This is why I mentioned the CBVAV. (constant speed fan at primary air loop)
Dx coil with fan has indivitual thermostat zone control. The compressor is pressure control with a storage tank. When there is no cooling load, the compressor shuts off as the coolent pressure is increased.
If the DX coil is in the AHU, there are two choises, the several choices.
1) constant reference node temperature for the duct, VAV damper and reheat in the zone. (VAV template)
2) constant reference node temperature for the duct, VAV damper no reheat.
3) constant reference node temperature for the duct, VAV damper no reheat, by-pass cooling of return air. (CBVAV)
The water tank has a set point. The VAV template plate method generates a tixed set point for the duct, therefore the zone temperature can be left to control bhe VAV damper or reheat heater.
VAV with reheat is not energy saving configuration.
Option two need some careful capacity designing to match the zone load.
Dr. Li
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: luke.dorna@xxxxxxxxx
Date: Tue, 24 Jan 2012 18:50:40 +0000
Subject: [EnergyPlus_Support] Re: Multiple Zones for Single Heat Pump
__._,_.___
Primary EnergyPlus support is found at:
http://energyplus.helpserve.com or send a message to energyplus-support@xxxxxxxx
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 currently allowed but be mindful that not everyone has a high speed connection. Limit attachments to small files.
EnergyPlus Documentation is searchable. Open EPlusMainMenu.pdf under the Documentation link and press the "search" button.
![]()
__,_._,___
Dx coil with fan has indivitual thermostat zone control. The compressor is pressure control with a storage tank. When there is no cooling load, the compressor shuts off as the coolent pressure is increased.
If the DX coil is in the AHU, there are two choises, the several choices.
1) constant reference node temperature for the duct, VAV damper and reheat in the zone. (VAV template)
2) constant reference node temperature for the duct, VAV damper no reheat.
3) constant reference node temperature for the duct, VAV damper no reheat, by-pass cooling of return air. (CBVAV)
The water tank has a set point. The VAV template plate method generates a tixed set point for the duct, therefore the zone temperature can be left to control bhe VAV damper or reheat heater.
VAV with reheat is not energy saving configuration.
Option two need some careful capacity designing to match the zone load.
Dr. Li
To: EnergyPlus_Support@xxxxxxxxxxxxxxx
From: luke.dorna@xxxxxxxxx
Date: Tue, 24 Jan 2012 18:50:40 +0000
Subject: [EnergyPlus_Support] Re: Multiple Zones for Single Heat Pump
The problem I find thus far is this:
AirLoopHVAC:UnitaryHeatPump:WaterToAir,
...
zoneA, !- Controlling Zone or Thermostat Location
....
I find that the HP turns off if zoneA is satisfied, even if zoneB which is also being served by the HP, needs additional conditioning. Or the opposite effect, where additional conditioning is pumped into a zone because of the minimum turndown ratio.
--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, YuanLu Li <yli006@...> wrote:
>
>
> What you have descibed is a standard HP with multiple fan coil units. Fan speed may be simply 1,2,3 selection. VAV diffusers are also available in EPlus . (variable damper cantrolled by zone thermostat.) May be it is not in the templete series, but has been in use for a long time.. Dr. Li
> To: EnergyPlus_Support@xxxxxxxxxxxxxxx
> From: luke.dorna@...
> Date: Tue, 24 Jan 2012 18:08:22 +0000
> Subject: [EnergyPlus_Support] Re: Multiple Zones for Single Heat Pump
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> The system actually uses heat pumps with variable volume fans to serve multiple zones. However, e plus only allows for on/off fans in the HP objects I'm using. I discovered that throwing vav boxes on the supply inlets to rooms allows the fan speed to modulate. Nifty work around.
>
>
>
> --- In EnergyPlus_Support@xxxxxxxxxxxxxxx, Karen Walkerman <kwalkerman@> wrote:
>
> >
>
> > Any reason you're not using ZoneHVAC:WaterToAirHeatPump? Put one in each
>
> > zone...
>
> >
>
> > Also, how does the building operate in reality? Does it really have heat
>
> > pumps serving VAV boxes?
>
> >
>
> > --
>
> > Karen
>
> >
>
> > On Mon, Jan 23, 2012 at 4:20 PM, luke_dorna <luke.dorna@> wrote:
>
> >
>
> > > **
>
> > >
>
> > >
>
> > > I'm doing exactly that, using a single heat pump and distributing the
>
> > > capacity.
