Energy Efficiency of Buildings Regulations and guidelines 2012

Transcription

1 D3 National Building Code of Finland Ministry of the Environment, Department of Built Environment Energy Efficiency of Buildings Regulations and guidelines 2012 DRAFT 28 SEPT 2010 Decree of the Ministry of the Environment on the Energy Efficiency of Buildings Issued in Helsinki on xx xx 2010 In accordance with the Decision of the Ministry of the Environment, the following regulations and guidelines on the energy efficiency of buildings to be applied in construction are enacted by virtue of Section 13 of the 1999 Land Use and Building Act (132/1999). The regulations and guidelines have been described in accordance with Directive 98/48/EC of the European Parliament and of the Council amending Directive 98/34/EC laying down a procedure for the provision of information in the field of technical standards and regulations. This decree will enter into force on 1 January 2012, and it will abrogate the Decree by the Ministry of the Environment on the thermal insulation of buildings, issued on 22 December 2008, and the Decree by the Ministry of the Environment on the energy efficiency of buildings, issued on 22 December Previous regulations and guidelines may be applied to permit applications initiated before the Decree entered into force. Issued in Helsinki on xx xx 2010 Jan Vapaavuori, Housing Minister Pekka Kalliomäki, Senior Technical Advisor European Parliament and Council Directive 2010/31/EU (32010L0031); OJ No. L 153, , p.13 European Parliament and Council Directive 2009/28/EU (32009L0028); OJ No. L 140, , p.16

2 D3 NATIONAL BUILDING CODE OF FINLAND MINISTRY OF THE ENVIRONMENT, Department of Built Environment Energy Efficiency of Buildings REGULATIONS AND GUIDELINES 2012 Contents 1 GENERAL 1.1 Scope 1.2 Mutual recognition 1.3 Definitions 2 ENERGY EFFICIENCY REQUIREMENTS 2.1 The total energy consumption of the building 2.2 Administration of the room temperature during the summer season 2.3 Air-tightness of the building envelope 2.4 Thermal insulation of the building components 2.5 Thermal loss of the building 2.6 Energy efficiency of the ventilation system 2.7 Temporary buildings 2.8 Holiday homes under 100 m Capacity of the heating system of the building 2.10 Renewable energy sources 2.11 Measuring energy consumption 3 BASIC DATA FOR ENERGY CALCULATION 3.1 Weather data 3.2 Indoor climate 3.3 Standard use and indoor thermal loads of the building 3.4 Domestic hot water 3.5 Air-tightness of the building 4 CALCULATION RULES 4.1 General 4.2 Net requirement of heating energy 4.3 Thermal loss of the building envelope 4.4 Heating system 4.5 Ventilation system 4.6 Cooling system 4.7 Electricity use of lighting and devices 5 EVIDENCE OF CONFORMITY 5.1 Energy declaration 5.2 Requirements on calculation tools 5.3 Result presentation requirements Information for guidance APPENDIX 1 Classification of buildings in accordance with use APPENDIX 2 Requirements for calculation tools APPENDIX 3 Presentation of the important initial data and results of the energy calculation Regulations are printed across a wide column using this large font size. The regulations are binding. Guidelines are printed across a narrow column using a small font size. The guidelines are not binding and it is possible to apply other solutions than those given in the guidelines, providing they meet the requirements set for construction work. s, which are printed across a narrow column in italics, provide further information and contain references to other regulations. 2

3 1 GENERAL 1.1 Scope These regulations and guidelines apply to new buildings, where energy is used for heating spaces and ventilation, and additionally possibly for cooling, in order to maintain appropriate indoor climate conditions. Holiday homes, where there is no proper heating system, are not included in the scope In these regulations the buildings are divided into the following use classes: Class 1: Separate small houses and terraced and linked houses Class 2: Building blocks Class 3: Office buildings Class 4: Commercial buildings Class 5: Commercial accommodation buildings Class 6: School buildings and day care centres Class 7: Large gyms, excluding indoor swimming pools and ice sports centres. Class 8: Hospitals Class 9: Other buildings In Appendix 1 there is a more detailed division into various use classes However, these regulations do not concern the following buildings: a) industrial buildings where the manufacturing process transfers so much thermal energy that to achieve the desired indoor temperature there is no need, or only a small need, for other thermal energy, or production spaces where heavy thermal insulation outside the heating season would harmfully increase the room temperature or would significantly increase the consumption of cooling energy, b) a building or an extension to a building, the area of which does not exceed 50 m 2, c) agricultural buildings, other than residential buildings, where the energy consumption is slight, d) a greenhouse, air raid shelter or other similar building, the intended use of which would be made unreasonably difficult if these regulations were complied with. 1.2 Mutual recognition Whenever information is given in these regulations and guidelines of currently used SFS standards, valid standards of a corresponding level from elsewhere in the European Economic Area or Turkey may be used alongside or instead of them. 1.3 Definitions

