English

A dynamic computer program was used to analyse the operation and performance of a thermal comfort controller for HVAC systems with forced-air ventilators. The software tool used was GEMS (Generalized Engineering Modeling and Simulation). Simulations indicated that when using a conventional thermostat, any form of mechanical ventilation is likely to increase the moisture content of the air inside a conditioned space in a cooing-dominated hot and humid climate. States that mechanical ventilators in this situation may contribute to indoor air quality problems of high moisture levels.

Describes the features of a prototype home designed for a large builder in Michigan, USA, and the results of a series of DOE-2.1E energy simulations performed to assess the impact of various energy efficient aspects. The new features included: improvements to the thermal envelope and mechanical equipment; use of structurally insulated panels (SIPs) for the envelope; high performance, low-E argon-filled windows; a smaller, more efficient boiler; passive cooling design via a central stairwell with operable skylight; a unique mechanical ventilation system that can be scheduled and zoned.

States that buildings in Saudi Arabia are often constructed without attention to the occupant discomfort caused by hot summer temperatures. Single-zone thermostats tend to limit comfort to the sun-side of office buildings, and there is also a possibility of asymmetrical radiation. Describes a pilot study conducted in a room in which airflows and temperatures were measured and then simulated using CFD techniques. Several factors were identified which contributed to the problem.

States that hybrid ventilation systems use the strengths of both mechanical and natural ventilation strategies. In the absence of many studies of the operational experience or performance monitoring of the systems, an school in Sweden was retrofitted with a hybrid ventilation system controlled by a building energy monitoring system. The main ventilation power source for this system was the six metre high solar chimneys, which were equipped with low-energy exhaust fans to supplement stack effect where necessary.

Heat transfer in loose-fill attic insulation was investigated in a large-scale model of a ventilated attic built in a climatic chamber. The particular aspect of this study was heat transfer by convection and its effect on heat losses through the attic floor. It was shown by thermal resistance measurements that the measured and calculated thermal resistance of the attic floor is within the margin of error. Air movements were detected in the insulation, sufficient to cause a decrease in the thermal resistance of the attic floor.

Discusses what benefits there may be in employing an effective quality assurance program for building envelope air barrier systems, and what elements it should include. Proposes a protocol for inspection and testing of building envelope air barrier systems. Cites literature to highlight how testing has been shown to improve a building's air permeance.

In situ measurements were compared with a numerical model to assess the effectiveness of the model for active envelopes as energy efficient building envelope solutions. There was good agreement for the mechanical flow active envelope, but not for the natural flow variant. States that taking into account the enthalpy change of the cavity air is essential for a correct evaluation of the energy efficiency of active envelopes.

Illustrates a procedure to optimise the building envelope during the early design stages, in respect to costs, construction and use and energy performance improvements. The tool is aimed at project authors and client. Of the tool's two linked modules, the first manages parameters for the project requirements, and the second, a graphics module, enables sketches and calculations for input to the first module.

Evaluates simple methods for the prediction of energy consumption or fault detection as a result of old equipment in a commercial building in Lyon, France. The correlation between electricity consumption and external temperature was analysed.

Faults and malfunctions in HVAC systems can be difficult to detect with current tools. The survey developed automatic faults detection diagnostic tools for the improvement of buildings facilities supervision.