[Equest-users] baseboards activating when zone is already above heat setpoint?

[Nicholas Caton]

Hi Matthew!

A couple thoughts:

  *   Baseboard operations can be specified at both ZONE and SYSTEM levels.  I’m not entirely sure (intuition alone) which takes precedent if you have both.  You may want to review what is entered at the SYSTEM level under the heating tabs… that could explain the delivery of heat at a time when the zonal temp conditions do not warrant the baseboard’s operation.
  *   Regardless, applying a schedule to the baseboards (and/or baseboard loop, if you have that set up as a distinct loop in the hydronic tab) can probably override this behavior by making the baseboards only available when seasonally appropriate (by calendar) and/or by utilizing an OADB snap temperature threshold to limit baseboard heating availability.
  *   An error popping up in application of a schedule is possibly what it’s saying on the tin: the schedule may simply an incompatible type (the only valid option for BASEBOARD-SCH is RESET-RATIO)… but sometimes the eQuest interface is just behaving badly.  If you’re uncertain the schedule (annual/week/day schedules inclusive) are of an appropriate/compatible type, then I’d advise starting from scratch by first loading in a compatible library schedule, and adjusting from there.  If you are confident the schedule is of the correct type, then I might try “forcing” this assignment by saving a separate copy of your project, closing eQuest, adding the appropriate assignment to 1 zone via the INP file in a text editor of your choosing, then opening that modified project to see if it “sticks.”  If so, then you may likely be able to proceed with assigning that schedule to the remaining zones as appropriate.
  *   Might be worth noting, if you want to control baseboard heating availability at the circulation loop level, you’ll have a couple few more viable options in terms of schedule type.

I hope this is helpful!


~Nick



[cid:image006.jpg at 01D67C6E.61F63320]
Nick Caton, P.E., BEMP
  Senior Energy Engineer
  Energy and Sustainability Services
  Energy Performance Contracting
D
M
E

913 . 564 . 6361
785 . 410 . 3317
nicholas.caton at se.com<mailto:nicholas.caton at se.com>
15200 Santa Fe Trail Drive
Suite 204
Lenexa, KS 66219

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From: Equest-users <equest-users-bounces at lists.onebuilding.org> On Behalf Of Matthew Yarmon via Equest-users
Sent: Thursday, August 27, 2020 12:16 PM
To: equest-users at lists.onebuilding.org
Subject: [Equest-users] baseboards activating when zone is already above heat setpoint?


[External email: Use caution with links and attachments]

________________________________


Hi all,

I hope you're able to see the image below. If not, I uploaded it here: https://imgur.com/a/WpQ8FSR<https://eur02.safelinks.protection.outlook.com/?url=https%3A%2F%2Fimgur.com%2Fa%2FWpQ8FSR&data=02%7C01%7CNicholas.Caton%40se.com%7C2b594d4a489b47c421ec08d84aacf77c%7C6e51e1adc54b4b39b5980ffe9ae68fef%7C0%7C0%7C637341454029975820&sdata=39WSmtUZhlhfTyFbUM2P1r2Pz4rqleOpnXIL8QeRxaQ%3D&reserved=0>   It shows eQuest 'hourly results', specifically it shows a warm day in the year, July 3rd, for a model I'm looking at.

In my model, from 1pm-4pm on July 3rd, the heating setpoint is 71 °F (grey column), cooling setpoint is 76 °F (blue).  Outdoor temp is ~84 °F (orange), zone temps are ~75-77 °F.  The question is, why are my baseboards (yellow column) activating and heating the zone?  The temp in the zone is above the heating setpoint, so the baseboards should not be turning on.

The baseboards are set to 'thermostatic' control.  I've been unable to set  baseboard schedule (see 2nd screenshot below - if anyone has a suggestion for this problem, I'd love to hear it).  But regardless of the schedule, if the zone heat setpoint is 71 °F, and zone temp is above 74 °F, why are baseboards turning on?

Cheers,
Matthew
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