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Scientific research plan of the HELTH project

1. Background
2. Objectives
3. Studied houses
4. Measurements and analysis
5. Expected results of the scientific research in project
6. Coordination, communication and publicity


1. Background
In the course of time, the use of traditional and historical rural houses has changed. Modern people have different requirements for comfort, function, and energy-efficiency of houses.
As the residential and tertiary sector, the major part of which is accounted for by buildings, accounts for more than 40 % of final energy consumption in the European Union, the EPBD Directive requires the energy performance of buildings to be enhanced. During last years many national laws and regulations are tightening the energy efficiency requirements of buildings. These requirements can be in conflict with requirements for traditional and historical buildings. Traditional rural houses and landscape are part of cultural heritage that is preserved.
The technical condition of the buildings is going to improve; the number of harmful damages decreases and the buildings become more enduring (they will not need too frequent replacements of construction). To make rural buildings more energy efficient and to improve the indoor conditions, the renovation of the their heating and ventilation systems as well as modern approach to renewable energies is a potential alternative. Selected technical solution should suit to the traditional houses and landscape.
Traditional houses are usually heated with fireplaces or other types of biomass based heating. This type of heating is based on sustainability, but it is not energy-efficient and satisfactory from the point of view of indoor climate.

The project is divided into two main parts:
• Research work to study the living- and technical conditions of traditional rural houses and landscapes;
• Training and educating of occupants of traditional rural houses as well deepening collaboration between participating universities as well between universities and museums.

During the project one continues to carry on with the fieldwork to inventory houses and determine their technical condition, energy efficiency and quality of indoor climate in selected test houses.
Based on the existent scientific material it is possible, already in the first year of the project, to start with theoretical training and seminars to educate future regional counselors, house owners, master builders as well as the general public. Besides practical knowledge the latter also acquire the general idea about the meaning of cultural heritage.

2. Objectives
This project has the following objectives:
• To determine the conditions and main problems of traditional rural houses from the aspect of living quality, energy efficiency, durability (of both the building and materials), structural and hygrothermal performance, etc. by carrying out building surveys in example houses;
• To find alternative ways for making rural buildings more energy efficient and to reduce fuel usage and carbon emissions by renovation of the building envelope, by changing direct electrical heating into heat pump heating or changing the natural ventilation system to a mechanical ventilation system with heat recovery as well as by using renewable energies;
• To improve the indoor climate in traditional rural houses in order to provide their occupants a healthier living environment;
• To study the indoor climate and moisture loads in periodically heated and unheated rural houses as well as to assess the influence of periodical moisture loads and periodical heating on the hygrothermal performance, risk of water vapour condensation and mould or rot growth in rural houses;
• To work out optimal solutions to improve the living conditions, indoor climate, and durability of traditional rural houses;
• To find out alternative solutions for renovation of traditional rural houses, for producing electricity in traditional rural houses either by using solar PV or wind, for producing solar thermal energy or for other problems in different fields and different countries.

3. Studied houses
The project concerns traditional and historical rural houses which are built before 1940 and are in common use, are heated periodically or seasonally, or unheated and unused during winter. Considering the similarity of the cultural heritage and nature conditions in the area of the project it is possible to study these areas by using the same research model.
In Estonia and Southern Finland the basic building material used in traditional rural houses is wood. In Gotland traditional rural houses older than one hundred years are mainly built of stone. The whole area of the project witnesses similar difficulties with the living conditions and quality, energy efficiency, durability and quality of both wooden and stone houses. Studied houses will be selected from (Figure 1.1):
• Estonia (Figure 1.2, above): mainly Harjumaa, Läänemaa, Raplamaa, Saaremaa, Järvamaa, Lääne-Virumaa, Pärnumaa, but also from adjacent area;
• Sweden (Figure 1.2, below): Gotland County;
• Finland: mainly Uusimaa, Varsinais-Suomi, but also from adjacent area.

Figure 1.1 Area of the Central Baltic Programme.

Figure 1.2 Traditional rural houses in Estonia (above), in Sweden (middle), and in Finland (below, source: The National Board of Antiquities).

4. Measurements and analysis
Research in this project includes field measurements and computer simulations of:
• indoor climate,
• energy efficiency,
• structural and hygrothermal performance of envelope etc.

The research uses the methods of large-scale field studies in traditional rural houses as well as computer simulations to compare and optimize the solutions.
Research concentrates on different type of houses:
• different structures: wooden house, stone house, manor type (wooden) house;
• different use and heating of the houses during winter.
During the project one year follow-up measurements will be carried out in approximately 15-30 houses per each country. Objective number of houses in each group of houses is shown in Table 1.1. The final number of studied houses depends on available candidates, extent of the measurements in each object and become obvious during research.

