[TRNSYS-users] Glazed air collector

[Nidal Abdalla]

Dear
David
Thank you for your valuable advice.
I agree with you that using type 33 (together with type 539) is somehow important to
predict the air properties at the outlet.
Best Regards
Nidal Abdalla 
________________________________
 From: David BRADLEY <d.bradley at tess-inc.com>
To: Nidal Abdalla <nidalabdalla at yahoo.com> 
Cc: Matt Duffy <duffy at tess-inc.com>; "trnsys-users at cae.wisc.edu" <trnsys-users at cae.wisc.edu> 
Sent: Monday, October 29, 2012 5:47 PM
Subject: Re: [TRNSYS-users] Glazed air collector



Nidal,
  There are a couple of things you need to be a little bit cautious
    about in this. First, Type539 only accounts for sensible heating and
    cooling. The assumption is that the absolute humidity ratio of the
    air entering and leaving the collector is the same. During daytime,
    this is likely not a problem but because the temperature changes
    through the collector, you'll need to put a Type33 at the outlet in
    order to correctly recalculate the outlet air relative humidity.
    Second, Type539 does not take into account longwave radiation loss
    that typically happens at night. Your working fluid will only cool
    down to ambient, not below it. While this is true for both water and
    air based collectors, the impact is a little more important for
    air-based collectors because, as I mentioned in the first caution,
    the Type only handles sensible energy so while in real life you
    might get some condensation occurring inside the collector at night,
    this effect will not be seen in the model.
Best,
 David
  


On 10/26/2012 17:33, Nidal Abdalla wrote:
 
Dear Matt 
>  
>Thank you v.much for your reply. 
>  
>Nidal Abdalla 
> 
  
>From: Matt Duffy mailto:duffy at tess-inc.com
>To: Nidal Abdalla mailto:nidalabdalla at yahoo.com 
>Cc: trnsys-users at cae.wisc.edu 
>Sent: Friday, October 26, 2012 7:26 PM
>Subject: Re: [TRNSYS-users] Glazed air collector
>  
>
>Dear Nidal Abdalla, 
>
>I have used Type539 (Glazed Flat Plate Solar Collector from TESS Solar Library) with success for a solar air collector. Since the solar air collector was here in the states, they had the SRCC rating numbers for the efficiency and IAM's, so I could simply enter those numbers into the parameters of Type539.  Since this solar collector model and many others in TRNSYS assume a constant fluid specific heat, you can implement solar air heating simulations with them. 
>
>Best regards, 
>
>Matt Duffy 
>
>On 2012-10-16 16:15, Nidal Abdalla wrote: 
>Dear all 
>>
>>I am trying to simulate glazed air collector for space heating using TRNSYS 17 with TESS libraries. Anyone can recommend the best choice for collector type can be used? I found at the TRNSY archives 2010 that  Mr. David had mentioned that there are a number of air-based solar collectors available in the TESS Solar Component. In fact, I found only unglazed air collector in the TESS lib. I am wondering if someone can help me. 
>>  
>>Regards 
>>
>>Nidal Abdalla 
>>
>>National Energy Research Center 
>>Amman - Jordan  
>>
>>    
>
>   
> 
>
>_______________________________________________
TRNSYS-users mailing list TRNSYS-users at cae.wisc.edu https://mailman.cae.wisc.edu/listinfo/trnsys-users   

-- 
***************************
David BRADLEY
Principal
Thermal Energy Systems Specialists, LLC
22 North Carroll Street - suite 370
Madison, WI  53703 USA P:+1.608.274.2577
F:+1.608.278.1475 d.bradley at tess-inc.com http://www.tess-inc.com
http://www.trnsys.com  
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/trnsys-users-onebuilding.org/attachments/20121029/f2e3a7fa/attachment-0001.htm>