6. Market possibilities
6.10 Summary of the market analyses
6. Market possibilities
This chapter reviews the market situation of Low Exergy systems in different countries and presents results from interviews that have been conducted among the main actors of the building field in different countries. The target groups for the interviews were: principal contractors, architects, consultants, manufacturers and suppliers, installers and end users. A deeper analysis is made of the situation in the Netherlands. A summary of the interviews is given in section 6.10.
The application of LowEx systems is far more common in new buildings than in existing buildings. For example in The Netherlands and in Norway it is more or less common practise to install low temperature heating or high temperature cooling systems in new residential buildings. For existing residential buildings it is more of an unknown concept but the trend is, however, positive. In Japan and Canada, hardly any cases with low exergy systems installed in existing residential buildings can be found.
The situation is somewhat similar for non-residential buildings. For these types of buildings, LowEx systems do not seem to be as common in the new building stock as for residential buildings. Table 13 summarises the market situation in nine different countries. A higher number of crosses indicates a more common use of LowEx systems, and a positive trend is marked with a star. Please note that information for this table has been collected through discussions with a small number of people from each country, and should therefore be considered indicative.
Table 13 Summary of the market situation in different countries.
The climate during the heating season in Saskatoon, Canada is very cold (6077 HDD, base 18 °C, -35 °C design temperature) resulting in a large amount of energy being used for heating buildings.
Most persons did not recognize the term "Low Temperature Systems," but all were familiar with its implementation in the form of in-floor heating.
Attitudes toward in-floor heating were unanimously positive. Some associated it with energy savings, but for most is was the comfort of the heat as compared to forced air that was seen as the key advantage.
Most commented on the drawback of additional cost. Those who were promoting the systems and stood to gain from the additional capital expenditures (installers, suppliers) considered the investment well worth the extra cost. The consultant and architect were more cautious, promoting it only where it made sense for the owners. One example where it does make sense is in a firehall where the extra thermal mass of the floor slab retained more heat when the doors were opened, and the warm floor provided a good surface to dry hoses on. Applications where radiant heating and cooling systems don’t make sense are where high air volumes are required, making the radiant heating system redundant. The key driver for consultants in the implementation of radiant heating and cooling systems was owner demand. Those who are familiar with the comfort advantages of low temperature heating claimed it was worth the extra investment for the additional comfort.
The key thermal comfort issue for nearly all persons surveyed was the demand for individual control of their environment. The end user surveyed was the operator of a building that had both radiant heating and cooling and was very pleased because he received almost no complaints from people of being either too hot or too cold.
Summary table of market analysis in Canada
In Finland, the concept "Low Temperature Systems" is rather well known among manufacturers and suppliers. Also, consultants know about the concept and have a rather positive attitude towards it. Most negative are end-users and principal contractors. Extra investment costs are not accepted even though the running costs are small. One reason for this is the extremely low price of energy in Finland - running costs will be lower, but not low enough to justify higher investment costs.
Water-based heating systems are becoming more and more popular in Finland. They are installed in 52% of newly built single-family houses. Of these, 80% are floor heating systems. This has also enhanced the use of ground heat pumps, which are the heat source for 11% of newly built single-family houses. Floor heating is not much used in apartment buildings. The most usual heating system in apartment buildings is high temperature radiators, which get their heat from a district heating network.
Summary table of market analysis in Finland
The French market analysis has been realised as a limited number of interviews of the main building actors.
The summary table shown, which gives the synthesis of the interviews, may be a little skewed, while other principal contractors (for example those who chose geothermal energy) would modify or reverse the image of the old floor heating installations, for example.
It also appears that it would have been interesting and important to present results on two different tables: one relating to the residential sector and the other to tertiary buildings. The appreciation of the heat emitters and of thermal comfort may be rather different.
The table given here below probably has a little of the "colour" of former residential collective buildings.
To summarise the comments given in the table, the name of LTS is quite familiar for all actors except for end-users. The "Low Temperature" may still be considered as non-sufficient. Comfort is still, for end-users, associated with a minimum level: a minimum level is all that people are used to asking for.
For about fifteen to twenty years a concept of "Soft heating" has introduced the idea of LT systems. The improvement and constraints of the latest regulations give an advantage to floor or ceiling heating at lower temperatures (under 28 °C for floors).