4 In these regulations and guidelines the following terms and definitions apply: 1) Energy form coefficients (-) coefficients of the energy sources or the form of energy production, with which the various forms of energy are multiplied to calculate the energy value; 2) A particularly warm space is a space where, due to the intended use, the indoor temperature is continuously or occasionally high compared to a normal heated space. Such a space may be, for example, the steam room in a sauna; 3) A log house is a building, where the primary building material of the primary structures are logs with a mean structural thickness of at least 180 mm; 4) Ventilation, which maintains the indoor air quality and improves the indoor air by exchanging it; 5) The quantity of heat needed for the thermal ventilation is the quantity of heat that is necessary for heating the ventilation air flow from outside temperature to room temperature; 6) The annual efficiency ratio of the heat recovery of the extract air of the ventilation is the relation between the annual quantity of heat that is recovered with the heat recovery equipment and the quantity of heat that is required for the heating of the ventilation, when there is no heat recovery; The energy consumption of the ventilation system is the fan electricity and the electricity consumption of possible accessory units. The heating of the supply air is considered as a part of the energy consumption of the heating system; 7) Specific electric power of a ventilation system: the overall electric power drawn from the power supply by the fans of the total ventilation system of the building divided by the entire design extract air flow rate or design outdoor air flow rate of ventilation system (whichever is greater); 8) The net heating energy need of the ventilation is the heating energy need that is created from heating the air after heat recovery to the temperature of the supply air and the possible heating before heat recovery in order to prevent freezing; 10) The air leakage value q50 is the mean air leakage flow per hour of the building envelope by a 50 Pa difference in pressure, calculated in accordance with the total internal dimensions, per area of the building envelope (m 3 /(h m 2 )). The outer walls including openings, as well as the upper and base floors, are included in the area of the building envelope; 11) A refrigerated cool space is a space, where an appropriate all-year round temperature of 17 C is kept with a cooling and possible heating system. These spaces can be cool basement and storage spaces; 12) A refrigerated building is a building, where the supply air or the building spaces are refrigerated; 13) The net cooling energy need is the net need of energy for the cooling of the spaces and the supply air, which is the energy needed to cool spaces and the supply air; 14) The energy consumption of the cooling system is the energy consumption for the production of the cooling energy and the electric consumption of the accessory units. The energy consumption of the cooling system is calculated from the net need of cooling energy, taking into account the loss as well as conversions of the production, storage, distribution and supply; 15) District heating is heat that is produced with central heat production and distributed in a public network to the buildings that are customers; 16) A holiday home is a building that is intended for secondary residency; 17) The heated net area (m 2 ) is the total area of the heated floor plates, including the internal surfaces of the outer walls surrounding the floor plates. The heated net area can also be calculated as the heated gross area, from which the building component area of the outer walls has been deducted; 4

5 18) An unheated space is a space that is not intended for continuous occupancy during the heating period, and which has not been intentionally heated. During the heating period the temperature of the unheated space follows the outdoor temperatures. The energy efficiency requirements do not apply to an unheated space, and they are not taken into account in the calculations of the thermal loss of the building envelope. Unheated spaces include, for example, glassed balconies, protruding porches and unheated garages; 19) The net heating energy need is the heating energy need, from which the internal thermal load energy from people, lighting and electrical devices, the energy recovered from the extract air and the radiation energy of the sun have been deducted. The net heating energy need is the energy that is brought into the spaces, the supply air and the domestic water with the heating system. The net heating energy need consists of the net heating need of spaces, the ventilation and the heating of the domestic hot water; 20) The heating energy need is the amount of energy needed to maintain indoor climate conditions and to heat the domestic hot water; 21) The energy consumption of the heating system is the energy consumption required to heat spaces, the ventilation and the domestic hot water. The energy consumption of the heating system is calculated from the net heating energy need, taking into account the system losses and conversions. System losses consist of losses and conversions from the production, storage, distribution and supply of heating energy and from the electricity consumption of the accessory units of the heating system; 22) The thermal transmittance coefficient U is the density of the air flow that in a continuous state penetrates the building component when the difference in temperature between the air spaces in the various building components is as big as the unit. W/(m 2 K) is the unit used; 23) A warm space is a space for which a dimensioned room temperature during the heating period of +17 o C or higher has been chosen for occupancy or other reasons; 24) The net heating energy need of the domestic hot water is the heating energy need that includes the heating of the consumed domestic hot water from the temperature of cold water to the temperature of hot water; 25) The energy conducted elsewhere is the energy that is conducted elsewhere from the building, for example electricity supplied to the electricity grid; 26) The net purchased energy is the energy from which energy conducted elsewhere has been deducted; The balance limit of the net purchased energy consumption and its formation of the net energy needs, the energy consumption of the building service technical systems, the renewable self-sustaining energy, as well as of other local energy yields and energy conducted elsewhere. Renewable self-sustaining energy can, for example, be solar heat, wind or solar electricity or energy extracted by a heat pump from a heat source. 5

