Category EuroSun2008-4

Economic evaluation

In order to extend the evaluation from ecological to economical aspects, investments and running costs (cleaning, energy, maintenance etc.) have to be considered as well. The evaluation system offers an EXCEL tool for calculating cost indices according to the morphological box, based on costs of fa? ade components. For purposes of overall judgement the cost indeces can be transformed to marks comparable to the energetical indices.

1.2. Comprehensive evaluation

Finally the separate energetic and economic evalutions can be combined to a comprehensive judgement by the user. For the different aspects of the evaluation relative weights have to be determined by the user. This allows him to stress certain criteria in an individual manner for a certain purpose. A building investor, e. g...

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Winter thermal behaviour

The Health Sector has a large glazed area facing the North that collects direct solar radiation in winter. The hourly sunlight projection on the wall of the North corridor entering through a window of the Health Sector, is shown in Fig. 4 for a winter day. The projection was calculated through the

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software LuzSol [5], developed at Universidade Federal de Sao Carlos, Brasil. The openings are 2m width and 1m high. Because solar radiation reaches the half bottom of the wall most of the day, a dark colour painting is Fig. 4. Sunlight projection on a North wall recommended to increase the absorbed solar energy in of a window in the Health Sector (winter). winter.

Подпись: (b)(a)

Fig. 5. Hourly thermal behaviour of the Health Sector in typical winter day. (a) North and central thermal

zones; (b) So...

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Solar Bicycle Lighting

In the bicycle market, battery powered lighting is more and more common. A disadvantage of battery powered lighting is that the battery has to be replaced frequently. This can be avoided by using PV solar energy. The battery will then recharge itself and battery replacement is only necessary when the battery is worn out, after 3 to 4 years. The bicycle light designed in this project
makes use of a separable battery pack. The battery pack houses the PV panel and the battery, which means that it can charge separate from the bicycle on a location with higher irradiance than where the bicycle is parked. An additional advantage of the battery pack is that it can be used for other applications...

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Problems in Operation

Actually, there are two major problems we could see in our projects. The first one is related to the interface to the distribution of chilled water in the buildings. Quite often flow of distribution is not balanced and optimized, return temperatures are very low and need careful evaluation already in the engineering but affect significantly operation. Otherwise the absorbtion chiller runs in modes very close to freezing temperatures that possibly can affect the chiller, however, adjusting existing systems can be a serious challenge.

Second, we can report some problems with the cooling towers that are not specifically connected to the solar system but typical for open cooling towers. Blocked flow and insufficient water supply caused a stop of a system several times.

Besides that, the system...

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Description of calculation methodologies

In this work only thermal solar systems which are pre-heat or solar only systems for preparation of hot water are considered, since this is the case where the Portuguese regulations [1] imposes a specific calculation methodology [2].

1.1 European Standard EN 15316 (part 4-3) Methodology

The objective of this series of European Standards is the calculation of system energy requirements and system efficiencies. According to the standard, for thermal solar systems, the heat balance corresponds to the schematic representation of Fig.1 (for pre-heat/solar only systems). In this figured the terms relevant for comparison with SolTerm [2] are signalled in red. Only hot water preparation is relevant for this purpose...

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Towards the implementation of the Passive houses in the Portuguese context

L. Brotas1, G. Carrilho da Gra^a2, H. Gonsalves1*, M. Lerer2 and P. Paredes2

1 INETI, Department of Renewable Energy, Campus do Lumiar do INETI, 1649-038 Lisbon, Portugal
2 Natural Works, Rua Ricardo Espnito Santo N7 CV-E, 1200-790 Lisbon, Portugal
* Corresponding Author, helder. goncalves@ineti. pt

Abstract

Achieving a pleasant indoor environment with low energy consumption is a major goal of good building design. Overheating, in particular, is a problem in southern European climates, where several approaches to achieving comfortable indoor conditions, while keeping the building’s energy consumption low, have been successfully established. The Passivhaus standard, developed in Germany, defines requirements for very-low energy homes with regards to space heating...

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Lighting index Cm according to the orientations of openings

Figure 4 presents the results of the lighting index for different d/h ratio and for two different opening azimuths. d represents the length of the overhang and h the height of the window. These values of Cm are also compared to the PERENE requirements.

One can notice that the objectives of PERENE are too difficult to meet. We have assumed that the glazing has a transmittance equal to 1 (the window is opened if it is used in natural ventilation). PERENE requires values of Cm of 0,3 and 0,25 for windows facing North and West respectively.

Values of Cm of 0,3 and 0,5 are respectively demanded for openings oriented East and South. Only a d/h ratio of 1.5 could allow to meet PERENE for an East-oriented window.

To meet acceptable values of Cm, it would be necessary to reduce the transmittance of...

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Simplified integration of PV in sealed glazing windows. – development and demonstration of a complete system

XP. Haugaard, 2D. Aara, 3P. Poulsen, 3B. Bentzen, P., 4P. M. Nielsen and 4J. Andersen

1 Esbensen Consulting Engineers A/S, Gammel Koge Landevej 22, 2500 Valby, Denmark
2 Gaia Solar A/S, Hammerholmen 9-13, 2650 Hvidovre, Denmark
3 FAKTOR 3 ApS, Vesterbrogade 24b 2. sal, 1620 Kobenhavn V, Denmark
4 Idealcombi A/S, Norre Alle 51, 7760 Hump, Denmark
* Corresponding Author, p. haugaard@esbensen. dk

Abstract

The project group is developing a low-cost PV-window for building owners and architects to use in building designs for both new and retrofit buildings. With a U-value of 1.20 W/m2K the developed PV-window fulfills the requirements within the Danish Building Regulation and as a bonus it produces electricity to the building.

Architects have found the PV-window interesting to use in building design...

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