Building envelope and construction

All six projects are located either in a cold or temperate climate, where a compact building form with a well-insulated and air-tight building envelope with minimized thermal bridges is essential to reduce heat losses through transmission or air leakage. The high quality of the building envelopes is shown in Figure 1.2.1. Except for the low energy project, Gelsenkirchen, the U-values for walls, roof and floor range from 0.10 to 0.15 W m2K. 2b. Gelsenkirchen (DE) B 2c. Gelsenkirchen (DE) H3....

Heat production and distribution

Part of the space heating demand is covered by usable heat gains from the occupants (circa 1200 kWh year) and by energy efficient appliances and lighting (2900 kWh year). The remaining space heating demand is covered by electric resistance heating (900 W) in the supply air. The houses have been designed for normal Scandinavian climatic conditions. Very low outdoor temperatures over extended periods are rare and are regarded as extreme. In such cases, the indoor temperature may drop by a degree...

Energy

Due to the high thermal quality of the building envelope, the heat load is only 9.4 W m2. The mean calculated space heating energy demand is 14.7 kWh m2a, assuming a room temperature of 20 C. The primary energy characteristic value for DHW, heating, ventilation and household electricity falls below the 120 kWh m2a maximum of the Passivhaus standard. This is achieved by using energy efficient household appliances. The calculated primary energy demand for DHW, heating and ventilation is 46 kWh...

Tools

PHLuft tool to calculate heat transfer from ducts and in heat exchangers www.passivehouse.com PHPP Passive House Development Package, Excel - based on the calculation of energy ratings www.passivehouse.com COMIS software package for multi-zone airflow simulation www.software.cstb.fr TRNSYS TRNFLOW software package for transient system simulation with multi-zone thermal airflow building model www.transsolar.com

Bus systems and transmission systems

Building control or home automation systems measure, control and manage the entire complex of building services by programmable microprocessors. Mostly, bus systems are used for these purposes. The technical term 'bus' originated from computer engineering, where various peripheral devices were connected to one computer - in other words, for networking. Today, communication bus systems are also used in automotive engineering, industrial automation and in building automation. Data can be...

PVT hybrid types

Water or air are the common heat collection media in PV T hybrids (Elazari, 1996 Hollick, 1998). Principal sketches of the two types are shown in Figure 14.2.3. The hot water can be used for space heating, DHW or pool heating, as was discussed in previous sections. The cold water is pumped into the hybrid collector in the lower part of the figure and is led through the module and out the top, and the heat is collected in a storage tank. Figure 14.2.4 shows a PV T water hybrid. For the PV T air...

A24 Energy Conservation in Buildings and Community Systems Programme

The IEA sponsors research and development in a number of areas related to energy. The mission of one of those areas, the Energy Conservation for Building and Community Systems Programme (ECBCS), is to facilitate and accelerate the introduction of energy conservation and environmentally sustainable technologies into healthy buildings and community systems through innovation and research in decision-making, building assemblies and systems, and commercialization. The objectives of collaborative...

Figure 332

Figure 3.3.5 Annual primary energy for heating and construction per house Figure 3.3.5 Annual primary energy for heating and construction per house The infrastructure of the settlement includes roads, sidewalks, park surfaces and garages, as well as wires for electricity and communication, and pipes for gas, water and wastewater. The CED breakdown is presented in Figure 3.3.2. It is surprising that the construction of the sewage system represents higher energy expenditure than the much larger...

Earthtoair heat exchangers

An earth-to-air heat exchanger (eta-hx) consists of one or more air ducts buried in the ground. Ambient air is drawn through the ducts by free or forced ventilation, allowing the ground to temper the incoming air flow. At increasing depths, the ground temperature becomes nearly constant over the year, assuming the average annual ambient temperature. Accordingly, the air passing through a pipe buried 2 m deep will be warmed in the winter and cooled in the summer. An eta-hx as part of a building...

Transparent insulation glazings

Most transparent insulation (TI) products can be described as glazings filled with transparent insulation material. There are some that, in addition, use the potential of low-e coating and noble gas fillings (see Figure 9.4.4) but many only rely on the insulation of air-filled structures. Glazings thicker than Figure 9.4.4 Cross-section of transparent insulation (Tl)-insulated glazing, utilizing noble gas filling and low-e coatings Figure 9.4.5 View of thin cardboard honeycomb structure (gap...

