{"action":"created","issue":{"url":"https://api.github.com/repos/NREL/EnergyPlus/issues/4568","labels_url":"https://api.github.com/repos/NREL/EnergyPlus/issues/4568/labels{/name}","comments_url":"https://api.github.com/repos/NREL/EnergyPlus/issues/4568/comments","events_url":"https://api.github.com/repos/NREL/EnergyPlus/issues/4568/events","html_url":"https://github.com/NREL/EnergyPlus/issues/4568","id":47313118,"number":4568,"title":"Controller:OutdoorAir \"Heat Recovery Bypass Control Type\" causing erratic oa rates","user":{"login":"kbenne","id":707488,"avatar_url":"https://avatars.githubusercontent.com/u/707488?v=3","gravatar_id":"","url":"https://api.github.com/users/kbenne","html_url":"https://github.com/kbenne","followers_url":"https://api.github.com/users/kbenne/followers","following_url":"https://api.github.com/users/kbenne/following{/other_user}","gists_url":"https://api.github.com/users/kbenne/gists{/gist_id}","starred_url":"https://api.github.com/users/kbenne/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/kbenne/subscriptions","organizations_url":"https://api.github.com/users/kbenne/orgs","repos_url":"https://api.github.com/users/kbenne/repos","events_url":"https://api.github.com/users/kbenne/events{/privacy}","received_events_url":"https://api.github.com/users/kbenne/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/NREL/EnergyPlus/labels/EnergyPlus","name":"EnergyPlus","color":"c7def8"},{"url":"https://api.github.com/repos/NREL/EnergyPlus/labels/Priority","name":"Priority","color":"e11d21"},{"url":"https://api.github.com/repos/NREL/EnergyPlus/labels/S1%20-%20High","name":"S1 - High","color":"e11d21"}],"state":"open","locked":false,"assignee":{"login":"mjwitte","id":4991075,"avatar_url":"https://avatars.githubusercontent.com/u/4991075?v=3","gravatar_id":"","url":"https://api.github.com/users/mjwitte","html_url":"https://github.com/mjwitte","followers_url":"https://api.github.com/users/mjwitte/followers","following_url":"https://api.github.com/users/mjwitte/following{/other_user}","gists_url":"https://api.github.com/users/mjwitte/gists{/gist_id}","starred_url":"https://api.github.com/users/mjwitte/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/mjwitte/subscriptions","organizations_url":"https://api.github.com/users/mjwitte/orgs","repos_url":"https://api.github.com/users/mjwitte/repos","events_url":"https://api.github.com/users/mjwitte/events{/privacy}","received_events_url":"https://api.github.com/users/mjwitte/received_events","type":"User","site_admin":false},"milestone":{"url":"https://api.github.com/repos/NREL/EnergyPlus/milestones/1","html_url":"https://github.com/NREL/EnergyPlus/milestones/EnergyPlus%208.4.0","labels_url":"https://api.github.com/repos/NREL/EnergyPlus/milestones/1/labels","id":1229491,"number":1,"title":"EnergyPlus 8.4.0","description":"Public release of EnergyPlus 8.4.0","creator":{"login":"Myoldmopar","id":849824,"avatar_url":"https://avatars.githubusercontent.com/u/849824?v=3","gravatar_id":"","url":"https://api.github.com/users/Myoldmopar","html_url":"https://github.com/Myoldmopar","followers_url":"https://api.github.com/users/Myoldmopar/followers","following_url":"https://api.github.com/users/Myoldmopar/following{/other_user}","gists_url":"https://api.github.com/users/Myoldmopar/gists{/gist_id}","starred_url":"https://api.github.com/users/Myoldmopar/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/Myoldmopar/subscriptions","organizations_url":"https://api.github.com/users/Myoldmopar/orgs","repos_url":"https://api.github.com/users/Myoldmopar/repos","events_url":"https://api.github.com/users/Myoldmopar/events{/privacy}","received_events_url":"https://api.github.com/users/Myoldmopar/received_events","type":"User","site_admin":false},"open_issues":129,"closed_issues":50,"state":"open","created_at":"2015-07-28T14:11:03Z","updated_at":"2015-09-09T14:05:49Z","due_on":"2015-09-30T06:00:00Z","closed_at":null},"comments":14,"created_at":"2014-10-30T19:01:45Z","updated_at":"2015-09-09T15:36:30Z","closed_at":null,"body":"An example file and graphs will be uploaded to demonstrate this issue.  A value of \"BypassWhenOAFlowGreaterThanMinimum\" in Controller:OutdoorAir \"Heat Recovery Bypass Control Type\" will produce very unusual results.  Generally, OA rates are found running way above spec, forcing fan to run at full capacity.  