The sector of collective housing has, in recent years suffered from the image of floor heating systems installed too early in poorly insulated buildings, where the systems had to be pushed to high temperatures to ensure the needs of these poor building envelopes. The discomfort that these too high temperatures caused (for legs) has left a negative trace in the minds of elderly people. This image has changed completely with a big effort and advertising from French energy distributors and the development of floor heating systems.
Architects and consultants see the benefit of saving surfaces and space using surface heating. From another point of view, principal contractors and users think it is important that heating systems integrated in the envelope may suffer less from intentional damage or cause injuries.
There is still a discussion in France about inertia, stability and control; it is less evident that inertia is actually needed, but a control, which allows a steady comfortable temperature, is desirable.
Summary table of market analysis in France
German climate conditions contain a warm summer period of about 3 months, a cold winter period with the lowest temperatures between –10 °C and –18 °C and the spring and autumn period with temperatures between 5 °C and 12 °C. Depending on the thermal insulation standard of the building the heating season begins at ambient temperatures between 15 °C (old buildings) and 10 °C (new buildings at "low energy level"). The temperature limit for heating in high insulated buildings (called "passive houses") with a net heat demand of about 15 kWh/m²a can be set to 5-6 °C. Due to the relative long heating period, nearly 30% of the end energy consumption in Germany is spent on space heating and domestic hot water preparation.
LTS systems have been known in Germany since the early 1980s. As a result of the first oil crisis in the mid 1970s the energy economy law (Energieeinsparungsgesetz) came into effect in 1976. Based on this law, decrees for the reduction of the heat demand of buildings (Wärmeschutzverordnung, 1977) and the quality/efficiency of heating systems (Heizungsanlagenverordnung) were developed. In 2002 these two decrees were combined in the energy economy decree (ENEV-Energieeinsparverordnung). The aim of this decree is to define the "low temperature" level as standard for buildings (for new buildings and for the retrofit of old buildings) and to define requests for the heating technology. Demands on artificial lighting and cooling systems are not integrated yet. The primary energy consumption of buildings for heating and domestic hot water preparation is limited and has to be proved. The detailed calculation methods are defined in DIN standards 4108-6 (heat demand – building side, based on EN 832) and 4701-10 (required energy - plant side).
The development of LTS started at the end of the 1970s / beginning of the 1980s with the development of low temperature gas and oil boilers by the industry. Additionally, heat pumps entered the market but were not accepted by users. The temperature level of radiator heating systems decreased from the traditional 90/70 °C level to 70/55 °C and floor heating systems became more popular. The development of gas condensing boilers in the 1990s caused a further decrease of the system temperature to an operation temperature level of 55/45 °C. In the 1990s even the use of solar energy began to influence the development and design of heating systems. The first steps of the technical integration were the use for only domestic hot water preparation, but now the use of combined systems for domestic hot water preparation and space heating is on the rise. The precondition for the use of solar energy for space heating in single family buildings and even in central solar heating plants with short or long term storage is the reduction of the heat demand of the buildings and the integration of LTS systems. In well insulated single family buildings (e.g. net heat demand between 30 and 50 kWh/m²a), a solar fraction between 25% and 40% can be reached. With long term storages, 40% to 50% solar fraction of the total heat demand can be covered. Plants up to a scale of 5.600 m² collector area and 12 000 m³ storage volume and greater are developed, built and tested.
For office buildings the demand of the reduction of the operational costs leads to the development of new energy concepts for buildings. In the framework of integral planning at an early stage in the planning phase of a rising number of projects, architects and engineers develop enhanced energy supply systems to reach low investment and operation costs. Buildings with advanced daylighting concepts and low temperature heating, high temperature cooling systems provided by renewable energy (e.g. foundation pile, ground water) are already developed and in use. Very popular is the realisation of concrete embedded coils for heating and cooling operating at temperature levels close to room temperature to improve the indoor climate in office buildings. The demand of thermal comfort for users plays an important role in the planning of these kinds of buildings.
Regarding the situation in Germany, it can be said that the government, architects, planners, engineers, installers and a great number of end-users are aware of the availability and the effectiveness of LT systems in the reduction of the operational cost and energy saving or reduction of CO2-emissions. At least low temperature heating systems in the combined use with gas condensing boilers can be defined as a standard solution in Germany.
