1. The Water Boiling Test (WBT) with ISO/IWA Metrics and ARC Equipment July 30, 2012 Stove Camp Updated by Abraham Mooney

2. The Water Boiling Test (WBT)  Standardized, reproducible lab test  Boil and simmer water  Measure the boil time, fuel use, efficiency, emissions  Trained tester carefully tends the fire (COV)  High and low power test phases  Cold stove and hot stove test phases  Allows for multiple pots on one stove

3. Stove Testing Continuum WBT CCT KPT Increasing cost Increasing sample size and variability Increasing measurement of in-home use Increasing relation to WHO air quality guidelines Increasing control of variables Increasing isolation of stove performance Increasing quantification of emissions Increasing intervention of testers Lab Field

4. Purpose of WBT Effective design tool to evaluate Effective design tool to evaluate design changes of a stove Stove Improvement through comparison Stove Improvement through comparison (High Accuracy equip.) (High Accuracy equip.)

5. Advantages of the WBT  Reproducible, standardized  Stoves from around the world can be compared  Stove design changes observed clearly and quickly   Benchmark evaluation and comparison

6. Disadvantages of the WBT  Not always reproducible Fuel irregularities, and “to error is human.”  Not representative of field use Only one simulated cooking task  Hard to do for some stoves Batch-loading stoves: TLUD’s, charcoal

7. WBT Procedure Phase COLD START HOT START SIMMER Task Bring to Boil 5L in first pot Bring to Boil fresh 5L in first pot Simmer remaining 5L for 45 minutes RecordTimeFuel Water Charcoal TimeFuelWater *Assume Same Charcoal as Cold Start* TimeFuelWaterCharcoal

8. WBT Procedure Time Water Temperature T boil T room T boil -6degC Fresh Water COLD START HOT START  45 min. SIMMER 

9. WBT – Preparing for the Test First do a practice test to: Get familiar with the stove Determine if the stove should be tested with 2.5 or 5 liters How much fuel is required? Boiling temperature of water (local)?

10. WBT – Preparing for the Test 1.Scale - 6000g range, 1g resolution 2.Temperature sensor – waterproof 3.Fixture for suspending temperature sensor 4.Wood moisture meter or oven for fuel MC Gather Supplies

11. WBT – Preparing for the Test 5.Timer or watch 6.Pot – standard or dedicated, no lid 7.Heat resistant pad for scale 8.Charcoal scooper/tongs 9.Char tray 10.Heat resistant gloves 11.Water – room temp, - at least 10 liters 12.Fuel – air dried, uniform - 2 bundles ~ 2kg each Gather Supplies

12. WBT – Conducting the Test Phase 1: High Power Cold Start Set the pots on the stove with 5000g of water with the temp sensor suspended in the water of Pot 1. Record: -Starting weight of pots with water -Starting water temperatures -Initial mass of the bundle of fuel Light the fire - record start time Tend fire and bring water to a boil

13. WBT – Conducting the Test Phase 1: High Power Cold Start When Pot 1 boils record:  time  temperature of all pots  pot plus water weights  fuel remaining break char off tips of burned sticks Put char on tray and record weight of char plus tray

14. WBT – Conducting the Test Phase 2: High Power Hot Start Refill the pots with cool water and repeat the boil procedure starting with a hot stove Use a new bundle of wood This time, when Pot 1 boils keep the char in the combustion chamber. DO NOT WEIGH THE CHAR Weigh the pots and place them back on the stove Weigh the wood, place it back in the combustion chamber, then re-light it.

15. WBT – Conducting the Test Phase 3: Low Power Simmer Record the start time once the fire is lit Transfer over the fuel weight, pot and water weights, and water temp from the results column at the end of the hot start Tend the fire to keep the water temp of the pot at 3- 6 degrees C below boiling for 45 min After 45 min of simmer record:  Final water temperature  Weight of Pot 1 plus water  Final weight of fuel and char remaining

16. Three test phases, real-time measurement (CO 2, CO, PM) WBT Results

17. THE NEW DEAL

18. WBT Results Thermal Efficiency (%) High efficiency ≠ low fuel consumption because high power stoves evaporate lots of water and also use lots of fuel *IWA Metric

