Submitted by Maria.Kapsalaki on Thu, 02/13/2020 - 11:03
Worldwide the food system is responsible for 33% of greenhouse gas emissions. It is estimated that by 2050, the total food production should be 70% more than current food production levels. In the UK, food chain is responsible for around 18% of final energy use and 20% of GHG emissions. Estimates indicate that energy savings of the order of 50% are achievable in food chains by appropriate technology changes in food production, processing, packaging, transportation, and consumption.
Submitted by Maria.Kapsalaki on Wed, 02/12/2020 - 13:12
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.
Submitted by Maria.Kapsalaki on Thu, 02/06/2020 - 16:46
Duct routing often poses a great challenge when planning the installation of a mechanical ventilation system with heat recovery. This is particularly true for retrofits, where the necessary space for supply and exhaust ducts was originally not accounted for. This extended summary presents an alternative approach for duct routing avoiding ducts in the dwelling, while allowing the installation of a centralized MVHR unit and the implementation of a cascading airflow through the dwelling.
Submitted by Maria.Kapsalaki on Tue, 02/04/2020 - 12:32
The present paper describes the design improvement of a single-room ventilation unit. This ventilation system presents many advantages, however, several drawbacks exist. The first one is the acoustic disturbance. As the facilities are directly installed within the rooms, the fans’ noise may create discomfort. Furthermore, in the cold or temperate climates, condensation or frost may appear. A dedicated management should then be implemented. Finally, as the system is not centralized, communication between the different units is required to ensure the global system efficiency.
Submitted by Maria.Kapsalaki on Wed, 04/17/2019 - 15:59
The implementation of decentralised ventilation units is growing, especially in the residential retrofit. These systems are typically simple to install on site (usually in the external façade with no additional ductwork) and allow room-by-room control strategies. Until now, decentralised systems are evaluated by applying the same methodologies as for centralised ventilation systems, even though different boundary conditions apply. Some differences are for example:
Submitted by Maria.Kapsalaki on Wed, 04/17/2019 - 15:16
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.
Submitted by Maria.Kapsalaki on Wed, 04/17/2019 - 15:13
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.
Submitted by Maria.Kapsalaki on Wed, 04/17/2019 - 14:54
Balanced ventilation units are well known to provide a sufficient amount of fresh air in residential buildings in a controlled way, without relying on ever-changing naturally driven forces. During colder periods, heat recovery ensures a reduction of the ventilation heating load. Outside the colder periods, recovery is reduced or shut off automatically, providing mechanical ventilative cooling. During warmer periods, the recovery is used again to provide a comfortably cool supply of fresh air.
Submitted by Maria.Kapsalaki on Mon, 04/15/2019 - 10:27
Energy performance of buildings has been continuously and systematically improved in Europe with next step of transition to nearly zero energy buildings (NZEB) in 2019-2021. Well insulated and airtight NZEB provide challenges or opportunities – depending on point of view – for ventilation systems. Heat recovery ventilation may be expected to be major ventilation solution because in Continental and Nordic climates, it is simply impossible to build nearly zero energy buildings without heat recovery.
Submitted by Maria.Kapsalaki on Thu, 11/23/2017 - 15:31
Energy renovations seek to improve the airtightness of dwellings and thus require ventilation and heat recovery to maintain or improve energy-efficiency, indoor climate, and durability. These ventilation systems often control the indoor air of an apartment as a single climate zone, which neglects the different demands of individual rooms. Renovations result in greater retention of heat and air inside the building envelope, so rooms become especially sensitive to gains from solar radiation, occupancy, moisture loads and pollutants.