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[EnergyPlus_Support] Re: Thermostat Control vs System Availability Schedule
Richard is spot on, as usual. This is most probable.
--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, Richard Raustad <RRaustad@...> wrote:
>
> For Case 1), a thermostat set back is used. For Case 2), no set back.
> This can inadvertently impact sizing.
> The program thinks it needs to pull the zone temp from the set back temp
> to the occupied temp which would be a much larger load.
>
>
> On 10/23/2012 2:08 PM, Jean marais wrote:
> > this sounds like a system with only a fan...what exactly are you turning on or off with the availability manager? Are there other manager type objects like nightventilation in your setup?
> > --- In EnergyPlus_Support@xxxxxxxxxxxxxxx, "rikards2342" <migue885@> wrote:
> >>
> >>
> >> Thank you for your suggestions, but I'm sure that the all the other conditions are the same, but the results don't match.
> >> To make de comparison I copied the initial idf file and only changed the System Availability Schedule to change it to a 24h availability schedule and I changed the thermostat from always 20/always 25 to the previous system availability (changing through two templates the periods which had the value of 1 in 20ºC and 0 in 0ºC for the winter, and 1->24ºC/0->50ºC for the summer) using the same previous templates for the system availability schedule, so the day types and schedules are the same.
> >>
> >> Watching the results I've seen that the consumption of energy don't change much (less than 0,5 %) but the equipment sizing (W) in the case 1) (thermostat schedule) is nearly double than the case 2) (with the system availability schedule).
> >>
> >> What could be the reason?
> >>
> >> Thank you very much for your help, it's very important for me to know the problem with these two cases.
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >>
> >> --- In EnergyPlus_Support@xxxxxxxxxxxxxxx, YuanLu Li <yli006@> wrote:
> >>>
> >>> Case 1) has to schedules, or two bands (tyoe 4 thermostat) Case 2) should also have two schedules, one for heating and one for cooling. Make sure that the day type, DST, and special holiday also matches. You will not know how to enter the transition period values to match the Type 4 thermostat operation. Place the zone air temperature values of the two cases side by side on a spread sheet should clearly show the differences.
> >>>
> >>> Dr. Li
> >>> To: EnergyPlus_Support@xxxxxxxxxxxxxxx
> >>> From: migue885@
> >>> Date: Mon, 22 Oct 2012 12:41:35 +0000
> >>> Subject: [EnergyPlus_Support] Thermostat Control vs System Availability Schedule
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> >>> Hi all,
> >>>
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> >>>
> >>> I tried these two ways to control the air conditioning system:
> >>>
> >>>
> >>>
> >>> 1) Imposing a Thermostat Schedule. For example, in the winter during office activity 20ºC and 0º during all other times, and in the summer 25ºC and 50 ºC. System Availability Schedule 24h/365days.
> >>>
> >>>
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> >>> 2) Imposing a System Availability Schedule defining office times with 1 and all other times 0 with a constant cooling and heating Thermostate setpoint (the same 20ºC/25ºC and office times).
> >>>
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> >>> I simulated these two possibilities with the same conditions and the results are different. Does anyone know what could be the reason?
> >>>
> >>> I used HVACtemplate:zone:unitary and HVACtemplate:system:unitaryheatpump:airtoair.
> >>>
> >
> >
> >
> > ------------------------------------
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> >
> >
>
> --
> Richard A. Raustad
> Senior Research Engineer
> Florida Solar Energy Center
> University of Central Florida
> 1679 Clearlake Road
> Cocoa, FL 32922-5703
> Phone: (321) 638-1454
> Fax: (321) 638-1439 or 1010
> Visit our web site at: http://www.fsec.ucf.edu
>
> UCF - From Promise to Prominence: Celebrating 40 Years
>
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