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Re: [EnergyPlus_Support] Reference to Weatherfile

The design day data in the weather files are taken from the ASHRAE  
Hanbook of Fundamentals and include data for several different design 
 points, Heating (99.6% and 99%), Cooling Dry Bulb (0.4%, 1% and  
2%), Wet  Bulb (0.4%, 1%, and 2%), and Dew Point (0.4%, 1%, and 2%).  
 From this information, you can then create design day objects as  
desired.  As Linda mentioned, the creation of design day objects will 
be automated in the v1.0.3 release.  

For each design day type, the user must decide which percentile to 
design to.  This may be dictated by local codes.  

For heating, most users typically use a single design day, typcially 
with no range in temperature (the high equals the low for the day), 
and with no sun (clearness=0).  This is a conservative assumption.

For cooling, one dry bulb design day is necessary, with sun 
(clearness = approximately 1.0), and with a range in temperature, 
specified by the daily range value in the design data.

In most climates, except very dry climates, it is also important to 
run a dew point day.  In applications with significant outside air 
requirements, the peak total (sensible+latent) cooling load on the 
dew point day can exceed the peak load on the dry bulb cooling day.

For cetain applications, it may also be necessary to run a wet bulb 
design day as well.


On 3 Oct 2002, at 6:26, Linda Lawrie wrote:

> At 06:39 AM 10/2/2002, Alexander wrote:
> >Dear Sir/Madam
> >The weatherfiles include design day and groundtemperature data. How
> >do these correspond to the IDF objects DesignDay and
> >GroundTemperatures?
> (Ground temperature question answered in a separate email)
> The design day information will be able to be transformed into
> DesignDay objects in release V1.0.3.     The entire set of "design
> conditions" will be available (along with location objects) as well as
> each individual weather file that includes design information can be
> generate this information separately.
> Linda
> EnergyPlus WebSite: http://www.energyplus.gov
> Owner: EnergyPlus_Support list
> Member: EnergyPlus Development Team

EnergyPlus Testing and Support      

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