Boiler Efficiency Directive - Advisory Committee. Comité Consultatif de la Directive du Rendement Appareils à chauffage central

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1 Document BED-AC N 027E Date Boiler Efficiency Directive - Advisory Committee Comité Consultatif de la Directive du Rendement Appareils à chauffage central FOR ACTION CONCERNING: Item: Draft guidance BED-Guide rev. 1 Agenda point 3.1 of doc. N 029E N 027E

2 PAGES 1-12 ITEM Definitions, standard boiler, matching, marking, modules ARTICLE 2, 5, 7.1, 7.2, 7.3 BACKGROUND Due to an ambiguous definition of the term boiler and an inconsistent use of the words boiler and appliance, differences between the separate language versions, and contradictions in each individual version, it is not clear to which products the directive applies and, in addition, which procedures are applicable to which products. Moreover, the requirements, to be set for issuing an EC type-examination certificate for a boiler and for a separately marketed appliance (boiler-body or burner), and the procedures for the EC-surveillance are laid down in such a way that it can be expected that they will not be applied in a consistent way. Also, due to the differences in the several language versions, national legislation can be divergent from Member State to Member State. To promote a uniform application of the provisions of the directive by manufacturers and Notified Bodies, the BEDAC has established the annexed set of interpretation documents. These interpretations reflect the provisions for the CE marking, as BEDAC thinks they are intended by the directive. BEDAC is aware of the fact that the directive is a binding document for national legislation and, formally, can not be changed by way of interpretations. However, a practical solution was thought to be necessary for achieving the ultimate aim of the directive, i.e. the free movements of the products concerned, when fulfilling the requirements for a rational use of energy. The interpretation documents are based on the English version of the directive. The guidance sheet is subdivided into 5 annexes. A Definition of a boiler (art. 2) B Efficiency requirements for boilers (art. 5) C Efficiency requirements for appliances (art. 7.3) D Application of the CE marking (art. 7.1) E Application of the modules for EC type-examination and EC surveillance (art. 7.2) 1

3 DEFINITION OF A BOILER Question ANNEX A The directive lays down the efficiency requirements for gas and oil fired boilers, with a rated output of kw, to be fulfilled for acceptance in the European market and the procedures for demonstrating the conformity to these requirements. Therefore, it has to be clearly defined what has to be understood to be a boiler. Discussion The definition of a boiler, given in article 2, is inadequate, since the definition itself refers also to the term boiler (a boiler is a boiler.). Moreover, the definition states that a boiler is a boiler, designed to transmit to water the heat released from the burner. A great number of products comply with this definition, e.g. an instantaneous water heater, a storage water heater and a cooker au bain Marie. Conclusion Starting from the assumption that the directive is intended to apply to so-called central heating appliances, the following definitions should apply: Boiler: Boiler-body: the combined body-burner unit, designed to transmit to water the heat released from burning, for the purpose of space heating. the part of a boiler that, together with a burner, constitutes a boiler. Remark In case of matching a boiler body and a burner, the burner is normally a forced draught burner. Future developments could be lead to the possibility that atmosferic burners can also be combined with boiler bodies. 2

4 EFFICIENCY REQUIREMENTS FOR BOILERS Question ANNEX B In article 5 the efficiency requirements are laid down for specific types of boilers, e.g.. a standard boiler, a low-temperature boiler and a gas condensing boiler. For each type of boiler this article specifies efficiency requirements, at full load as well at part load, for issuing the EC type-examination certificate. A boiler, according to the definition being a gas-fired condensing boiler, shall meet the requirements specified for this type of boiler ( logPn at full load and logPn at part load). Discussion If, for example, the measured efficiency of a condensing boiler at full load is just below the required level, the EC type-examination certificate can not be issued. According to the directive this boiler is not allowed to bear the CE marking on the basis of this directive and, therefore, the are excluded from free movement within the European market. A standard boiler, being less efficient, will be accepted. Example: Boiler (30 kw) Eff. Full load % Eff. Part load % Standard boiler 87,0 84,5 Accepted Gas condensing boiler 92,0 100 Refused Assuming that it is not intended that the acceptance on the market depends on the design of the boiler, the only requirements for the efficiency of a boiler, irrespective of its design, shall be those specified in the directive for the standard boiler. This results in: The useful efficiency requirements to be complied with are set out in the following table: Type of boiler Range of power output kw Efficiency at rated output Average boilerwater temperature (in C) Efficiency requirement expressed in % Efficiency at part load Average boilerwater temperature (in C) Efficiency requirement expressed in % Standard boilers 4 to logPn logPn Low-temperature 4 to logPn logPn Boilers (*) Gas condensing boilers 4 to logPn 30 (**) logPn (*)Including condensing boilers using liquid fuels. (**) Temperature of boiler water-supply 3

