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AlllOS flTieOE 31-2214

A Review of Measurements,

Calculations and Specifications of

Air Leakage Through Interior Door

Assemblies

Daniel Gross

Center for Fire Research

National Engineering Laboratory

U.S. Department of Commerce

National Bureau of Standards

Washington, DC 20234

February 1981

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S. DEPARTMENT OF COMMERCE

mONAL BUREAU OF STANDARDS

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National Bureau ot Standards

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NBSIR 81-2214 m.

A REVIEW OF MEASUREMENTS,

CALCULATIONS AND SPECIFICATIONS OF

AIR LEAKAGE THROUGH INTERIOR DOOR

ASSEMBLIES

Daniel Gross

Center for Fire Research

National Engineering Laboratory

U.S. Department of Commerce

National Bureau of Standards

Washington, DC 20234

February 1981

U.S. DEPARTMENT OF COMMERCE, Malcolm Baldrige, Secretary

NATIONAL BUREAU OF STANDARDS, Ernest Ambler. Director
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TABLE OF CONTENTS

Page

LIST OF TABLES iv

LIST OF FIGURES Iv

Abstract 1

1. INTRODUCTION 1

2. GENERAL PRINCIPLES 3

3. TEST METHODS 6

4. SPECIFICATIONS 8

5. MEASUREMENTS 9

6. DISCUSSION 11

7. CONCLUSIONS 12

8. REFERENCES 14

ill
LIST OF TABLES

Page

Table 1. Values of exponent in equation 1 17

Table 2. Measured and estimated air leakage rates for doors . . 18

Table 3. Measured and estimated air leakage rates for building

components 19

LIST OF FIGURES

Page

Figure 1. Discharge coefficients for orifice flow 20

iv
A Review of Measurements, Calculations and Specifications

of Air Leakage Through Interior Door Assemblies

Daniel Gross

ABSTRACT

A review was made of measurements and calculations

of air leakage through door assemblies in order to

evaluate their effectiveness as barriers to smoke

flow. It was noted that typical "fire doors" are

not capable of meeting proposed limitations of air

leakage at ambient temperatures. It was also noted

that significant air leakage may occur through

interior walls which contain fire doors. It was concluded that first priority should be given to

developing and validating a standardized test

method for the accurate and consistent measurement of air leakage through door assemblies.

Key Words: Air leakage, building, door, fire door,

fire test, infiltration, smoke control, smoke

movement

.

1. INTRODUCTION

For fire safety purposes, smoke is defined as the airborne solid

and liquid particulates and gases evolved when a material undergoes

pyrolysis or combustion. It is obvious that an open door will readily

permit smoke to pass from its source in a building fire to other areas

in the building. It is also generally accepted that a closed door will

limit the passage of smoke, and, in controlled occupancies such as hospitals, schools, and certain office and apartment buildings, doors

1
are required to be self-closing or to close automatically upon operation

of an installed smoke detector device. However, the effectiveness of a door as a barrier to smoke is not well established, and it is the intent

of this report to provide a review of the current status of our knowledge

of air (and smoke) flow measurements through door assemblies in terms of

occupant protection in the event of fire.

From the standpoint of fire, there are several different types of

doors, each of which serves a specified purpose in current building

codes^. A fire door is mandated as part of the building fire containment

system primarily for property protection purposes. When installed in a fire separation wall of three or four hour rating, a fire door having a three hour rating is generally required. There is no expressed requirement for the prevention of smoke passage by a door in a fire separation

wall. An exit stair door is expected to provide ready access to the

stairshaft for fleeing occupants while maintaining its integrity and

preventing passage of flames or heat for an extended period of exposure

to a fire located in the corridor. In the usual case, where the stair

enclosure walls are required to have a two hour fire resistance rating,

the exit stair door assembly is required to have a 1-1/2 hour fire

resistance rating. However, there is no mention of the ability of the

door assembly to prevent the passage of smoke. A horizontal exit door

is expected to provide a barrier to horizontal fire spread while permitting building occupants to pass through the horizontal exit to (a)

seek refuge on the unexposed side of the exit, or (b) continue on to an exit leading directly to the outside. The exit door is also required to

have a 1-1/2 hour fire resistance rating and also to serve as a "smoke

barrier". However, there is no prescribed test method or meaningful

performance criteria on which to assess the door’s effectiveness as a smoke barrier. A corridor/room separation door is expected to have a dual function; (a) to keep a fire located in the corridor from entering

a room (patient room, school room, apartment, etc,), and (b) to keep a

^ In common practice, fire doors are classified by a letter designation

according to the opening for which the door is suitable and an hourly

rating designation [1]; the type description according to use is

considered more appropriate here.

