Ventilation

The ventilation flow rate can be specified for both the heat loss calculation and the building simulation. This is possible using multiple input methods and different units:

Ventilation flow rate specified by

 HL BS
In this field it is determined whether the flow rate is specified by supply or exhaust. For example, habitable rooms need to be provided with fresh air, whereas the air should be extracted in toilet compartments and bathrooms.

§ Supply, the ventilation flow rate is specified as supply

§ Exhaust, the ventilation flow rate is specified as exhaust

Heat loss

 HL

§ According to building decree: the ventilation flow rate is determined automatically based on the utility function and room type as specified below Use > Room usage. The corresponding ventilation flow rate is taken from the table Ventilation flow in the Dutch Building Code.

§ More ambitious than building decree [Factor]: the ventilation flow rate is determined automatically from Use > Room usage. The corresponding ventilation flow rate is taken from the table Ventilation flow in the Dutch Building Code. This flow rate is then multiplied by the specified multiplication factor.

§ User defined [Select units *]: the ventilation flow rate is specified manually.

 1/h, dm³/s, m³/s, m³/h, m³/(s.person), m³/(h.person), m³/(s.m² floor), m³/(h.m² floor), m³/(s.m² facade), m³/(h.m² facade), m³/(s.m² outside surface), m³/(h.m² outside surface). If the input is given per m² floor, the calculations are performed using fixed wall dimension, i.e. direct measures excluding wall thicknesses.. See Dimensions.

Ventilation source determined by

 HL
The software attempts to determine where the air originates as well as possible. For this purpose, you can specify how the ventilation source is determined:

§ Room type and ventilation system; The software determines the origin of the air based on the Room type as defined in the template Use, and the selected  in the HVAC template;

§ Room properties: the ventilation balance can be specified manually atAir Exchange and Ventilation Balance below room properties.

Ventilation system choice:
In case of ventilation systems with natural supply of ventilation air, the outside air is used in the calculations for habitable rooms and spaces.

•      In mechanical supply, the air of the system is used in the calculations;

•      In natural supply the outside air is used in the calculations (irrespective of the presence or absence of mechanical exhaust), unless an interior room is considered. In the latter case, the air is extracted from an adjacent room.

•      In other rooms, the air from adjacent rooms is used in the calculations by default.

Note that the software will not execute these choices well in all cases; therefore, a thorough verification on its performance is recommended. Additionally, the software will not make a ventilation balance of the surcharged air. The choice of room type and ventilation system is used to perform a ventilation calculation quickly and automatically using the minimum ventilation requirements and the user-defined flow rates. When choosing ‘room properties’, a balance can be made by indicating the amount of air which enters and/or leaves the room.

In Properties> Rooms> Ventilation Balance it can be indicated how much air enters from other rooms or from outside. The total amount of air is in balance at all times, i.e. the amount of air which enters the room is the same as the amount of air leaving the room. A correct balance can be made by specifying the right flow rates of ventilation air and the origin of the air.

Building simulation

 BS
The ventilation properties for the building simulation are specified for day, night, and night (conditional). These correspond to the daytime operation and night time operation as defined in Schedule of HVAC.

§ Custom value [select units *]: a ventilation flow rate is specified.

Ventilation through open windows

Depending on the wind [select units *] BS
This is the ventilation flow rate in case the windows are fully open, which is defined for various wind speeds. This flow rate is only included when the windows are open; it is not included if Building operation >Openable windows > Windows stay closed has been activated.

The installed ventilation power is higher than prescribed by the Dutch Building Code

 EPG
The actual ventilation power which is to be installed can be applied in the EPG calculation. By checking this box, the ventilation flow rate for the room can be specified. If this option has been chosen in one of the rooms within a zone, the specified ventilation power is summed for all rooms within the zone. Additionally the true ventilation power is used in the calculations for the ventilation system defined within the zone (and possibly in multiple zones). If this box is not checked in any of the rooms within a zone of the ventilation system, then the minimum ventilation requirements are used in the calculations.

Ventilation power installed in room

[Select units *] EPG
The actual ventilation power in the room within a zone can be specified using multiple units. In the EPG calculation, the flow rates are computed in dm³/s and displayed in the results.

Share decentralized heat recovery, required for system X

[Number, choice] EPG
This field allows you to indicate what share of the air is preheated using the heat recovery. It applies to housing and it is used in the energy performance calculation EPG.  The share can be specified as a fraction, or based on the utility surface of the rooms (living room). This fraction or utility surface does not hold per room, but rather for the complete zone in which the room is located.

Purge facility

 EPG
The purge facility which is used in the building or part of the building can be indicated here. By default, openable windows are assumed in housing, irrespective of the input for the purge facility. If a purge facility is defined it is applied in the complete system, potentially also in different zone.

Installed ventilation capacity is maximum used for cooling

 EPG
This indicates the installed ventilation capacity is used completely for cooling of the building. In this case the cooling load for the building can be reduced.

Installed purge ventilation capacity is maximum used for cooling

 EPG
This indicates the installed purge ventilation capacity is used completely for cooling of the building. In this case the cooling load for the building can be reduced.

*) 1/h, dm³/s, m³/s, m³/h, m³/(s.person), m³/(h.person), m³/(s.m² floor), m³/(h.m² floor), m³/(s.m² facade), m³/(h.m² facade), m³/(s.m² outside surface), m³/(h.m² outside surface). If the input is given per m² floor, the calculations are performed using fixed wall dimension, i.e. direct measures excluding wall thicknesses.. See Dimensions.