MIS 3005 version 3.0. A practical example of how to Design, Install, Commission and Handover a domestic single phase HP system

Transcription

1 MIS 3005 version 3.0 A practical example of how to Design, Install, Commission and Handover a domestic single phase HP system

2 MIS 3005 version 3.0 A practical example of how to Design, Install, Commission and Handover a domestic single phase HP system This is a practical example. It is a suggested method for meeting MIS It is not a guarantee of obtaining MCS certification or a Certification Body approved method for obtaining MIS However, it is an engineer's interpretation of the new edition of the HP standard and it also discusses how to cover issues such as new build and vertical boreholes which are not in the direct scope of the course.

3 Scope This course is for retrofitting of heat pumps to single phase domestic properties. Therefore, it covers: Up to 24 kw central heating (central heating is the provision both hot water and space heating) Existing homes i.e. retrofit applications Horizontal ground loop collectors connected to GSHP systems ASHP systems Sizing DHW cylinders in relation to HP power rating HP controls Using the HE Guide and communicating with the customer Design, installation, set-to-work, commissioning & maintenance

4 Scope It does not cover: Cooling New build properties... more during today on this... Vertical ground loop collectors. GSHPA can advise on... see Summary... more on vertical during this... Commercial and industrial applications It establishes a whole house method for quotations and a roomby-room methodology for heat pump sizing before the contract has been signed. Please note that a room-by-room method is required to properly match the heat pump to the heat emitters in the property and evaluate its final performance.

5 Agenda to Brief Summary points 1 to 6 mainly based on laptops using DHDG based Sizing Spreadsheet inc power, energy & cost It's your day; please ask questions. 1 to 1.30 Lunch to Brief Summary points 7 to 22 HE Guide, MIS 3005 Table 3, Reynold's number, Commissioning & Documentation Chariots hours of training

6 Round Robin of Intros Your Name and Company What you hope to gain from today? Any thoughts or questions about MIS 3005 v3.0 Any thoughts or questions about HP vs Gas/Oil Why you are here? Thoughts about life, the universe and everything Whilst also being brief! HP data used in the webinar is from Companies starting with D. And I'm David Matthews. This course is manufacturer agnostic. Please use any HP, cylinder, circulation pump or antifreeze data when you are going through the exercises.

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8 Air Collector Systems: Getting it wrong Noise Location (good air flow & connection) Defrost cycles Under-sizing Over-sizing Inaccurate heat loss calculation Poor heat distribution design or install Inadequate control strategy Commissioning, Handover & Maintenance

9 Ground Collector Getting Systems: it wrong Under-sizing Over-sizing Inaccurate heat loss calculation Poor heat distribution design or install Inadequate control strategy Commissioning, Handover & Maintenance Inadequate collector design Inadequate collector install

10 Some Ground Collector Faults: it s expensive to put right Not enough surface area/depth or proximity Overlapping pipework Poor materials (pipes, antifreeze etc) Poor hydraulic design (massive pumps) Poor backfilling or grouting Poor drilling/trenching practice No capping off Poor purging and filling Inadequate joints

11 Heat Loss Calculation (HLC) complies BS EN National Annex allows for CIBSE Domestic Heating Design Guide (DHDG) This spreadsheet uses DHDG and CIBSE Guide A ROOM / LOCATION Downstairs JOB 2 Bed End Terrace Design Room Temp 21 Degree Days 2033 Amount Air Design Power Energy Outside Design Temp -1.8 No of air air heated change Temp Heat Loss Heat Loss Design Temp Diff 22.8 changes per hour factor Difference VENTILATION HEAT LOSS per hour Length m Width m Height m m3/hour W/m3K C Watts kwh Downstairs Table 6.16 FABRIC HEAT LOSS Area m2 U-Value FLOOR Suspended Table 6.13 FLOOR EXT WALL (gross area) WINDOW GLAZING Single Glazing Table 6.8 WINDOW GLAZING DOOR Single Glazing Table 6.8 DOOR EXT WALL (net area) Subtract glazing & door from gross ext wall area Table 6.2 CEILING or ROOF (gross area) Table 6.15 CEILING or ROOF (gross area) Table 6.15 ROOF GLAZING ROOF GLAZING CEILING or ROOF (net area) Subtract roof glazing from gross roof area no insulation Table 6.7 INTERNAL WALL Table 6.5 INTERNAL WALL Table 6.5 PARTY WALL Table 6.5 OTHER DESIGN HEAT LOSS FOR ROOM (Sum of Watts for all elements) EXPOSED LOCATION Yes If YES, add 10% 0 % to DESIGN HEAT LOSS 0 HIGH CEILING No If YES, add % to DESIGN HEAT LOSS 0 INTERMITTENT HEAT Yes If YES, add 15% 15 % to DESIGN HEAT LOSS 363 TOTAL ROOM HEAT LOSS 2780