2
fire located in a room or apartment from entering the corridor. While

it is not anticipated that these doors will resist a fire for long

durations, codes currently anticipate that such doors will serve as both

fire and smoke barriers for a period of 20 minutes [2] although 3/4 hour

fire ratings were commonly required in the past. A smoke barrier door

is one which is expressly intended to prevent smoke passage for occupant,

protection purposes. Such doors are required by code in building corridors where heavy fire exposure is not anticipated and may be specified

as having a fire resistance rating of up to 20 minutes. However, as before, there is no prescribed test method to measure effectiveness as a smoke barrier.

It is clear that the roles played by doors in the event of fire are different. Certain doors are only intended to withstand severe fire

exposure; others are intended only as barriers to relatively cool smoke;

and some doors are intended to serve as both fire and smoke barriers.

In addition, sophisticated building smoke control systems are now being

used (primarily in tall buildings) that utilize zones of pressurized

air to prevent smoke entry; in these cases, the air leakage characteristics of door assemblies (and other building elements) are important

design features. It follows that standardized procedures are needed for

measuring the leakage of air and of smoke laden air over the range of

temperatures and pressures likely to be experienced in buildings.

2. GENERAL PRINCIPLES

The flow of air throughout a building depends upon existing or induced pressure differences. Typically, pressure differences arise as a result of (a) forced ventilation from mechanical (HVAC) systems, (b)

differences between Internal and external temperature (stack effects)

and (c) wind effects. In a building fire of limited extent, it may be

assumed that smoke particulates and combustion gases will be carried

along with the air, provided their concentrations and densities do not

result in an air and smoke mixture whose properties differ considerably

from normal air. In addition to these three sources of pressure differ3
ence, there is also a pressure effect due to the expansion of hot gases

in the vicinity of the fire. In a large building, this effect will be

fairly localized.

The flow of air through a corridor, through an open doorway, or through small cracks in walls or small gaps around closed doors follows

the same general relationship. Thus, the flow of air at constant

temperature through an opening (or passageway) is expressed in terms of

the area of the opening and the static pressure differential across the

opening as follows:

Q

= KA(Ap)^ [1]

where Q

= volume flow rate of air

K = a flow factor incorporating the discharge coefficient (C,)d

of the leakage openings, and the relationship between the

units used

A = area of the opening or passage

Ap = pressure difference

n = exponent which can vary between 0,5 and 1,0

3 2

When Q is expressed in m /s, A in m , and Ap in Pa, K = 0,827

In considering flow through cracks around closed door assemblies,

it has been common to assume that n = 0.5 and C, = 0.6 to 0.7, which are

a typical values for flow through thin-walled, square-edged (or sharp-edged)

orifice plates or other small openings. Then, A represents the "equivalent area of opening".

The exponent n should not automatically be assumed equal to 0.5.

At fairly high Reynolds numbers, corresponding to sizable characteristic

dimensions and velocities where the flow is turbulent and the flow

resistance is due mainly to inertia forces, n approaches 0.5. However,

in laminar flow, where the resistance is mainly due to viscous forces

and the Reynolds number is low, n approaches 1. Table 1 lists examples

of assumed or derived values of n.

4
In practice, the exponent and flow factor may be determined by

measuring flow rate over the anticipated range of pressure differences,

either in a laboratory or in an actual installation. It has been

suggested that in-place wall leakage is significantly higher in actual

houses than in wall sections measured in the laboratory [3].

Discharge coefficients for thick walled orifices have been tabulated

as a function of the geometry of the orifice and the Reynolds number

[4]. These are plotted in Fig. 1, using the Bernoulli relation (n = 0.5)

for convenience. This shows the critical importance of both the Reynolds

number and the geometry of the leakage path. For closed doors designed

to be effective smoke barriers, the geometry of the leakage path will

more closely approximate a thick-walled than a thin-walled orifice, and

the Reynolds number will be quite low (less than 1000) . Since the flow

coefficient varies so greatly, particularly at the anticipated low

values of Reynolds number, it becomes critically Important to make

direct and accurate measurements of the leakage around closed doors over

the necessary pressure range.