List of Acronyms and

ATS architecture towards sustainability CERT Committee on Energy Research and Technology CO2eq carbon dioxide equivalent CPC compound parabolic concentrator ECBCS Energy Conservation in Buildings and Community Systems EHSA European Home Systems Association EHX earth-to-air heat exchanger EIBA European Installation Bus Association EnBW Energie Baden-W rttemberg EPS expanded polystyrene insulation ERDA US Energy and Research Administration eta-hx earth-to-air heat exchanger heating, ventilating...

Design insights References

Kluttig, H., Erhorn, H. and Hellwig, R. (1997) Weber 2001 - Energiekonzepte und Realisierungsphase Energy Concepts and Their Stages of Realisation , Report WB 92 1997, Fraunhofer Institute for Building Physics (IBP), Stuttgart Erhorn, H., Reiss, J., Kluttig, H. and Hellwig, R. (2000) 'Ultrahaus, Passivhaus oder NullHeizenergiehaus ' 'Ultra, passive, or zero energy buildings ' Eine Statusanalyse anhand praktisch realisierter Energiesparkonzepte', Bauphysik vol 22, vol 1, pp28-36,...

Introduction

The success of the exemplary buildings presented in the previous section is the result of good design, but also of the capabilities of high-performance systems and components selected to work effectively together as a whole building system complex. This section examines the systems which together make a high-performance housing project possible. It begins with the building envelope, since providing a highly insulating and air-tight shell for the building is the first priority. When the envelope...

Foreword

Achieving housing that consumes four to ten times less end energy for space heating is an ambitious goal. A growing number of projects demonstrate that this is not only possible, but affordable, in a real market situation. This volume of a two-volume set presents a selection of six exemplary housing projects representing single family, row and multi-family housing in climates ranging from Lindas, Sweden, to Zurich, Switzerland. The projects combine aesthetics and high performance with regard to...

Influence on transmission losses

Calculation results of the effect of thermal bridges on heat transmission losses in housing with different envelope insulation standards are illustrated in Tables 9.2.3 to 9.2.5 (single family detached house, row house and apartment building). The contribution of thermal bridges to the transmission heat losses are up to 25 per cent. The target for the heat transmission through thermal bridges in Passivhaus constructions is below 4 per cent. In highly insulated house construction, thermal...

Lessons

Planning the heating and ventilation system at an early stage was necessary in order to optimize the arrangement of the pipes. On the one hand, room air conditioning could be improved on the other hand, costs were reduced. Prefabricated wooden elements for the interior walls were advantageous regarding the installation of the piping. Concerning indoor temperatures in winter, all apartments reached impressive values except for one apartment at the top floor where the ventilation system did not...

Project description

Source Schoeberl and Poell OEG, Vienna, www.schoeberlpoell.at Figure 6.1.1 The Vienna Utendorfgasse Passivhaus Apartment Building During the planning and construction of the Utendorfgasse Passivhaus apartment building in Vienna, many fundamental questions regarding the planning of social housing according to the Passivhaus standard were addressed. The challenge was to meet this standard while keeping costs within the limited budget allowed for social housing. Sch berl und P ll OEG succeeded in...

S Robert Hastings 11 Realities

Houses being built or renovated today should be designed considering two simple realities 1 Within the building's lifetime, oil and natural gas will cease to be an inexpensive and reliable energy source. 2 Renewable energy, which must replace these fossil fuels, will be more expensive. Accordingly, it only makes sense that housing design should aim for very low energy consumption. This is almost embarrassingly easy to achieve, in theory. The simple steps needed are to - reducing heat and air...

Latent heat storage

13.2.1 The physical principle of latent storage Latent heat storage uses the principle of the change of phase of a material to absorb or release heat. When a material is heated and changes its state (between a solid, liquid or gas), it will store much more heat than would occur from just 1 Kelvin temperature increase. When the material cools down and reverses back to the original state, this heat is then released. This heat of fusion is typically 80 to 100 times larger than the heat required...

Joachim Morhenne 1121 Concept

By heating spaces with large surfaces - that is, a wall or a floor - large quantities of heat can be transferred by radiation at comfortable low temperatures. Houses with very small heat demand are ideal candidates for such heat delivery. To ensure that the heat is primarily transferred by radiation, the heating surface temperature has to be close to the room air temperature, otherwise convection quickly becomes the main path of heat transfer for normal room temperatures. Because the radiant...

