Category Archives: BACKGROUND

A New Building as a CO2 Sink — Wooden Parish Centre with a Regenerative Energy Supply

Lichtblau Florian, Lichtblau Architects BDA

Competition in 1994: Complex task — parish centre in the heterogenous outskirts of a town. Building design defined in dialogue with the Alpine backdrop.

Planning from 1998: Without access barriers, located in a predominantly natural setting, modular, flexible, pre-fabricated in wood and glass. Immediacy of the structure, materials, artistic design.

Energy, ecology: "Passive" efficiency due to the optimised envelope (heating balance, daylight, airtightness). "Active" technology solely with regenerative energy sources (ground heat source/sink, sunlight, biomass).

Southern aspect, baptismal chapel, northern aspect

Synergetic balance: Maximal comfort for minimal energy (2/3 from environment, 1/3 from wood). Solid wooden construction + regenerative energy = positive CO2 balance for standard costs!

Eco House

The eco house project has been prepared for the architectural competition “Bio-climatic Dwellings” in Tenerife, Canary Islands. The eco house is an ecologically designed cubic dwelling that is 120 m2 and has two stories and a basement. Cubic dimensions of the building optimize heat load because of less surface to build. Building has simple modular plan having axes of (3.20m+1.60m+3.20m). That enables of designer flexibility to set services; kitchen, toilet, bath and circulation in-group as of 1.60m quarter multiples etc. and living dining 3.20m+0.80m multiples.

Entrance, living, dining, kitchen and 2 bedrooms are located to access of South East wind. Greenhouse serves as a tampon area in summer conditions or to collect heat when needed. Greenhouse is at the center of building. Its design eases to conduct desired air to other spaces via direct openings plus special details for conduction. That is living and bedrooms adjacent to greenhouse heat is collected and stored adjacently to the thermally linked spaces.

South region of the Tenerife island is a place, with sunny and arid climate, having large amount of solar energy all the months and with very small temperature swings between the seasons and also between the day and night. Ordinary flat plate photo thermal converters needs can easily supply domestic hot water. The energy for the appliances and lighting for a self-sufficient house can be produced by a stand-alone solar cell modules and battery system. The climate of this region of the island is so suitable that the amount of reserve capacity for the batteries is relatively small as the region being sunny and arid (Green, 1982) and the efficiency decrease due to temperature increase of the Pv cells is also small because of the moderate temperatures and low temperature swings. Temperature increase of the cells can further be reduced by a proper installation taking into account the direction ofthe wind.

Monthly-average solar energy values on horizontal surface are estimated using a quadratic relation between the solar radiation and bright sunshine hours. The universality of this relation was verified by using the measured data of 100 locations all over the world (Akinoglu, and Ecevit, 1990). Diffuse component is calculated using Page’s correlation (Page, 1964).

Solar radiation values on tilted surface are estimated using the procedure outlined in Duffie and Beckman (Duffie, and Beckman, 1991) for the three different tilt angles. Calculations are carried out for all seasons (tilt=latitude), winter (tilt=latitude+12) and summer (tilt=latitude-12) applications and the results showed that the winter application is relatively better for designing the systems, with a minimum value of around 18 MJ/m2 days for the summer months. However, the differences between the monthly radiation values for the all seasons and winter applications are very small. Note that the calculations are carried out for 6 m2 installation and more that the sun according to the year 1995’s conditions can supply 80 % of the load.

Total daily requirement of electricity is obtained to be around 3100 W-hr/day. The reserve capacity of the batteries is assumed to be 3 days, which is quite reasonable for sunny and arid regions having very short rainy and cloudy periods. This gives around 12 lead-acid batteries of 260 A-hr capacity (Roberts, 1991).

The climate of the south region of the Tenerife Island is excellent to build a self-sufficient house. A wise insulation and may be the use of thermal mass walls for some of the rooms might be effective in solving insignificant requirements of cool nights and hot afternoons. According to estimations the total cost of the building is $ 80.500,00 for the year 1995. The materials have been selected with aspect to renewable resources and re-used; materials are mainly brick, wood, volcanic stone and natural insulation.