12 provide at least 100% of the calculated design space heating power requirement at the selected internal and external temperatures, the selection being made after taking into consideration the space heating flow temperature assumed in the heat emitter circuit and any variation in heat pump performance that may result. Please note:-100% includes defrost cycles and no immersion heater within space heating design zone

13 Theoretical max eff point

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15 Floor Heat Loss - local annual average external air temperature. Location Altitude (/m) Belfast Birmingham Cardiff Edinburgh Glasgow London Manchester Plymouth Hourly dry-bulb temperature ( C) equal to or exceeded for 99% of the hours in a year Use local annual av. air temp for solid floors In the absence of more localised info, data from the closest location decreased by 0.6 C for every 100m height above sea level - may be used, i.e. take account of local internal and external conditions

16 Internal and external temperatures recommended in CIBSE Guide A: Environmental Design Room Living room 21 Dining room 21 Bedsitting room 21 Bedroom 18 Hall and landing 18 Kitchen 18 Bathroom 22 Toilet 18 Internal design temperatures ( C) from the UK national annex to BS EN For whole house sizing, use 21 C living areas & 19 C bed & bathrooms And use these figures for roomby-room maths

17 Info on the HL Calculator Red indicates a cell you probably need to change Blue italic indicates a cell you probably don't need to change Nothing is locked, you are responsible for the results. Check, check and check again. Please note: Garbage in Garbage out It is based on the CIBSE DHDG model and also includes energy & cost calculation

18 Changes to HL Calculator House/Room dimensions to handout Check blue italic cells and results Insulate cavity walls, loft to 300 mm and solid floor with 100 mm (n.b. note ground temp). Double glaze. Localised temps. London. Please note: Garbage in Garbage out Assume 45 C flow temp for space heating And use 50 C as flow temp to HW cylinder on Totals page. HE temps discussed soon.

19 Changes to HL Calculator House/Room dimensions to handout Check blue italic cells and results Insert a row in the middle of Windows/Doors section of the spreadsheet & add another round window at top of stairs 0.5 m diameter. Please note: Garbage in Garbage out Assume 45 C flow temp for space heating And use 50 C as flow temp to HW cylinder on Totals page. HE temps discussed soon.

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21 Lunch Well Done!!

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25 Bivalent fossil-fuel & HP heat sources must be fully integrated into single CH control circuits. CH = Space & HW Don't use immersion on space heating above design temp Bi-valent fossil fuel is allowed if one CH control circuit For bivalent fossil-fuel & HP heating circuits, the percentage fossil-fuel and HP contribution must be clearly stated in the quote Adapt the spreadsheet to cover % from HP & other heating system For DHW design purposes, use BS 6700 and take into account the number and type of points of use There is a comment about HW cylinders needing larger HX with HPs Check with your Cylinder supplier for your HP flow rate & power Legionella and other bacteria management with HP and HW circuits e.g. pasteurised for 60 C for 60 minutes every 24 hours or 4 to 7 days as covered by a risk assessment & manufacturer's advice