Summary table of market analysis in Germany
In Japan, most professional people and end-users do not know much about the concept of low exergy systems for heating and cooling of buildings. There are few buildings designed using this concept in Japan. Those who know the low exergy concept, e.g. some building scientists and engineers, recognise so far that low exergy systems are good for thermal comfort, but difficult to use and expensive.The primary reason for such a situation in Japan is that the low exergy concept is only consistent with the new buildings designed to meet the code requiring a high level of thermal insulation building envelopes. Buildings constructed more than 20 years ago are generally very poor in thermal insulation. Most of the existing single detached houses are wooden so that the heat capacity of the envelope is small. Most of the existing apartment buildings have a reinforced-concrete structure so that they already have enough heat capacity in many cases, but the level of thermal insulation is usually low. Therefore, the low exergy concept will not be applied soon to those buildings. The level of thermal insulation of the building envelopes needs to be improved first.
The other reason for the situation in Japan is the lack of experience in experiencing the pleasantness provided by the thermal environment designed by the low exergy concept. Laypepople, and even professional people, usually do not know how pleasant the thermal environment provided by the low exergy concept is. Such pleasantness is hardly ever explained by words alone and it would be important to make it possible for a wider audience to experience the pleasantness given by the low exergy concept. Appropriate built-environmental education is also necessary.
Summary table of market analysis in Japan
Due to the low price of electricity and large production of hydropower, direct electric heating (electric panel oven) has dominated in Norway during the last few decades. Direct electric heating is still regarded as the most economical and preferred solution, but the share of hydronic heating is increasing. The statistics show that about 35% of all new, detached houses constructed the first six months of 2002 had hydronic floor heating systems. In 1997, the corresponding share was 11%. Almost all of new houses with hydronic floor heating systems use electricity to heat water, instead of a renewable energy source. Only a very few (10-20%) use heat pumps, gas, oil or bio-fuel (pellets, wood fire) to heat water.
The marketing of floor heating systems has focused on the comfort aspects, e.g. showing small babies crawling around on the floor. This is probably an important reason why the floor-heating system (low-temperature) is preferred in many new houses. Radiators are rarely used in new houses, but are more common in larger buildings (office buildings etc.).
Summary table of market analysis in Norway
Low exergy systems for heating and cooling is by no means a new branch on the Swedish market. The reason for the wide use of such systems is however rarely the goal to save energy but rather issues like comfort and in some cases the lower cost of installation and maintenance. Over the years, the efforts to save high quality energy such as electricity have directed the heating of houses towards hydronic heating systems coupled to district heating, but with a relatively limited emphasis on efficient use of exergy. This market analysis addresses the history and the present market situation for low exergy heating and cooling systems and the future potential for a relative growth in the use of such systems.
Low exergy systems – history and the state of the art
The most common heating systems over time in Sweden have been hydronic radiators and direct electrical radiators. In the sixties, before the national discussion about nuclear power, it became quite common to use electricity for heating. The common energy sources for heating have been boilers using oil, electricity and district heating from large power plants with co-generation of heat and electricity or the burning of waste. District heating companies have identified some advantages of getting lower return temperatures in the district heating systems but this has hitherto rarely been reflected in the price tariffs for delivered energy. When it comes to different types of systems that could be classified as low exergy systems we have a large variety of systems.
Floor heating
Floor heating with pipes embedded in in-situ cast concrete floor slabs is quite common. They have more often been installed to provide comfortable heating where radiator heating has not been considered feasible for architectural reasons. Also, there has been a certain demand for the extra comfort provided by floor heating. There has been a lengthy debate on the possible influence of floor heating on the energy consumption in buildings. There are examples where floor heating has advantages in this context but in other cases energy use has increased due to poor insulation in the ground and bad regulation and control of the systems. Several systems for fixing the pipe system before casting are available on the market. In recent years, surface oriented floor heating systems have increased their market share. Originally, they were developed for implementation of floor heating into lightweight floor constructions in wood frame buildings. Earlier systems where piping without any flanges were put in light weight constructions had failed due to the poor heat transfer to the surface and problems arose in the construction due to high thermal gradients resulting in deformation of the wooden floor beams. Usually, these systems consist of a sheet metal or a metal foil layer that is connected to the piping to provide necessary lateral heat transfer in the construction. The present development has lead to prefabricated material layers with straight and bent grooves where the heating coil is pressed in before the floor covering is laid on top. The time constant for such an arrangement is just a fraction of that for pipes embedded in concrete, yielding more favourable precondition for regulation and control. These systems are now also used on concrete floor and since the extra floor heating layer can be made as thin as 12 mm this gives the possibility to mount hydronic floor heating in existing buildings. It has not been common in Sweden to use floor based hydronic coils for space cooling.
