English

Mechanical ventilation systems with heat recovery are considered the most optimal systems for residential ventilation. This research focuses on decentralized ventilation which do not need any ducting. Therefore, this system is very suitable for use in retrofitting. The performance criteria of these units are similar to those of central systems. A recuperative and two regenerative ventilation units were tested in a double climate chamber where temperature, air velocity and contaminant concentration were monitored on a fixed 80 point grid.

In a recently built zero-carbon neighborhood, demand controlled exhaust ventilation systems (DCMEV) and mechanical ventilation systems with heat recovery (MVHR) are compared under operational conditions, with focus on the energy performance of both systems. The analysis is based on automatically gathered monitoring data, complementary in situ measurements and occupants surveys. 

The use of heat recovery ventilation systems is becoming more and more common. It is clear that these systems contribute to energy efficiency and good indoor air quality. Still there is room for improvement. Analyses by monitoring and modelling have uncovered drawbacks and flaws, especially for the use and application of HR ventilation in highly energy efficient dwellings. This paper will deal with these issues, turning them into suggestions to improve HR ventilation systems. 

The concentration of carbon dioxide is used as an important index of indoor air quality representative of body odor or bioeffluents in Japan. In the construction field of Japan, there is a CO2 concentration standard of a thousand ppm or less. However, property of occupants (such as sex, age and nationality) has non-nogligiblw effect on the room odor environment. Thus the standard of ventilation air volume should be decided suiting up for building use and occupants.

Product connectivity makes products and systems remotely controllable and possibly interoperable with other devices in the house. 
The most common way to achieve this interoperability is to connect these devices locally. On the other hand, products may also be cloud-connected, which allows an easier and seamless interoperability between devices. Hence, data are collected and stored in the cloud. As soon as the measured data is sent to the cloud, large set of data are available and can be anonymously retrieved and statistically analyzed. 

Buildings represent a major end use of energy throughout the world and are typically the dominant sector for electricity.   The use of that energy is to provide buildings services, the most important of which is Indoor Environmental Quality (IEQ).  Heating and air conditioning systems typically handle the thermal comfort aspects of IEQ; the energy impacts and economics of such systems is well studied.  The most important remaining aspect of IEQ is Indoor Air Quality (IAQ).

Indoor carbon dioxide (CO2) concentrations have been used for decades to purportedly evaluate indoor air quality (IAQ) and ventilation. However, many applications of CO2 as a metric have reflected a lack of understanding of the connection between indoor CO2 levels, ventilation and IAQ. In many cases, an indoor concentration of 1800 mg/m3 (1000 ppmv) has been used as a metric of IAQ and ventilation without understanding its basis or significance.

Advancing energy efficient renovation solutions in buildings necessitate adopting high-insulation and airtightness to avoid heat loss through transmission and infiltration, which can result in overheating. Elevated indoor temperatures have a highly negative effect on building occupants’ health, wellbeing and productivity. With the possibility of remote working, people spend more time at home, and therefore addressing the elevated indoor temperatures and the overheating risks in residential buildings proves to be essential.

The interest in phase change materials (PCMs) as a solution for thermal energy storage has been growing for the last decades. It is clear that PCMs are promising for reducing the summer heat peaks without increasing the energy demand for cooling. A new modular, reversible, lightweight retrofitting system was developed and integrated in a real size experimental test cell.

Controlled Natural Ventilation (CNV) is one of the potential most effective passive cooling technique to reduce cooling needs of buildings in temperate-hot climate zones. However, a correct balance amid internal heat capacity, thermal insulation, and net opening area is important to achieve optimal results. The present paper shows results from an original simulation process carried out within the Course “ICT in building design” of the Master degree programme ICT4SS (ICT for smart societies) at the Politecnico di Torino.