Low Pressure Hot Water Heating for Non-domestic Buildings

Transcription

1 Unit 42: Low Pressure Hot Water Heating for Non-domestic Buildings Unit code: F/601/1335 QCF level: 4 Credit value: 15 Aim This unit provides learners with an opportunity to develop the skills to analyse the need for, and design and specification of, low pressure hot water (LPHW) heating installations for non-domestic buildings. Unit abstract Effective, energy efficient and controllable heating installations, sympathetic to the form and function of the building, are expected in today s energy conscious world. Learners will explore the legislation, standards and design guides associated with heating installations and apply these in producing design solutions for industrial, public and commercial buildings. Learners will have the opportunity to establish heating strategies, design briefs and perform calculations required to determine the heating loads for these buildings. Learners will produce design drawings and perform calculations necessary to size, select and specify the pipework, plant and equipment associated with these heating installations. This unit focuses on the application of the principles, standards and legislation associated with the design, control, testing and commissioning of the boiler plant or other heat sources for LPHW heating. Learning outcomes On successful completion of this unit a learner will: 1 Be able to analyse the need for heating installations and develop design briefs 2 Be able to determine space heating loads and energy requirements for heating systems 3 Be able to apply legislation and standards to the design of heating systems for non-domestic buildings 4 Be able to apply principles, standards and legislation to the selection, specification and commissioning of primary heat sources. 211

2 Unit content 1 Be able to analyse the need for heating installations and develop design briefs Client and building heating requirements: establish the scope of a design brief (client and building operational requirements), provision of heating for non-domestic buildings eg balance between client needs, legislative requirements, commercial constraints, building form, structure, configuration and spatial arrangement, range and scope of other mechanical and electrical building services, health, safety and welfare considerations, aesthetic and energy strategies and efficiency considerations Design briefs: constraints and publications (that influence the design of heating installations in industrial and commercial buildings) eg statutory requirements, standards, guides and other relevant publications; production of heating installation design briefs 2 Be able to determine space heating loads and energy requirements for heating systems Thermal comfort: factors affecting thermal comfort; thermal indices; thermal comfort design parameters; other factors affecting thermal comfort eg temperature variations within a space, air and radiant temperature differences, effect of local radiation on comfort, local discomfort and asymmetry; use of predicted mean vote and predicted dissatisfaction Steady state heat transfer in buildings: selection of design data; steady state energy transfer networks; calculation of steady state heat losses to maintain operative comfort (using various types of emitter and the resulting space temperatures) Non-steady state heat transfer in buildings: transient heat transfer factors and equations; calculation of response and heating plant correction factors (for systems with intermittent operation); admittance values; heating loads for systems (with highly intermittent operation) Total heating loads and heating plant capacity: heating plant capacity for buildings; assessment of total heat losses and heating plant output; comparisons with heating benchmarks, energy efficiency targets and standards; minimising heat loads; computer software to determine heating loads for rooms, zones and building 212

3 3 Be able to apply legislation and standards to the design of heating systems for non-domestic buildings Heat emitters: direct and indirect fired radiant, convection and mixed output heat emitters (selection criteria and performance); configuration, operating temperatures and emission rates for underfloor heating and heated ceilings; natural and forced convection emitters, controls of heat emitters Design of heating systems: layout; control arrangements for heating installations; design of plant rooms (for heat generation plant); space requirements for installation, maintenance and commissioning; controls for heat generation plant; boiler configuration (to achieve total heating load); integration of heating requirements (with ventilation, air conditioning and other services installations); accommodation and control of expansion (water and pipework); support and suspension systems (for plant and pipework); sizing, specification and selection of plant, equipment and distribution network; effect of distribution network on total installed load; use of manufacturer s data, sizing and selection software; design implications (space, maintenance and commissioning requirements, capital and operating costs) Commissioning and testing requirements for heating installations: current standards and procedures (for the commissioning of water circulation heating systems); instruments and procedures (for the measurement of flow, temperature and pressure); commissioning schedules and documentation 4 Be able to apply principles, standards and legislation to the selection, specification and commissioning of primary heat sources Principles, standards and legislation associated with: fuels; chemistry of combustion; firing equipment; boilers and primary heat sources; boilerroom ventilation, draught and flue requirements Fuels: properties; characteristics, performance; environmental implications of commercially available solid (including biomass), liquid and gaseous fuels; health, safety and welfare implications; legislation and standards Chemistry of combustion: principles of combustion; stoichiometric air fuel ratios; flue gas analysis arising from stoichiometric combustion; need for and effect of excess air, instrumentation for flue gas analysis; determining air fuel ratios and combustion efficiency (flue gas analysis); combustion standards Firing equipment: operational characteristics and features (of burners found in non-domestic boilers and hot water generation plant); control and safety monitoring systems (for burners); air/fuel adjustment and burner commissioning requirements Boilers and primary heat sources: commercial LPHW boiler and air and ground source heat pumps (construction, operation characteristics and features); control arrangements (for single and multiple boiler/heat pump installations); fuel consumption and operational efficiency; testing and commissioning Boilerroom ventilation, draught and flue requirements: legislation and standards (flues/chimneys and boiler plant ventilation); natural and mechanical draught in boiler plant (principles and applications); single and multiple boiler installations (principles, construction, materials and applications of flue systems); condensate in flues; design and installation of flue systems (for single and multiple boiler installations using various fuels) 213

