MIS 3005 developments and the RHI

David Matthews, Chief ExecutiveGround Source Heat Pump Association

Cardiff, 27th Sept 2012

1st good system: Economy 10 Smart Grid-System eff 2.98

2nd good system: SPF 3.42-CoP coldest day 3.17-HW eff >2

3rd good system: Sys eff 3.04 inc flow temp 47 °C & HW

4th good system: ASHP sys eff 2.29 >=2.1 evap temp 0°C

5th good system: Next slide....

Fifth good performance systemProperty type Semi-detached bungalowLocation CornwallSAP rating 43 points (Band E)System Type 3.5 kW GSHP with boreholeHE flow temp 35 °C (3 radiators)HW flow temp 45 to 50 °CCoP +/- 3.4 ext temp +/- 0°CCoP +/- 2.6 HW for 4 hrs/nightSys eff 2.2 (large losses HW system)Notes Unlike many, doesn't cycle

1st poor system: Sys eff 1.79-CoP on GSHP 3.5-direct elec

2nd poor system: Sys eff 2.35-CoP on GSHP 3.33-direct elec

3rd poor system: Sys eff 2.45 G.C. flow -10 °C ret -7 °C-trip out

4th poor system: Sys eff 1.8-Ground temp diff start 3 K end 10 K

5th poor system: Undersized HW cylinder

6th poor system: high losses HW cylinder 7th poor system: high losses HW cylinder 8th poor system: rad flow temp too high

ASHP-no weather comp45 to 50 °C flow temp

Reset & in phase 29th poor system: underfloor flow too high

HP cycles rapidly & flow >50 °C by end of cycle

10th poor system: excess use circ. pumps

MIS 3005 version 2 to 3

Room-by-room heat loss calc to BS EN 12831

CIBSE Guide A internal & external temperatures

100% sizing (or fossil-fuel bivalent system)

Energy calculation (using degree day or bin data)

Hot water calculation to BS 6700 (or BS EN 806)

Single “interlocked” control system

Full running cost disclosure

Full explanation & use of Heat Emitter Guide

For ASHP, consideration of noise and location issues

MIS 3005 version 2 to 3

ADDRESS 1 House, A Street, Newtown JOB 2 Bed End TerraceCounty, SW1 1XX GEOG. London

Design Room Temp 21 Degree fk, Temp Amount Air Design Power Energy U-ValueLower Design Temp -1.8 Days Correction air heated change Temp Heat Loss Consumptio Taken fromDesign Temp Diff 22.8 2033 Factor per hour factor Difference & NotesVENT HEAT LOSS AC/hr Length mWidth m Height mp.u. m3/hour W/m3K °C Watts kWhKitchen Diner 1.5 4.9 2.7 2.4 47.63 0.34 22.8 369 790FABRIC HEAT LOSS Area m2 U-ValueFLOOR 4.9 2.7 0.3 13.23 0.24 22.8 22 46 Table 6.9 (100 mm) (7.6 m)EXT WALL (gross area) 7.6 2.4 18.24WINDOW GLAZING 1.1 1.05 1 1.16 1.6 22.8 42 90 Table 6.8 (triple, low-E, argon)WINDOW GLAZING 0 0 1 0.00 0 22.8 0 0 DOOR 2.1 1.75 1 3.68 1.6 22.8 134 287 Table 6.8 (triple, low-E, argon)EXT WALL (net area) Subtract glazing & door from gross ex 1 13.41 0.29 22.8 89 190 see U-values (15” filled cavity wall)CEILING or ROOF (gross area) 0 0 0.00ROOF GLAZING 0 0 1 0.00 0 22.8 0 0ROOF GLAZING 0 0 1 0.00 0 22.8 0 0CEILING or ROOF (net Subtract roof glazing from gross roof 0.9 0.00 0 22.8 0 0PARTY WALL 2.7 2.4 0.3 6.48 0.2 22.8 9 U-Value = Part L maxOTHER 0 2.4 0 0.00 0 22.8 0 0DESIGN HEAT LOSS FOR ROOM (Sum Watts-all elements frh, Reheat Subtotal room HL & energy 665 1403EXPOSED LOCATION Yes If YES, add 10% 0 % to DESIGN HEAT LOSS 0 0INTERMITTENT HEAT 4.9 2.7 6 13.23 79 Room W/m2TOTAL ROOM HEAT LOSS & ENERGY CONSUMPTION 744 1403 56

MIS 3005 version 2 to 3

Main Variables Table Results TablesHeat Pump Make & Model Good Pump 5 groundxl Power Required TableNo of Bedrooms 2 rooms Occupation level = No. bedrooms + 1 person Space Heat Loss 2.53 kW Flow temp in HW mode 50 °C from design choices Power required for HW heating 0.60 kW HP capacity in HW mode 4.75 kW from Manufacturer's data Total power from HP 3.13 kW Flow temp in Space Heat mode 45 °C from design choicesHP capacity in Space Heat mode 4.8 kW from Manufacturer's data Energy Consumption TableMarginal Electricity Cost 12 p/kWh electricity price without standing charge Space Heat Consumption 4412 kWhRunning mode for CH pump FLEQ (hrs) If not FLEQ, enter number of operational hours HW Consumption HP 2865 kWhPower CH Pump 105 W Default setting for speed 3 on 5m CH pump Total Energy Consumption HP 7277 kWhPower Ground HX pump 120 W 2.5% or lower of space heating power Mean Power Output HP 4.78 kW