Toilet solid wastes, kitchen and garden organic wastes, leaves roots are collected, stored and composed to be fertilizer in the edible landscape in and outside house. A specially designed toilet leads urine separately collecting pipe system to be stored in the basement and sold in the market. Pipe equipment set leads gray waters to basement and ponds in the garden to be clarified, re-used and at the end for watering. Detergents waters are used in the same washing cycle. Separated detergent sold to be re-fabricated and re-used. Rainwater collecting from roof, surface waters and well supplies go directly to pond.

For gray water treatment and mix, it is recycled in basement, emerges in cascades into one of the two ponds. Total 400m2 area of garden and greenhouse is supported by homebred fertilizer and water supports %80 of annual consumption of the vegetable, fruit
and white meat of the family. Edible landscape is designed according to their light, water irrigation requirements, aesthetic and creative demands of the people living in the house.

Biogas collection produced by composting process and house unit wind energy is researched for gas production for kitchen and alternative electricity supplement. Wind speed of 5-7 m/s can be used to supply up to 1 kW of energy with a wind turbine having a diameter of 1.5-2.5 m (Randell, Ed., 1988). A rotor type windmill can be installed in the vicinity of the building, which may be attracting due to its easy construction and noise-free operation.

Table 1. Ecological evaluation ofthe buildings and projects

ECOLOGICAL CRITERIA

BUILDINGS & PROJECTS EVALUATION

1

2

3

4

5

6

7

DESIGN

Energy efficiency

kkk

kkk

kkkk

kkkk

irkirk

kkkk

kkk

Renewable energy use

kirk

kkk

kkkk

kkk

kkkk

kkkk

kkk

Flexibility and sustainability in design

kkk

kkk

kkkk

kkkk

kkk

kkk

kkk

Optimization in material use

kkkk

kkkk

kkkk

kkkk

kkk

kkk

kkk

Renovation of existing buildings

kkkk

Structural resistance

kkk

kkkk

kkkk

kkkk

kkkk

kkkk

kkk

MATERIAL

Low embodied energy use

kkkk

kkk

kkkk

kkkk

kkk

kk

kkk

Durable materials

kkk

kkk

kkkk

kkk

kkk

kkk

kkk

Maintenance facility

kkk

kkk

kkk

kkk

kkk

kkk

kkk

To avoid from harmful gas emission materials

kkkk

kkkk

kkkk

kkkk

kkk

kkk

kkk

Use and preference of regional materials

kkkk

kkk

kkkk

kkkk

kkkk

kk

kkk

Preference of recycled materials

kkk

kkk

kkk

kkkk

kk

kk

kk

To utilize waste materials

kkk

kk

kk

kkkk

kk

kk

kk

LAND USE

Minimum automobile use

kkk

kkk

kkkk

kkk

kkk

kk

kk

Development of mix-use functions

kkk

kkk

kkk

kkk

kk

kkk

kk

To utilize the resources in site

kkk

kkk

kkkk

•kkk • kk kkk I kkk kkk • kk

kkkk • kkk kk : kkk kk ; kkk

kkk

kkk

kk

kkk

kkk

kkk

kkk

kkk

kkk

kkk

kkk

kk

kk

To settle the buildings in minimum impact to the environment і ***

kkkk

kkk

To utilize the existing landscape

kkkk

kkkk

kkkk

SYSTEM

EQUIPMENTS

Energy efficient heating and ventilating system

kkk

kkk

kkkk

High efficiency in lighting system

kk

kk : kk

High efficiency in water cycling system

kk

kk ; kk

To provide mechanical ventilation system

— ; **

BUILDINGS:

