ASHRAE 62.2 and Passive House: an Interpretation Request

6th Annual North American Passive House Conference

ASHRAE 62.2 and Passive House: An Interpretation Request

Katrin Klingenberg

©Passive House Institute US 2011 ©Passive House Institute US 2011 Ventilation Rate /hr of Operation Kitchen + Dining Area 5 ACH: 258 ft²*8=2064 ft² Passive House Ventilation Rate: 2064 ft³*5=10320 ft³ 83 cfm 10320 ft³/60= 172 cfm Kitchen+Dining+Living:

258 ft²+176 ft²=434 ft²

434 ft²*8=3472ft³

3472 ft³*5=17360 ft³

17360ft³/60= 289 cfm

©Passive House Institute US 2011 Passive House Ventilation Rate

Two bath@24 cfm + Kitchen @ 35 cfm

83 cfm

©Passive House Institute US 2011 Thermal Balance Point Heating

Out > In Out = In ° 0 F 0°F

72 °F 68 °F

10+ W/ft² 1 W/ft²

©Passive House Institute US 2011 Current Passive House Criteria

Annual Heat Demand ≤≤≤ 4.75 kBTU/ft 2yr (15 kWh/m²a) Peak Heat Load ≤≤≤ approx. 3.17 BTU/hr.ft 2 or 1W/ft 2 (10 W/m² )

Primary Energy Demand ≤≤≤ 38 kBTU/ft 2yr (120 kWh/m²a) ≤≤≤ Airtightness 0.6 ACH 50 Ventilation ≥≥≥75% Recovery, ≥0.76 W/cfm

Thermal Envelope: R ≥≥≥ 38.5 hr. ft 2 °F/BTU, U ≤≤≤ 0.026 BTU/hr. ft 2 °F Thermal-bridge Free Ψ ≤≤≤ .006 BTU/ hr. ft °F ≤≤≤ 2 ° Windows installed: Uw-install 0.15 BTU/hr. ft F

SHGC 50 – 55 %

*Note: Window and Thermal envelope 1 W/ft² criteria Listed are for a Central European Climate. Recommendations for these values vary In N America based on climate

©Passive House Institute US 2011 Annual Mean Total HDD

©Passive House Institute US 2011 Annual Mean Total CDD

©Passive House Institute US 2011 Annual Mean Relative Humidity

©Passive House Institute US 2011 1200 Nov cooling and 1000 dehumidification Dec

800 Jan 66-76F

600 heating and Feb dehumidification 400 Mar

Apr

Qlatent (watts) (watts) Qlatent Qlatent 200 May 0 30-60%rh June -200 cooling and heating and humidification humidification July -400 -3000 -2500 -2000 -1500 -1000 -500 0 500 1000 1500 2000 Qsensible (watts) Aug

Grafics: Newell Instruments, Inc. ©Passive House Institute US 2011 ASHRAE 62.2 Ventilation Rate 1 Kitchen:

86 cfm+40 cfm ( 2 bathrooms)=126 cfm

172 cfm+40 cfm ( 2 bathrooms)=212 cfm

289 cfm+40 cfm (2 bathrooms)=339 cfm

©Passive House Institute US 2011 ©Passive House Institute US 2011 ©Passive House Institute US 2011 Passive House Ventilation Rate

Two exhaust@24 cfm + Kitchen @ 35 cfm

83 cfm

All areas connected 5ACH

650 cfm

©Passive House Institute US 2011 INTERPRETATION IC 62.2-2007-X Reference: This request for interpretation refers to the requirements presented in ANSI/ASHRAE Standard 62.2-2007, Section 5.3 and Table 5.2, relating to continuous mechanical exhaust requirements for kitchens. Background: The Passive House Institute US is advocating and promoting the international Passive House Building Energy Standard to be widely adopted in the United States. The Passive House Building Energy Standard core technical piece is an optimized continuous balanced mechanical ventilation system. The supply and exhaust airflows required under this standard are determined a) by indoor air quality fresh air requirements based on occupants under consideration of the airtightness of the envelope and b) the exhaust air requirements based on the number of bathrooms and kitchens. Bathrooms require 24 cfm continuous exhaust and kitchens require 35 cfm continuous exhaust. The kitchen exhaust is part of the continuous balanced mechanical ventilation system with very high heat recovery efficiency and does not need to be vented directly to the outside. Charcoal filtration at the source of cooking is required before the kitchen exhaust air enters the kitchen exhaust intake. In fact, direct venting is to be avoided in a Passive House to minimize unnecessary heat loss through penetrations of the envelope and to optimize the overall energy balance of the home. ©Passive House Institute US 2011 Interpretation No.1 : The Passive House kitchen exhaust requirement of 35 cfm continuous does not meet the requirements of Table 5.2 of Standard 62.2. Question No.1: Is this Interpretation correct?

Interpretation No.2 : The requirement that a continuous kitchen exhaust have a capacity to provide 5 air changes per hour is due to the difficulty of a non-hood exhaust to adequately capture and remove contaminants released during cooking from kitchens which may be quite large, have an open-plan design, or have high ceilings. Question No.2: Is this Interpretation correct?

©Passive House Institute US 2011 Interpretation No.3 : Standard 62.2 does not dictate how the volume of the kitchen is calculated. It is up to the designer and the local building code to define kitchen volume. Question No.3: Is this Interpretation correct?

Q2: The kitchen in a new house opens into the family room. There is no wall between the rooms. Where do I measure the kitchen volume? A2: It is up to the designer (and code official) to determine where the kitchen ends and the living room begins. However, basing the design on a larger volume would be a conservative choice. ©Passive House Institute US 2011 The work around...