This mode is intended for a mechanical ventilation system with a minimum ventilation rate expressed in l/s/m^2 which will be supplemented by additional ventilation that will be controlled from a single zone's dry bulb temperature. The minimum ventilation rate will be specified in l/s/m^2. The additional ventilation will start when the temperature in the zone reaches the lower limit and increases proportionally until the upper limit is reached and the additional ventilation value plus the minimum value will apply. The additional ventilation rate will start to reduce when the inside and outside temperatures are equal and will be completely off when the outside temperature is one full degree above the inside.
This mode requires the following parameters.
Parameter |
Description |
Zone |
The zone number whose dry bulb temperature will control the ventilation. If you enter 0 for this value, the ventilation will be controlled on the temperature of the zone that this internal condition is applied to. |
Lower limit |
The additional ventilation will be off if the controlling zone dry bulb temperature is below this value. |
Upper limit |
The function will give the maximum ventilation value equal to the additional ventilation plus the minimum rate when the controlling zone dry bulb temperature is above this value. |
Minimum Ventilation Value |
The minimum amount of ventilation used at any given hour where this function is used. It is measure in l/s/m^2. |
Addition Vent Value |
The maximum amount of additional ventilation used at any given hour where this function is used. It is measure in air changes per hour. |
For example, 'tmmvc,0,24,26,1.11,5' would define the following strategy for ventilation.
There will be a minimum ventilation rate of 1.11l/s/m^2 supplied during the occupied period, it will be independent of dry bulb temperature. As the dry bulb temperature in the adjacent zone rises above 24 deg. C an additional ventilation rate will be provided. The additional ventilation will be on at its peak value of 5ACH when the temperature within the zone is at or above 26 deg C. The minimum ventilation rate will be added onto this value. The additional ventilation will stop whenever the outside temperature is greater than the inside temperature. The additional ventilation rate starts to reduce when the two temperatures are equal and will be completely off when the outside temperature is one full degree above inside, leaving only the minimum ventilation in the zone. For a full description of how final ventilation values are calculated, please see the section: Ventilation Functions.