[Bldg-sim] ASHRAE Appendix G EER Calculation

[Arpan Bakshi]

Sam

Great example. Would you kindly provide a detailed citation, so it is
recorded in the archives.

Thanks

Arpan


On Mon, Jan 31, 2011 at 5:30 PM, Sam Mason <sam.mason at atelierten.com> wrote:

>  Karen,
>
> From the user’s guide, the fan power should be removed from the standard
> EER rating of packaged cooling systems. Excerpt below but let me know if you
> have any further questions.
>
>
>
> A 15-ton packaged rooftop single-zone system having an *EER *of 8.6 (*COP
> *of 2.5) is
>
> specified for a building. The following table gives the design
> specifications. How should
>
> this be modeled?
>
> Equipment parameter                               Value
>
> Net Cooling Capacity (Btu/h)                   174,000
>
> Total Packaged Unit Input Power (W)        20,128
>
> *EER                                                         *8.64
>
> Gross Cooling Cap (ARI conditions)         182,000
>
> *A*
>
> The supply fan power is the difference between the gross and the net
> cooling capacity.
>
> Supply Fan Power  = (182,000 - 174,000 Btu / h) / 3.413 Btu /W h =  2343 W
>
>
>
> From the equation for cooling system *COP*, the cooling provided by the
> compressor and
>
> the condenser into the airstream in Btu/h per Btu/h of electrical power
> input is:
>
> COP  = (182,000 Btu / h) / {(20,128 - 2343 W)* 3.413 Btu / W h } = 3.0
>
> Some simulation programs use an energy input ratio (*EIR*), which is 1/*
> COP*. In this case,
>
> the *EIR *for this piece of equipment would be 1/3 or 0.333.
>
>
>
> --
>
> Sam Mason
>
> Atelier Ten
>
>
>
> T  +1 212 254 4500 x221
>
>
>
> *From:* bldg-sim-bounces at lists.onebuilding.org [mailto:
> bldg-sim-bounces at lists.onebuilding.org] *On Behalf Of *Karen Walkerman
> *Sent:* Monday, January 31, 2011 3:53 PM
> *To:* bldg-sim at lists.onebuilding.org
> *Subject:* Re: [Bldg-sim] ASHRAE Appendix G EER Calculation
>
>
>
> A clarification:
>
>
>
> My question pertains to baseline models, with baseline systems.
>
>
>
> --
>
> Karen
>
>
>
> On Mon, Jan 31, 2011 at 12:09 PM, Karen Walkerman <kwalkerman at gmail.com>
> wrote:
>
> Hi All,
>
>
>
> G3.1.2.1 in ASHRAE 90.1 says that "Where efficiency ratings, such as EER
> and COP, include fan energy, the descriptor shall be broken down into its
> components so that supply fan energy can be modeled separately."
>
>
>
> However, I am a little unclear as to which baseline systems this applies
> to.  It seems that it would apply to systems 1 - 2, and not to systems 3 -
> 8?
>
>
>
> Thanks,
>
>
>
> --
>
> Karen
>
>
>
> _______________________________________________
> Bldg-sim mailing list
> http://lists.onebuilding.org/listinfo.cgi/bldg-sim-onebuilding.org
> To unsubscribe from this mailing list send  a blank message to
> BLDG-SIM-UNSUBSCRIBE at ONEBUILDING.ORG
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.onebuilding.org/pipermail/bldg-sim-onebuilding.org/attachments/20110131/e2d5f81d/attachment-0001.htm>