On the influence of the air infiltration heat losses on the energy performance of Italian residential buildings

It is often discussed about the possibilities that more efficient windows offer to reduce the energy loads in residential buildings. Often such results can be achieved reducing the thermal transmittance or optimising the solar gains, not so often the influence of the air permeability is taken into account. This issue is, on the contrary, very important in countries, as Italy, where the age of the building stock is accompanied by the installation of very old windows, characterised by high air leakage, which causes strong heat losses and discomfort phenomena for users.

Ventilation retrofitting of public office buildings in Greece

This paper presents aspects of an office renovation project of the Social Insurance Institute (SII), the largest Social Security Organization in Greece. The project refers to small and larger SII office buildings, including various stages of intervention, ranging from the construction of new buildings, to renovation of existing buildings. Construction and electro-mechanical studies for each building were carried out in order to implement the appropriate and feasible actions.

Solar chimneys for residential ventilation

An increasing impact of ventilation and air-conditioning to the total energy consumption of buildings has drawn attention to natural ventilation and passive cooling. The very common way of natural ventilation in residential buildings is passive stack ventilation. The passive stack ventilation relies on the stack effect created by the temperature difference between air temperature inside and outside a building.

The impact of energy efficient refurbishment on the airtightness in english dwellings

Fan-pressurisation method was used to test the air infiltration rate of 191 dwellings in England. All tested homes were either pre or post the introduction of energy efficient retrofit measures such as cavity wall insulation, loft insulation, draught stripping and energy efficient heating system. Results show that the average air infiltration rate of the post dwellings is only marginally lower by 4% compared to the pre dwellings.

Testing a method for the evaluation of the airtightness of ventilation systems in existing buildings

The airtightness of ventilation ductwork is an important element of the global performance of ventilation systems.

Optimization of hybrid air-conditioning system with natural ventilation by GA and CFD

This study aims at the development of an optimal design tool using a genetic algorithm (GA) andcomputational fluid dynamics (CFD). To represent a realistic building environment, random variables(fluctuating outdoor conditions), passive control variables (model variables) and active control variables (HVAC system) were set up. A combination of designs are determined based on the relationship between the fluctuating outdoor conditions and the HVAC system in the optimization inquiry.

Natvent buildings versus HVAC buildings - A new Dutch thermal comfort guideline

A new thermal comfort guideline for moderate environments has been developed: the ATG guideline. The underlying method distinguishes between ‘type Alpha’ versus ‘type Beta’ buildings to provide for different adaptation effects. Type Alpha indicates buildi

Measurement of building leakage by unsteady pressurisation

The paper describes the development of unsteady pulse pressurisation techniques for measuring the leakage of buildings. The original version of the technique (the UP technique) has been investigated experimentally and theoretically in a single cell test space. The initial results are very promising, with a good degree of repeatability and similar sensitivity to changes in leakage levels as the conventional steady (DC) technique. An interesting outcome of these early tests was the observation that quasi-steady flow could be established in a short time.

Low energy cooling techniques for retrofitted office buildings in central Europe

Until the 1970’s most office buildings in central Europe were not equipped with mechanical cooling (airconditioning). Due to increasing requirements for thermal comfort and warmer summers, nowadays mechanical cooling is often applied to such buildings, ho

Glass partitions, ventilation and thermal mass as retrofitting measures in an attached sunspace

In this paper the effectiveness of retrofitting strategies in a sunspace attached to a one-storey building has been investigated. Natural and hybrid ventilation, air-tight glass partitions, awnings and increased thermal mass retrofitting scenarios were implemented, mainly for the Greek climate. Window openings and sensor-controlled fans were used to create a controllable and secure environment. Combined ventilation and thermal simulation were applied, taking into account all the related physical phenomena, such as ventilation, infiltration and solar radiation.