Presented at the 2009 ProGreen EXPO in Denver, CO on 16 January 2009.

2. Energy Dollars Heat = 70-85%

5. Natural Gas Prices Continue to Rise

6. Other Fuel Sources Fuel Oil (used by interruptible customers) No. 1 Slightly heavier than kerosene No. 2 Small greenhouse heaters No. 4 Common for boilers No. 5 Boilers (cheap if available) No. 6 Requires pre-heating

7. Other Fuel Sources Coal -- (out of favor for greenhouses, why?) Anthracite Hard coal – greatest heat Semi-anthracite Bituminous Soft coal Sub-Bituminous Western coal Lignite Low grade coal

9. Other Fuel Sources Gas (Most common in greenhouses) Natural Storage tanks not required Burns clean Easier to maintain boiler Propane Butane Same advantages as natural gas However, must be stored on site More expensive

25. Solar Energy Solar Panels Hot air from gable Under bench heat

26. Storage of low grade heat from solar gain in under-bench TES (Thermal Energy Storage) system

27. Greenhouse earth solar thermal storage EAHE – Earth to Air Heat Exchanger SHCS – Soil Heating and Cooling System Air intake plenum Air return plenum PARAMETERS Air  T i-o Pipe Depth Pipe Material Pipe Diameter Air Flow rate Soil T Soil H 2 O & texture

28. Greenhouse earth solar thermal storage SHCS – Soil Heating and Cooling System “ Slinky” type Heat Exchange Coil trenched 5 ft deep UNDER greenhouse structure Essentially an electric heater which captures solar gain and adds “heat of compression” Higher COP (SEER rating) = less $ for electric heating Can be combined with other recovery systems; Boiler economizers, A/C condenser heat Fan/coil heat exchanger High Efficiency “variable scroll” compressor Ground Source Heat Pump

29. HOT WATER TANK High pressure refrigerant vapor condenses Circulation pump for slab Heating at night. Float valve blocks vapor from returning to low-pressure liquid supply tank Lift pump

30. The Hobbit House http://www.sunnyjohn.com:///index.html

31. Heat Storage Scott Skogerboe Greenhouse

32. Heat Storage Scott Skogerboe Greenhouse `

34. Phase Change Salts

35. Phase Change Salts

41. Polyethylene Film

42. Single Polyethylene over Glass

43. Inflated Polyethylene Tubes

45. Retractable Curtains 1-3/8” PUSH TUBE ALUM. ANGLE 7/8” ALUM. LEAD EDGE GALV. 2” SQ. TUBING INT. TRUSS MEMBER ALUM. ANGLE INTERMEDIATE ROLLER BRACKETS COVERING MATERIAL GALV. ANGLE IRON STATIONARY LINES

46. Automated Heat Curtain

47. Heat Curtains

48. Heat Transmission

49. Preliminary Results Cumulative run time or the amount of time that the heating device was in operation during a heating cycle in hours. The heating degree days in a season are derived by summing the difference between the average outdoor temperatures above a base (e.g., 65 °F) each 24 hours and the base temperature. Heating degree hours (equal to heating degree days x 24) are used in computing seasonal energy flows in a building due to both conduction and convection.

50. Preliminary Results Heating began with less than 25 HDH when curtains open

51. Preliminary Results Heating began with less than 285 HDH when curtains closed

52. Preliminary Results At 436 HDH and curtains open, 2.69 hours of heater time were required At 436 HDH and curtains closed, 0.295 hours of heater time were required