5 Conclusion All boilers shall meet the requirements for type standard boiler mentioned in the table of article 5 as being the condition for issueing the EC type examination certificate. However, manufacturers can denominate their boilers being a low-temperature boiler or a condensing boiler. The designation is on a voluntary basis. In that case however the boiler has to fulfil the relevant requirements as specified in the table of article 5. 4

6 ANNEX C EFFICIENCY REQUIREMENTS FOR BOILER BODIES AND BURNERS Question Article 7, paragraph 3, states that when separately marketed boiler bodies and burners are placed on the market, they must bear the CE marking and be accompanied by the EC declaration of conformity, which defines the parameters enabling them after assembly to achieve the useful efficiency levels laid down in Article 5 (1). Discussion Decisive for the efficiency of a boiler, assembled from a boiler-body and a burner, is the boiler-body. A boiler-body, together with an appropriate burner, can be tested to the requirements for a boiler. From the approved combination of boiler-body and burner, the parameters can be derived for choosing and adjusting other appropriate burners. A burner can not be tested to the efficiency requirements. Only the parameters can be specified for choosing the boiler-body and for a correct adjustment, as required for an optimal functioning in combination with this boiler. Conclusion Matching Question The following is the verbatim text of GADAC guidance sheet for matching. Article Iast indent is applied differently across EU. To avoid different interpretations it is necessarily to decide on a harmonised procedure. This procedure has to describe the possibilities in case of matching a certified boiler body and a certified forced draught burner. Discussion The notified bodies must be able to judge the technical instructions for matching a certified boiler body and a certified forced draught burner leading to a safe operation of the assembly. Related to the existing different ways of certifying the procedure of matching in the countries, a harmonised procedure with two options will solve the problem of divergence in a practical way. Conclusion (other equivalent solutions may be used). 1 General The burner shall be certified according to EN 676 (gas) or EN (oil). The boiler body shall be certified according to EN At least one assembly (a boiler body with a forced draught burner) has been tested according to EN (gas) or EN 304 (oil). 2 Options 5

7 2.1 List The manufacturers establish a list of recommended combinations in accordance with article (last indent) of annex I of GAD (concerning gas appliances). This list shall be based either on tests or on criteria set out in the annex to this guidance sheet. Under this option the installer may select the appropriate combination of boiler body and burner by reference to the list. 2.2 Technical instructions The manufacturer shall provide, in the technical instructions intended for the installer, the necessary information to permit the competent installer, responsible for the installation, including the commissioning of the burner and boiler body combination, to verify that when installed it does meet the essential requirements applicable. The procedure for supervision is part of the manufacturers installation code which is certified by a notified body. SEE ANNEX TO. 6

8 Annex to guidance sheet boiler/burner matching 1 Procedure The procedure mentioned hereafter will be part of the manufacturer's instruction for the installer. 1.1 Criteria for matching a boiler body/burner The criteria mentioned hereafter do not apply to assemblies designed as units and tested as such. Such an assembly will be marketed as a complete boiler (unit) The minimum dimensions of the combustion chamber shall not be smaller than the values specified in diagram ,5 1 a 0,8 0,6 0,4 b 0,2 Diagram 1: Nominal useful output P n in kw a = Minimum length b = Minimum sectional diameter in the combustion chamber Minimum dimensions of the combustion chamber whereby: - the dimension "a" is the distance from the deflector plate of the burner up to the opposite wall of the combustion chamber. For a combustion chamber designed for reverse flame and with a heat input greater than 300 kw, the length "a" can be reduced by 20%. For boilers with a heat input between 10 kw and 300 kw the reduction of "a" occurs proportionally to the heat input between 0% and 20%. - the dimension "b" is the diameter of the circular combustion chamber or the minimum sectional diameter in the case of a non circular combustion chamber. 7

9 1.1.2 The resistance of the combustion chamber corresponding to the nominal heat input shall be in accordance with the working diagram of the burner, as defined in EN 676 (gas) or EN 267 (oil) The operation mode of the burner (on/off, two stage or modulation) shall be in accordance with the instructions given by the boiler body manufacturer The minimum heat input of the burner shall not be set to a lower value than the minimum heat input, declared by the boiler body manufacturer. 1.2 Technical documentation The boiler body manufacturer shall specify in accordance with EN 303-1/EN for gas and EN 303-1/EN 303-2/EN 304 for oil, the following data: - nominal heat input; - the operation mode for which the boiler body has been designed (on-off, multistage, modulating). The minimum heat input, below which value the burner may not operate in case of boiler bodies intended to be fired by a multistage or modulating burner; - the flow resistance of the combustion chamber (l = 1,2) at nominal heat input; - the type of combustion chamber (direct evacuation or reversed combustion); - the length (a) of the combustion chamber, see figure 1; - the diameter or, in case of a non circular combustion chamber minimum, the sectional dimension; - the burner penetration and the geometry of the assembly flange, see figure 2; - relevant warnings (operation). Figure 1 x a a = depth of the combustion chamber with or without fire brick x = distance between burner flange and nozzle specified by the manufacturer 8

