Re: [EnergyPlus_Support] Re: Indoor humidity

[Chaoqin Zhai <chaoqinz@xxxxxxxxxxxxxx>]

Thanks for your reply. Actually I have no doubt about the little latent 
cooling load. What really confuses me is the supply air humidity and indoor 
humidity ratio. Why would the supply humidity ratio lower than the indoor? 
And it is continuously lower.

Thanks again,
Chaoqin

--On Wednesday, October 27, 2004 4:24 PM +0000 donbshireyiii 
<shirey@xxxxxxxxxxxx> wrote:

>
> Depending on the inlet air conditions to the cooling coil, the outdoor
> temperature (seen by the air-cooled condenser), the air flow rate
> across the cooling coil, and the cooling coil characterictics (SHR,
> capacity, etc.), you very well may be getting only sensible cooling
> from the coil.
>
> If the air entering the cooling coil is around 7 g/kg, that's about
> 30-35% RH at 27C.  The coil would likely provide mostly sensible
> cooling with these entering air conditions (maybe 5-10% of the total
> capacity would be toward latent removal).
>
> --- In EnergyPlus_Support@xxxxxxxxxxxxxxx, Chaoqin Zhai
> <chaoqinz@a...> wrote:
>> Yes, I checked the temperature as well. The indoor temperature is
> around
>> 23oC, which is my setpoint. The temperature of the air coming from
> the
>> cooling coil is around 12 oC. There is sensible cooling on the coil,
> but
>> very little latent cooling.
>>
>> Thanks,
>> Chaoqin
>>
>> --On Wednesday, October 27, 2004 2:38 PM +0000 donbshireyiii
>> <shirey@f...> wrote:
>>
>> >
>> > Are you sure that the DX cooling coil is operating during the time
>> > when you are seeing these conditions?
>> >
>> > From what you describe, it seems like you are mixing about 40-50%
>> > outdoor air with 50-60% return air from the zone, and this air is
>> > being supplied back to the zone (with the cooling coil OFF).  Did
> you
>> > check the temperatures as well?
>> >
>> >
>> > --- In EnergyPlus_Support@xxxxxxxxxxxxxxx, "zhaicq98"
> <chaoqinz@a...>
>> > wrote:
>> >>
>> >> Hi,
>> >>
>> >> I have a unitary system with DX cooling coil to condition a
>> > one-zone
>> >> building. I output the supply air condition as well as the indoor
>> > and
>> >> outdoor air condition and I found something strange. The supply
> air
>> >> humidity ratio is around 7 g/kg dry air, but the indoor humidity
>> >> ratio is around 5 g/kg. At that period the outdoor humidity ratio
>> > is
>> >> around 9-10 g/kg. I have some occupants inside the zone. I do not
>> >> have infiltration when the HVAC is working. It seems so confusing
>> > to
>> >> me and I would greatly appreciate it if someone can give me some
>> >> hints on it.
>> >>
>> >> Thanks a lot!
>> >
>
>
>
>
>
> The primary EnergyPlus web site is found at:
> http://www.energyplus.gov
>
> The group web site is:
> http://groups.yahoo.com/group/EnergyPlus_Support/
>
> Attachments are not allowed -- please post any files to the appropriate
> folder in the Files area of the Support Web Site.
>
>
>
> Yahoo! Groups Sponsor
> ADVERTISEMENT
>  [Image: "click"]
>  [Image: "width=1"]
>
> __________________________________________________
> Yahoo! Groups Links
>
>   * To visit your group on the web, go to:
> http://groups.yahoo.com/group/EnergyPlus_Support/
>
>   * To unsubscribe from this group, send an email to:
> EnergyPlus_Support-unsubscribe@xxxxxxxxxxxxxxx
>
>   * Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.






------------------------ Yahoo! Groups Sponsor --------------------~--> 
Make a clean sweep of pop-up ads. Yahoo! Companion Toolbar.
Now with Pop-Up Blocker. Get it for free!
http://us.click.yahoo.com/L5YrjA/eSIIAA/yQLSAA/dkFolB/TM
--------------------------------------------------------------------~-> 

The primary EnergyPlus web site is found at:
http://www.energyplus.gov

The group web site is:
http://groups.yahoo.com/group/EnergyPlus_Support/

Attachments are not allowed -- please post any files to the appropriate folder in the Files area of the Support Web Site.
 
Yahoo! Groups Links

<*> To visit your group on the web, go to:
    http://groups.yahoo.com/group/EnergyPlus_Support/

<*> To unsubscribe from this group, send an email to:
    EnergyPlus_Support-unsubscribe@xxxxxxxxxxxxxxx

<*> Your use of Yahoo! Groups is subject to:
    http://docs.yahoo.com/info/terms/