Ventilation Options Brett Dillon CEO, The Dillon Group, Inc 2015 Midwest Regional Energy Conference
About Me• Trainer
• Quality Assurance Designee
• RESNET Board Executive Committee Member
• RESNET Standards Management Board Member
• Chair RESNET/ANSI Standards Development Committee 300
• Former
• rater
• home builder
Why do we need to ventilate homes? When do we need to ventilate homes?
How should we ventilate homes?
What ventilation standard should we use?
Where are these tactics appropriate?
Which software tools are better?
Conditional
• What is the occupancy rate?
• What is the climate like?
• What kinds of pollutants are in the home?
How do we do it?• intermittent source control
• whole house
• supply only
• exhaust only
• balanced (?)
Controls?• No controls
• Timer controls
• Humidity controls
• Temperature controls
• Humidity & Temperature controls
Where?• Intermittent source
• Supply only
• Timer control
• Humidity control
• Temperature control
• Exhaust only
• Timer control
• Balanced
• Timer control
• Humidity control
• Temperature control
Standards• ASHRAE 62.2-2013
• Building Science Corp. Standard 01-2013
• Legacy standards
• ASHRAE 62.2-1989
• ASHRAE 62.2-2004
• ASHRAE 62.2-2007
• ASHRAE 62.2-2010
How do we calculate it?
• ASHRAE 62.2
• Ventilation Rate = (CFA x 0.03) + (7.5 x (Nbr + 1))
• Building Science Corp
• Ventilation Rate = (CFA x 0.01) + (7.5 x (Nbr + 1))
How much Ventilation?ASHRAE 62.2 2004, 2007, 2010
Whole house ventilation 7.5 cfm/person +
1 cfm/100 square ft Local exhaust Kitchens > 100 cfm Bathrooms > 50 cfm Source control
Test for backdrafting if sum of 2 largest exhaust fans >
15 cfm/100 sq ft Air handlers in garage
must be tested for airtightness
EXEMPT: Houses in hot climates w/o air
conditioning, houses conditioned < 876 hours/yr, houses in hot dry climates
Mandatory: Providing local exhaust ventilation to
rooms with unvented combustion appliances
More Rules: Unducted range hoods are only permitted
in kitchens w/ a mechanical exhaust system providing 5 kitchen ACH (cont. or
intermittent)
ASHRAE 62.2 Required Airflow
• 1 CFM/100 sf
• 7.5 CFM/person
• Number of bedrooms plus 1
• Bath, 50 CFM
• Kitchen, 100 CFM
• 2,000 sf, 3 bedroom home
Flow = (2,000 / 100) + (4 x 7.5)
Flow = 20 + 30
Flow = 50 CFM continuous
ASHRAE 62.2 Fractional On-Time
• 1 CFM/100 sf
• 7.5 CFM/person
• Number of bedrooms plus 1
• Bath, 50 CFM
• Kitchen, 100 CFM
• Daily run time
• 4 hours = 17%
• 6 hours = 25%
• 7 hours, 55 minutes = 33%
• 12 hours = 50%
• 15 hours, 50 minutes = 66%
• 18 hours = 75%
• 19 hours, 55 minutes = 83%
• 22 hours = 92%
ASHRAE 62.2 Ventilation Effectiveness
• 3 hours
• < 35%, 0.33
• 35% - 60%, 0.50
• 60% - 80%, 0.75
• > 80%, 1.0
ExampleFlow = Required air flow /
(effectiveness x fractional on-time)
Flow = 50 / (1 x 0.25) Flow = 50 / 0.25
Flow = 200
ExampleFlow = Required air flow /
(effectiveness x fractional on-time)
Flow = 50 / (0.33 x 0.17) Flow = 50 / 0.056
Flow = 893
Example• Required: 50 CFM continuous
• Measured: 75 CFM intermittent
• Timer setting: 40 minutes
• Hours: 40/60 = 0.67 x 24 = 16
• 16 - 9 = 7 hours additional
• Fan wattage: 1276 watts
• Result: 8.9 kWh/day, 3,248 kWh/yr
Software Tools• RESNET-accredited
• Hourly simulations
• Energy Gauge
• Ekotrope
• Residential Energy Dynamics
Brett Dillon CEO
www.thedillongroupinc.com [email protected]