What I meant is to use the ASHRAE Clear Sky Model to calculate clear sky values for each day of the year. The second suggestion is that if you don't have a program that can do this, you can do it for one day of each month, expand that to an entire year by repeating those "design day solar" values for all days of each month, and then put that 8760-hour sequence of solar values in place of what's on the weather file. There are slight changes in solar position from day to day within a month, but not enough to worry about.
Joe
Joe Huang White Box Technologies, Inc. 346 Rheem Blvd., Suite 205A Moraga CA 94556 yjhuang@xxxxxxxxxxxxxxxxxxxxxxxx http://weather.whiteboxtechnologies.com for simulation-ready weather data http://www.whiteboxtechnologies.com (o) (925)388-0265 (c) (510)928-2683 "building energy simulations at your fingertips"
On 4/24/2015 4:57 AM,
tecotonelli@xxxxxxxxx [EnergyPlus_Support] wrote:
Thanks Joe for replying so fast.
Let me see if I can unsderstand that.
You are suggesting to use the ASHRAE Clear Sky Model, but I would have the same problem: that I can only use it on design days, and not for the whole year weather file.
Than you suggest to get the radiation values for each 21st of each month and repeat for all the other days of that month. All this configuring the Design Days? 365 design days ?
As I said I`m trying to evaluate the incident solar radiation with no clouds during the whole year. I would like to have the radiation just changing with the solar geometry for my latitude, and not influenced by clouds.
Thanks again for your time.
---In EnergyPlus_Support@xxxxxxxxxxxxxxx, <YJHuang@...> wrote :
It sounds like you want to modify the solar radiation on the weather file to be always clear, i.e., with Cloud Cover of 0. Algorithmically this is quite straight-forward, just run the ASHRAE Clear Sky Model for all days. Unfortunately, although the ACSM is quite simple, you will need to give it the solar altitude every hour. What you might do is to save the solar radiation values from the design runs as you have described for the 21st of each month, and repeat those for all days of that month. The errors would be minimal.
Sent from my iPhoneJoe HuangWhite Box Technologies346 Rheem Blvd Suite 108DMoraga CA 94556(o) 1(925)388-0265(c) 1(510)928-2683
On Apr 22, 2015, at 6:08 PM, "Matheus Tonelli Santos mtonellis@... [EnergyPlus_Support]" <EnergyPlus_Support@xxxxxxxxxxxxxxx> wrote:
Hello.
I`m trying to simulate the radiation for the whole year with the clean sky.I`m currently doing this with the design day at the solar model indicator setting the sky clearness to 1. But it`s just for a design day. Is there any way I could set the sky clearness to 1 for the whole year?
I`m trying to evaluate the incident solar radiation with no clouds during the whole year. Can somebody help me with that ?
Thanks for your time.
arquiteto matheus tonelli santos
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Posted by: Joe Huang <yjhuang@xxxxxxxxxxxxxxxxxxxxxxxx>
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