Photovoltaicthermal hybrids and concentrating elements

Johan Nilsson, Bengt Perers and Bj rn Karlsson 14.2.1 Co-generation of electricity and heat A photovoltaic-thermal (PV T) hybrid is, in principle, a cooled PV module where electric energy and heat is extracted simultaneously. A typical hybrid is shown in Figure 14.2.1, where polycrystalline silicon cells laminated on a conventional solar absorber with a copper tube are visible. The heat from the hybrid absorber shown in Figure 14.2.1 is collected by water running in the copper tube. Another...

Mechanical ventilation

Mechanical ventilation by electricity-powered fans can provide fresh air for a whole building or for special rooms only. In the latter case, such 'decentralized ventilation units' are not treated here. This section describes 'central ventilation systems' for a house, apartment or whole apartment building. In the case of the simplest mechanical ventilation, air is extracted only. This creates an internal under-pressure that draws supply air through planned openings in the building envelope. At...

Household appliances

During the last decades, electricity consumption for household appliances has increased substantially. For example, between 1970 and 1999, the energy use for household appliances in Swedish dwellings doubled from 9.2 to 19.6 TWh (Energimyndigheten, 2000). This fact clearly shows the necessity of taking a closer look at the energy use of household appliances. The different kinds of household appliances discussed in this section can be summarized as follows washing machines and Figure 14.2.9 A fa...

Biomass

12.5.1 Forms of biomass for heating housing Biomass is a very broad term this section addresses one form of biomass wood products. These can be in the form of firewood, bark and wood chips from the forests, and as remnants of the wood processing industry compressed into pellets. Modern wood-fired boilers offer a high degree of automation, operational safety, and low noise and dust production. The environmental advantage of biomass is clearly that it is simply completing the natural cycle, from...

A23 Solar Heating and Cooling Programme

The Solar Heating and Cooling Programme was one of the first IEA implementing agreements to be established. Since 1977, members have been collaborating to advance active solar, passive solar and photovoltaic technologies and their application in buildings. A total of 36 tasks have been initiated, 27 of which have been completed. Each task is managed by an operating agent from one of the participating countries. Overall control of the programme rests with an executive committee comprised of one...

Overheating protection by solar shading

If the solar wall heating is designed for a large contribution to heating (large solar fraction), passive measures against overheating in summer might not be sufficient. In this case, active shading elements have to be used. This also occurs if inhabitants do not tolerate temperature swings (for example, in an office building). The costs for active shading are considerable. The reason is that either the shading device must be integrated within the transparent insulation product or an external...

A11 Assumptions for the lifecycle analyses

In the life-cycle analyses (see Chapter 3 in volume 1 of this series) the Union for the Coordination of Transmission of Electricity (UCTE) electricity mix was used. Table A1.2 shows the primary energy factors for electricity used for the life-cycle analyses (UCTE electricity mix) and the energy analyses of the typical solutions (EU 17 electricity mix). The difference between the two values is caused by the different production mix for electricity within the UCTE and the EU 17 countries. Further...

Solar wall heating

With a transparent insulation element covering the outside of a massive wall, this part of the building can be converted to a solar wall heating area. Solar energy is converted to heat at the absorber and conducted with a phase delay of some hours - depending on thickness and building material -through the massive wall into the interior. This is the reason why windows and solar wall heating with transparent insulation fit very well together the solar gains of a south-oriented solar wall reach...

Water storage technology

Storing heat in water serves to bridge sunless periods in the case of solar hot water and combined heating systems, to increase the system efficiency in combination with cogeneration systems, and to shave the peak in electricity demand and improve the efficiency of electricity supply in the case of an electrically heated hot water tank. Water tank storage technology is mature and reliable. Sensible heat storage in water is still unbeaten in terms of simplicity and cost. In refined systems, the...

Groundcoupled and geothermal heat

Hans Erhorn and Johann Reiss 12.10.1 Concept Geothermal heat can be used to generate electricity and heat but the geology of Central Europe limits its application for heating purposes. In spite of its huge energy potential, this environmentally friendly technology is currently only rarely used. In comparison to solar energy that reaches the Earth (5.4 x 1015 MJ a), the terrestrial heat flux through the Earth's crust is nearly 6000 times smaller (1012 MJ a). This is, however, still three times...

