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BOA HVAC
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BOA HVAC

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  1. BOA HVAC

  2. Outline • Thermostats • Efficient use of ventilation fans • System overrides • Building automation systems • Indoor air quality • Energy savings tips • Maintenance issues

  3. Piner Olivet Lifestyle Program • Lifestyle Campaigns • students and teachers • custodian support • Examples • Computers off • Lights off • Waste less

  4. Piner Olivet Technical Program • Student technical audits • Building Operator Training • Technical audits • Energy monitoring and savings reports • Building retrofits

  5. Importance of custodian • Focus of Piner Olivet program in schools • Interface between district, teachers and students • Source of technical information • Provides continuity • Knows schools better than anyone • Can produce large savings • Key to Piner Olivet program success

  6. Piner Olivet district update • Lifestyle Program news • Recent events • Upcoming events • Technical Program news

  7. Piner Olivet in your school • Success stories • Areas to improve

  8. Benefits of energy efficient HVAC • Reduces energy use and cost • Improved quality and comfort • Less maintenance required • Longer equipment life • Scheduling and complex control strategies easily programmed • Positive impact on climate change issues

  9. Expectations of comfort • Wide range of operating conditions • Realistic expectations • Comfort conditions not always perfect • Impossible to satisfy everyone

  10. Thermostats • Pneumatic, electric, or electronic • Control furnaces, radiation heating valves, heat pumps or unit ventilators • Often damaged or vandalized

  11. H V A C Thermostats A thermostat and its workings

  12. Thermostats • Avoid covering thermostat • May not sense actual room temperature • Room becomes too cold or too hot • Do not constantly change setpoint • Calibrate and service regularly

  13. Thermostat mythology • A high temperature setting means quicker warm-up • Furnace works harder after temperature setback • Inadequate heating or cooling is due to a faulty thermostat

  14. HVAC in portables • Thermostat controls ventilation fan plus heating and cooling • Vacant periods in warm weather: • Furnace fan set to “off” position • Cooling setpoint as high as possible • Heating setpoint at 15°C • Vacant periods in cold weather: • Furnace fan set to “auto” position • Cooling setpoint as high as possible • Heating setpoint at 15°C

  15. HVAC in portables • Are programmable thermostat setbacks working? • Advise maintenance staff if need adjustment • Cooling setpoint of 21°C or lower can damage equipment

  16. HVAC in portables • Thermostat “Auto/On” ventilation fan setting • Auto: fan cycles on call • use during vacant periods • On: fan operates continuously • use during occupied periods for improved indoor air quality • No outside air ventilation if fan is off

  17. Efficient use of ventilation fans • 30% of total energy use • Electricity for large motors • Energy to heat or cool outside air • Shut off ventilation fans during vacant periods • Operate fans only when needed • One of the most important energy savings strategies

  18. H V A C Air handling system

  19. H V A C Return air fan

  20. H V A C Return air fan Axial return air fan with variable inlet vanes

  21. H V A C Supply air

  22. H V A C Centrifugal supply fan

  23. Cooling and night purging • Don't run fans all night • Two hours before occupied periods to cool down the facility (night purge) • Outside air coolest between 4 a.m. and 7 a.m.

  24. HOA switches • Hand-Off-Auto switch • Controls fans, pumps, etc. • “Hand”: manual bypass of BAS or time clock • Used as override • Equipment will operate continuously

  25. HOA switches • “Off”: equipment off completely • For repairs, safety, etc. • Do not switch to “On”or “Auto” unless verified safe • “Auto”: links equipment to time clocks and BAS schedules • Should be usual position

  26. H V A C HOA switch

  27. System overrides • Activating HVAC system after hours • Short-term intermittent use • 2 or 3 hour limit is best • Spring-wound timers often used for fans

  28. H V A C System override Spring-wound timers

  29. H V A C System override Air system override

  30. System overrides • Day/night thermostats may have push button overrides • Dedicated override switch preferred to HOA switches • Ask to have one installed if needed

  31. Time clocks • Automatically switch HVAC equipment • Check and reset for: • Changing schedules • Clock going out-of-time • Daylight savings time • Correct schedule for the application?

  32. H V A C Electronic time clock

  33. Building Automation System (BAS) • Centralized computer control operates HVAC, alarms and lighting • Makes automatic decisions • Computer used to access system • Available in a variety of configurations

  34. Building Automation System (BAS) • Also called: • Energy Management System (EMS) • Direct Digital Control (DPiner Olivet) • Replaces old system of mechanical time clocks and pneumatic controls

  35. H V A C Pneumatic control panel

  36. H V A C Pneumatic controls

  37. H V A C Building Automation System

  38. H V A C How a BAS is networked

  39. H V A C BAS for an air handling unit

  40. Advantages of BAS • Optimum start/stop • Temperature reset • Economizer control • Night purge

  41. Advantages of BAS • Intelligent control • Trend logging • Flexibility • Reliability • Global and networked control

  42. Indoor Air Quality (IAQ) • Acceptable levels of: • Carbon dioxide • Carbon monoxide • Temperature and humidity • Respirable particulates • Fungi and bacteria • Miscellaneous

  43. Indoor Air Quality (IAQ) • IAQ is a complex issue • Can be blamed for unrelated health problems • Increasing attention paid to IAQ • Regulations and standards being developed

  44. Indoor Air Quality (IAQ) • Custodians can note potential IAQ problems • Simple IAQ improvements: • Comfortable temperatures • 19 to 24.5°C in winter • 22 to 26.5°C in summer • Optimum humidity • 40 to 60% • Avoid sources of contamination

  45. Some ways IAQ is affected • Inadequate fresh air • Inadequate local exhaust • Contamination of outdoor air intakes • Low efficiency or dirty filters • Mould and bacteria growth

  46. Some ways IAQ is affected • Polluting sources: • Cleaning solutions and chemicals • Off-gassing from synthetic carpets and furniture • Dry sewer traps emitting sewer gas • Trash stored indoors • Tobacco smoke

  47. H V A C How IAQ is affected Filters in poor condition

  48. Miscellaneous energy savings tips • Vestibule heaters - reduce temperature • Use vestibule doors effectively • Note if temperature setback is working • Effective use of blinds and curtains • Use ceiling destratification fans • Shut off exhaust fans if not required

  49. H V A C Energy-saving tips Do not overheat vestibules with heaters

  50. H V A C Energy-saving tips Keep inside entrance doors closed