Changes required to implement ventilation using the air conditioning systems
The 2019.a version of CYPETHERM RECS Plus and CYPETHERM EPlus allows users to simulate the entrance of outdoor air to ventilate the building via the air conditioning system. In previous versions, the program considered that the air that was required to ventilate the building entered directly via the spaces.
Within each Zone, in the “Ventilation and infiltrations” section, the new variable: “Type of ventilation” appears, where users can choose amongst:
- Natural
Is the possibility that existed in program versions up to the 2019.a version to contemplate ventilation. - Mechanical
This type of ventilation was already available in CYPETHERM RECS Plus and as of the 2019.a version, is also available for “CYPETHERM EPlus”. The mechanical ventilation can consider the consumption of the fans associated with this function. - Via the air conditioning system
This type of ventilation is the type that must be chosen to simulate air entering via the air conditioning system associated with the zone.
The “Heat recovery” option has disappeared from the “Ventilation and Infiltrations of the Zone” panel. As of the 2019.a version, heat recovery is defined for the air conditioning systems that can carry out this function, which implies a significant improvement in the design model.
Furthermore, to carry out the ventilation via an air conditioning system, equipment that can carry out this function must be defined in the zone. With this purpose in mind, new options have been habilitated, in the 2019.a version, in “constant performance equipment” and “air-air conditioning systems of the “Rooftop” and “Single-zone AHU””. Heat recovery units have also been included as new equipment.
Heat recovery in constant performance equipment
In “Constant performance equipment”-type terminal units, the “Heat recovery” option has been included, which allows users to simulate the exchange of sensible and latent energy between the renewal and extraction air flow. To do so, users must define the efficiency of this exchange. During the simulation, the constant performance equipment will only recover heat when the indoor air conditions are more favourable than those of the outside air.
Outdoor air inlet in air-air conditioning systems such as Rooftop and Single-zone AHU
Within "Air conditioning systems of constant volume", the "Rooftop" and "AHU" type of single-zone systems have the new option "With outdoor air intake". If users enable this option, the ventilation air of the zones to which this system is connected will enter through it. Additionally, the heat recovery and free cooling functions can be defined for this equipment.
New air conditioning systems: single-zone and multi-zone heat recovery units
As of the 2019.a version, it is possible to simulate sensible and latent heat recovery units, with an external air bypass function. Two versions of this type of equipment have been added: as a terminal unit (single-zone) and as a centralized system (multi-zone).
Within "Terminal Units", users can select the type of "Heat recovery unit". This equipment will be assigned to the zone in which it is defined.
The new category: "Centralized ventilation system" has been added in "Air-air conditioning systems", where users can select the heat recovery equipment. Like the rest of air conditioning systems, this equipment is connected to the zones via the corresponding terminal units. Within air-air conditioning terminal units, the Heat Recovery unit is compatible with the Air discharge terminal.
