Dear All,
we’re currently involved in a project of an office building pursuing LEED certification. The majority of building areas will be endowed with natural ventilation, complying with ASHRAE 62.1-2010 requirements. In what relates with simulation for purposes of energy performance calculation we have the following doubts:
- how shall we model ventilation in proposed building? We are planning to consider a permanent infiltration of outdoor air corresponding to the minimum outdoor air flowrate according to ASHRAE 62.1-2010 (only during occupied periods);
- regarding baseline building, ventilation will be integrated in HVAC system components. Since proposed building is endowed with natural ventilation, we are planning to consider a ventilation effectiveness equal to 1 for baseline building outdoor air calculations.
Do you validate the assumptions above?
Regards,
Tyler Thumma
7GroupLEEDuser Expert
60 thumbs up
February 5, 2021 - 12:47 pm
1. If your simulation program has the ability to model natural ventilation directly, then that would be a more accurate option. Otherwise, your approach of modeling the ASHRAE 62.1-2010 minimum rates via infiltration is acceptable.
2. The Baseline must be modeled identically to the Proposed (natural ventilation), not mechanically ventilated.
santiago sanchez
Energy AnalystSpinnaker Group
November 17, 2021 - 10:27 am
Section G-3.1.2.6 specifies that outdoor air ventilation rates are the same in both models (see USERS MANUAL).
Users manual example G-F stands: "However, the baseline building HVAC system, as defined in G3.1.1, provides
cooling during periods of time when natural ventilation is not adequate, for example when the red light
is on."