6 The net purchased energy consumtion balance limit The purchased energy balance limit Solar radiation through the windows BUILDING ENERGY NEED Heating Cooling Ventilation Domestic water Lighting Devices People Heat losses NET NEEDS heating energy cooling energy electricity Renewable selfsustaining energy TEKNISETJÄRJ ESTELMÄT TECHNICAL Järjestelmähäviöt ja muunnokset System losses PURCHASED ENERGY electricity district heating district cooling fuel ENERGY CONDUCTED electricity heating energy cooling energy Net purchased energy (electricity, district heating, district cooling, fuels) 27) A semi-warm space is a space that is not designed for constant occupancy by occupants dressed only in normal indoor clothes.the temperature is maintained during the heating season at a minimum of +5 C but below +17 C, or the temperature of the space would be the temperature of the air, within these limits, that is produced by the production process; 28) The total energy consumption, the E value (kwh/(m 2 a)), is the calculated annual net purchased energy consumption of the building accentuated with the coefficients of the energy forms with the rules and initial values provided in these regulations calculated per heated net area; 29) The specific thermal loss of the building envelope (W/(K m 2 )) is the total thermal loss sum of the conduction losses and the leakage air divided by the heated net area; 30) The purchased energy of the building is energy that is acquired to the building from, for instance, the power grid, the district heating network, the district cooling network and the energy contained in renewable and fossil fuel. The purchase energy consists of the energy consumption of the heating, ventilation and cooling systems, as well as of the energy consumption of electrical devices and lighting, specified per energy form, where the deductions of selfsustaining energy have been taken into account. The energy consumption of electrical devices includes the energy consumption of the consumer appliances in the building. The electrical consumption of the building service technical systems is included in the energy consumption of the systems; 31) The building envelope is the building components that separate the warm, semi-warm, very warm and refrigerated cold spaces from the outdoor air, ground or unheated spaces. The envelope does not include the building components that separate the various internal spaces of the building from each other; 32) The thermal loss of the building is the sum of the thermal loss of the envelope, leakage air and the ventilation; 33) The reference thermal loss of the building is the sum of the thermal loss of the envelope, leakage air and the ventilation calculated in accordance with the formulas and reference values of the regulations; 34) The design solution is the design to be implemented in the building in question; 35) The net heating energy need of spaces is the heating energy need that is formed by the warming of the conduction thermal loss, the leakage air loss, the replacement air and the supply air to room temperature, and from which the solar and internal thermal loads have been deducted; 6

7 36) Self-sustaining renewable energy is the renewable energy produced from renewable energy sources with equipment belonging to the building, with the exception of renewable fuels. Renewable self-sustaining energy is, for example, energy produced by solar panels and collectors, local wind energy and the energy extracted by heat pumps from a heat source. Renewable fuels are considered as part of the renewable purchased energy; 37) Renewable fuels are wood and wood-based and other bio fuels, with the exception of peat, which in these regulations is considered as a fossil fuel; and 38) A reference value is a value used for calculating the reference thermal loss: - The value of the thermal transmittance coefficient of the building component, - The sum of the window area of the building, - The annual efficiency ratio of the extract air of the heat recovery of the building, or - The air loss value of the building envelope. The reference values can be exceeded in the design solution as long as the provided maximum values are not exceeded and the calculated thermal loss of the building to be built is at least as great as the thermal loss of a reference building that meets the requirements in full. 7

8 2 ENERGY EFFICIENCY REQUIREMENTS 2.1 The total energy consumption of the building The net purchased energy consumption of the building shall be calculated using the outdoor weather data presented in these regulations and the initial values of the use and operating times of the systems, as well as the internal thermal loads of the building (standard use of the building type). The other initial data necessary for energy calculation are taken from the design documents The total energy consumption of the building (the E value) must be calculated. The E value is the annual net purchased energy consumption of the building accentuated with the coefficients of the energy forms per net area heated with the building type standard consumption. The E value is the sum of the net purchased energy and the results of the energy form coefficients by energy form The energy form coefficients are the following: Electricity 2.0; District heating 0.7; District cooling 0.4; Fossil fuels 1.0; Renewable fuels used in the building 0.5; The E values of a new building must not exceed the following values: When calculating the E value the self-sustaining energy is not purchased energy, but it reduces the consumption of purchased energy and net purchased energy. The energy form coefficients are only used for net purchased energy. The regulations concerning the renewable energy are presented in Class 1 Separate small house, terraced or linked house A net kwh/(m 2 a) when A net <150 m 2 and A net when Anetto 150 m 2 Log house A net kwh/(m 2 a) when Aneo <150 m 2 and A net kun Anet 150 m 2 Class 2 Class 3 Class 4 Class 5 Class 6 Class 7 Class 8 Class 9 Building block Office building Commercial building Commercial accommodation building School building and day care centre Large gym (excl. public swimming pool and ice sports stadium) Hospital Other buildings and temporary buildings 8 No E value required for holiday homes below 100 m kwh/(m 2 a); 190 kwh/(m 2 a); 270 kwh/(m 2 a); 280 kwh/(m 2 a); 190 kwh/(m 2 a); 180 kwh/(m 2 a); 500 kwh/(m 2 a); No E value required