In some cases very large discrepancies between supply outlet node flow rate and demand inlet node flow rate.  Using a value of \"BypassWhenWithinEconomizerLimits\" corrects the issue.  This can be demonstrated in models that don't even have heat recovery devices on the oa system."},"comment":{"url":"https://api.github.com/repos/NREL/EnergyPlus/issues/comments/138949466","html_url":"https://github.com/NREL/EnergyPlus/issues/4568#issuecomment-138949466","issue_url":"https://api.github.com/repos/NREL/EnergyPlus/issues/4568","id":138949466,"user":{"login":"rraustad","id":5778156,"avatar_url":"https://avatars.githubusercontent.com/u/5778156?v=3","gravatar_id":"","url":"https://api.github.com/users/rraustad","html_url":"https://github.com/rraustad","followers_url":"https://api.github.com/users/rraustad/followers","following_url":"https://api.github.com/users/rraustad/following{/other_user}","gists_url":"https://api.github.com/users/rraustad/gists{/gist_id}","starred_url":"https://api.github.com/users/rraustad/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/rraustad/subscriptions","organizations_url":"https://api.github.com/users/rraustad/orgs","repos_url":"https://api.github.com/users/rraustad/repos","events_url":"https://api.github.com/users/rraustad/events{/privacy}","received_events_url":"https://api.github.com/users/rraustad/received_events","type":"User","site_admin":false},"created_at":"2015-09-09T15:36:30Z","updated_at":"2015-09-09T15:36:30Z","body":"\nOn 9/9/2015 11:04 AM, Michael J. Witte wrote:\n>\n> @rraustad <https://github.com/rraustad> But this isn't testing if \n> OAflow is > minimum anymore.\n>\nCorrect, it just senses the heating coil activity and resets flow to \nminimum. The OA flow should not be above the minimum if the heating coil \nis active, that is no longer an economizer and would just waste energy.\n>\n> And BypassWhenOAFlowGreaterThanMinimum should only touch the HX bypass \n> flag, and it should only take action when OAflow /is/ > minimum. So \n> resetting OA flow to minimum based on this flag seems wrong.\n>\nHard to disagree with that unless the flag name is misleading (what if \nit were OptimizeEconomizerAndHXOperation). There is also other logic \nthere that looks at a calculated mixed air temperature, and if \nconditions are right, will allow the HX to turn on if it calculates that \nthe heating coil would turn on. See line 4306\n             if ( OAController( OAControllerNum \n).HeatRecoveryBypassControlType == BypassWhenOAFlowGreaterThanMinimum ) {\n                  // Optional heat recovery bypass control flag uses \nadditional logic to allow ERV optimization\n\nThere is also another OAMassFlow = MinOutAir line of code in there.\n>\n> My simple mind says the economizer should make it's decision about OA \n> flow rate regardless of the HX bypass option (which I think it is \n> already doing).\n>\nI'm not saying there is no possibility of a logic mistake. It's just \nthat in this case the SA flow is lower than the minimum, which wasn't \nexpected. And that this was working very well for the original defect \nfile (both the user and I agreed, I can't recall if you reviewed).\n>\n> Then Heat Recovery Bypass Control Type option should set the bypass \n> flag true if within economizer limits (BypassWhenWithinEconomizerLimits)\n>\nagreed\n>\n> or OA flow > min (BypassWhenOAFlowGreaterThanMinimum). Nothing more. \n> It shouldn't touch any flow rates.\n>\nSo if the heating coil is on and the flow > min, leave the flow alone (I \nthink this was the original complaint)? Maybe, but in that case \nshouldn't the HX turn on to minimize heating energy (or users should be \nable to optimize this themselves without logic intervention).\n>\n> So, I need to look back at the original problem that prompted this \n> code and see where the disconnect is.\n>\n> —\n> Reply to this email directly or view it on GitHub \n> <https://github.com/NREL/EnergyPlus/issues/4568#issuecomment-138939666>.\n>\n\nAlso note the forced iteration flags at line 4363 that were added to get \nthis to work.\n\n-- \nRichard Raustad\nFlorida Solar Energy Center\n1679 Clearlake Road\nCocoa, FL 32922\nPh: (321)638-1454\nhttp://www.fsec.ucf.edu/en/\n\nProgram Director\nElectric Vehicle Transportation Center\nhttp://evtc.fsec.ucf.edu/\n\n"}}