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,
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@xxxxxxxxxxxxxxx]
On Behalf Of jeannieboef
> > Sent: Monday, August 30, 2010 4:40 AM
> > To: EnergyPlus_Support@xxxxxxxxxxxxxxx
> > 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,
"jeannieboef"
> > <jeannieboef@> wrote:
> > >
> > > anybody have an idea as to how to do this?
> > >
> >
> >
> >
>
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