Air heating
In the seventies, with increased use of mechanical ventilation, air heating became popular. The ventilation system could then be used for heating as well. However, with the necessary heat load the inlet airflow had to be increased by re-circulating air in the system. This in turn led to increased contamination of the ducts and of the inlet air. Re-circulation of air was eventually ruled out by the building code and this resulted in a severe set back of air heating. In recent years several projects have been based on a strategy where the heat loss factor for the building is reduced by excessive thermal insulation, high performance windows and good air tightness to such a degree that the heating load for the building can be met with heating the normal hygienic heat flow. Since the possible temperature difference has then to be fully utilised this can hardly be referred to as a low exergy solution.
Hollow core floor decks (Termodeck)
A commonly used solution during the seventies and the eighties was to take the ventilation air to office spaces in through hollow cores in prefabricated concrete floor elements. The inlet air could be preheated or cooled for distribution via the construction surfaces as well as with the air. With a certain ventilation strategy the building structure could also be cooled down with cool night air to avoid the need for cooling during daytime. A discussion around the hygienic properties of the core surfaces and also the increase in cooling loads has lead to a decrease in the market share for this type of solutions.
Cooling beams and radiant panels
The increasingly negative attitude towards re-circulated air in ventilation systems during the eighties called for new solutions. Obviously, the hygienic airflow did not come close to be a carrier for the ever-increasing need for cooling. A common solution was to separate ventilation and cooling in such a way that the ventilation air flow was limited to a minimum and the cooling was provided individually for every room by a hydronic system based on either fan coil units, cooling beams or radiant cooling panels in the ceiling. Since Scandinavians seem to be rather sensitive to noise and cold air jets, the cooling beams and radiant cooling panels have been successful and won an increasing market share. Since the cold carrier is water at 15 °C minimum these systems can be characterised as low exergy systems. Taking into account the difference in mechanical energy that is necessary to transfer heat by water instead of air, this also leads to a lower use of exergy. It is also believed that the annual cost for investment and operation can be less for a split system than a pure ventilation system.
Heated crawl spaces
One of the weak spots of the building technology has been the foundations, especially for single-family houses. The earlier technology with a slab on grades gave rise to many problems and the crawl space foundation gained market. Several different solutions were developed that in some way utilised the crawl space for heat recovery or heating. The simplest solution was to lead the exhaust air down to the crawl space and thereby increase the temperature and subsequently the heat loss through the floor. In another solution the crawl space was insulated towards the ground and heated to give basic heating through the floor construction. In a still more elaborate solution the inlet air is taken in trough the insulated crawl space and heated and then lead to the house through a slot along the outer perimeter of the building. In this way the house is heated with a combination of floor heating and air heating.
Different forms of heated crawl spaces have a significant market share in Sweden. The main reasons of homeowners for this choice are presumably comfort and the problems with moisture in non-heated crawl spaces.
Low temperature radiators
A common and economically viable form for heating has been the use of a ground coil coupled heat pump. The condensation temperature has been governed not so much by the heating system but by the minimum temperature for domestic hot water at 55 °C to avoid the legionella bacteria. However, this has generated the need for hydronic radiators designed for lower temperatures than those coupled to boilers or district heating.
Energy supply and the need for low temperature systems
In the present situation, the biggest advantage of low exergy systems for heating seems to be their usefulness for projects with heat pumps, long term heat storage and condensation gas boilers. For district heating it has been estimated that the economic contribution of reduced return temperatures could amount to 5 SEK/MWhK. In single projects however, a better efficiency in the heating systems could replace investment in the distribution grid if, for instance, new fill in housing areas were run on return water only. Furthermore, in the near future one can foresee large projects with conversion from electrical heating into other forms of heating and there the heat from local heat pumps will be a competitive alternative to the expansion of the district heating grid. In the last decade also, the energy for space cooling has moved in the direction of the low exergy solution. We have district cooling coupled to the large heat pump plants for the district heating systems and we have numerous projects where the hydronic cooling system is connected to ground coils with or without a heat pump. In these projects it is often favourable to combine with some form of low temperature heating in wintertime to avoid gradual upward drifting of the coil temperature. Projects with solar collectors and seasonal heat storage are, in the present situation, not considered economically viable without considerable subsidies. However, it can be worthwhile to explore the change in economic preconditions if the buildings are equipped with low exergy systems, especially for borehole storages. Also, improvements in technology may change the picture.