1. Adobe house in Hasandede

2. Durudeniz dwellings in Mugla

3. Bodrum ikizada Turkcell base Station

4. Straw-bale house in Hasandede.

EVALUATION GRADES: * : Poor

** : Average

*** : Good **** : Excellent

PROJECTS:

5. Bio-climatic house for 5 house-holders,

6. Metropolitan Istanbul Municipality; Headquarter.

7. Ecorenovation in Batikent

Conclusions

SHAPE * MERGEFORMAT

DURUDENIZ

STRAWBALE HOUSE

ECO-RENOVATION

TURKCELL

ADOBE HOUSE

SHAPE * MERGEFORMAT

Figure 1. Ecolagically considered buildings


MUNICIPALITY;

HEADQUARTER

ECO-HOUSE

Figure 2. Ecological projects


Examples of application of the scanning sky simulator

Since 2002, a number of different studies have been carried out at the Daylighting Laboratory, ranging from site planning to single indoorenvironments ordaylighting components analysis.

Most studies carried out in the facility refer to one of the following categories:

— comparison of environmental performances of different daylighting systems (openings, glazed surfaces, shading devices)

— optimisation, during the design stage, of a specific daylighting system.

The different goals of the studies belonging to the two categories imply different procedures in the use of the scanning sky simulator and artificial sun.

Forthe comparative evaluation ofdifferent daylighting systems, models reproducing sample environments are used. Besides, reference conditions are assumed, both forsky conditions and sun positions, and repeated in orderto compare environmental performances due to

assessed systems. At present, for this category, most studies have been carried out to evaluate the performances ofdifferent shading systems (overhangs, vertical fins, Venetian blinds, light-shelves, PVC, wood or aluminium louvered screens) for both residential and non-residential environments (e. g. attics, offices, classrooms, etc.)19,20,21.

The optimisation of a specific daylighting system is carried out during the building design stage and it is related to the distributive and photometric characteristics ofthe space for which the system has been conceived. At present, forthis category, most studies have been carried out to optimise the design of shading systems such as mobile or fixed, matt or specular, continuous or micro-perforated louver shades. Aim of the studies has been concerned with maximising the amount of admitted daylight while screening direct sun­light, hence controlling glare and overheating phenomena and meeting at the same time the Daylight Factorstandard requirements. In these cases, quantitative (illuminance and Daylight Factor levels) and qualitative (images taken inside the scale model) data were collected fordifferent louver tilt angles and for maximum and minimum daylight availability during the year (clear and overcast skies, June and December, morning and noon)22,23.

Sun-on-ground

The "sun-on-ground” module of the programme SENCE calculates the shape of the building shadow in a chosen moment. With a sequence of calculated shadows we can exactly see how the shadow "travels” over the building site. In the paper we calculated minimum recommended duration of building shadows at four reference days. The required duration of solar radiation upon the living room window is: 1 hour at December 21, 3 hours at March 21 and 5 hours at June 21. In the research the time around noon was taken into account. The shadows-on-ground were calculated for each hour during the required number of hours at the reference days (11.30-12.30 at 21st Dec., 10.30-13.30 at 21st Mar. and 9.30-14.30 at 21st Jun.). Then the shadows were overlaid. A pattern of shadowing during the selected time was obtained (Fig 4).

Figure 2: Floor plan area of solar volume designed for a pote. Leftacording to foe solar right. s regulation 1-3-5 hours duration, right: the 2-4-6 hours duration. North is on the top of side.

Iso-shadow

The "Iso-shadow" module of the programme "SENCE" (Fig. 5) calculates the duration of the solar radiation on horizontal surface. It is quantified as thermal flow received on a site.

Figure 3: Floor plan area of solar volume designed for a pole. Left:the 3-5-7 hours duration, right: the 4­6-8 hours duration. North is on the top of side.