Several additional factors should be considered in air leakage

measurements. Although the ftmdamental relationship still applies, the

flow of air through openings at elevated temperatures is more complicated

due to effects of buoyancy, mixing, and heat exchange between hot air

(gases) and cool surfaces. Except where wind and pressurization are

dominant, the typical flow through a door opening in a compartment is

bidirectional, with heated air flowing out at high levels and cool air

flowing in at low levels. Furthermore, to prevent the convective flow

of smoke-laden air resulting from an increase in temperature, one effective technique involves the use of pressurized air in shafts and

corridors, and this introduces flow in the reverse direction.

The basic theory of volumetric air exchange due to natural convection

through an opening in a vertical partition was clearly presented by

Brown and Solvason [5]. The resultant equation for the convective flow

through each half of an opening of width W and height H is given by:

5
1/2

Q [ 2 ] = C,WH

d

3/2

]

where g = gravitational constant

p = (avg) fluid density

Ap = difference in fluid densities

This was extended by Shaw to take into account the combined effect

of natural convection and forced air flow; subsequently Shaw and Whyte

calculated the forced air supply required to counter the effects of

small temperature differences (0 to 12 K) so as to prevent the exchange

of contaminated air through open or partially open doors in hospitals [6],

The following equation represents the leakage flow of air through an opening against the forced air supply of velocity V^:

Q

3 gAp ^ - x-* [3]

It may also be used to determine the value of which will reduce Q

to zero.

For the specific application involving a closed door, measurements

are needed of the minimum flows of cool air and the corresponding

pressure differences., to prevent any air from flowing from the heated

area through the door assembly. There are no known measurements of this

kind.

3. TEST METHODS

Standard test methods for measuring air leakage through exterior

building elements have been used for at least 15 years. The current

ASTM method for determining the air infiltration resistance of exterior

windows, doors and walls [7] was originally published in 1965. The

ASTM E 283 test method consists of sealing the test specimen into or against one face of an air chamber and supplying air to (or exhausting

air from) the chamber at the rate required to maintain the specified

6
test pressure difference across the specimen. Since this test is used

for exterior building elements, air leakage measurements are commonly

2

made at a pressure difference of 75 Pa (1.57 Ibf/ft ) corresponding to a wind velocity of 11.1 m/s (25 mph) , although other pressure difference

levels are possible.

A similar test method was adopted in 1968 as a British Standard [8]

in which the pressure is applied in 50 Pa steps up to a maximum of 1000

Pa. In the test method adopted in 1975 as a European Standard [9] and in

the version being balloted as an ISO standard by ISO Committee TC 162 on Windows [10], the pressure is also applied in stages (50, 100, 150, 200,

300, 400, 500, 600 Pa) up to the maximum pressure required for the test.

From the standpoint of pressure differences likely to exist under

fire conditions, including winter stack effect in tall buildings and smoke

control pressurization techniques, interior building pressures as high as 100 Pa are unlikely. ISO Committee TC 92 on Fire Tests is currently

considering three separate test methods for measuring air flow through

interior door assemblies. The test method proposed for use at ambient

indoor temperature (25 °C) also measures air flow across a door assembly

at several pressure difference levels (5, 10, 20, 30, 50, 70 and 100 Pa)

[11]. It is intended that other test methods would be developed for

measuring air leakage at elevated temperatures, (e.g., at temperatures

which correspond to the standard fire exposure for fire doors [12]) and

at moderate temperatures (e.g., 300-500 °C)None of these methods

actually addresses the more direct but difficult question of measuring

the quantity of smoke particulates which flow past the door assembly,

the apparent assumption being that (a) the particulates will not be

filtered or deposited out in passing through the door gaps or (b) the

flow of smoke-laden air is essentially equivalent to the flow of air

mixed with CO and other "smoke" gases.

In the usual case, these test methods do not prescribe the apparatus

in detail, providing only the measurement principle and a stated measurement accuracy. Thus the apparatus may be small, large, or adjustable in

7
size and temporary or permanent. There are approximately 20 laboratories

in the U.S. equipped to perform the ASTM E 283 test, although it is

likely that there are wide variations in the size of the test chamber,

the method of sealing, the type of flow and pressure measuring devices,

etc. No data on interlaboratory testing are known or provided. The

2 situation is similar for the proposed international test methods .

