IBPSA2011

This document is a case study of the design and construction of a 30,000 sq.m office tower that has achieved an excellent energy efficiency outcome close to the simulated potential when modelled with actual weather data. The design features and processes contributing to the result have been considered.  Some of the lessons learnt throughout the simulation and results reconciliation work have been articulated to promote interchange of ideas and experiences amongst simulation practitioners.

The William McCormack Place Stage 2 (WMP2) building is located in Cairns, North Queensland. The climate is classified as tropical equatorial, hot and humid. It is a government tenanted office building comprising 9 levels and just over 9500 m2 net lettable area (NLA). This paper summarises the key strategies employed in the HVAC systems and discusses the thermal and CFD modelling involved during the design stage to optimise the building’s environmental performance.

Infiltration is rarely considered a critical factor in AC design. Purposed built buildings such as libraries or shopping centres with dynamic occupants may prove otherwise. The main access to Macquarie University Library is through three large doors in the foyer. Infiltration/exfiltration rates through these doors warranted a careful analysis for its HVAC design and sizing. The Airflow Network model in EnergyPlus was utilised to simulate the bulk air flow throughout the whole building driven by the inflow/outflow through these doors with wind-tunnel-tested wind pressure coefficients.

This paper outlines a methodology for determining the thermal performance of a complex ventilated glazed facade system through desktop analysis and computer simulation.There is a limited amount of published work on the overall thermal performance values of complex doubled skin facades with a ventilated cavity between the facade layers.

Computational Fluid Dynamics Simulation (CFD) has been mainly used for building scientists as an analysis tool to assess the complex phenomenon of building physics. It has recently been used as a design support tool. However, its utilization in the later phase of design restricts the applicability, mainly due to the lack of integration with geometry software application and optimization. This paper explores a method to integrate CFD with NURBS Modelling program (CAD) to optimize the building form in order to reduce the adverse wind.

A simplified model of a primary HVAC system comprising an on-off boiler, thermal storage and solar thermal collectors is simulated in hourly resolution. The simulation passes the results to an optimization algorithm that sizes the system. The objective is to minimize total costs and reach a desired solar ratio. Results show good model performance and short simulation run time.

Buildings and their renewable energy systems typically operate for a lifecycle of well over 20 years. Due to this the climate that a new building or renewable energy system will experience, will change over their effective functional lifetime.  It is therefore crucial that these buildings and systems are designed with due consideration of a changing climate (BRANZ, 2005).  This paper discusses how Ersatz Future Metrological Year (EFMY) climate files are created and used to more reliably predict future system responses in changed climates.

Conventional air-conditioning methods in hospitals have often involved air-recycling and indefinite pressure regimes, which increase cross-infection risk.  Poor comfort conditions and indoor air quality (IAQ) have also been issues.  These were major considerations in the design of the $1.8B Fiona Stanley Hospital. Active chilled beams (ACBs) were selected for the wards.

CFD modelling was identified as the only tool able to predict accurately the performance of a cooling system for a 200m high glazed building lift shaft located in Brisbane, Australia. A conjugate heat transfer, multiband radiation and moving mesh transient CFD modelling strategy was used to assess and design the most energy efficient environmental control possible for this design. The lift movement within the shaft increased the convective heat transfer by a factor of 5, top-down air distribution and transient CFD modelling analysis reduced by 60% the cooling load compared to a steady state

The introduction of the Energy Performance of Buildings Directive (EPBD) in Poland established minimal building energy performance requirements for new and retrofitted buildings without changing the U-value requirement for the building envelope in the building code. This change in the Polish law has sometimes caused investors to draw the wrong conclusions about thermal standards for single-family residences. With this in mind, this paper seeks to optimise the thermal performance of buildings using both fuzzy sets and Zadeh probability with simple hourly 6R1C building energy simulation.