9 Buildings in Class 9 must comply with the energy efficiency requirements, except the E value requirement If the building has more than one use, it is divided into parts according to class of use. The parts must comply with the requirements in If any part of a specific use is below 10% of the heated net area it can be considered to be part of the other areas. 2.2 Administration of the room temperature during the summer season The building shall be designed and constructed in such a way that the spaces do not heat in a harmful way. The room temperature during the summer season must not exceed the cooling limit value of of Table 2 in residential buildings by more than 150 degree hours and in other building by more than 100 degree hours during the period from 1 June to 31 August, as calculated using the weather data. In order to prevent the overheating of spaces, structural and other passive means, and during the night improved ventilation, are primarily used. Structural and passive means include, for example solar protection solutions, the size of the surface and direction of the windows, as well as the massing of the structures In order to comply with the summer season room temperature requirement it may be necessary to use a cooling system. In that case, calculations of the energy consumption of the cooling system and the net cooling energy need are included in the energy calculation Conformity with the summer season room temperature requirement is shown with a temperature calculation for the various types of spaces The temperature calculations of the summer season room temperatures are made for the types of space where the thermal loads are most abundant, for example the spaces or small flats on the south or western facades, on spaces with large glass surfaces or spaces with a heavy equipment load. The temperature calculations in residential buildings are made at least for the bedroom and living room having the heaviest thermal loads. In other buildings, temperature calculations are made for all typical spaces, for example an office space, an open office space, a conference room, and a teaching room. A space corresponding to the above-mentioned properties is chosen to represent the respective typical space The temperature calculation during the summer season is not necessary for a small house if the following conditions are simultaneously met: 1) The solar penetration coefficient (g value) of the windows larger than 1 m 2 in the facades facing west and south is smaller than 0.4, or other similar solar protection solutions are used to protect the windows. 2) The surface of the glass part of the windows in the living rooms and bedrooms having walls facing west or south does not exceed 30% of the area of the outer walls of the whole building; and 3) The area of the ventilation windows and other openings, for example hatches and balcony doors, in the living rooms and bedrooms is at least 5% of the area of these spaces Summer season temperature calculations are generally not needed for holiday homes and for buildings in class 9. 9

10 2.3 Air-tightness of the building envelope The air-tightness of both the building envelope and the structures between the spaces must be so good that the air flowing through the leakage points does not cause significant harm to the users and structures of the building, or to the energy efficiency of the building. Particular attention should be paid to the design of junctions and leads-in in the structures and to the thoroughness of the construction work. If needed, the structures must have a separate air barrier. There are regulations and guidelines concerning the humidity technical design of the building in part C2 of the National Building Code of Finland. The low air leakage value of a building does not guarantee the faultless functioning of the envelope structures, because there may still be locally significant air leakage points in the envelope. Therefore, it is very important that all the seams and holes of the air barrier are carefully sealed The air leakage value of the building envelope may be at the most 4 (m 3 /(h m 2 )) in class 1 buildings and 3 (m 3 /(h m 2 )) in other buildings. The air-tightness must be proven by measurements. The air-tightness of building blocks can be proven by measuring at least 20% of the flats. The measurement of the air-tightness can also be performed with the ventilation machines of the building, in which case a maximum of 25% of the net area of the spaces can be excluded from the measurement Ventilation systems other than those of dwellings are equipped with facilities to measure the air-tightness. The measurement of the air-tightness with a pressure test method is presented in Standard SFS-EN Thermal insulation of the building components The thermal transmittance coefficient of a wall, upper floor and base floor or a building component bordering on a semi-warm space may not exceed 0.60 W/(m 2 K). The thermal transmittance coefficient of a window or a door of a heated space may not exceed 1.8 W/(m2 K), and those of a semi-warm space 2.8 W/(m2 K) The thermal transmittance coefficient of a small part of a building component may be greater than what is indicated in if this is necessary for strength or other special reasons. The deviation from the requirements (coldbridge) of a small part of a building component may not cause a densification of the humidity or too high a relative humidity on the surface of the structure or in the structure when the building is in normal use The thermal transmittance coefficient of the wall and intermediate floor between the cold space and the other spaces to be cooled may not exceed 0.27 W/(m 2 K) and that of the door 1.4 W/(m 2 K) When designing the thermal insulation of the building, account must be taken of the correct thermal and humidity technical functioning of the building components. This is especially true when values that are lower than the reference values given in are used as thermal transmittance coefficients of the building components. 10

