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Re: [EnergyPlus_Support] Possible issue with documentation/function of Controller:Outdoorair



This is a tricky object, but is pretty nice once you get to grips with it. You always have to test, test, test, so keep doing that. From memory, you need to watch out which fields have numerics, which have zero or non-zero and which fields may be left blank.

The minimum outdoor air field (somewhere near the top) always trumps. It is the minODA. What you are doing is multiplying the total, i.e. you are setting the ODAdamper possition (0.5 = 50% ODA). It overrides the other control stradegies:

 "This field overrides Minimum Outdoor Air Schedule and Minimum Outdoor Air Flowrate"

"stradegies", not ensueing MinODA. 

With your stradegy, the damper will not close more than the set minODA.

As I said, this is a tricky object and also handles the economizer function, so don't trust my memory on this. Test, test, test.

Mit freundlichen GrüÃ?en- Sent from my iPhone (excuse the brevity)

i. A.
Jean Marais
b.i.g. bechtold
Tel.   +49 30 6706662-23

On 19.03.2015, at 05:06, "ben_coelho@xxxxxxxxxxx [EnergyPlus_Support]" <EnergyPlus_Support@xxxxxxxxxxxxxxx> wrote:

 

Hello

 

I've noticed that the Controller:Outdoorair object does not behave exactly as the documentation says it should.

 

The field I'm looking at is 'Minimum Fraction of Outdoor Air Schedule Name'.

The documentation states that "These values are multiplied by the total (design) air flow rate" AND "This field overrides Minimum Outdoor Air Schedule and Minimum Outdoor Air Flowrate"

 

I've found that if I assign an always 0 schedule to this field, the system still takes in outdoor air at the minimum rate. This suggests to me that this field doesn't override the "Minimum Outdoor Air Flowrate" field as the documentation says it should. It also does not appear to override 'Minimum Outdoor Air Schedule'.

 

It seems to work as expected if the fraction assigned calls for a higher flow rate than "Minimum Outdoor Air Flowrate".

 

I've attached an IDF that I've been testing this on. The EPLUS version is 8.2 and my weather file was "AUS_VIC.Melbourne.948680_RMY".

 

I'd appreciate any thoughts on this.

 

Also, I tried submitting this as a ticket on energyplus.helpserve.com but i get an error message "Error 503 Service Unavailable".

 

 

Many Thanks,

Benson Coelho | ESD Engineer

Setmetrics | 28 Gwynne St, Richmond, VIC 3121 Australia

ï?§ 03 9421 4005 | ï?§ 043 441 6790 | ï?ª bcoelho@xxxxxxxxxxxxxx


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Posted by: "jeannieboef@xxxxxxxxx" <jeannieboef@xxxxxxxxx>


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