energy

The aim of the European SSHORT (Sustainable Social Housing Refurbishment Technologies) project is to increase and promote rational and efficient use of energy in the retrofitting of social housing buildings. In this scope, one step was to evaluate with simulation studies the technical and economical interest of selected sustainable technologies on standard collective social housings in participating countries.

This paper describes four simulation models, which reproduce energy and temperature measurements of occupied buildings very well. These buildings represent small to medium size residential low-energy buildings of different construction type, which are typical for mid-Europe. For the simulation, the software TRNSYS is used. The reproduction of measured energy and temperatures in time steps of 15 minutes is well suited for precise predictions on heating energy demand and comfort of the buildings and modifications of them.

Due to its simplicity in installation and maintenance on the one hand, and to its potential to conserve energy on the other hand, the refrigerant modulating air-conditioning system has become very popular. This paper presents the results of an IAQ energy audit of two buildings in Singapore that use that kind of system. The results are compared to those obtained from conventional air-conditioning systems.

The purpose of continuous fan operation is to bring in fresh outdoor air to the conditioned space in order to maintain acceptable indoor air quality. Ventilation not only uses more energy, but it also impacts air distribution system efficiency.This is partially due to various system interactions. The objective of this paper is to quantify the impact of continuous fan operation on energy use and distribution efficiency by introducingtwo new parameters: energy use ratio (EUR) and distribution efficiency ratio (DER).

The infiltration term in the building energy balance equation is one of the least understood and most difficult to model. For many residential buildings, which have an energy performance dominated by the envelope, it can be one of the most important terms. There are numerous airflow models;
however, these are not combined with whole building energy simulation programs that are in common use in North America. This paper describes a simple multizone nodal airflow model

The impact of infiltration and ventilation flows on energy use in commercial buildings has received limited attention. One of the reasons for this lack of study is that the commonly used programs for estimating the energy use of buildings do not incorporate the interzonal airflow modeling techniques
required to adequately account for the effect of these factors on energy usage. To address this issue and provide insight into the impact of these flows, the CONTAM airflow modeling tool

The CEN TC 156 / WG2 (ventilation for residential buildings) has prepared a new European draft for the test method of Heat Recovery Units (prEN 13141-7). This method should ensure a common way of testing these units all over Europe. In order to determine if the draft procedure is sufficient enough, both VTT and CETIAT has proceeded to some tests according to the new European standard on the same unit. Results on this first intercomparison give interesting data on the test method applied.

Even in cold climates, offices normally need to be cooled due to the internal heat loads from people, equipment and lighting. Either a chilled ceiling or chilled beams with cooled water as medium or chilled air can be used. In the case with chilled ceiling or chilled beams, a constant air volume system (CAV) is used. In the case of air only, a variable air volume (VAV) system must be used. This paper presents the advantages of the two methods of cooling with respect to energy use, which was calculated from climate data.

The annual energy cost and first cost of the HVAC system, life-cycle costs (LCC) and benefits of improved productivity were simulated in an office building located in a cold climate when improvements of air quality were made by increasing the outdoor air supply rate and by reducing the pollution loads. The building was ventilated by a variable air volume (VAV) system with an economizer or a constant air volume (CAV) system with heat recovery. The pollution loads were assumed to be similar to those in a non-low-polluting or low-polluting building.

As part of the European SAVE project ENPER, an international workshop on the implementation of the European Energy Performance Directive (EPD) was organised in Brussels on May, 19. Some 115 delegates from 21 countries attended this workshop. This directive obliges the Member states as well as the 10 candidate members to implement a range of regulatory measures regarding the energy performance assessment and certification of buildings. Presentations were made by the people listed above in the author grid.