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Local Exhaust Fans

Local Exhaust Fans. Local Exhaust Fans. Biological Contaminates Moisture Combustion gases - If not burned properly can intro. CO. Gas cooktops Gas ovens Furnace Gas Hot H20 heaters Woodstoves Leaky chimneys. Multi Point Ventilation. Heat Recovery Ventilator. HRV.

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Local Exhaust Fans

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  1. Local Exhaust Fans

  2. Local Exhaust Fans

  3. Biological Contaminates • Moisture • Combustion gases - If not burned properly can intro. CO. Gas cooktops Gas ovens Furnace Gas Hot H20 heaters Woodstoves Leaky chimneys

  4. Multi Point Ventilation

  5. Heat Recovery Ventilator

  6. HRV

  7. HRV

  8. Bath Ventilation

  9. Bathroom Exhaust Fans

  10. Bathroom Exhaust Fans CODE for Baths with bathing or spas facilities: • Minimum 80 CFM Intermittent Ventilation required orContinuous Ventilation System at 20 cfm CODE for Toilet Rooms without bathing or spas facilities: • 3SF Minimum Window ½ of which must be openable • Minimum 50 CFM Intermittent Ventilation

  11. Home Ventilation Institute Recommendations - Baths • Bathrooms to 80SF - 80CFM fan (Code) • Bathrooms 81sf to 100 sf – 1 cfm per square foot (~ 8 air changes/hour) • Bathrooms over 100 sf add the CFM for each fixture • Allow 50 CFM per standard toilets, shower and steam shower (put on timer) • Allow 100 CFM per Whirlpool, garden and hot tubs • HVI recommends continuous ventilations as augmentation to intermitent venilation

  12. Bathroom Exhaust Fans • A toilet in its own enclosure should have its own fan • Fans approved for wet areas should be placed over or very near the shower or tub when possible. • Bath doors should be undercut at least 3/4” • Leave fan on for 20 minutes after use of the bathroom

  13. Web Resource • HVACquick.com • Home Ventilation Institute

  14. Ventilation Considerations Fan Type • Propeller Fan – Limited air capacity and noisy • Axial Fan – Better air movement but still noisy • Centrifugal Blower (Squirrel Cage) The best

  15. Propeller Fan

  16. Axial Fan

  17. Centrifugal Blower

  18. Sound Levels • Sound is measured in Sones • 1-Sone equals the loudness of a pure tone having a frequency of 1,000 hertz at 40 decibels.

  19. Decibels • 0 -The softest sound a person can hear with normal hearing • 10 -Normal breathing • 20 Whispering at 5 feet • 30 Soft whisper • 50 Rainfall • 60 Normal conversation • 110 Shouting in ear • 120 Thunder • .9 Sones = approx. 28.2 decibels

  20. Sones • The Home Ventilation Institute sets a limit of 9.0 sones for kitchen fans up to 500 CFM • Reference – A fan with a sone rating of 8.0 sones is twice as loud as one rated at 4.0 sones. • Reference - Refrigerators run at about 1.0 sone.

  21. In-Line Ventilator Fan 110 CFM 1.0 Sones 210 CFM 2.0 Sones

  22. Broan Silent Series 110 cfm .7 Sones

  23. Switching Fans • Humidistat

  24. Kitchen Ventilation

  25. Kitchen Exhaust Fans CODE (ASHRAE) The American Society of Heating, Refrigerating and Air-Conditioning Engineers 100 CFM Intermittent Or 25 CFM Continuous

  26. Home Ventilation Institute Recommendations - Kitchens • Wall Mount Hoods – 100 cfm per foot of width • Island Mount Hoods – 150 cfm per foot of width

  27. Air Flow Rules of Thumb • Rule of Thumb 1:Take the hood area (in square feet) and multiply it by 75 to get the CFM (cubic feet per minute) for a wall hood, or multiply it by 100 for an island hood. Rule of Thumb 2:Allow 15 air changes per hour (ACH) for the kitchen. Take the kitchen volume (length x width x height) and divide by 4 to get the required CFM.

  28. Air Flow Rules of Thumb • Rule of Thumb 3:Allow 1 CFM per 100 BTU's per hour (BTUH) heat output.Take the output of the oven and cooktop (if together or close) and divide by 100 to get the required CFM. Rule of Thumb 4: (this applies to commercial type ranges)Allow 100 CFM per linear foot of hood.Take the perimeter of the hood and multiply it by 100 to get the required CFM. Which rule of thumb is the best one to use?The most popular rules of thumb are #1 and #3. We typically use rule of thumb #1 when we size fans.

  29. NKBA Recommendations

  30. Multi Point Ventilation

  31. Vented Hood System

  32. Recirculating Fan in Microwave Combo

  33. Kitchen Ventilation (HOGSS) • Heat • Odor • Grease • Steam • Smoke

  34. Recirculating Range Hood

  35. Recirculating Ventilation System • This type of system will only remove two • Heat • Steam

  36. Downdraft

  37. Down Draft Ventilation

  38. Down Draft Ventilation

  39. Range Hood Installation

  40. Integral Fan Vented Through Roof

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