26 Some Notes on Legionella Legionella and other bacteria is in all water. It is the concentration that is important. High concentrations are dangerous, especially for the young, old and those in poor health. Legionella is a form of pneumonia and often kills or leaves permanent effects. As a heating industry, we have a duty of care as bacteria grow in water, especially dirty water, between 20 and 50 C. The bacteria can be reduced (please note not eliminated) by many methods such as UV. sterilisation. We use thermal disinfection and heat the water to 60 C for one hour or 70 for 10 minutes. 32 minutes at 60 C kills 90% of the bacteria so an hour at 60 C will kill off almost 99% of the bacteria. Stagnate water which enables bacteria to grow can occur before, in or after the hot water cylinder. After the cylinder, keep pipe runs as short as possible, avoid all dead legs, however short, and be aware that hard water and plastic pipe is not as safe as copper pipe and soft water. This is because scale and plastic have more tendency to harbour the bacteria. Copper without scale is a natural biocide.

27 Some Notes on Legionella continued The water entering the property should be (it's your duty to check this) clean and be mildly chlorinated and so very low in bacteria. If this water is directly fed to an unvented cylinder, thermal store or instantaneous water heater (e.g. a combi boiler), it will remain clean. However, if it is fed up to a cold water tank, there is plenty of opportunity for bacteria to grow and enter the system. Therefore the cold water tank should be modern, insulated and have screens on the vents. If I find an old rusty galvanised and no lid cold water tank, I include a new tank as part of the customer quote and decline work if this is not changed. Thermal stores and combi boliers with their low water storage are the lowest risk. However, if left at the suitable for growth temperatures, there is enough Legionella bacteria in 100 mm of 15 mm dia copper pipe to kill someone and this has happened. It is your call as to the Legionella and bacteria pasteurisation cycle you choose. If risk is high (e.g. CW tanks), pasteurise frequently. If risk is low (e.g. mains water, frequent turnover and no dead legs), then you might, in consultation with your supplier, choose to have a 4 or 7 day cycle. However, if in doubt, pasteurise.

28 Domestic HW cylinder selection guide These recommendations are based on the guidelines in BS Guidance should be sought for unusual applications. e.g.: high flow-rate showers, large baths etc Minimum sizes recommended in BS 6700 For storage situations without rapid reheat, an allowance should be made of 45 litre per occupant. This can be reduced to 35 litre per person for 10 to 15+ kw heat pumps on suitably sized heat exchangers. The sizes below are for indirect cylinders with limited stratification and mixing being the heat method within the cylinder. No of Baths 3 kw HP 6 kw HP 8 kw HP 10 kw HP 15+ kw HP 1 Bathroom 122 litre 88 litre 73 litre 70 litre 70 litre 2 Bathrooms 260 litre 200 litre 131 litre 130 litre 130 litre Cylinder Sizing Example: a manufacturer produces a range of 90 to 300 litre indirect domestic cylinders in 30 litre between cylinder size capacities up to 210 and then 250 and 300 litre cylinders. The following would be their recommended cylinder sizes Hot Water Demand Bedrooms 3 to 6 kw 10 to 15+ kw 1 Standard Bath Bedsit / 1 Bed* or Shower 2 3 Bed Bed Standard Baths ** 3 4 Bed Please refer to & use the notes

29 Point 4 of Brief Summary Contractor shall communicate to the customer the running cost of the system under normal design conditions including: Estimated annual HP electricity cost Electricity cost of CH & GL pumps, especially any 24/7 pumps HL associated with storage vessels (Part L cyl & pipework insulation, England & Wales) or (Section 6 in Scotland) Electricity cost of any HW immersion heater usage You must work to the local, regional and National regulations and standards

30 Point 5 of Brief Summary Heat Emitter Guide Customer aware and see Room Heat Loss Emitter type and emitter temperature (worst room) Temperature Star Rating and possible improvement Flow temperature SPF

31 Outer Cover of HE Guide (rads)

32 Inside of HE Guide (Guidance Table & all emitter types)

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34 Point 6 of Site Brief Specific Summary Issues The heat pump system shall be installed such that all of the manufacturer's instructions are followed. Where the requirements of this standard exceed manufacturer, the requirements of this standard shall take precedence. For ASHP, include consideration of factors that may detrimentally affect the performance of the heat pump system such as recirculation of chilled air. Don't put an ASHP in a gulley or a wind-stream Where installations wish to apply for Permitted Development rights for ASHPs in England and Wales, MCS 020 Planning Standards must be complied with. 42 db at 1m from neighbour's window And please don t forget the disclaimer: 'The performance of Microgeneration heat pump systems is impossible to predict with certainty due to the variability of the climate and its subsequent effect on both heat supply and demand. This estimate is based upon the best available information but is given as guidance only and should not be considered as a guarantee.'

