pt;}#yiv8318395501 span.yiv8318395501msohyperlink {}#yiv8318395501 span.yiv8318395501msohyperlinkfollowed {}#yiv8318395501 span.yiv8318395501emailstyle17 {}#yiv8318395501 span.yiv8318395501emailstyle18 {}#yiv8318395501 p.yiv8318395501msonormal1, #yiv8318395501 li.yiv8318395501msonormal1, #yiv8318395501 div.yiv8318395501msonormal1 {margin:0in;margin-bottom:.0001pt;font-size:12.0pt;}#yiv8318395501 p.yiv8318395501msobodytext1, #yiv8318395501 li.yiv8318395501msobodytext1, #yiv8318395501 div.yiv8318395501msobodytext1 {margin-right:0in;margin-left:0in;font-size:12.0pt;}#yiv8318395501 span.yiv8318395501msohyperlink1 {color:blue;text-decoration:underline;}#yiv8318395501 span.yiv8318395501msohyperlinkfollowed1 {color:purple;text-decoration:underline;}#yiv8318395501 span.yiv8318395501emailstyle171 {color:#1F497D;}#yiv8318395501 span.yiv8318395501emailstyle181 {color:windowtext;}#yiv8318395501 span.yiv8318395501d2hbreadcrumbslinkseparator {}#yiv8318395501 span.yiv8318395501EmailStyle30 {color:#002060;}#yiv8318395501 .yiv8318395501MsoChpDefault {font-size:10.0pt;} _filtered #yiv8318395501 {margin:1.0in 1.0in 1.0in 1.0in;}#yiv8318395501 div.yiv8318395501WordSection1 {}#yiv8318395501 _filtered #yiv8318395501 {} _filtered #yiv8318395501 {} _filtered #yiv8318395501 {} _filtered #yiv8318395501 {} _filtered #yiv8318395501 {} _filtered #yiv8318395501 {} _filtered #yiv8318395501 {} _filtered #yiv8318395501 {} _filtered #yiv8318395501 {} _filtered #yiv8318395501 {}#yiv8318395501 ol {margin-bottom:0in;}#yiv8318395501 ul {margin-bottom:0in;}#yiv8318395501 Hi John, I haven’t opened/picked apart your model, but some time ago I provided the following outline to this mailing list for a procedure to consider: Hi Nikola, good to hear from you! An approach I like to start with (sometimes this is a rough approximation, other times it is very accurate & appropriate), is:1.       Establish an outside temperature at and below which the waterside economizer is designed to handle the building’s cooling loads (or largely so)2.       Create a “free cooling” chiller with an EIR a hair above zero (something like 0.0000001), attach it to the CHW loop(s) servicing your coils, alongside the regular chiller(s)3.       Create a pair of equipment control sequences:  “Free” and “Normal”a.      For the “Free” control sequence, assign the “free cooling chiller” in the first row to handle loads first. You may optionally also assign the actual chillers and associated capacity ranges for each.b.      For the “Normal” control sequence, specify your normal chiller sequence of operations4.       Then create a Load Management of type OA-TEMP.  a.      Set the outside air temperature below which free cooling is active under management sequence 1, and assign the free cooling control sequence defined in the previous step.b.      Set management sequence 2 to a maximum OSA temp of 999, and assign the normal control sequence from the previous step Integrating WSE into eQuest is one of those things I always plan on spending extra time on – the devil is in the details!  I don’t believe waterside economizer systems are something you can make a simple rote procedure around, as actual waterside economizer system operations/limitations are varied and nuanced.  Consider this a simple outline to convey the approach concept & get you started.  I would particularly advise paying close attention to your pumping and heat rejection energies from this point forward. Hope that helps get you started - Happy new year! ~Nick I have simulated  a number of different WSE arrangements since posting that, but still follow the same general outline/strategy.  The sequencing part in particular is where the meat of the puzzle lies, project to project.  You should be able (and I advise) to describe for yourself in writing exactly how the chiller(s) and free cooling operation should sequence with each other.  Then go and translate that into a meaningful set of equipment control sequence inputs.  I have found actually entering the “capacity” of free cooling at the chiller makes complicated sequencing a bit more manageable as an extra tip, but it may come down to just how your brain processes the problem what approach is easiest. Best of luck! ~Nick NICK CATON, P.E.