>
> > >
>
> > > I was hoping there was a work around that would allow me to treat these as
>
> > > per a standard AHU with VAV outlets, but it doesn't appear that Energy+ is
>
> > > going to cooperate.
>
> > >
>
> > > Thanks,
>
> > >
>
> > >
>
> > > --- In EnergyPlus_Support@xxxxxxxxxxxxxxx, "Jim Dirkes" <jim@> wrote:
>
> > > >
>
> > > > Dear Luke,
>
> > > >
>
> > > > Thinking about this, it is common for a WSHP to serve more than one room,
>
> > > > but uncommon for there to be more than one thermostat (i.e. multi-zone).
>
> > > > These devices are pretty much a one zone component.
>
> > > >
>
> > > > That said, you can only do what the software allows or for which there
>
> > > is a
>
> > > > reasonable work-around. When you think of it, a reasonably designed
>
> > > system
>
> > > > will normally include zones with similar occupancy, schedule, set points,
>
> > > > etc. If that's true, just assign one heat pump per zone, using the same
>
> > > COP,
>
> > > > fan performance, etc. as for a larger multi-zone heat pump. If it's not
>
> > > > true, one WSHP per zone is still the best available solution, since E+
>
> > > does
>
> > > > not have a multi-zone WSHP object (as you already note).
>
> > > >
>
> > > >
>
> > > >
>
> > > > The Building Performance Team
>
> > > > James V. Dirkes II, P.E., BEMP , LEED AP
>
> > > > 1631 Acacia Drive NW
>
> > > > Grand Rapids, MI 49504
>
> > > > 616 450 8653
>
> > > >
>
> > > >
>
> > > >
>
> > > > From: EnergyPlus_Support@xxxxxxxxxxxxxxx
>
> > > > [mailto:EnergyPlus_Support@xxxxxxxxxxxxxxx] On Behalf Of luke_dorna
>
>
> > > > Sent: Monday, January 23, 2012 3:05 PM
>
> > > > To: EnergyPlus_Support@xxxxxxxxxxxxxxx
>
> > > > Subject: [EnergyPlus_Support] Multiple Zones for Single Heat Pump
>
> > > >
>
> > > >
>
> > > >
>
> > > >
>
> > > >
>
> > > > I am currently using the the AirLoopHVAC:UnitaryHeatPump:WaterToAir
>
> > > object
>
> > > > to model distributed heat pumps throughout a building. Unfortunately, the
>
> > > > object only allows for a single controlling thermostat, but the design
>
> > > calls
>
> > > > for heat pumps that serve multiple rooms.
>
> > > >
>
> > > > Has anyone encountered/found a way around this?
>
> > > >
>
> > > > I've tried attaching reheat VAVs to the different zones but didn't have
>
> > > much
>
> > > > luck.
>
> > > >
>
> > > > Thanks,
>
> > > >
>
> > > > Luke
>
> > > >
>
> > >
>
> > >
>
> > >
>
> >
>
AirLoopHVAC:UnitaryHeatPump:WaterToAir,
...
zoneA, !- Controlling Zone or Thermostat Location
....
I find that the HP turns off if zoneA is satisfied, even if zoneB which is also being served by the HP, needs additional conditioning. Or the opposite effect, where additional conditioning is pumped into a zone because of the minimum turndown ratio.
--- In EnergyPlus_Support@xxxxxxxxxxxxxxx, YuanLu Li <yli006@...> wrote:
>
>
> What you have descibed is a standard HP with multiple fan coil units. Fan speed may be simply 1,2,3 selection. VAV diffusers are also available in EPlus . (variable damper cantrolled by zone thermostat.) May be it is not in the templete series, but has been in use for a long time.. Dr. Li
> To: EnergyPlus_Support@xxxxxxxxxxxxxxx
> From: luke.dorna@...
> Date: Tue, 24 Jan 2012 18:08:22 +0000
> Subject: [EnergyPlus_Support] Re: Multiple Zones for Single Heat Pump
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
> The system actually uses heat pumps with variable volume fans to serve multiple zones. However, e plus only allows for on/off fans in the HP objects I'm using. I discovered that throwing vav boxes on the supply inlets to rooms allows the fan speed to modulate. Nifty work around.