11 2.4.5 The thermal insulation of the base floor must be designed together with the frost insulation and the thermal insulation of a possible base wall that does not form part of the building envelope, and be implemented so as to avoid frost damages. Special attention must be given to the design and construction of the frost insulation, especially when the base floor is built with an insulation that is better than the reference values given in The thermal transmittance coefficients are calculated in accordance with part C4 of the National Building Code of Finland, or alternatively in accordance with the corresponding SFS-EN Standards. 2.5 Thermal loss of the building The thermal loss of the building envelope, the leakage air and the ventilation is limited in order to achieve good energy efficiency. The maximum thermal loss of the building must not exceed the reference thermal loss defined for a building in accordance with The conformity of the thermal loss is shown with a calculation of compensation that is made separately for warm and semi-warm spaces. The thermal loss is calculated in accordance with the following items. The size and geometry data of the planned building are used in the calculation. The areas of the various building components are defined in accordance with the total internal dimensions of the building The thermal loss of the building envelope is calculated in accordance with formula (1) The compensation of the thermal losses of a building is the calculated method to meet the requirement set for the thermal loss. A thermal loss that is greater than the comparative thermal loss of a specific factor (envelope, leakage air, ventilation) requires at least a reduction of the corresponding thermal loss of another factor. ΣH der = Σ (U external wall A external wall ) + Σ (U upper floor A upper floor ) + Σ (U base floor A base floor ) + Σ (U window A window ) + Σ (U door A door ) (1) where ΣH der the total sum of the specific thermal loss of the building components, W/K U the thermal transmittance coefficient of the building component, W/(m 2 K) A the area of the building component, m 2. If the base floor borders a ventilated crawl space, the number of ventilation openings of which does not exceed 8 thousandths of the area of the base floor, the specific thermal loss of the base floor is multiplied by the value of With the value of 0.8, the mean temperature of the crawl space, which is higher than the outdoor temperature, is taken into consideration. When calculating the reference thermal loss of a building, the following thermal transmittance coefficients per building component and the reference value of the window area are used. 11

12 The following reference values are used as thermal transmittance coefficients U of the building components of the warm, specially warm and cooled cold spaces when calculating the reference value of the thermal loss of the building envelope: wall 0.17 W/(m 2 K) 0.40 W/(m 2 K) log wall (the minimum thickness of the log structure 180 mm) upper floor and base floor bordering on outside air base floor bordering on crawl space (total area of ventilation openings not exceeding 8 thousandths of the base floor area) 0.09 W/(m 2 K) 0.17 W/(m 2 K) building component against the ground 0.16 W/(m 2 K) window, roof window, door 1.0 W/(m 2 K) The following reference values are used as thermal transmittance coefficients U of the building components of a semiwarm space when calculating the reference value of the thermal loss of the building envelope: wall 0.26 W/(m 2 K) log wall (the minimum thickness of the log structure 180 mm) upper floor and base floor bordering on outside air base floor bordering on crawl space (total area of ventilation openings not exceeding 8 thousandths of the base floor area) 0.60 W/(m 2 K) 0.14 W/(m 2 K) 0.26 W/(m 2 K) building component against the ground 0.24 W/(m 2 K) window, roof window, door 1.4 W/(m 2 K) The reference value of the total window area in the building is 15% of the floor area of the floors that are wholly or partly on the ground, but may not exceed 50% of the total area of outside walls. The window area is calculated in accordance with the external frame dimensions Part G1 of the National Building Code of Finland includes provisions on access to natural light in a dwelling room and on a minimum size of a window s glazed area. When calculating the thermal loss of the design solution of the building, the designed building component specific thermal transmittance coefficients and window areas are used. 12

13 2.5.6 The thermal loss of the building is calculated in accordance with formula (2) H leakage air = ρ i c pi q v,leakage air (2) where H leakage air the specific thermal loss of the leakage air, W/K ρ i the air density, 1.2 kg/m 3 c pi the specific heat capacity of the air, 1000 Ws/(kgK) Leakage air, m 3 /s. q v,leakage air The leakage air flow q v,leakage air is calculated in accordance with formula (5) The leakage air value q 50 = 2.0 m 3 /h m 2 is used in the calculation of the reference thermal loss of the building When calculating the thermal loss of the design solution of the building, the design value of the air leakage value of the building envelope is used From the point of view of the humidity technical safety, good indoor climate and energy efficiency, the air leakage value q 50 of the building envelope should not exceed 1 m 3 /h m 2 (one cubic metre per hour flows through a square metre of the building envelope when the difference of pressure between the indoor and the outdoor air is 50 Pa). The thermal loss of the ventilation of the building is calculated in accordance with formula (3) H iv = ρ i c pi q v,extract t d t V (1 - η a ) (3) where Hiv the specific thermal loss of the ventilation, W/K ρ i the air density, 1.2 kg/m 3 c pi the specific heat capacity of the air, 1000 Ws/(kgK) qv, extract the calculated extract air flow, m 3 /s, in accordance with standard use td tv η a the mean operating time ratio per 24h of the ventilation system, h/24h the weekly operating time ratio, day/7 days the annual efficiency ratio of the heat recovery of the extract air, which is the ratio between the used energy that is annually recovered with a heat recovery equipment, and the energy required for the heating of the ventilation, when no heat recovery exists. The thermal loss of the ventilation of the building is calculated, when needed, separately for each ventilation unit When calculating the reference thermal loss and the thermal loss of the design solution the same air flows are used The ventilation air flow is calculated in accordance with 3.3. Necessary ventilation is not considered in the calculation of the reference thermal loss and the thermal loss of the design solution. The ventilation operating time is calculated in accordance with