35 Designing ground heat exchangers is a complex engineering problem... the installer shall adopt Ground a conservative approach... Collector This course applies to domestic horizontal single phase 24 kw properties only 30kW or incorporate ground loop replenishment through cooling or otherwise, the installer should undertake the design process making use of specialist recognised design tools and/or seek advice from an expert. for list of consultants or talk to your manufacturer/supplier Software. validated for UK use... following parameters are used a) Site average ground temperatures (or annual average air temperatures). b) Site ground thermal conductivity values (in W/mK), including...water table depth c) Accurate assessment of yearly CH energy consumption (kwh) d) Accurate assessment-max ground power extracted (kw) (i.e. HP evap capacity) e) Accurate assessment-temp of the thermal transfer fluid entering the heat pump. The DHDG Heat Loss Calculation does not include internal heat gains, solar heat gains, thermal bridging, MVHR or powered fan ventilation effects, uses degree day rather than binned data and is a static rather than dynamic model. However, more advanced modelling doesn't always give better results.

36 Other (advanced?) HL Calculators Trade off between complexity and ease of use SAP 2009 assesses the annual energy performance of dwellings using a monthly model. PHPP (PassivHaus Planning Package) a tool specifically designed to model low energy demand buildings IES (Integrated Environmental Solutions); TAS (Environmental Design Solutions Limited) commercially available dynamic simulation tools Energy Plus an open-source dynamic simulation engine developed by the US Department of Energy SBEM (Simplified Building Energy Model) the tool which is used to assess the carbon compliance of new non-domestic buildings under the Building Regulations.

37 Other (advanced?) HL Calculators dynamic modelling may not give significantly better results than a simpler approach.

38 Other (advanced?) HL Calculators dynamic modelling may not give significantly better results than a simpler approach.

39 The temp of the thermal Ground transfer fluid entering Collector the heat pump shall be designed to be >0 C at all times for 20 years. If you use the look-up tables and calculation method on table 3, this will ensure that this happens Simplified design methods, (including look-up tables and nomograms)... validated for UK ground conditions and installation practices... VDI 4640 & other EU info is not designed for UK conditions. MIS 3005 supplementaries tables are designed for the UK. If proprietary software is not being used, systems 30kW without ground loop replenishment... shall use the following procedure to designing ground HX: Total yearly CH energy consumption (kwh) shall be estimated including internal heat gains, solar insolation heat gains local external air temperature Building heating pattern used (e.g. continuous, bi-modal, Economy10 etc.) Heat Loss Calculator needs to be chosen & used for the building in question

40 Table 3 Table 3 App B for Annual mean air temp BGS borehole & horizontal surveys GSHPA VBS for TRT App C for rock types

41 MIS 3005 Appendix B

42 MIS 3005 Appendix Appendix C C

43 British Geological Survey British Geology BGS Map & IGSHPA Guides

44 MIS 3005 Supplementary Vertical 1800 FLEQ table

45 MIS 3005 Supplementary Horizontal 1800 FLEQ table

46 MIS 3005 Supplementary Slinky 1800 FLEQ table

47 Table 3 Table 3 App B for Annual mean air temp BGS borehole & horizontal surveys GSHPA VBS for TRT App C for rock types

48 Table 3 Table 3 cont'd Rpt = 2 boreholes, 1 - horizontal & min pipe length to trench length slinky

49 Shall ensure... turbulent flow... Reynolds number. should be 2500 Iterative process to select hydraulic layout for pipes based on thermal transfer fluid viscosity and pipe roughness Geological situation on drilling or digging show substantial deviation... design ground HX... recalculated If geological conditions are different to design spec, redo the maths Hydraulic layout of the ground loop... pumping power... < 2.5%... HP capacity Iterative process to select hydraulic layout for pipes based on thermal transfer fluid viscosity and pipe roughness Pressure from Ground Collector pump > Pressure loss Ground Collector loop + Pressure loss Heat Pump evaporator + Pressure loss in Header

