[EnergyPlus_Support] Re: PSZ-AC w/district heating? AirLoopHVAC:Unitary:Furnace:HeatCool only has gas or

["jeannieboef" <jeannieboef@xxxxxxxxx>]

In my case you're bang on. very small LEED project, purchased heat.
LEED's brought out some new guidlines which divert (on purpose) from ASHRAE on some small points. I referenced the document earlier. gas is no longer an option in my case, hence the whole water loop coil effort. The simulation I set up seems to be running and I'll check it tomorrow for the outputs, but I still don't know exactly how to match up the system no 3 with the min. eff tables in chapter 6 of the standard. That's why I put down my best guess for your opinion on which tables apply to PSZ-AC w/district heating equipment.

--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, "James V Dirkes II, PE" <jvd2pe@...> wrote:
>
> Dear Jeannie and Vinay,
> 
>  
> 
> .         I have not followed this thread of conversation from the
> beginning, and cannot give you too much time to look it up. but I'll try.
> 
> .         Assuming that you are involved with a LEED project, your baseline
> HVAC is PZ-AC only if the building 
> 
> o   has 3 floors or less
> 
> o   is also less than 25,000 sq.ft.
> 
> o   and the proposed system is fossil-fueled or purchased heat
> 
> .         That means your baseline system should be defined with a DX
> cooling coil and fossil-fueled heating coil.  I think that I would use a gas
> coil for the baseline; it's simpler to create (no water loop).
> 
> .         I use component efficiencies appropriate for the modeled system
> (the entire air or water loop, not individual zones).  Baseline systems
> require autosizing per ASHRAE 90.1, so you will have to get the model
> running, then check the reports to see what capacity E+ has determined, then
> adjust your input efficiencies as needed to match the 90.1 requirements.
> 
> .          The proposed system will be exactly as designed by you (or
> whomever is the designer), including components and efficiencies.
> 
>  
> 
> The Building Performance Team
> James V. Dirkes II, P.E., LEED AP
> 1631 Acacia Drive NW
> Grand Rapids, MI 49504
> 616 450 8653
> 
>  
> 
> From: EnergyPlus_Support@xxxxxxxxxxxxxxx
> [mailto:EnergyPlus_Support@xxxxxxxxxxxxxxx] On Behalf Of jeannieboef
> Sent: Monday, August 30, 2010 9:00 AM
> To: EnergyPlus_Support@xxxxxxxxxxxxxxx
> Subject: [EnergyPlus_Support] Re: PSZ-AC w/district heating?
> AirLoopHVAC:Unitary:Furnace:HeatCool only has gas or
> 
>  
> 
>   
> 
> Mr. Dirkes,
> 
> I'm also having trouble pinning down the required efficiencies.
> 
> I'm guessing the following at the moment:
> System Type: Packaged rooftop air conditioner
> Fan Control: Constant Volume
> Cooling Type: Direct Expansion (DX)
> Cooling Capacity: (zone dependant, ranging from 5.2 kW to 0.1 kW)
> 
> Min Efficiency Requirements as per Table 6.8.1A Air Conditioners,
> Equipment Type: Air Conditioners, air cooled (as DX coils are air cooled),
> Size Category: <19 kW (rated cooling capacity?),
> Heating Section Type "All"
> Subcategory or Rating Condition: Single Package
> Minimum Efficiency (cooling?): 3.18 SCOP (as of 1/23/2006)
> 
> Heating Type: Normally Fossil fuel furnace, but as per Treatment of District
> or Campus Thermal Energy in LEED V2 and LEED 2009 - Design & Construction,
> August 13 2010 - Purchased District Heating
> 
> Heating Capacity: (zone dependant, ranging from 4.4 kW to 0.1 kW)
> 
> What will the heating coil efficiencies be? I see options for implementing
> cooling coil efficiencies (using the modifier curves as per DOE-2.1E) and
> part load functions, but not for a hot water coil. Is there any requirement
> for how much heat must be transfered from the coil to the air?
> 
> --- In EnergyPlus_Support@xxxxxxxxxxxxxxx
> <mailto:EnergyPlus_Support%40yahoogroups.com> , Vinay Devanathan
> <vinay.devanathan@> wrote:
> >
> > Mr. Dirkes,
> > 
> > Do we have to use only coil:hot water or can we also use coil:gas?
> > 
> > Thank you.
> > 
> > On Aug 30, 2010, at 6:59 AM, "James V Dirkes II, PE" <jvd2pe@> 
> > wrote:
> > 
> > > Dear Jeannie,
> > >
> > >
> > >
> > > Just construct an Air Loop which has a fan, (hot water) heating coil 
> > > and DX cooling.
> > >
> > >
> > >
> > > There is nothing magical about the Furnace:HeatCool object; it just 
> > > has a cycling (on:off) fan, a heating coil and a cooling coil.
> > >
> > >
> > >
> > > The Building Performance Team
> > > James V. Dirkes II, P.E., LEED AP
> > > 1631 Acacia Drive NW
> > > Grand Rapids, MI 49504
> > > 616 450 8653
> > >
> > >
> > >
> > > From: EnergyPlus_Support@xxxxxxxxxxxxxxx
> <mailto:EnergyPlus_Support%40yahoogroups.com>  
> > > [mailto:EnergyPlus_Support@xxxxxxxxxxxxxxx
> <mailto:EnergyPlus_Support%40yahoogroups.com> ] On Behalf Of jeannieboef
> > > Sent: Monday, August 30, 2010 4:40 AM
> > > To: EnergyPlus_Support@xxxxxxxxxxxxxxx
> <mailto:EnergyPlus_Support%40yahoogroups.com> 
> > > Subject: [EnergyPlus_Support] Re: PSZ-AC w/district heating? 
> > > AirLoopHVAC:Unitary:Furnace:HeatCool only has gas or
> > >
> > >
> > >
> > >
> > >
> > >
> > > Is everyone on holiday?
> > > --- In EnergyPlus_Support@xxxxxxxxxxxxxxx
> <mailto:EnergyPlus_Support%40yahoogroups.com> , "jeannieboef" 
> > > <jeannieboef@> wrote:
> > > >
> > > > anybody have an idea as to how to do this?
> > > >
> > >
> > >
> > >
> >
>




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