14 When calculating the reference thermal loss, a value of 45% is used as the annual efficiency ratio of the heat recovery of the ventilation extract air When calculating the thermal loss of the design solution of a building, the value of the annual efficiency ratio of the heat recovery of the ventilation extract air as well as the operating times in accordance with Table 3 and the air volumes in accordance with Table 2 are used 2.6 Energy efficiency of the ventilation system The energy efficiency of the ventilation system is, from the point of view of the building, guaranteed with appropriate means, without compromising a healthy, safe and comfortable indoor climate The specific fan power of the mechanical supply and extract air system may generally not exceed 2.0 kw/(m 3 /s). The specific fan power of the mechanical extract air system may generally not exceed 1.0 kw/(m 3 /s) The specific fan power of the ventilation system may be higher than 2.0 kw/(m3/s) if, for example, the administration of the indoor climate of the building requires non-standard air-conditioning. Guidelines on how to calculate the specific fan power (SFP) can be found in the Guide (SFP Guide 2004) A quantity of heat, corresponding to at least 45% of the quantity of heat necessary for the heating of the ventilation must be recovered from the extract air of the ventilation of the building. The corresponding reduction of the necessary heat energy can be achieved by: 1) Improving the insulation of the building envelope; 2) Improving the air-tightness of the building envelope; or 3) Reducing the quantity of heat necessary for the heating of the ventilation in other ways than recovering the heat from the extract air. The corresponding reduction of the need for heat energy is shown in the balance calculation of the thermal loss of the building in accordance with 2.5 of the National Building Code of Finland. The quantity of heat needed by the heating of the ventilation of the building can be reduced by other means than by the recovering the heat of the extract air using a solution where the outdoor air is preheated, which reduces the energy consumption of the building. This is, for example, a liquid circulating geothermal circuit preheating radiator, which prevents the freezing of the heat recovery unit The annual efficiency ratio of the extract air heat recovery of the ventilation of the building can be defined based on the certified annual efficiency ratio informed by the manufacturer of the heat recovery equipment. Guidelines on defining the annual efficiency ratio are given in Publication 122 of the Ministry of the Environment. The possible 14

15 reduction of the temperature ratio resulting from the freezing protection of the heat recovery unit can be considered in the form described therein The heat recovery of the extract air for a single space in the building can be disregarded without a corresponding reduction of the energy consumption if the construction of the heat recovery is proven to be inexpedient The construction of the heat recovery can be proven inexpedient, for example when the exceptional uncleanness of the extract air prevents the heat recovery function or if the temperature of the space during the heating season is below +10 C and the heat of the extract air cannot be recovered in a cost-efficient manner. 2.7 Temporary buildings The energy efficiency of a temporary building is only subject to the requirements of the thermal loss of a building. The calculated thermal loss of a temporary building may not exceed the defined semi-warm space reference thermal loss, in accordance with 2.5.4, for a building. 2.8 Holiday homes under 100 m For holiday homes over 50 m 2 but less than 100 m 2, where energy is used to heat the ventilation and the spaces, the energy efficiency requirements apply only to the thermal loss of the envelope. The calculated thermal loss of the building envelope may not exceed the defined semi-warm space reference thermal loss, in accordance with 2.5.4, for the building envelope. 2.9 Capacity of the heating system of the building The thermal efficiency of the thermal system is dimensioned so that the temperature conditions can be maintained at the design outdoor temperatures of the heating season presented in Part D5 of the National Building Code of Finland The internal and solar induced thermal loads are not considered in the dimensioning of the thermal efficiency Renewable energy sources The quantity of the renewable self-sustaining energy or the energy produced with renewable fuels must be at least 25% compared to the net energy need of the spaces of the building and the heating of the ventilation. The renewable selfsustaining energy or the energy produced with renewable fuels can be used anywhere in the system of the building, or it can be energy transferred elsewhere Electricity produced from renewable sources and available from the electricity distribution network is not considered here. Thermal energy from passive energy sources, where a lower energy consumption is passively achieved with structural solutions in the building or with heat that is produced with energy from non-renewable sources, for example solar radiation through the windows, is not considered as renewable energy. 15

16 Air heat energy from thermal pumps, geothermal thermal energy and hydrothermal thermal energy are considered as renewable energy, subject to the mean annual thermal coefficient of the thermal pump being at least 2.0. Part D5 of the National Building Code of Finland provides guidelines on calculating the thermal coefficient of thermal pump systems The requirement in does not apply to a building connected to district heating. District cooling is considered as renewable energy for 60% of the consumption of district cooling Measuring energy consumption In general, buildings are equipped with devices or possibilities to measure the use of energy, so that the quantities of energy can be easily clarified The buildings are equipped with electricity meters that show information on the total electrical energy consumption of the building The buildings are equipped with thermal meters that show information on the total thermal energy consumption of the building Buildings other than separate small houses and terraced and linked houses are equipped with meters showing domestic hot water consumption and, if necessary, meters to measure the water flow and temperature of the domestic hot water circulation circuit return Ventilation systems of buildings other than separate small houses and terraced and linked houses are equipped with meters. The ventilation system must be designed and constructed so that the specific fan efficiency of the system can be easily measured In buildings other than residential buildings, the heat recovery devices are equipped with meters, with which the extracted energy can be defined Cooling systems of buildings other than separate small houses and terraced and linked houses are equipped with electricity consumption meters. The cooling system must be designed and constructed so that the extracted electrical information and the produced cooling energy can be easily measured Fixed lighting system in buildings other than residential buildings are equipped with electricity consumption meters. 16