19. WBT Results Low Power Specific Consumption (MJ/min/L) *IWA Metric

20. WBT Results High Power CO (g/MJ d ) *IWA Metrics Low Power CO (g/min/L)

21. WBT Results High Power PM (mg/MJ d ) Low Power PM (mg/min/L) *IWA Metrics

22. WBT Results *IWA Metrics Indoor Emissions CO (g/min) Indoor Emissions PM (mg/min)

23. WBT Results Temperature Corrected Specific Fuel Consumption (g/L) = dry wood mass – -- equivalent mass of wood stored as char wood mass that was consumed to evaporate the moisture in the wood Eq. dry wood consumed Best indicator of fuel consumption

24. WBT Results Average Firepower (W) How big is your stove

25. WBT Results Turndown Ratio

26. WBT Sample Size

27. Aprovecho Emissions Equipment PEMS & LEMS Portable (or Lab) Emissions Measuring System IAP Meter Indoor Air Pollution Meter

28. PEMS Collection hood collects stove emissions Collection hood collects stove emissions Sensor box measures: Sensor box measures: 1. CO 2. CO2 3. 3. PM (laser) 4. Flow rate in duct 5. Temp in duct 6. Pot temp Uses: Uses: 1. Measure stove emissions (WBT, CCT) 2. Stove design tool

29. PM Sensor: Scattering Photometer PEMS

30. CO Sensor: Electrochemical Cell  Diagram Courtesy Monox PEMS

31. CO2 Sensor: NDIR PEMS

32. PEMS Data Processing Software Outputs include: Outputs include: Graph of emissions vs. time Graph of emissions vs. time Standard performance measures Standard performance measures Specific fuel consumption (grams/liter) Specific fuel consumption (grams/liter) Total emissions (grams) Total emissions (grams) Specific Emissions (grams/liter) Specific Emissions (grams/liter) Emissions Factors (grams/kg fuel) Emissions Factors (grams/kg fuel) Efficiency and Firepower Efficiency and Firepower PEMS

33. LEMS and Gravimetric

34. Why use gravimetric?  Photometer: Estimates the REAL TIME mass concentration of particulate matter from optical measurements  Gravimetric: Measures total mass concentration of particulate matter, at end of test (scale c10^-5 g). LEMS With gravimetric we move to… Categorization studies (e.g. Tier 4)

35. Laser vs. gravimetric  Photometer  Output = scattering coefficient (1/m)  Physical meaning: fraction of light scattered away for every meter a light beam travels PEMS Mass concentration estimated by:

36. Indoor Air Pollution Meter Measures concentrations of: Measures concentrations of: CO (Carbon Monoxide) CO (Carbon Monoxide) PM (Particulate Matter) PM (Particulate Matter) Uses: Uses: Measure room concentration Measure room concentration Measure personal exposure Measure personal exposure wear meter in backpack with sample tube wear meter in backpack with sample tube CCT, KPT, other comparative tests CCT, KPT, other comparative tests Stores data on SD Memory Card Stores data on SD Memory Card

37. Why use gravimetric?  Gravimetric  Particles are collected on a filter and weighed.  PEMS

38. PM Sensor: Scattering Photometer (same as PEMS) Indoor Air Pollution Meter

39. CO Sensor: Electrochemical Cell (Also used in PEMS)  Diagram Courtesy Monox Indoor Air Pollution Meter

40. Features Sample speed selection Sample speed selection Fast:Every 10 seconds Battery life: 3 days Medium: Every 1 minute Battery life: 2 weeks Slow: Every 10 minutes : Battery life: 1 month LED indicates meter is on LED indicates meter is on Serial port for live graphing Serial port for live graphing Indoor Air Pollution Meter

41. Data Processing Software Outputs include: Outputs include: Graph of emissions vs time Graph of emissions vs time Average concentrations Average concentrations Maximum and minimum concentrations Maximum and minimum concentrations 15 minute average concentrations 15 minute average concentrations IAP Meter

42. Summary PEMS Measures emissions: CO, PM, and CO2 Measures emissions: CO, PM, and CO2 Stove total emissions Stove total emissions Measures pot temp for WBT Measures pot temp for WBT Cost: $10,000 USD Cost: $10,000 USD IAP Meter Measures emissions: CO and PM Measures emissions: CO and PM Room concentrations and personal exposure Room concentrations and personal exposure Cost: $2,400 USD Cost: $2,400 USD

43. More Information www.aprovecho.org Spec sheets Spec sheets Brochures Brochures Manuals Manuals Data processing spreadsheets Data processing spreadsheets

44. Documentation  www.aprovecho.org/lab/pubs/testing www.aprovecho.org/lab/pubs/testing Download testing protocols