HVAC System
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An HVAC system type must be selected from the list.
All the included rooms within the currently selected zone are assumed to be
served by the system type. The
HVAC System Type shows a list of standard
HVAC system types. Selecting one of these HVAC systems will automatically set
up the appropriate HVAC data.
The
Include Zone check includes the selected
zone and enables several controls in Heating System and in System Adjustments.
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Heating System
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You need to specify the Heating system heat source, which
defines how heating is supplied to the HVAC system. In addition, the fuel type
is selected for the heating system. The remaining data items are used to
determine the efficiency of the heat generator (boiler). The required data is:
- Seasonal efficiency
– If the efficiency is known, this should be entered directly, if not, the
remaining data items are used to infer the efficiency.
- Generator radiant
efficiency – If the efficiency is known, this should be entered directly, if
not, the remaining data items are used to infer the efficiency. If the HVAC
system is a Radiant heater, then you can specify a Generator radiant efficiency
if it is known, if not, the efficiency will be assumed based on whether the
heating is on the Enhanced Capital Allowance (ECA) list.
- On ECA list –
defines whether the boiler is on the Enhanced Capital Allowance (ECA) list. If
not, you define whether the boiler was installed after 1998.
- Installed on or
after 1998.
- System uses CHP –
this enables CHP generator data to be defined for the zone on the General tab.
A copy of the ECA list is included with the PartL program as a
reference.
The
Bi-Valent systems section allows a bivalent
heating system to be setup. This is when the heating is supplied by two or more
different types of heat sources.
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Cooling System
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If the HVAC system requires cooling, then you must specify a
Cooling system packaged chiller type and the Chiller rating.
If the chiller seasonal efficiencies (Seasonal EER and Nominal
EER) are known, they should be entered, if not, the efficiencies will be
assumed based on whether the chiller is on the Enhanced Capital Allowance (ECA)
list.
Mixed mode operation strategy – if the HVAC system has mixed
mode operation strategy.
A copy of the ECA list is included with the PartL program as a
reference. The button, will show the ECA list for the selected chiller type.
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System Adjustments
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The following system adjustments can be applied.
- Ductwork leakage –
if the system has been leakage tested, the CEN classification (e.g. Class A)
can be selected.
- AHU leakage – if the
AHU meets CEN leakage standards, the relevant standard (e.g. L1, L2) can be
selected.
- Specific fan power –
if the specific fan power (SFP) is known, it can be defined, otherwise a
default value will be used.
- Auxiliary energy –
if the HVAC system is a Flued/Non-flued forced convection air heater and the
auxiliary energy of fanned warm air heaters is known, it can be defined,
otherwise a default will be used.
Variable speed pump – If specified HVAC
system is one where variable speed pumping can be used these options become
available.
- Type of pump.
- Type of variable
speed control.
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Heat Recovery, Controls and Metering
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Zone based heat recovery – Heat recovery
for the HVAC system can be set up. Depending on the type of HVAC system heat
recovery is either specified at the zone level or the room level.
- Heat recovery –
depending on the HVAC system specified, heat recovery can be defined by
selecting the type of heat recovery.
- Seasonal efficiency
– if a heat recovery system is selected and the seasonal efficiency is known,
it can be defined, otherwise a default value will be used.
Metering provision – The effect of system
controls can be considered as follows. These are not available if Type of
analysis is set to Scottish Building Regulations.
- Metering – metering
should be included if there is energy metering of plant and/or metering of
plant hours run and/or monitoring of internal room temperatures.
- Out of range values
– you can specify whether the metering warns of out of range values.
Heating system controls – Various heating
system controls are available if Type of analysis is set to an EPC calculation.
These will trigger certain recommendations from being omitted from the
recommendations report automatically. The following options can be selected:
- Central time
control
- Optimum start/stop
control
- Local time control
(ie., room by room)
- Local temperature
control (ie,. room by room)
- Weather
compensation control
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