Summary table of market analysis in Sweden
Results and analysis of interviews in 1997
A market analysis was conducted in the Netherlands in 1997 (van Bruchem & Op’t Veld 2000). The interviews and questions were mainly limited to low temperature heating in the residential sector.
Principals
General: This target group is interested in LTS if it has an extra value in exploitation, social relevance (environment) and comfort. An important boundary condition is that the end users do not have to make any concessions concerning user friendliness, reliability, comfort and maintenance.
Principals need practical experience with LTS and demonstration projects to see "that it works". Firstly, because they need to be convinced that the implementation of LTS does not bring additional risks. Secondly, a principal needs good arguments to be able to convince buyers and tenants that LTS gives advantages (positive side effects) and is worth investing in.
In general, the professional principals do recognise the term low temperature system. However, very few were able to give an exact definition and qualification of LTS.
The most important aspects mentioned in the interviews were:
Attention points: reliability, arguments and development of a social basis for end users.
Architects
General: Architects are very positive about the application of floor and wall heating. The most important prerequisites for further application in design are knowledge concerning the technical consequences for building and reliable partners. Architects need partners in the building process who are capable of designing and dimensioning LT systems. They also need information about the consequences of LTS on the design.
In general, the architects recognise the term low temperature system, but in most cases it is associated with floor heating (only), and few could give an exact definition and qualification of LTS. Architects are aware of the technical consequences of floor heating to the building.
Most important aspects mentioned in the interviews were:
Installation consultants
This target group appeared to be quite diverse. Some consultants had a lot of experience with LTS and they promote these systems while others did not have any experience at all. This diversity in experience and knowledge highlights a general need for information about LTS and more specificly, guidelines and tools for engineering.
Most important aspects mentioned in the interviews were:
Attention points: knowledge, experience, design tools.
Suppliers
In this target group, a lot of information and knowledge about LTS is available and suppliers also have quite a good know- ledge of the market although extended and very specific experience is sometimes missing. Because of the interest of this target group in LTS the development of an extended marketing strategy is not necessary. However, support and streamlining of information and communication is necessary for the market introduction. This target group could easily identify barriers in the market, and they also knew the right arguments for how to make a positive influence on different target groups (Table 14).
Communication to the other target groups is often not streamlined. Information that is available does not give a consistent picture about the possibilities and properties of LTS. This group must be supported to build a system of communication and dissemination of information to the other groups, providing clear and adequate calculations, designs and decision models. Support is also needed for the creation of demonstration projects.Suggestions for stimulation:
Attention points: communication to other target groups, demonstration projects with independent monitoring and support to other groups.
Table 14. Suppliers’ opinion of main barriers and positive influencing methods concerning LTS in the Netherlands.
Building contractors
General: building contractors form one of the main barriers for LTS in the building process. If a building contractor is developing projects at his own risk, he will only be interested in LTS if benefits will be recognised by the market. In all cases, the lack of trust for LTS will be translated into higher margins on the installation costs. Especially floor and wall heating systems stand in conflict with traditional building logistics with financial and technical consequences. Contractors believe that extra costs at an average of 5000 Euro per dwelling is involved.
The major building contractors recognise the term "Low Temperature System". Few were able to give an exact definition and qualification of LTS.
Identified barriers are:
Arguments for positive influencing of LTS:
Suggestions for stimulation:
Also building contractors need practical experience with LTS. All indicated barriers are caused by a lack of knowledge or experience with LTS. Contractors also need good arguments in order to convince principals and buyers/consumers.
Attention points: reliability, arguments and development of social basis for end users.
Installers
This group has quite a big amount of information about the market attitude towards LTS. In spite of this, none of the companies would refuse to work on LTS, even if they are lacking the necessary knowledge. This is an important aspect that has to be taken into account when discussing the reliability of the LTS system!
The level of knowledge is very mixed within this group, varying from a mere recognition of LTS to a relatively broad experience in design and engineering of LTS. The first group lacks the view about the advantages of LTS for installers (in other words: LTS is different, difficult and not interesting), and they also lack knowledge and skills important for good engineering of LTS projects. Thus, they cannot provide their customers with good information and the right arguments.
