| Design basis
|
Used to display key design parameters considered
for the CIBSE heat gain calculation. Selecting Design basis in the selector
panel (left) updates the reports display panel (right), scrolling to the Design
basis display.
-
Location — Displays the project location set for the project in the Properties
dialog box’s
Properties For: Site
panel.
- Design
Day — Displays the day on which the greatest loads are experienced. The design
day is used to compute sun positions and solar gains and to calculate the
hourly outside dry and wet bulb temperatures using the weather database
information for the specified location.
- Air
room design temperature used, no room heat losses are allowed to project totals
— Indicates the room inside summer design temperature will be maintained
throughout the calculation.
- Fins
are/are not considered — Indicates fins are or are not considered. The use of
external shading for gains calculations is set in the Default
Manager dialog box’s
Simulation run-time control
panel.
-
Outside dry bulb, wet bulb — Displays the outside dry bulb and wet bulb
temperatures. Maximum and minimum design dry bulb and wet bulb temperatures are
computed from the Meteorological Office data on the weather database. This
defines the design temperatures for the peak month (usually July) and the
minimum month (usually January). Design temperatures for the day of the
calculation (eg June 15) are computed by assuming sinusoidal temperature
variations through the year, with a peak at July and minimum in January. The
actual design day for the calculation determines the position on the sine wave
and hence the maximum and minimum outside dry bulb temperatures. Wet bulb
temperatures are computed hourly, using a similar technique to dry bulb.
- Room
temperatures not allowed to rise — Indicates room temperatures are not allowed
to rise higher at the peak hour. If temperatures are allowed to rise, the peak
load in the room will be reduced.
- Rooms
included — Displays the number of rooms included in the calculation.
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| Results for room [Room name]
|
For all included rooms, the heat gains for each
design day hour will be displayed. The room loads are produced by adding room
loads on an hour-by-hour basis for each of the 24 hours of the design day. The
coincident peak hour for all rooms is that hour which has the maximum
coincident load. If fresh air loads are specified with the design data, these
will be included in the project total loads.
- Sun
Time — Displays the hour of the peak design day from 1 through 24.
-
Outside temp. — Displays the outside temperature for each hour of the design
day. The outside temperature is derived from the weather data associated with
the project location.
- Solar
load — Displays the solar heat gains for the room.
- Fabric
load — Displays heat gains through the room surfaces. For each included rooms,
heat flow through each exposed wall is computed for each hour of the design day
from the wall area, U value, cooling and load temperature differences. The
temperature difference value is automatically included in the calculation, and
a correction is made for wall color, inside temperature and average outside
temperature. The wall color correction is carried out using the wall absorption
coefficient to solar radiation.
-
Convective load — Displays the room heat gains through convection.
- Latent
load — Displays the latent gains for each room. Latent loads are the gains at
peak time which are due to people and equipment.
- Casual
load — Displays the casual gains for each room. Casual loads are the gains at
peak time which are due to lighting, people and the casual gain during
occupancy.
- Total
load — Displays the sum of all the room loads.
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| Project total results
|
For the sum of all included rooms, the peak heat
gain and peak hour will be displayed. The project total loads are produced by
adding room loads on an hour-by-hour basis for each of the 24 hours of the
design day. The coincident peak hour for all rooms is that hour which has the
maximum coincident load. If fresh air loads are specified with the design data,
these will be included in the project total loads.
- Sun
Time — Displays the hour of the peak design day from 1 through 24.
- Outside
temp. — Displays the outside temperature for each hour of the design day. The
outside temperature is derived from the weather data associated with the
project location.
-
Building loads — For all included rooms, heat flow through each exposed wall is
computed for each hour of the design day from the wall area, U value, cooling
and load temperature differences. The temperature difference value is
automatically included in the calculation, and a correction is made for wall
color, inside temperature and average outside temperature. The wall color
correction is carried out using the wall absorption coefficient to solar
radiation. The load is broken down into:
-
Sensible – Displays the building load due to solar, fabric, casual and
infiltration heat gains.
-
Latent – Displays the building load due to people and equipment.
- Fresh
air loads — For all included rooms, and for each hour of the design day, fresh
air may be introduced locally to rooms, in which case it will affect the room
load. Fresh air from the central plant will form part of the supply air and
will be a load on the central plant as well. Conditioned primary air will be
supplied at the defined supply temperature, with optional supply humidity
control. Conditioned primary air will affect both room loads and central plant
loads. If conditioned primary fresh air is specified and this fresh air
requires heating at the central plant, when the building requires cooling (or
vice versa), then the fresh air heat load will be excluded from the central
plant loads.
-
Sensible – Displays the fresh air load due to solar, fabric, casual and
infiltration heat gains.
-
Latent – Displays the fresh air load due to people and equipment.
- Plant
total loads — Displays the loads originating from the building’s central plant.
Fresh air from the central plant will form part of the supply air and will be a
load on the central plant. Conditioned primary air will also affect both room
loads and central plant loads. The load is broken down into:
-
Sensible – Displays the plant load due to solar, fabric, casual and
infiltration heat gains.
-
Latent load – Displays the plant load due to people and equipment.
-
Total – Displays the sum of the two plant load components.
- Peak
coincident plant load: — Displays the total load on the plant at the peak hour.
For each included room, the peak heat gain and peak hour is computed. The
project total load for all the included rooms are produced by adding room loads
on an hour-by-hour basis for each of the 24 hours of the design day.
- at
[peak hour] h – Displays the peak hour for all rooms which is the hour that has
the maximum coincident load.
- (
[peak load/area] and [peak load/volume] ) – Displays a breakdown of the peak
load into:
- Peak load per unit area
- Peak load per unit volume
- Supply
air flow rate: — Displays the total supply air flow rate required to handle
peak loads on the building.
- Fresh
air flow rate: — Displays the total amount of additional fresh air required to
handle peak loads on the building.
-
(Total [number of people] occupants) – Displays the amount of people who occupy
the building at peak time.
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