Table 1.1 Objective number of measurement objects in each group of houses

The research, inventory, structural survey and measurements will be divided into following groups:
• inventory of barn-dwellings in Estonia;
• indoor climate measurement will be done as well background information will be collected from all measured houses for making simulations as well working out renovation solutions;
• some selected houses (that will be used as generic model houses) will be studied, measured and investigated more thoroughly to get enough information for simulations;
• at least four type of house will be selected for example houses that will used for simulations, optimisations and for working out principle renovation solutions.

Inventory methodology of barn-dwellings
The main aim of the research inventory is get an overview of the current state of barn-dwellings. (i.e. how many of them are left, what state they are in etc), to find culturally and historically valuable elements and to give advice on their perseverance. After pilot studies, the current database will be developed and probably an Internet-based application for data gathering and analysis will be made for improved utilization. The goal of the current project is to make an inventory in 526 barn-dwellings by April 2013.
Inventory is carried out by researchers, who have undertaken training courses held by HELTH project (July 2010 and March 2011). Methodology includes preliminary searches, fieldwork and data input. The first step is finding houses according to inventory criteria which are:
• the main building is built prior to 1940;
• walls of the drying-room are intact;
• the barn-dwelling is considered sustainable.
Last criteria means – taken the current situation into consideration – that the house could be restored in a way to sustain modern functions and needs and at the same time preserve (or restore) it’s cultural-historical value. Buildings are found mainly by house-holders who have contacted us as a reply to ads placed on the Internet and in magazines or through fieldwork.
Fieldwork consists of filling out a datasheet, taking photos and taking measurements of the main building. Measurements are done with a measuring tape with an accepted error of 0,1 meters, since more accurate information would be too time-consuming and it is sufficient for a sketch of the building plan. Photos are taken of all the adjacent buildings and each constructional element of the main building should be covered at least on one photo.

Datasheet will consists of over a 100 separate entry fields:
• Metadata (inc. who and when made the inventory);
• Information on the farmstead:
- How and when was it acquired,
- Overview of the farmsteads history,
- Owners plans for reconstructions,
- Overview of the garden and near-by landscape (inc. wells and walkways);
• Barn-dwelling:
- Measurements and dating (inc. method of dating),
- Overview of the main constructional elements of the exterior and their current state (walls, foundation, roof, windows, doors, gates, insulation etc.),
- Overview of the main constructional elements of the interior and their current state (walls, floors, ceilings, doors, layout and use of the rooms, heating system etc.),
• Adjacent buildings:
- Dating (inc. method of dating),
- Main constructional elements (walls, foundations, roof),
- Evaluation of the building current state.

Finally data is entered to a Microsoft Access database. Photos will be provided with keywords and stored in separate folders, but with the development of an Internet application, will be tied with respective data fields. From there on information can be processed into various statistical applications (Microsoft Excel, Statistica, SPSS etc) for analysis.
Indoor temperature and humidity measurements
The values of temperature and relative humidity (RH) will be measured with data loggers (accuracy of ± 0.4 ºC, and ±3 %RH) at one–hour intervals from inside the building over long time period (~1year) in all the studied houses. Outdoor climate will be measured near the studied dwellings or climatic data will be retrieved from nearest weather station.
The number and the locations of measurement points depend on the type of the use and heating of the house. Figure 1.3 shows the example of the house, which is partially and periodically used and heated during winter. If there exists thermally different zones, indoor climate measurements will be done parallelly in each zone (in characteristic room).

Figure 1.3 Example of the periodical use and heating of the house during winter

Measurements of ventilation and infiltration
The air change rates of selected houses will be calculated on the basis of the measured exhaust air flows in the ventilation ducts (in each house with mechanical ventilation system) or based on measurements by using the active or passive tracer gas air infiltration measurement technique (in selected example houses, preferably in wintertime).
Investigation of building envelope
The air tightness of the building envelope of selected houses will be measured with the fan pressurisation method (EN 13829) using blower door equipment.
Depending on the purpose, air tightness measurements will be done under three different conditions. To determine the air tightness of the building envelope, depressurising and pressurizing tests will be conducted. All the exterior openings: windows and doors will be closed; ventilation ducts and chimneys will be sealed. To estimate the natural infiltration rate in houses with natural ventilation and in houses with mechanical exhaust ventilation without a working fan, a third series of tests will be conducted with normally opened passive fresh air inlets, opened window airings, and sealed ventilation exhaust ducts under negative indoor pressure conditions. The influence of tightening works to the air tightness of houses with log walls will be studied where possible (if suitable buildings are available) by air tightness measurements before and after the renovation works (in selected example houses).
To determine typical air leakage and thermal bridge places and their distribution, an infrared image camera and a smoke detector will be used. The thermography tests will be made during the winter period. Thermography investigations will be done twice. First, to determine the normal situation, the surface temperature measurements will be performed without any additional pressure difference. Next, to determine the main air leakage places, the 50 Pa negative pressure under the envelope will be set with fan pressurization equipment. After the infiltration airflow had cooled the inner surface (30 min) of the envelope, the surface temperatures were measured with the infrared image camera from the inside of the building. Surface temperature of possible thermal bridges will be measured with surface temperature sensors and data loggers in selected houses.
In selected houses the growth of mould will be investigated with tape lift sampling for the determination of inhabiting fungi on the surface of structure elements and interior. In selected houses the growth of wood-destroying fungi will be investigated with microscopic analyses.
Hygrothermal performance of the building envelope in example house with additional thermal insulation will be done over one year period (continuous temperature, RH, air pressure difference measurements).
If the structure and/or thermal properties of the building envelope of example houses for simulations are not clear, heat flow plate will be used to determine thermal transmittance of the building envelope. The thermal uniformity of the building envelope will be studied with infrared thermal image camera.

