1 / 20

XIV. MODIFYING LIGHT INTENSITY

XIV. MODIFYING LIGHT INTENSITY. A. Supplementary Artificial Light. 1. Light Intensity and Quality Quality 400-800 nanometers Intensity 100-300 mmols/sec/m 2 500-2000 ft. cds. Distance vs. Intensity decrease the greater the distance. 2. Types of Lamps a. Incandescent

heavynne
Download Presentation

XIV. MODIFYING LIGHT INTENSITY

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. XIV. MODIFYING LIGHT INTENSITY

  2. A. Supplementary Artificial Light 1.Light Intensity and Quality • Quality • 400-800 nanometers • Intensity • 100-300 mmols/sec/m2 • 500-2000 ft. cds. • Distance vs. Intensity • decrease the greater the distance

  3. 2. Types of Lamps a. Incandescent • primarily red light • point source • short life b. Fluorescent • deficient in red? • 2', 4', 8' lengths • greater uniformity • shadows

  4. c. Combination: -fluorescent lamps -incandescent lamps • complete spectrum • shadows • suitable for growth room

  5. d. High intensity discharge (HID) • Mercury vapor • not used today • Metal halide • good spectrum • lower eff. than HPS & LPS

  6. High Pressure Sodium • high light intensity • 400-1000 watt • eff. conversion of energy • Low Pressure Sodium • narrow band of light • efficient conversion

  7. New Lights for Greenhouses Sulfur and microwave Diode

  8. 3. Commercial Application a. Crops • Roses, chrysanthemums, seedlings, lettuce, tomatoes b. Benefits • timing • quality • less prod. time; lower cost • less fuel costs • increasing branching • increased keeping quality • roses; fewer blind shoots

  9. 3. Commercial Application (contu.) c. Where used • northern latitudes • growth rooms d. Installation/operating costs • fixture + ballast $150+ • fixture + installation $2.25/sq. ft. • operation: $1.50/sq.ft./yr • depreciation • interest on money borrowed

  10. 3. Commercial Application (contu.) e. Management • Greenhouse • HPS • 400watt; spaced 10’ x 10’: 10 ft above plant • 30-60 umols/sec/m2; 280-460 ft.cd. • Oct to Apr • night & cloudy days

  11. High pressure sodium light arrangement

  12. Growth room

  13. Growth room • 20 sq. ft. • 2 ft. above plants • 106 umols/sec/m2: 750 ft.cd. • 7 tubes: @ 40 watts • 200 umols/sec/m2: 1400 ft.cd. • 13 tubes: @ 40 watts

  14. 3. Commercial Application (contu.) f. Accumulated light • 200 umol/sec/m2 for 18 hrs. • equals 23 mol/day/m2 • Summer - natural light • 48 mol/day/m2 • Winter - natural light • 19 mol/day/m2

  15. A. Reducing light intensity - Why - External • shading compounds • Latex paint: 1 part to 8-10 parts H2O • Saran cloth • Internal permanent • Saran cloth • Aluminum strips • Internal movable

  16. B. Increasing light intensity • Clean covering • White or reflective surface • Reduce shade producing items

More Related