Owner Caton Energy Consulting
  306 N Ferrel  Olathe, KS  66061  office:  785.410.3317www.catonenergy.com From: Equest-users [mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of John Aulbach
Sent: Thursday, November 05, 2015 11:21 AM
To: Bishop, Bill; Julien Marrec
Cc: Equest-users
Subject: Re: [Equest-users] Water side economizer Gentlemen: Here is the model. Pick away. I just don't think it makes sense in SoCal vs an air side. Please keep the client close to your vest. This building is on the site of the old Gene Autry studios.  On Thursday, November 5, 2015 8:39 AM, "Bishop, Bill" <bbishop at pathfinder-ea.com> wrote: John,The energy savings for air handler water-side economizers (WSE) will largely depend on the pumping energy, as you note. These are different than the water-side economizers that are cooling towers for serving chilled water systems, allowing chiller(s) to turn off. The default coil head is pretty high (20’) so override the default if appropriate to your design.  The DOE2.2 help menu description for WSE is in this section: Volume 2: Dictionary > HVAC Components > SYSTEM > Cooling EquipmentPart of the description mentions operation to supplement (not entirely replace) the cooling coil and/or air-side economizer:The water-side economizer coil is assumed to be downstream of the mixed air plenum, and upstream of the cooling coil. As such, the cooling coil may supplement the operation of the water-side economizer. The air handler may also have a conventional outdoor-air economizer, in which case the outdoor-air economizer will operate first to meet the supply-air setpoint, then the water-side economizer will supplement the outdoor-air economizer, and the cooling coil will pick up the remaining load, if any. Regards,Bill William Bishop, PE, BEMP, BEAP, CEM, LEED AP | Pathfinder Engineers & Architects LLP
| Senior Energy Engineer |    |
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| 134 South Fitzhugh Street                 Rochester, NY 14608 |
| T: (585) 698-1956                        F: (585) 325-6005 |
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 From: Equest-users [mailto:equest-users-bounces at lists.onebuilding.org] On Behalf Of Julien Marrec
Sent: Thursday, November 05, 2015 11:17 AM
To: John Aulbach <jra_sac at yahoo.com>
Cc: Equest-users <equest-users at lists.onebuilding.org>
Subject: Re: [Equest-users] Water side economizer John,Never did a waterside economizer for RTUs, but a couple of points I think I remember:The waterside economizer in eQuest is all or nothing: if it can satisfy the entire load, then it's on, otherwise it's off. Are you autosizing or hardsizing it?It also poses the questions of how you reset the condenser water loop temperature, and how you reset the rooftop supply air temperature during low load condition.What are your current settings?Julien 
--
Julien Marrec, EBCP, BPI MFBA
Energy&Sustainability Engineer
T: +33 6 95 14 42 13

LinkedIn (en) : www.linkedin.com/in/julienmarrec
LinkedIn (fr) : www.linkedin.com/in/julienmarrec/fr 2015-11-05 15:11 GMT+01:00 John Aulbach <jra_sac at yahoo.com>:
Hello all and HALP !! I have an office building in Los Angeles that is looking to go LEED Core and Shell. It has some exterior and back of the house lighting, so the savings there make sense. But the building has 6 DX 30-50 ton Trane rooftop package units, two on the 1st floor and one for each of the other 4 floors. These are WATER COOLED units. These units have a central outside air stream, and have WATER SIDE ECONOMIZERS. My Base model has an air side economizer (still water cooled condensers). The proposed model removes the air side and replaces it with the water side. The units themselves are EER 14+, whereas the Base units are 10.8 EER. Results show a SLIGHT savings in Space Cooling, which I attribute to the EER improvement MINUS the air side economizer removal (Jan and Dec space cooling load INCREASES in the Proposed Case). But the pumping energy skyrockets about 50% (remember, no chilled water). I am unsure if I am running the water side correctly. There is only the one line of data at ever SYSTEM level. Help?? John R. AulbachAging engineer (by the minute)
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