Ventilation Options

Ventilation OptionsBrett 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?

What is the purpose of residential ventilation?

Purpose

• Moisture control

• Odor control (?)

• Pollution dilution

• Yankee revenge (?)

When do we need to ventilate a home?

Conditional

• What is the occupancy rate?

• What is the climate like?

• What kinds of pollutants are in the home?

How should we ventilate homes?

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 are these appropriate?

Where?• Intermittent source

• Supply only

• Timer control

• Humidity control

• Temperature control

• Exhaust only

• Timer control

• Balanced

• Timer control

• Humidity control

• Temperature control

What standard should we use?

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)

More Rules

• Hot humid climates exhaust limits

• Very cold climates supply limits

What about intermittent?

• Required air flow

• Fractional on-time

• Effectiveness

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

Simple Calculator

Counting Infiltration

How do we model it correctly?

Impact

• RESNET required, 2007

• ENERGY STAR required, 2011

• IRC required, 2012

HERS Index Impact

HUGE!

HERS Ratings

• Measure the flow rate

• Field measured fan wattage

• Product Data

Example:

• Carrier 58STA-110-100-22

• 115 volts

• 11.1 amps

• 115 x 11.1 = 1276.5 watts

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

Which software tools are better?

Software Tools• RESNET-accredited

• Hourly simulations

• Energy Gauge

• Ekotrope

• Residential Energy Dynamics

Questions?

Brett Dillon CEO

www.thedillongroupinc.com info@thedillongroupinc.com