Heat Pump Field Trials and Implications for Design

Transcription

1 Heat Pump Field Trials and Implications for Design GSHPA 26 th June 2012 Chris Laughton Managing Director The Solar Design Company 1

2 Contents German Fraunhofer trials 2011 Comparison with UK Heat Pump trials EST: Phase One 2010 (re-analysed 2012) Are these two studies fairly compared? Actions taken in each country? Implications for design? 2

3 German subsidies Marktanreizprogramm (Market Incentive Programme) GSHP System Subsidy Under 10kW kW-20kW per kw above 10kW Additional solar thermal support

4 German regulations 4

5 Comparison of heat pump trials 5

6 Comparison of heat pump trials Ground Source Fraunhofer Mean = 3.88 EST Mean = 2.39 Individual heat pumps Sources: Fraunhofer (2011) EST (2012) 6

7 Comparison of heat pump trials Air Source Fraunhofer Mean = 2.88 EST Mean = 1.82 Individual heat pumps Sources: Fraunhofer (2011) EST (2012) 7

8 Fair comparison? Fraunhofer sample: [ ] mainly new energy efficient residential buildings Mean heating demand of 72 kwh/m²/a. 8

9 Fair comparison? EST Phase One sample: [ ] representative sample of air and ground source heat pump installations in a variety of property types, focussing primarily on retrofit installations 9

10 Heat emitter comparison Fraunhofer sample EST Phase One sample Source: Fraunhofer (2011) Source: EST (2012) 10

11 System measurement boundaries: Fraunhofer SPF also available including two more appliances 11

12 System measurement boundaries: EST 12

13 Comparison of heat pump trials Ground Source GeoT*SOL used for estimates EST Mean (Under floor systems only) = 2.58 Fraunhofer Mean = 3.88 EST Mean = 2.39 Sources: Fraunhofer (2011) EST (2012) Individual heat pumps Revised Fraunhofer Mean including thermal store loading pump = 3.75 Estimated Fraunhofer Mean including central heating circulation pump = 3.55 Estimated Fraunhofer Mean including tank losses =

14 Reports recommendations Fraunhofer EST phase one Modest design tweaks: Ground collector primary pump sizing Comments on use of buffer tanks Poorly performing combined thermal storage Fundamental issues: Heat pump under-sizing Ground collector undersizing 14

15 Key outcomes Fraunhofer software (GeoT*SOL) Simulation design software (Hourly) Hourly climate data files Iterative error reporting System temperature predictions Manufacturers 7 test points to EN for individual heat pumps EST Manual calculation MIS 3005 manual calculation (revised) Annual totals / Regional climate No feedback to incorrect calculations Not explicitly provided Utilises single COP figure from Heat Emitter guide 15

16 Modelling performance Water Output temperature Air Source Air Input Temperature 16

17 Software verification Borehole Heat Exchanger: 160m Second year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 17

18 Software verification Borehole Heat Exchanger: 70m Second year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 18

19 Implications for design: Ground collector sizing Software simulation tools mitigate: Under sizing Min 0 C thermal transfer fluid, extracting more heat than can be replenished. (MIS ) Over sizing (increased cost of installation) Manual calculation errors Manufacturer data entry errors 19

20 The Solar Design Company