17 3 BASIC DATA FOR ENERGY CALCULATION 3.1 Weather data The energy calculation and the room temperature calculation of the summer season are made with the weather data of weather zone II of Part D5 of the National Building Code of Finland. 3.2 Indoor climate The energy calculation is made with the set values of room temperature, corresponding to a standard use of building type and the ventilation volumes presented in Table 2. The total supply air flows and the total extract air flows are equal in this calculation method. In the simplified residential building energy calculation, where the room temperature is standard, the set values of Table 2 are used as standard values. A value lower than the cooling value in Table 2 can, if necessary, be used as the set value of room temperature. Using this value, a room temperature lower than the set value can in certain cases be considered. Table 2. Set values of room temperature and volumes of ventilation to be used in energy calculations. The air flows are given per heated net area. Type of building Air flow Heating limit Cooling limit dm 3 /(s m 2 ) C C Separate small house and terraced and linked house Residential building block Office building Commercial building Commercial accommodation building School building and day care centre Gym, large Hospital The ventilation of buildings other than residential buildings is designed and constructed so that the outdoor air flow of the building, during periods outside the period of use, is at least 0.15 dm 3 /(s m 2 ) In ventilation systems of residential building blocks in which inhabitants can control the ventilation, a value of 0.4 dm3/(s m2) can be used for the ventilation of the building For buildings equipped with adequate ventilation, the air flows of Table 2 are used as maximum air flows and the periods of use of ventilation of Table 3. If the changing ventilation system is dimensioned in accordance with the cooling need and the maximum air flow is greater than the air flow of Table 2, the maximum air flow is used as design air flow. The appropriate ventilation system is controlled so that the carbon dioxide concentration does not exceed 900 ppm when the outdoor concentration is 400 ppm with the loads shown in Table 3 and the activity level shown in In buildings other than residential buildings, the necessary minimum air flow of the ventilation system is at least 0.5 dm3/(s m2) during periods of use. Mean air volume can be calculated per space type. The mean air volume of the building is then attained as a mean value weighted with the area of the typical spaces. 17

18 3.3 Standard use and indoor thermal loads of the building The standard use of the buildings and the corresponding thermal loads are defined in Table 3. The values of small houses are also used for semi-detached, terraced and linked houses The period of use shows how many hours per 24 hours and days in a week the building is in use. The utilisation factor is the average utilisation factor of lighting and devices, as well as the presence of persons in the building during the period of use. The thermal loads of the lighting and devices are considered the same as their use of electricity. The annual energy use of lighting and devices Q [kwh/(m 2 a)] is calculated: τ d τ w 8760 Q = kp, k utilisation factor Ρ thermal load W/ m 2 τd the number of hours of use of the building per 24 hours h τw the number of days of use of the building per week d Table 3 shows the design values for lighting in new buildings. If there is an adequate lighting control in the building, the hours of the use of lighting are calculated using the periods of use in Table 3. In the calculation of the average lighting effect, the model to be used must be per space and the spaces must meet their set lighting requirements according to use. The calculation of the average lighting effect can be made per space type. The average lighting effect of the building is then attained as a mean value weighted with the area of the typical spaces A lower lighting effect can be used if the lighting level is maintained. A separate clarification of the lighting level must then be presented as part of the energy calculation initial data. The lighting level design values of the lighting per space are provided, for example, in Standard SFS-EN The thermal load from persons is calculated based on the thermal effects (W/m 2 ) or the density of people. In calculations based on the density of persons the total thermal emission value of 125 W is used. A person s total thermal emission of 125 W corresponds to a metabolic effect of 1.2 met on a body surface of 1.8 m 2. In schools, gyms and day care centres a thermal emission of 110 W is for children, which corresponds to 1.0 met if a body surface of 1.8 m 2 is used The operational time of the ventilation system is attained based on Table 3, the period of use of the building, so that the ventilation is started 1 hour before the beginning of the period of use of the building and switched to the outdoor state 1 hour after the end of the period of use, with the exception of buildings in constant use. Table 3. Standard use of buildings and internal thermal loads to be used per heated net area. Appliances denotes consumer appliances. (4) Type of building Period of use Degree hours h/24h d/7d of use - 18 Lighting W/m 2 Devices W/m 2 Persons a W/m 2 Density of persons m 2 /person Separate small house and terraced and 00:00-24: b,c linked house Residential building block 00:00-24: b,c Office building 07:30-18: c