50 Reynold's number >2500

51 Purging Ground Commissioning HX Loops Closed-loop ground heat exchangers The following commissioning procedure shall... Ground arrays (including header pipes and manifolds)... flushed as one system to remove all debris and purged to remove all air... First of all, flush vertical, horizontal and slinky ground arrays in both directions... HP (and its pipework) shall be isolated from ground HX during this process... Then, flush and purge HP (and its pipework) as another system, in isolation from the ground array... Once the ground array is free from debris and visible air bubbles/pockets, purging should continue on the entire system... at least 15 minutes with a minimum flow velocity of 0.6m/s... see Table 4

52 MIS 3005 Table Table 4 4

53 Once purged... shall... Commissioning pressure test... entire ground source HX to BS EN 805 section Antifreeze... freeze protection down to -10 C Antifreeze quantity and type... appropriate for the system design... flow rate... viscosity... choice of ground array circulation pump. Quantity of biocide recommended by the antifreeze manufacturer/supplier... added 2 separate, random samples... refractometer tested... confirm -10 C... Evidence should be provided to the customer that this has been achieved. The Ground Source Heat Pump Association Closed-loop vertical borehole design, installation and materials standard (VBS). further commissioning guidance Water can be used to check calibration of refractometer

54 EN 805 Pressure Test c). Leak tightness test (pressure test) Leak tightness (pressure) testing has to follow the EN 805 prescriptions. For polyethylene (PE) tubes, the pressure testing has to be carried out as a 'compression test'. An overpressure (inside outside) is applied to the pipe over the whole length. This step inflates slightly the PE pipe over its whole length. Then a sudden pressure drop of around 10% of the testing pressure is applied (Fig. 5). This pressure drop allows the pipe to compress again. If the pipe is tight, a pressure increase is measured. To perform such a test, the following equipment is needed: * A high-pressure pump or a manually operated pump * 2 stop valves * 1 manometer 0-16 bar * A de-aeration device, if both circuits are tested at once This pressure test must be carried out immediately after having finished the grouting and when the grout material has still not hardened.

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56 Test pressure for PE100/PN16/SDR11 tubes is recommended as follows: * Pressure of Ground Heat Exchanger > 7.5 bar (it doesn't need to reach 12 bar). Test procedure in detail (Fig. 6): * 1 h Idle period. No overpressure is applied to the tube (1) * Apply the test pressure. For PE100/PN16/SDR11 Ground HX see pressures above. For other materials follow the manufacturer s specification (2) * 10 min Keep up pressure test (3) * 1 h Idle period. The tube is going to expand over the whole length * Pressure measurement. The pressure drop may not exceed the manufacturer s specifications (4) * Sudden pressure drop of at least 10% of the test pressure (5) * 10 mins. First pressure measurement (6)A * 20 mins. Second pressure measurement (6)B * 30 mins. Third and final pressure measurement (6)C

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58 The Ground HX has passed the test if the pressure difference (pressure drop) between (6)C and (6)A does not exceed 0.1 bars. The test should not be conducted in cold weather, when there is a risk of freezing. BHE = Borehole Heat Exchanger

59 Points 19 Documentation to 23 of Brief Summary A comprehensive documentation pack. including... Sizing Domestic hot water services Emitter design Ground heat exchanger design System performance

60 Documentation

61 A well designed, installed, commissioned and maintained Heat Pump system is: Cheaper than Gas*, Oil, Wood, Coal or Economy 7 Has no Carbon Monoxide or flueing issues Easily achieves a 10% or much more RE target Can heat and cool the building Compatible with Domestic Solar Hot Water * if CoP > 2.5 (electricity 12 p/kwh & gas 4 p/kwh)

62 Help is available Your Manufacturer or Supplier Engineering Consultants Your Certification Body wants you to gain accreditation MCS website will contain more advice e.g. Guidance on MCS 001

63 Thanks for Listening & Good Luck