Trial / Demo
Alexander submitted an excellent entry, highlighting the use of IESVE modelling and simulation tools for a laboratory complex in Colombia.
Building performance
This case study is a laboratory complex consisting of two main levels, one of which is underground, located in a hot, humid climate in Colombia. The design process, based on the project objectives, required climate response strategies to achieve a comfortable place as energy efficient as possible.
Key achievements:
· Reduced cooling plant size
· Operation point optimized
· 54% energy use reduction
· Materials embodied carbon optimization
· LBC certification / LEED certification (80,200 sqft)
Phase One
The first phase was to evaluate the solar protection of the project with a canopy structure on the upper floor. IESVE software was used to determine how much solar protection was achieved by the structure (SunCast), which material should be used and how translucent it could be to provide enough daylighting without generating discomfort (Apache). It also analysed the air velocities/ temperatures to study the structure microclimate, Microflo (see below). The canopy was made up of several layers, including a tile with a shade coefficient of 0.53 and a T3 film, as well as a Patula pinewood ceiling, built in such a way as to achieve the desired design and allow only 2% to pass of solar radiation.
Phase Two
The second phase of the strategy was to evaluate the basement, which was designed as a semi-open space with perimetral voids that allow the air to be pre-cooled, taking advantage of the effect of thermal mass and geothermal exchange. IESVE was used to correctly model the elevated concrete floor assembly, the perimetral walls assemblies with ground contact effect (surface temperature) and the openings that allowed the air to circulate through the thermal maze.
In addition to the evaluation of geothermal and thermal mass effects, there was an inherent benefit of so-called pre-cooling as the project AHUs are located in the basement and their air intakes point directly to the central corridor which is open to the outside.
By using ApacheHVAC and its connection to Apache, the corridor was modelled as a supply plenum which, in combination with the previous analysis, provided sufficient information to determine that the cooling load could be reduced by 14% by capturing the Outside Air (OA) from the corridor, rather than directly from the outside.
Phase Three
There are some laboratories with specific setpoints and humidity control, which led the modelling team to identify that wall and roof conduction could affect the more stringent spaces, depending on the loads of the adjacent spaces. Therefore, each façade is simulated with some specific R-values, to establish the best R-value for each of the spaces.
Phase Four
HVAC optimisation was carried out using ApacheHVAC, where the following scenarios were considered:
· VAV AHU Vs. AHU – chilled beams
· Best humidity control (chilled water, refrigerant, desiccant) (gas or electric)
· Energy recovery
· Central plant type and COP, EER
This process provided the opportunity to explore chemical dehumidification using ApacheHVAC energy recovery units as dehumidifiers, which was one of the challenges in finding the best HVAC system layout.