10 1.2.2 The burner manufacturer shall specify in accordance with EN 676 (gas) or EN 267 (oil) the following data: - maximum and minimum heat input; - the working diagram; - the dimensions of the burner head; - the burner penetration (y) and the geometry of the assembly flange, see figure 2; - the connection dimensions; - relevant warnings (operation). Y Figure 2 x a a = depth of the combustion chamber with or without fire brick x = distance between burner flange and nozzle given by the manufacturer Penetration of the burner in the combustion chamber 1.3 Test report The installer shall draw up a test report containing notifications and adjustments related to the boiler body and the burner specifications and the adjustments carried out The installer shall indicate: - the address and name where the assembly is installed; - the name and type of the certified boiler body to EN 303-1/303-3 for gas or EN 303-2/304 for oil; - the name and type of the certified burner to EN 676/303-3 (gas) or EN 267/304 (oil); - the maximum and minimum heat input declared by the manufacturer for the boiler body and for the burner; - the operation mode for which the boiler body has been designed (on-off, multistage, modulating); - the flow resistance of the combustion chamber declared by the boiler body manufacturer; - the type of combustion chamber (direct evacuation or reversed combustion); - the length of the combustion chamber as indicated in figure 1; - the diameter or minimum sectional dimension in case of a non circular combustion chamber; - the burner penetration into the combustion chamber as indicated in figure 2; The installer shall make the following adjustments: - the heat input, in accordance with the instructions of the manufacturer of the burner; - the minimum heat input in case of multistage or modulating burners; 9

11 - the ignition rate of the burner in accordance with the instructions of the manufacturer of the burner; - the combustion air and shall calculate the global efficiency (Siegert formula). After the adjustments the installer shall note: - the heat input; - the minimum heat input; - the ignition rate; - temperature of the combustion products as well as the C0 2 and CO values. These values shall not exceed those given by the manufacturer. - the ambient temperature. NOTE: Each burner manufacturer shall indicate in the instructions for the installer to send back a complete test report after matching boiler body/burner. The test reports which have been sent back to the burner manufacturer or his representative, shall be at the disposal of the notified body which is responsible for the surveillance. Burner A draught burner shall be tested on the completeness and suitability of the manufacturer s instructions. These instructions shall at least include: the working diagram of the burner, the parameters for the assembly with a boiler-body in such a way that the boiler will meet with the requirements for a boiler, as set out in article 5. This must include a statement that adjustments must be done in accordance with the boiler manufacturer s instructions. The manufacturer has the possibility to issue a not exhaustive list of boiler bodies to combine with; specified instructions for modulating burners. 10

12 APPLICATION OF THE CE MARKING Question ANNEX D In article 7, paragraph 1 it is stated that Member States shall deem that boilers which comply with the harmonised standards,, to be in conformity with the essential efficiency requirements stipulated in Article 5 (1). Such boilers must bear the CE marking referred to etc. Discussion It can be concluded that for boilers, not complying with the harmonised standards, but nevertheless meeting the requirements, the CE marking is not obligatory. Only in case of a declaration of conformity, according to module E, it is stated in Annex IV that a CE marking is to be affixed on the boiler. The other surveillance modules only refer to boiler bodies and burners. It is assumed to be intended that the CE marking is obligatory to all boilers. In article 7,paragraph 4 it is stated that When appliances marketed separately are placed on the market, they must bear the CE marking.etc. Conclusion In relation to article 8, paragraph 3, of the Gas Appliances Directive, the following provisions shall apply: After completion of the procedures laid down in Annex III, the CE marking of conformity shall be affixed to conforming boilers and appliances in accordance with Article 7, paragraph 4, and the provisions in Annex I. 11

13 ANNEX E APPLICATION OF THE MODULES FOR EC TYPE-EXAMINATION AND EC SURVEILLANCE Question Article 7, paragraph 2, states that the conformity of series-produced boilers shall be certified by: - examination of the efficiency of a boiler type in accordance with module B as described in Annex III, and - a declaration of conformity to the approved type in accordance with module C, D or E as described in Annex IV. For appliances no provision for the application of these procedures is laid down in the articles of the directive. Discussion In Annexes III and IV, the modules B, C and D refer to appliances only. Module E refers to boilers and appliances. As a result of these contradictions, it is not clear which procedures apply to which products. Conclusion Assuming that for boilers, as well as for appliances, an EC type-examination certificate has to be issued on basis of an EC type-examination, carried out by a Notified Body, and that for both, boilers and appliances, an EC-surveillance is required for applying the CE marking, the following provisions shall apply: Boilers and appliances shall be subject to an EC type-examination, carried out by a Notified Body, according to the procedures as they are laid down in Annex III, module B for boilers. Boilers and appliances shall be subject to an EC product(ion) surveillance, carried out by a Notified Body, according to the procedures as they are laid down in Annex IV, module C, D and E for boilers and/or appliances. Note To discuss again because of UK legislation and modules B, C and D cannot be applied for oil fired burners. 12