Other means of heat storage

When more heat should be stored in a small volume than is possible with sensible heat storage, phase-change materials offer one solution. The change of phase can be a melting or a vaporization process. Melting processes have energy densities of 100 kWh m2 compared to 25 kWh m2 for sensible heat storage. Vaporization processes are combined with a sorption process. Energy has to be withdrawn at a low temperature when charging and be delivered at a high temperature when discharging the storage....

Energy savings and system performance

Radiant heating with reduced indoor temperature In a room with radiant heating, the same comfort is perceived at a lower temperature than in a room with convective heating. Due to the smaller temperature difference between inside and outside, each degree lower room air temperature decreases the heating demand by approximately 6 per cent (assuming that the radiant heating surfaces are not located on exterior walls). However, the savings decrease the more efficient the heat recovery in the...

Exemplary buildings

Each of the exemplary projects was selected for a special feature. The Lindas row houses in Sweden are impressive because they achieve high-performance in a cold northern climate with long winter nights. Equally notable is the courage of the client and architect to build not just one prototype house, but a whole housing tract of row houses. It is also interesting to see solar hot water production given the very short and often overcast days during half of the year in Sweden. This is offset,...

Carsten Petersdorff 1231 Concept

In high-performance houses, while the heat demand is reduced to a very low level and occurs during only a few months of the year, it does not decrease to zero. Certainly, a significant part of the space heating and major part of the hot water demand can be covered by solar energy. However, to cover 100 per cent of the demand would be economic nonsense. Such a system would be grossly over-dimensioned most of the year, having to dispose of heat. A backup heating system to cover the peaks is...

Primary energy savings

For the different row houses in Zurich's climate, the space heating demand (see Figure 9.4.8) and primary energy savings were calculated (see Figure 9.4.9). The lower the space heating demand, the higher the specific primary energy demand per kWh heating. For the reference house, a low temperature gas heating system with radiators was assumed for the passive house standard, a heat pump mainly heating warm water and air was assumed. Since the tool used was a German tool (PHPP), the conversion...

I34 Heat production

Even 'net zero energy houses' and, even more extreme, 'energy plus houses' still need heat production. Both concepts typically achieve zero or a plus by producing enough solar electricity from photovoltaic panels to equal or exceed their total yearly energy consumption - calculated on the basis of primary energy. This is by no means to say that these houses do not need energy input. Given the weak solar radiation during the short winter days, the energy production is minimal in winter, when...

Outlook

Vacuum glazing may be a further development to obtain lower U-values (Ug 0.4 W m2K) with double glazing, separated by a thin evacuated space of 0.5 mm to 1.0 mm. Vacuum glazing is already used for freezers and refrigerators that need (small) windows. This technology requires large numbers of produced units at moderate costs. High-performance housing and its corresponding components, such as windows, described in this section, are a challenge for the building industry during the next few years....

Discussion

Assuming that the energy use could be cut radically by 50 per cent by using only the best available technology, the annual energy use for household appliances in Sweden would decrease from 19.6 TWh to 9.8 TWh. If everyone who had to invest in a new household appliance would choose the most energy efficient product available, this decrease in energy use could be a reality within the next 15 years, assuming that this is the average lifetime of household appliances and that the use of electrical...

Fossil fuels

Table 12.3.1 Fossil fuels, reserves and projected availability (reach) Note G 109 T 1012 Source BMWA (2003) Commonly used fossil fuels for space heating can be divided into fuels that can be stored on site (for example, coals, oil and propane) and fuels delivered by a network (such as natural gas). The characteristics of the different fossil fuels are given in Table 12.3.2. Table 12.3.2 Characteristics of common fossil fuels Natural gas Propane Light fuel oil Hard coal Lignite Table 12.3.2...

Exhaust air heat pump systems

These systems extract heat from the exhaust air to produce useful heat for DHW or for space heating (or both) by means of electric power. Three configurations are common 1 air-to-liquid systems for preheating the water supply for DHW and or 'wet' central space heating 2 air to both liquid and air for combined hot water heating and warm air space heating and 3 air-to-air systems to supplement air-to-air heat recovery by a heat exchanger. Often an 'air-to-liquid' heat pump is used in which the...

Lifecycle analysis

Within the system boundaries, energy consumed for the production, renewal and disposal of materials were considered. The underground parking was excluded from the system boundaries. In the calculation of primary energy for electricity used by the technical systems of the house, the mix of Swiss electricity production were assumed. Household appliance electricity was excluded. Table 4.3.1 shows selected basic parameters of the house. The data on the amount and type of materials used in the...