In addition to heating and ventilation, rural buildings need also electricity for lighting, appliances and many other purposes. The electricity is taken from the grid. To make rural buildings more energy efficient and to improve the indoor conditions, the renovation of the building heating and ventilation systems as well as modern approach to renewable energies is a potential alternative. Producing electricity on site using solar PV or wind and producing solar thermal energy, changing direct electrical heating into heat pump heating and changing the natural ventilation system to a mechanical ventilation system with heat recovery will be analysed to reduce the carbon footprint of these buildings. Influence of renovation solutions on indoor climate, energy efficiency and hygrothermal performance is found out by building simulation. Optimal renovation strategies are find out by sensitivity analysis or optimisation depending on the case.

Simulations in this project include:
• indoor climate and energy efficiency simulations (IDA-ICE):
- validation of simulated energy consumption and indoor climate against measured energy consumption and indoor climate of example houses,
- distribution of heat losses,
- energy consumption of systems (heating, ventilation, domestic hot water),
- modelling of stove heating,
- influence of moisture buffering of internal surface of building fabric,
- alternative energy resources (e.g. PV-panels, solar energy, ground heat),
- alternative heating systems (e.g. heat pump),
• simulations of hygrothermal performance of building envelope (Delphin, WUFI, 1D-HAM):
- additional thermal insulation,
• sensitivity analysis and optimisation (GenOpt):
- improving the indoor climate to provide healthier living environment,
- improving of energy efficiency (heat loss of thermal envelope, infiltration, improvement of windows etc.),
- decreasing of renovation costs (combination of building envelope and HVAC-systems),
- aspect of fuel usage and carbon emissions.
Simulations will be based mainly on data retrieved form field measurements.

A questionnaire will be completed for each house, where the building characteristics, fuel and electricity consumption of houses used building materials, type of HVAC systems and its use, occupants’ habits, typical complaints and symptoms related to indoor air quality etc. will be interviewed from the occupant acting as contact person of the study. Similar questionnaire will be used for each country

Time schedule of research

5. Expected results of the scientific research in project
The expected results of this research:
• Overview is given about the conditions and main problems of traditional rural houses from the aspect of durability, indoor climate, energy efficiency, living quality etc.
• Optimal solutions are worked out to improve the indoor climate in historical rural houses, to provide their occupants with a healthier living environment;
• Optimal solutions are worked out to improve the energy performance of historical rural houses to reduce fuel usage and carbon emissions from heating and ventilating;
• Providing a better understanding of the hygrothermal function of the buildings in order to facilitate improved energy efficiency and indoor climate;
• To optimize the solutions for renovation of traditional rural houses considering the problems in different fields and countries;
• The collaboration between the participating universities as well as between universities and museums becomes deeper;
• Occupants of traditional rural houses are educated to use their houses in more energy efficient ways;
• To deepen the research collaboration between universities, the change of researchers will take place. Researchers will be educated on international scientific conferences;
• Results will be presented in joint publications in scientific journals and conferences (international and national);
• The collected and processed research material makes the basis for future research projects and for education of students in universities.

6. Coordination, communication and publicity
The Estonian Open Air Museum co-ordinates the joint activities of all partners, compiling of financial and activity reports, educational and communication activities.
The theme will be introduced to the target groups in the form of conferences (local and international), seminars, workshops, publications, homepage (in four languages – Estonian, Finnish, Swedish, English) and exhibitions. The last three methods are addressed to the general public, to give a wider audience the information about methods of sustainable renovation and healthy living environment.
The local press informs the local householders about the problems of maintaining their historical buildings and the corresponding training courses.
Participation in international conferences gives the possibility to share the research results with experts all around the world (Indoor Air 2011, Building Physics in the Nordic Countries 2011, RoomVent 2011, Healthy Buildings Conference 2012, International Building Physics Conference 2012, CLIMA 2013 etc.).
The counselors trained in the project areas can be addressed by the owners of traditional houses for advice concerning renovation or energy economy even after the project.