Automated fault detection and diagnostic (FDD) systems have the potential to reduce equipment downtime, service costs, and utility costs. However, very few commercial products exist and the ones that do exist are very specialized. This may be surprising to some, considering that FDD is very well developed for other applications such as for nuclear power plants, aircraft, chemical process plants...

The Aldo Leopold Legacy Center is designed to be a net-zero energy building. This paper explains how simulation modelling was integrated into the design process to achieve the design goals. Simulation was used to evaluate the building shell, including natural ventilation potential as well as evaluate individual HVAC components. The simulation model was also used to size HVAC equipment and evalu...

This paper is the second of a two-part review of methods for automated fault detection and diag-nostics (FDD) and prognostics whose intent is to increase awareness of the HVAC&R research and development community to the body of FDD and prognostics developments in other fields as well as advancements in the field of HVAC&R. The first part of the review focused on generic FDD and prognostics, pro...

Improving the control strategy of building HVAC (heating, ventilation, and air-conditioning) systems can lead to significant energy savings while preserving human comfort requirements. This paper formulates the optimization problem to obtain the setpoints of control variables with the lowest HVAC system energy consumption. The optimization problem is nonlinear, strongly coupled, and has both di...

Heating, ventilation, and air conditioning (HVAC) ducts in buildings are typically hollow metal pipes which can be used as waveguides to carry signals and provide the network access to offices. Knowledge of channel properties is crucial to designing such a communication system. This paper presents a propagation model for a straight HVAC duct terminated at both ends. At high frequencies this duc...

Building Automation Systems control HVAC systems aiming at optimizing energy efficiency and comfort. However, these systems use pre-set configurations, which usually do not correspond to occupants’ preferences. Although existing systems take into account the number of occupants and the energy consumption, individual occupant preferences are disregarded. Indeed, there is no way for occupants to ...

One of the major factors in HVAC design is the occupant load, both in terms of heat gains and fresh air needs. Internal heat gains that result from human occupancy, commonly use a predicted maximum occupancy and an estimated occupancy diversity factor. This may have two problems. First, the maximum number may be far away from true value, Secondly, in a dynamic organizational environment, it is ...

A significant step in the design of Heating, Ventilating, Air Conditioning, and Refrigeration (HVAC-R) systems is to calculate the room thermal loads which often vary dynamically. A self-adjusting method is proposed for real-time calculation of heating/cooling loads in HVAC-R applications. In this method, the heat balance calculations are improved by realtime temperature data to achieve more ac...

The paper presents the development and application of Model Predictive Control (MPC) and Fault Detection and Diagnostics (FDD) technologies to a large-scale HVAC system, their on-line implementation, and results from several demonstrations. The two technologies are executed at the supervisory level in a hierarchical control architecture as extensions of a baseline Building Management System (BM...

Flexible loads, especially heating, ventilation, and air-conditioning (HVAC) systems can be used to provide a battery-like service to the power grid by varying their demand up and down over a baseline. Recent work has reported that providing virtual energy storage with HVAC systems lead to a net loss of energy, akin to a low round-trip efficiency (RTE) of a battery. In this work we rigorously a...