Applications

The high investment costs limit electrical power generation to only a few specific geological regions with near-surface steam storages. Otherwise, the normal temperature gradient of 3.5K per 100 m of depth requires too deep borings (for example, 5000 m) to get the required temperatures to produce electricity. Using lower temperature heat is, however, often very plausible for heating buildings - ideally, groups of buildings or large buildings. For a single family home, the costs are usually...

A22 International Energy Agency

The International Energy Agency (IEA) was established in 1974 as an autonomous agency within the framework of the Organisation for Economic Co-operation and Development (OECD), to carry out a comprehensive programme of energy cooperation among its 25 member countries and the commission of the European Communities. An important part of the Agency's programme involves collaboration in the research, development and demonstration of new energy technologies to reduce excessive reliance on imported...

Direct electric resistance heating

12.4.1 Electrical space and water heating Electricity is a high-level energy form (100 per cent exergy) that can provide almost all energy services, from supplying electric light, the mechanical drive of electric tools and modern information technology. For all of these activities, there is no substitute for electricity. On the other hand, there are many possible substitutes for the task of space and water heating -for example, the needed heat can be produced directly from burning fuels. From a...

Active solar heating Water

Heating DHW with solar energy in a high-performance house is sensible. In such houses, the energy needed to heat domestic water can equal or even exceed the energy needed for space heating since the latter has been so far reduced by insulation and heat recovery. Furthermore, demand for heating domestic water is a 12-month energy demand, including the high insolation summer months. Using a solar system is therefore an effective way of reducing the total primary energy demand. Increasingly, the...

Fuel cells

Karsten Voss, Benoit Sicre and Andreas Buhring 12.6.1 Concept Fuel cells, like batteries, are electrochemical power sources. Whereas batteries store energy, fuel cells transform energy. A fuel cell steadily supplied with fuel generates electricity. The fuel can be virtually any chemical substance containing hydrogen. When hydrogen alone is not readily available as a fuel, it can be produced from substances such as natural gas, oil or methanol by a process called 'reforming'. Reforming, however,...

Types of systems

In atmospheric boilers, fuel (oil or gas) is burned under atmospheric pressure. For oil, this results in an inhomogeneous fuel-air mix, varying flame temperatures and the formation of carbon monoxide (CO) and volatile organic compounds (VOCs) harmful to man and the environment. Unburned fuel adds to this. Atmospheric burning gas boilers, however, have very low emissions. They are still common because of their technical simplicity, high reliability and good fuel utilization ratios up to 90 per...

Primary Energy and CO2 Conversion Factors

The delivered and used energy in buildings for heating and DHW is conventionally fossil fuels (gas and oil), district heating, electricity or renewable resources that cause different CO2 emissions when converted to heat. To judge the different environmental impacts of buildings during operation, two indicators are used in this book 1 The primary energy this is the amount of energy consumption on site, plus losses that occur in the transformation, distribution and extraction of energy. 2 CO2...

Opaque building envelope

Hans Erhorn and Johann Reiss 9.1.1 Concept Typically, 50 per cent to 75 per cent of the heat losses of conventional buildings results from transmission losses through the building envelope. These losses can be drastically reduced - for example, in Germany a 50 per cent reduction has been achieved since 1970. This reduction has been halved again by high-performance houses. The transmission losses of a typical house (with 1.5 to 2.0 m2 of building envelope per m2 heated floor area) can be...

Figures

1.1 Single family house in Thening 2 1.2 Installation of a vacuum-insulated roof panel 3 1.3 A compact heating system 5 1.4 A solar water storage 'tank in tank' 6 1.5 Wall section of the row houses in Lindas 7 1.2.1 U-values of the building envelope components 12 2.1.1 Twenty terrace houses in four rows solar collectors on the roof 15 2.1.5 View from the south 17 2.2.1 Energy supply for domestic hot water (DHW), space heating and ventilation 18 2.2.3 Windows in the end wall 20 2.2.4 U-values of...

Photovoltaic systems

Karsten Voss and Christian Reise 14.1.1 Concept High-performance houses need very little heat, but a considerable amount of electricity, which is all the more significant when considered in primary energy terms. In this chapter, we assume that 1 kWh of heat from natural gas requires 1.14 kWh of primary energy, while 1 kWh of electricity requires 2.35 kWh of primary energy to produce. For this reason, it is highly attractive to consider ways of producing electricity from a renewable source,...