>
>
>
> --- In EnergyPlus_Support@xxxxxxxxxxxxxxx, Karen Walkerman <kwalkerman@> wrote:
>
> >
>
> > Any reason you're not using ZoneHVAC:WaterToAirHeatPump? Put one in each
>
> > zone...
>
> >
>
> > Also, how does the building operate in reality? Does it really have heat
>
> > pumps serving VAV boxes?
>
> >
>
> > --
>
> > Karen
>
> >
>
> > On Mon, Jan 23, 2012 at 4:20 PM, luke_dorna <luke.dorna@> wrote:
>
> >
>
> > > **
>
> > >
>
> > >
>
> > > I'm doing exactly that, using a single heat pump and distributing the
>
> > > capacity.
>
> > >
>
> > > I was hoping there was a work around that would allow me to treat these as
>
> > > per a standard AHU with VAV outlets, but it doesn't appear that Energy+ is
>
> > > going to cooperate.
>
> > >
>
> > > Thanks,
>
> > >
>
> > >
>
> > > --- In EnergyPlus_Support@xxxxxxxxxxxxxxx, "Jim Dirkes" <jim@> wrote:
>
> > > >
>
> > > > Dear Luke,
>
> > > >
>
> > > > Thinking about this, it is common for a WSHP to serve more than one room,
>
> > > > but uncommon for there to be more than one thermostat (i.e. multi-zone).
>
> > > > These devices are pretty much a one zone component.
>
> > > >
>
> > > > That said, you can only do what the software allows or for which there
>
> > > is a
>
> > > > reasonable work-around. When you think of it, a reasonably designed
>
> > > system
>
> > > > will normally include zones with similar occupancy, schedule, set points,
>
> > > > etc. If that's true, just assign one heat pump per zone, using the same
>
> > > COP,
>
> > > > fan performance, etc. as for a larger multi-zone heat pump. If it's not
>
> > > > true, one WSHP per zone is still the best available solution, since E+
>
> > > does
>
> > > > not have a multi-zone WSHP object (as you already note).
>
> > > >
>
> > > >
>
> > > >
>
> > > > The Building Performance Team
>
> > > > James V. Dirkes II, P.E., BEMP , LEED AP
>
> > > > 1631 Acacia Drive NW
>
> > > > Grand Rapids, MI 49504
>
> > > > 616 450 8653
>
> > > >
>
> > > >
>
> > > >
>
> > > > From: EnergyPlus_Support@xxxxxxxxxxxxxxx
>
> > > > [mailto:EnergyPlus_Support@xxxxxxxxxxxxxxx] On Behalf Of luke_dorna
>
>
> > > > Sent: Monday, January 23, 2012 3:05 PM
>
> > > > To: EnergyPlus_Support@xxxxxxxxxxxxxxx
>
> > > > Subject: [EnergyPlus_Support] Multiple Zones for Single Heat Pump
>
> > > >
>
> > > >
>
> > > >
>
> > > >
>
> > > >
>
> > > > I am currently using the the AirLoopHVAC:UnitaryHeatPump:WaterToAir
>
> > > object
>
> > > > to model distributed heat pumps throughout a building. Unfortunately, the
>
> > > > object only allows for a single controlling thermostat, but the design
>
> > > calls
>
> > > > for heat pumps that serve multiple rooms.
>
> > > >
>
> > > > Has anyone encountered/found a way around this?
>
> > > >
>
> > > > I've tried attaching reheat VAVs to the different zones but didn't have
>
> > > much
>
> > > > luck.
>
> > > >
>
> > > > Thanks,
>
> > > >
>
> > > > Luke
>
> > > >
>
> > >
>
> > >
>
> > >
>
> >
>
__._,_.___
Primary EnergyPlus support is found at:
http://energyplus.helpserve.com or send a message to energyplus-support@xxxxxxxx
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 currently allowed but be mindful that not everyone has a high speed connection. Limit attachments to small files.
EnergyPlus Documentation is searchable. Open EPlusMainMenu.pdf under the Documentation link and press the "search" button.
Your email settings: Individual Email|Traditional
Change settings via the Web (Yahoo! ID required)
Change settings via email: Switch delivery to Daily Digest | Switch to Fully Featured
Visit Your Group | Yahoo! Groups Terms of Use | Unsubscribe
Change settings via the Web (Yahoo! ID required)
Change settings via email: Switch delivery to Daily Digest | Switch to Fully Featured
Visit Your Group | Yahoo! Groups Terms of Use | Unsubscribe
__,_._,___