19 Commercial building 08:00-21: c Commercial accommodation building 00:00-24: c School building and day care centre 08:00-16: c Gym, large 08:00-22: c Hospital 00:00-24: c a does not include heat bound to humidity. Divide by the coefficient 0.6 to get the total emission. b in residential buildings, the degree of use of the lighting is 0.1. c there is no detailed data on the design value for new buildings. A smaller lighting effect can be used if the lighting level is maintained and a separate clarification is presented If no more detailed data are available, the thermal loads that are freed from the loss of the domestic hot water and the boiler and their utilisation are calculated in accordance with Part D5 of the National Building Code of Finland. 3.4 Domestic hot water The heating energy needed for domestic hot water is calculated using the specific consumptions of Table 4 and the corresponding net needs of heating energy. The temperature used for domestic cold water is 5 C and that for domestic hot water is 55 C. Table 4. Specific consumption of domestic hot water and its corresponding net heating energy need per heated net area. Type of building Specific consumption of DHW dm 3 /(m 2 a) Heating energy kwh/(m 2 a) Separate small house and terraced and linked houses Residential building block Residential housing block, measurement of water per flat 1) Office building Commercial building 68 4 Commercial accommodation building School building and day care centre Gym, large Hospital ) The measurement of water per flat must be made for both cold and for hot water. 3.5 Air-tightness of the building The design value is used as the air leakage value of the building envelope. The air leakage exchange is calculated from the air leakage value with the calculation formula in

20 4 CALCULATION RULES 4.1 General The net purchase energy is calculated in accordance with the initial data presented in Chapter 3 and the calculation rules in this chapter. The requirements regarding the calculation tool and the presentation of the results are presented in Item 5 and Appendix If there are semi-warm spaces to be heated in the building, the energy use in them is accounted for, but the area of the spaces is not added to the heated net area Restaurants, catering establishments, cafés, laboratories and other specialised spaces are not included in the calculations, and the energy calculation is performed with the initial data corresponding to the use of the building. Other technical systems not listed in this calculation method, such as professional kitchens, outdoor lighting, elevators, freeze protection cables, are not taken into account in the calculation It is not required to divide buildings into detailed calculation zones in the energy calculation. Small houses and other buildings for single use can be treated as a single calculation unit. Larger buildings are divided into zones corresponding to the use and times of use. 4.2 Net requirement of heating energy If there is an up-to-date calculation model for the building with a more detailed division into zones, the energy calculation can be made using that model. In this case, the initial data of the model are checked for conformity with these regulations In addition to the conduction, the warming of the leakage air in a space and the warming of the supply air from the temperature of the air being blown in to room temperature is calculated into the net thermal energy need of spaces The net energy need of the heating of the ventilation is calculated using the heat recovery and is formed from the heating of the supply air before and/or after the heat recovery. The net heating energy need of the radiators of the ventilation devices is calculated based on the temperature of the supply air, the temperature ratio of the supply air of the heat recovery equipment and the anti-freezing temperature. Guidelines on the calculation of heat recovery can be found in Part D5 of the National Building Code of Finland and Publication 122 of the Ministry of the Environment In the calculation of the solar energy entering the building, the solar protection solutions (structural, awnings, sun blinds, etc.) and their control, as well as the shadowing effect of the surrounding buildings and the vegetation are taken into account. 20

21 4.3 Thermal loss of the building envelope The thermal losses are calculated using the internal dimensions of the building envelope in accordance with the guidelines of Part C4 of the National Building Code of Finland. The regular and irregular coldbridges are taken into account in the calculation The thermal losses into the ground are calculated using the calculation method of Part D5 of the National Building Code of Finland, the applicable SFS-EN Standard or other more detailed calculation methods. The calculation can, for example, be made with the method presented in Standard SFS-ISO or one-dimensionally with a 1-m thick earth layer, with the standard temperature of 7 C on the lower surface The leakage air exchange qv,vuotoilma (m 3 /s) is calculated using the following formula: q v, vuotoilma q50 = A 3600 x q 50 the average leakage air exchange of the building envelope m 3 /(h m 2 ), Item A the area of the building envelope (base floor included) m 2 x a coefficient, which is 35 for buildings with one floor, 24 for buildings with two floors, 20 for buildings with three and four floors, and 15 for buildings with five or more floors a coefficient which converts the air flow from a m 3 /h unit to a m 3 /s unit. 4.4 Heating system The energy use of the heating system is the energy use required for heating spaces, heating the ventilation and producing domestic hot water In the calculation of the energy consumption of the heating system, the heat distribution and heat emission losses, the heating energy production losses and conversions, the transfer of domestic hot water, the storage and circulation duct losses, as well as the electricity consumption of the accessory devices of the heating system, are taken into account The energy consumption of the heating of the spaces of the heating system can be calculated by dividing the net heating energy need by the efficiency ratio of the heat distribution and emission of the heating system. This result is further divided by the efficiency ratio of the boiler or the annual mean thermal coefficient of the thermal pump, resulting in the energy consumption of the heating system as regards the heating of the spaces. The design values of the efficiency ratios and the thermal coefficients are presented in Part D5 of the National Building Code of Finland. The energy consumption of the heating system as regards the heating of ventilation and domestic hot water is calculated in the same way by dividing the net heating energy needs by the efficiency ratio of the boiler or the annual mean thermal coefficient of the thermal pump. If there is a circulation duct of domestic hot water in the building, the loss of it is, for example, taken into account in the way described in Part D5 of the National Building Code of Finland. The losses of the radiators of the ventilation equipment and the domestic hot water boilers can, for example, be taken into account in the way described in Part D5 of the National Building Code of Finland. (5) 21