The second group with experience can provide many valid arguments in favour of LTS and also give information about the different LTS options. However, they often face a lack of knowledge and understanding among their clients and also among the end users.
Installers need a two-track approach:
Identified barriers are:
Arguments for positive influencing:
Suggestions for stimulation:
Attention points: reliability, arguments and communication.
End users
The majority of the end users do not recognise the term LTS and are not able to give a definition. The term creates negative associations in terms of being inferior, low valued, new, complex, not reliable and full of risks. However, the few end users with real practical experience are very positive about LTS. The majority is still in the introduction phase of the acceptation process. To accelerate this process it is necessary to inform end users about the positive experiences gained from other users.
The most important aspects mentioned in the interviews were:
Attention points: the term LTS, reliability and experiences with systems.
Summary of the Dutch analysis
Notable was that the suppliers as well as some of the installation consultants and installers have sufficient knowledge about the advantages of LT heating systems. The other target groups could, in the most favourable cases, recognise LTS and also mention some advantages. However, in most cases target groups could identify many (suggested) barriers. In general, the term LTS is hardly recognised and if it is, it creates more negative than positive associations. On the other hand, all groups, especially the end-users, having experienced LT systems are unanimously positive.
Only the target groups between the supply and demand side (consultants, installers, suppliers) show sufficient basic knowledge of LTS. However, there are differences in the levels of knowledge within the groups. The most important barriers are:
The general conclusion of this analysis is that looking at the total market, LTS has rather a moderate score on the five essential and crucial points when analysing the acceptation of a new innovative concept (Table 15)
Table 15. Assesment of acceptation criteria for LTS systems in the Netherlans
Follow-up actions
The market analysis gave a good view of the existing barriers for the acceptation of LTS in the Netherlands. Also, in the interviews a number of suggestions were presented for actions to stimulate the acceptation and implementation of LTS. As the results of the first market analyses were available by the end of 1997, many suggestions and barriers were worked out by Novem and led to several concrete actions, which are presented in the original report by van Bruchem and Op’t Veld (2000).
Summary table of market analysis in The Netherlands
6.10 Summary of the market analysesThe arguments for the use of LowEx systems need to be communicated more clearly for all the target groups in most countries in order to reach a wider application of these systems. The positive associations need to be supported by good examples gained from the use of LowEx systems. When the additional benefits are reliably presented, people will most propably be willing to accept extra investment costs. Thermal comfort is seen as an important target, but in some countries end users are ready to accept incomplete comfort.
End users are usually not familiar with LT systems, except in Germany they are quite well known. Manufacturers and suppliers, instead, are usually familiar with LT systems. Variation in the other groups is considerable among the countries and even inside the countries. One group we should be concerned about, is the architects, who are not very familiar with LTS. This is the group, which has a great influence in implementing the systems into the market. In addition, although we know that LowEx systems offer some advantages for the architectural design, it seems that the architects are not aware of these advantages.In general, LowEx systems seem to bring very positive associations, like energy efficiency, comfort, soft heating or safety. There were a few comments about suspected comfort problems, but these were exceptional. Some doubts about the functionality and ease-of-use of the systems were expressed. Sometimes the systems are regarded as new and exceptional systems, and therefore something to be careful with. There are groups, which will rather stick to the traditional systems. In many cases Low Temperature Heating was associated with floor heating, especially by architects, but also by other groups. Often the systems were associated with renewables. It seems that inadequate information about the systems is the major cause for negative associations.
There is a lot of variation in attitudes towards extra investment costs. In Finland, France and Germany extra costs are less accepted than in Sweden, Netherlands or Norway. In Canada people are mostly willing to pay for the extra benefits offered by the LowEx systems. Extra costs are sometimes accepted also in Japan, when the additional benefits are clearly communicated. In other countries, too, good arguments are needed to change the negative attitudes towards extra investments. In some countries LowEx systems are considered as luxury systems.
In most countries thermal comfort is seen as a very important target for building design by all interviewed groups. Incomplete comfort is, however, tolerated by end users in many countries. It seems that they do not know that they could demand good thermal comfort in their houses. Also, architects often ignore thermal comfort as a target. Controllability is often considered more important than thermal comfort.
A summary table of the market analysis in the participating countries is persecuted in the following page.
Figure 50. Thermal comfort is important, but people sometimes tolerate incomplete comfort, like this man sitting in an igloo on an ice sofa.