VC

Research indicates that low-energy dwellings are more sensitive to overheating than regular dwellings. In this research the ventilative cooling potential of low-energy dwellings is considered. A low-energy dwelling based on the Active House concept, “House of Tomorrow Today” (HoTT), has been investigated as representative for low-energy dwellings in general. A computational model of the house was created with the software TRNSYS (in combination with CONTAM) and this model has been calibrated with actual (intervention) measurements in the HoTT.

The increasing number of highly insulated and air tight buildings leads to the concern of indoor environment overheating and related comfort and health issues. This can already happen in a temperate climate as found in the Netherlands. This work studies the ventilative cooling process as a possibility to avoid overheated dwellings. A monitored dutch passive house was modelled in Trnsys and the impact of increasing air flow rates on indoor temperatures was simulated. The most overheated zone was chosen to be analysed.

Reducing primary energy consumption is an essential issue for the sector of building construction. This paper refers to building ventilation systems and focuses on low pressure flat plate heat exchangers, designed for low pressure drops and low air velocity, minimizing the electrical consumption of fans. The device is conceived for working within passive ventilation systems, as a ventilation heat recovery stage during winter and sensible heat dissipation during summer.

This paper presents the general concept of the NAC (Natural Air Conditioning)-wall system and some experimental results on a first prototype. The originality of the system is to perform a solar DEC (Desiccant, Evaporative Cooling) open cycle by exploiting natural buoyancy driven ventilation, thus avoiding the use of fans.

The supply air is dehumidified by a zeolite based adsorption bed and is cooled indirectly by an evaporative cooler, through a low pressure heat exchanger.

The study proposes and compares low-cost strategies to improve the quality of existing building stocks, with special regard to a widespread Indian residential typology. A dynamic energy model of this particular local building typology was simulated with Energy Plus software and validated by comparing it with some original in situ measures, recorded by hourly step. The validated model was used to simulate a selection of low-cost and technically simple interventions, whose effects on the energy performance and indoor comfort were compared to the baseline case study.

The present study reports the results of a 12-month-long monitoring campaign of an earth-to-air horizontal heat exchanger (EAHX) system in a school complex in Imola, Italy. With more than 2 km of buried pipes, it represents one of the biggest Italian applications of this technology. Considerable differences between inlet and outlet air temperature have been noticed both in winter and in summer. Air temperature and relative humidity have been represented over a psychrometric chart while the energy performance of the system was analysed based on data of sensible heat exchange.

This special issue on Breakthrough of natural and hybrid ventilative cooling technologies: models and simulations, together with the connected issue Breakthrough of natural and hybrid ventilative cooling technologies: strategies, applications and case studies (vol. 16, issue 1), focuses on methods, tools and technologies for reaching the above-mentioned goal through the use of ventilative cooling, i.e. cooling by controlled natural ventilation (CNV). This strategy is one of the most cost-effective alternatives to air-conditioning systems.

This study analyses the climate-dependent passive ventilative cooling (PVC) potential in central and southern Europe. This analysis was carried out in two phases: (1) evaluation of PVC potential as a climate-dependent variable, in different locations representative of European climate zones for both wind-drive airflow (comfort ventilation) and temperature gradient (environmental and structural cooling); (2) verification of the above PVC potential through dynamic energy simulations on a reference-building model located in selected cities.

The present study aims at assessing the geo-climatic potential applicability of controlled natural ventilation (CNV) as a natural ventilative cooling (NVC) technique in the Mediterranean area. This assessment was carried following two approaches: (1) a climate-dependent evaluation of the NVC potential of different locations considering a “virtual space”; (2) a calculation of the NVC potential of different locations considering a “real” building through dynamic energy simulations.

Different simplified simulation models of a Passive Downdraught Evaporative Cooling tower (PDEC) were compared by using experimental data. Among these, a series of tests on a Passive Downdraught Evaporative Cooling tower (PDEC) were carried out at the SyTIn (Systems for Technology Innovation) Laboratory of the Department of Architecture and Design, Politecnico di Torino. In addition, other monitored databases were taken from literature and used as input data for the simplified models.