4 Learning outcomes and assessment criteria Learning outcomes On successful completion of this unit a learner will: LO1 Be able to analyse the need for heating installations and develop design briefs Assessment criteria for pass The learner can: 1.1 analyse client and building heating requirements 1.2 evaluate alternative strategies for providing space heating 1.3 discuss legislative requirements, design standards and publications that influence the design of heating installations 1.4 produce design briefs for heating installations LO2 Be able to determine space heating loads and energy requirements for heating systems 2.1 evaluate the factors that contribute to human thermal comfort and the use of comfort indices 2.2 justify heating installation design parameters and standards 2.3 perform calculations to determine heating loads for buildings requiring steady state, intermittent and highly intermittent heating 2.4 follow guidelines to achieve a reduction in heating loads LO3 Be able to apply legislation and standards to the design of heating systems for non-domestic buildings 3.1 justify strategies for the selection of heat emitters 3.2 design heating and installations including their control strategies and plant room arrangements 3.3 perform the calculations necessary to size, select and specify pipework, plant and equipment for heating installations and primary heat sources 3.4 follow guidelines to develop commissioning schedules for heating installations 214

5 Learning outcomes On successful completion of this unit a learner will: LO4 Be able to apply principles, standards and legislation to the selection, specification and commissioning of primary heat sources Assessment criteria for pass The learner can: 4.1 describe physical, supply and combustion properties of common fuels 4.2 perform calculations to determine air fuel ratios and resulting flue gas compositions for stoichiometric combustion 4.3 perform calculations to determine operating efficiencies for boilers 4.4 discuss the construction, operation, and features of commonly used LPHW primary heat sources 4.5 illustrate boiler installation and control arrangements for single and multiple boiler/heat pump installations 4.6 produce combustion air and flue/chimney design solutions for single and multiple commercial boilers 215

6 Guidance Links This unit links with other Edexcel BTEC HN Construction and the Built Environment units, for example: Unit 2: Science and Materials for Construction and the Built Environment Unit 10: Building Services Design, Installation and Maintenance in Construction Unit 40: Thermofluids and Acoustic Criteria for Building Services Engineering Unit 44: Air Conditioning for Complex Industrial and Commercial Buildings Unit 46: Piped Distribution Services for Non-domestic Buildings Unit 58: Application of Scientific Principles to Building Services Engineering. The content of this unit has been designed and mapped against the current CIC National Occupational Standards and the current NVQs at levels 4 and 5. Completion of the learning outcomes will contribute knowledge, understanding and skills towards the evidence requirements of the NVQs. See Annexe B for summary of mapping information to NVQs. This unit has also been mapped to illustrate the links to the NQF units. See Annexe D for summary of mapping information to NQF units. Essential requirements It is essential that a culture of health and safety is embedded in all the units to ensure that the learners understand the importance and relevance of health and safety issues. Therefore there should be clearly signposted aspects of current legislation and health, safety and welfare implications throughout the delivery and assessment of this unit. Employer engagement and vocational contexts Tutors should organise site visits, for example to boiler, heat pump and burner manufacturers. To ensure site visits are successful tutors should outline the aims and objectives of the visits, conduct preparatory briefings and encourage learners to review the site visits once completed. Tutors should organise presentations by visiting speakers, for example commissioning engineers on the principles, practices and standards for the commissioning of heating installations and commissioning/testing of boilers and firing equipment. Tutors should use real-life case studies, based on site visits, for part of the assessment for this unit. 216