ashrae 62.2 and passive house: an interpretation requestpassivehouse.pdf · 2018-12-12 · in...

ASHRAE 62.2 and Passive House:

An Interpretation Request

6thAnnual North American

Passive House Conference

©Passive House Institute US 2011

An Interpretation Request

Katrin Klingenberg

Ventilation Rate /hr of OperationKitchen + Dining Area 5 ACH:

258 ft²*8=2064 ft²

2064 ft³*5=10320 ft³

10320 ft³/60=172 cfm

Passive House Ventilation Rate:

83 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 Ventilation Rate

Two bath@24 cfm + Kitchen @ 35 cfm

83 cfm


Thermal Balance Point Heating

Out = InOut > In

0°°°°F0°°°°F


1 W/ft²10+ W/ft²

72°°°°F68°°°°F

Current Passive House Criteria

Annual Heat Demand ≤≤≤≤ 4.75 kBTU/ft2yr (15 kWh/m²a)

Peak Heat Load ≤≤≤≤ approx. 3.17 BTU/hr.ft2 or 1W/ft2 (10 W/m² )

Primary Energy Demand ≤≤≤≤ 38 kBTU/ft2yr (120 kWh/m²a)

Airtightness ≤≤≤≤ 0.6 ACH50

Ventilation ≥≥≥≥75% Recovery, ≥0.76 W/cfm

Thermal Envelope: R ≥≥≥≥ 38.5 hr. ft2°F/BTU, U ≤≤≤≤ 0.026 BTU/hr. ft2

°F


Thermal Envelope: R ≥≥≥≥ 38.5 hr. ft2°F/BTU, U ≤≤≤≤ 0.026 BTU/hr. ft2

°F

Thermal-bridge Free Ψ ≤≤≤≤ .006 BTU/ hr. ft °F

Windows installed: Uw-install ≤≤≤≤ 0.15 BTU/hr. ft2°F

SHGC 50 – 55 %

1 W/ft²*Note: Window and Thermal envelope

criteria Listed are for a Central European

Climate. Recommendations for these

values vary In N America based on climate

Annual Mean Total HDD


Annual Mean Total CDD


Annual Mean Relative Humidity


400

600

800

1000

1200

Qla

ten

t (w

att

s)

Nov

Dec

Jan

Feb

Mar

Apr

heating and

dehumidification

cooling and

dehumidification

66-76F


-400

-200

0

200

-3000 -2500 -2000 -1500 -1000 -500 0 500 1000 1500 2000

Qsensible (watts)

Qla

ten

t (w

att

s)

Apr

May

June

July

Aug

heating and humidification

cooling and

humidification

30-60%rh

Grafics: Newell Instruments, Inc.

Kitchen:

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

ASHRAE 62.2 Ventilation Rate 1


Kitchen+Dining base area:

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



Kitchen+Dining+Living:

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



Smith House


Passive House Ventilation Rate

Two exhaust@24 cfm + Kitchen @ 35 cfm

83 cfm


All areas connected 5ACH

650 cfm

ASHRAE 62.2 Ventilation Rate


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

INTERPRETATION IC 62.2-2007-X


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.

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


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.


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.



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.

The work around...


The work around...

Thank you


Thank you

ashrae 62.2 and passive house: an interpretation requestpassivehouse.pdf · 2018-12-12 · in...

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