HVAC systems

Heating, ventilating, and air conditioning (HVAC) systems attempt to achieve a uniform indoor environment. However, this can be challenging, because the placement and control of HVAC systems and sensors are affected by many unpredictable factors. The efficacious exploitation of this nonuniformity can lead to an improvement of indoor environment around occupants. Of the many indoor environment variables, we focused on the CO2 concentration associated with ventilation.

Despite being provided by mechanical ambient conditioning systems or not, all building have to a certain extent a degree of adaptation. Studies have shown that with either a weak or strong dependency to outdoor conditions there always are adaptive opportunities that might have a significant impact on comfort perception.

In this paper, the new capabilities of PowerDomus to simulate central HVAC systems combined to its whole-building hygrothermal model is presented. First, models for the primary (chiller, cooling tower, primary pumps and condensation pumps) and secondary (cooling and dehumidifying coil, humidifier, fan and mixing box) systems are presented. Those mathematical models have been integrated into the whole-building PowerDomus program.

The stock housing of England (UK) constitutes the oldest housing stocks in the world. Indeed, 63 per cent of all dwellings were built before 1960s and thus most of the people in the UK live in an old house or at least a house that is more than 50 years old. The most common dwelling types in the UK are the semi-detached and terraced houses, and particularly within deprived communities. In deprived communities, houses suffer from poor indoor conditions and building standards of energy performance.

The growing interest in Italy for the tutelage, the restoration and the valorisation of the historical-cultural resources and the necessity of a better conservation of the artworks of great value require that the museums be provided with appropriate HVAC systems for the control of the ambient conditions. The suitable microclimate for the conservation of the works inside a
museum can be identified by means of a multisubject investigation.

The paper concerns the definition of guidelines in the design of a new urban settlement, based on system energy utilization and building environmental impacts and sustainability improvement. The study refers to a 160000 m2 area sited on the outskirts of Carmagnola, a city close to Torino, where the municipality decided to locate about 1260000 m3 of commercial buildings: offices, shopping centres, a trade fair area, a cattle market, a multi-hall cinema, hotels, restaurants, industrial sheds.

The authors have created a Neural-Fuzzy Assistant which acts as a Decision Support System and helps to perform quickly and easily the estimations of office building energy consumption. The Neural-Fuzzy Assistant presented in this paper allows the user to determine the impact of eleven building parameters on the electrical annual and monthly energy consumption, annual and monthly maximum electrical demand and cooling and heating annual consumption and demand.

Discusses good control of heating, ventilating and air conditioning systems as the best way to improve energy efficiency in air conditioned buildings. Looks at the Human Science Building at the University of Pretoria in this light. Simulations were performed using QUICKcontrol, a new software tool. Control methods investigated included air bypass, reset control, setback control, improved start-stop times, economiser control and carbon dioxide control. Sixty percent savings were predicted in HVAC power consumption, giving a payback period of nine months.