HW Consumption Immersion 860 kWhHot Water Energy Calculation Total Energy Consumption 8137 kWhNo of occupants/bedroom 1 persons Increase this if house > 1 person/roomHot water / occupant 45 litres/day (35 or 40 if steps taken to reduce HW consumption) Information for Householder Quoteη pipework loss HP to cyl 70 % eff of HW system. Set to 85% if tank-in-tank estimated costs for central heating provisionFinal HP secondary HW temperature 45 °C equals flow temp in HW mode – 5 °C Cost Space Heating £143.08HP SPF (at HW flow temp) 3.4 Cost HW Heating from HP £101.13HP HW electrical energy/day 2.31 kWh/day Cost HW heating from immersion £103.16Immersion HW electrical energy/day 2.36 kWh/day Cost CH Pump £19.18Total HW electrical energy/day 4.66 kWh for HW/day Cost Ground HX pump £21.92

Total estimated CH running cost * £347.37Estimated Running Costs Calculations Electrical System Performance** 2895 kWhSPF space heating 3.7 * As pumping costs in HE Guide, only Space & HE costs inFLEQ space heating 919 hours ** Electrical system performance as defined Section 4.3 MISFLEQ HW heating 603 hoursFLEQ total 1522 hours Information for Householder Commissioning CertificateElectrical Energy HP space heating 1192 kWh Cyl & Pipework Part L *** Yes see belElectrical Energy HP HW heating 843 kWh Best practice for HW implemented**** Yes see belCost Space Heating £143.08 Bacteria pasteurisation implemented YesCost HW Heating from HP £101.13 Antifreeze to -10 °C YesCost HW heating from immersion £103.16 Biocide to Spec in Antifreeze YesCost CH Pump £19.18 Antifreeze checked 2 samples YesCost Ground HX pump £21.92 *** Cylinder and pipework must be insulated to

Domestic Building Services Compliance Guide.

MIS 3005 version 2 to 3

MIS 3005 version 2 to 3

MIS 3005 version 2 to 3

Constants and AssumptionsSHC Water 4187 J/kgKJ to kWh 3600000water mains input temp 10 °Ckg to litres water 135 Heating HW flow temp °C 4.3 SPF40 Heating HW flow temp °C 4.1 SPF45 Heating HW flow temp °C 3.7 SPF50 Heating HW flow temp °C 3.4 SPF55 Heating HW flow temp °C 3.1 SPF60 Heating HW flow temp °C 2.8 SPF65 Heating HW flow temp °C 2.5 SPF

MIS 3005 version 2 to 3

For GSHP, new look-up tables and: Fluid entry temperature of 0 °C for 20 yearsReynold’s number > 2500Collector pump power < 2.5% Heat pump powerResizing if variation in geological conditionsPurging to robust guidelinesPressure testing to BS EN 805 section 11.3.3.4Antifreeze solution to –10 °C with suitable biocide & tested twice with a refractometerFor all HP systems, a comprehensive document pack

What makes a good wet heating system? (combustion or HP)

Safe (no explosions, scalds, bacteria or CO deaths)Reliable (Build services 2nd most important element)Cheap-to-run (is efficient, doesn't use direct electric)Easy-to-control (time & temp in all rooms & HW)Well insulated (property, HW cylinder & pipework)Well ventilated, no drafts (adequate fresh clean air)Low or zero carbonAttractive or unobtrusive appearanceQuiet running (no noisy pumps or pipes)Well maintained (no rad cold spots, no leaks, etc)

What makes a heat pump system function well?

Correctly sizedundersized-lots of electricity, oversized-cyclingLowest possible flow temperatures (space & HW)large, low temp rads or well spaced underfloorHighest possible collection temperaturebig ground collectors & well placed air sourceGood control systemsweather compensation, simple-to-use time & temp control, appropriate TRVs, low energy circ pumpsSuitable HW systemlarger cylinder & HX or instantaneous points-of-use

Conclusion: a carefully designed HP system should feature:

Carefully sized HP: doesn’t require lots of direct electrical back-up (or is a bi-valent system with energy efficient fossil fuel back-up)Low temp heat emitters (not covered in heavy carpets or washing)Appropriately sized HW cylinder with a large HX coil (or instant)All cylinders & pipework insulated to Part L (esp. unheated spaces)Weather compensationAppropriately sized circulation pumps (preferably A or B rated)User-friendly time & temperature control of the heating systemCarefully commissioned, appropriately explained during handover & well maintainedFor ASHPs, consideration of noise & location requirementsFor GSHPs, a ground collector matched to heat emitter circuit

A good GSHP system is correctly: DesignedInstalledCommissionedMaintainedGood GSHP is cheaper to run & lower emissions than a Gas Condensing Boiler

Thanks for listening