Heated Rooms Page
Use this as a guide to entering data on the Heated Rooms page.
All heated spaces within a property must be accounted for in order to calculate an accurate heat load.
Room Type
The room type selected determines the default room temperature and minimum air change rate for the room.
TIP
If the type of room you are adding is not listed, select the closest match and override the temperature and air change rate if necessary.
Max Ceiling Height
The maximum ceiling height of the room should be entered accurately so that we can calculate the correct volume and heat loss areas.
TIP
If the ceiling height is unknown, a typical ceiling height of 2.4m can be used.
Design Room Temperature
The design room temperature will be pre-populated based on the room type selected, but can be overridden to a higher temperature if desired. However, it is not possible to enter a lower temperature than the default.
NOTE
For default values for internal room temperatures, see Design Conditions.
Minimum Air Change Rate
The minimum air change rates will be pre-populated based on the room type and age of the property.
NOTE
For default values for air change rates, see Ventilation Rates.
Heat Emitter Type
When the ceiling height is over 4m high, the heat emitter type must also be entered.
The heat emitter type will determine the heat loss profile across vertical building elements that are also over 4m high.
Advanced Options Expert users only
Intermittent heating
Where rooms are heated intermittently, the heating power required to get the room up to the desired temperature in an acceptable time may be significantly greater than the calculated peak heat load of the room.
This option allows you to add an additional allowance for heating up a room from a setback temperature. The intermittent heating load is calculated as a percentage of the total room heat loss.
MIS 3005-D requirement
By default, the design external air temperature is taken from CIBSE Guide A Table 2.5 covering 99.6% of dry-bulb hours. MIS 3005-D states that when this 99.6% temperature is used, no uplift is required for intermittent heating
NOTE
For more detailed information on how to estimate intermittent heating, please refer to CIBSE Domestic Heating Design Guide (2021) Section 3.5.5.
Heat gains
If there are significant heat gains in a room, these can be added as an absolute figure (in Watts) to offset the total heat load.
These heat gains would typically only occur in non-domestic environments and may come from machinery, high occupancy levels or solar gains (through full facade glazing).
Solar Gains
Peak heat loads would normally be calculated at extreme conditions on winter nights, i.e. no sunlight. So adding any solar gains should be used with extreme caution.