Iso-shadows are the ratio of the received solar irradiation on a given site to unobstructed solar irradiation received on the same site, expressed as a percentage. ‘ of iso-shadow chart. The chart consists of iso-shadow contours, marking the areas, which receive the same percentage of solar radiation. The quantity of incident radiation is divided into 10% steps, from 0% to 100%, during the optionally selected period of time: day, month or year. In this way it is possible to determine the exact extent and duration of solar radiation on the basis of which the evaluation of the chosen site layout can be made.

In our case the 80% yearly iso-line on a given site was chosen as the minimum satisfactory value. The area arround the 80% iso-shadow line comprises the long morning and evening shadows with low incidence angles. This area has high fraction of received solar irradiation and can be used for neighbouring buildings.

BACKGROUND

The traditional design methods has producted, in recent times, buildings that:

• are built with materials characterized by high contents of embodied energy;

• use high amounts of nonrenewable energy sources;

• produce notable quantities of polluting substances;

• set the problem of disposal of material and/or recycling in maintenance, renovation and dismantling phases of buildings.

Environmental considerations related to traditional design methods of buildings urgently need a different approach.

New ‘sustainability oriented’ design criteria have to be set, in addition to new materials, building components, building techniques and technologies.

A meaningful goal may be the design of buildings that require less energy without loss of comfort. That means reducing building services powered from nonrenewable energy sources. Therefore, design and realisation of natural ventilation systems constitute an important subject in the research field on the ability of buildings to respond to climatic conditions.

The ‘passive-type based’ solutions characterized by using components or parts traditionally already existing in buildings seem particularly interesting. This approach avoids the introduction of additional components in the building fabric and, above all, it allows the selected solutions to be inserted in existing buildings.

This study aims to evaluate how the stairwell can be an essential element of natural ventilation systems in low-rise buildings.

This research evaluates how parts of buildings can act as an indoor microclimate control system. Computational Fluid Dynamics (CFD) codes [3] were used in order to design/verify the behaviour of the building components as a natural ventilation system.

This study focuses on building types that are very common, such as the blocks of in-line houses (three — to five-storey with a single stairwell and with two apartments on each floor). The natural ventilation system studied is characterized by easy implementation in energy retrofitting of buildings and by inexpensive installation and management, furthermore, the related operation is quite easy.

In the energy retrofitting of buildings, the finalization of systems with the aforesaid characteristics would allow their implementation on a significant percentage of the building stock in the followings sectors:

— indoor air quality, when the system is designed for only natural ventilation;

— energy savings when the system deals with passive cooling.

In this study, in fact, the main innovation is the different architectural and functional conception of traditional building components, such as the stairwell. In addition, the stairwell is not only used as a chimney in order to increase the air-change rate in the cold season, but it can be used also as a wind-catcher in summer.

The main results of CFD simulations concern the design of the stairwell openings (location, size, aerodynamic characteristics) and the design of an aerodynamics control system.

The behaviour of the examined natural ventilation system is governed by a very large number of parameters. The results shown concern only a certain number of the typical boundary conditions. However, these results can be useful for the designing of other similar natural ventilation systems.

Future research projects will concern the evaluation of different boundary conditions. The further aim is the definition of the most relevant parameters for the designing of similar systems.

Initial situation, competition

The high energy consumption of the existing building stock will give us headaches for decades to come. To prevent the new buildings of today from becoming the inherited burdens of tomorrow, the Protestant parish of Waltenhofen in Allgau built its new Parish Centre according to an integrated ecological and energy-conscious concept. The Church as an institution aimed to give a signal concerning responsible building according to the current state of the art.

Kirchplatz

Erdg«choss mit Aussenanlagen

Floor plan of the complete property

Ecological construction

As well as meeting the operating energy demand with solar energy, the energy associated with the construction itself and the materials cycles were also optimised. To compensate for the CO2 emission associated with the production of glass and concrete, solid wood was used as a construction material. Compound materials were avoided, the roof was covered with plants and the rainwater is used. The choice of regional building companies and re-use of the excavated earth and rocks in the landscaped grounds minimised the energy needed for transport.

Construction detail