4. SPECIFICATIONS

Air leakage rates are sometimes specified for selected types of

exterior doors to limit energy losses due to air infiltration. Although

the air leakage rate may be specified in terms of the door area, it seems more reasonable to express it in terms of the crack length

(perimeter) through which the leakage occurs. For example, one standard

2 3

[13] sets a limit of 1,25 cfm/ft (equivalent to 7.62 m /h*m of crack

length for a 1 by 2 m door) at a pressure difference of 0.3 in wg (75

Pa) for a residential-type swinging door. For a similar application, a specification for insulated steel door systems [14] specifies a value

approximately 40 percent of this limit, whereas another specification

[15] permits a leakage rate four times as large, i.e., equivalent to

30,5 m^/h*m.

Whereas exterior doors are specifically designed with weatherstripping and seals to limit air leakage, interior doors are not so designed except for special applications. In the U.S., there are no known specifications limiting air leakage through interior door assemblies

for smoke control purposes. The Uniform Building Code Standard No. 43-2

(1979 edition) defines a smoke and draft control door assembly in terms

of performance in the standard fire endurance test for an exposure period

of not less than 20 minutes. The acceptance conditions are based on limitations on (1) flaming on the unexposed surface, (2) excessive movements, and (3) emission of excessive smoke from the door. In addition.

One known commercial source for an apparatus for measuring air leakage

of doors and windows is: ALCO - Fensterpriif stand Typ 3030 SP, manufactured by ALCO Bauzubehorgesellschaf t MBH & Co.

Goslar, W. Germany.

8
it is required that "smoke and draft control door assemblies shall be

provided with a gasket so installed as to provide a seal where the door

meets the stop on both sides and across the top. The gasketing need not

be installed on the test assembly". It is clear that the effectiveness

of sealing methods are not quantitatively prescribed. In 1977, the NFPA

Committee on Fire Doors and Windows prepared a Recommended Practice for

the Installation of Smoke and Draft Control Door Assemblies (NFPA No. 105-

1977) . This proposal was Intended to assist public safety authorities

in considering methods for restricting and minimizing the potential flow

of smoke and gases through door opening assemblies. It contained

recommendations on frames, doors, hanging means, closing, holding and

releasing means, detection, latching and sealing. As part of the recommendation for sealing, gasketing was to be provided along the door

perimeter, and clearances (e.g., for carpeting) were to be "kept to a minimum". While this Recommended Practice was never adopted, it seems obvious that a quantitative performance level based on a suitable

standard test method would have made such a Recommended Practice and

other general requirements more meaningful and practical.

It may be of interest to note that in Germany the following tentative requirements have been proposed to limit the flow of heated (200°C)

3 air through Interior door assemblies: (1) 60 m /h at Ap = 10 Pa for the

O complete door assembly as used, (2) 20 m /h at Ap = 10 Pa for the door

assembly with the threshold taped. The second measurement using an impervious seal at the bottom ledge of the door takes into account the

fact that doors are usually undercut and that leakage at the threshold

(floor) level would be disproportionately high in the (uniform pressure)

laboratory test compared to the actual situation in a building.

5 . MEASUREMENTS

A summary of some published information on air leakage rates for

doors is given in Table 2, Data for windows, walls, and complete

buildings are given in Table 3.

9
It may be noted first that exterior wall leakage rates are listed

per unit area and for a pressure difference of either 75 or 200 Pa

whereas windows and doors are listed per unit crack length and for a pressure difference of 25, 75 or 100 Pa. The leakage (crack) length is

taken to be equal to the perimeter for a single leaf door and to the

perimeter plus height for a double leaf door. Where interior doors are of principal concern, the maximum pressure difference due to stack

effect, due to expansion of gases, and due to building pressurization is

not considered likely to exceed 50 Pa. In certain cases, higher pressure

differences could conceivably be attained across an interior door, e.g.,

due to high wind pressure where the window is broken, but this would not

be common.

Secondly, there is a wide range in the air leakage rates among

different doors, even of similar construction, and among different types

of walls. It is clearly necessary to make sure that air leakage measurements are accurate and consistent before performance criteria are

selected.

The leakage rate through conventional walls without windows is not

negligible. Whereas the leakage rate at a pressure difference of 200

3 2

Pa may range up to 30 m /h*m , it is still substantial at 50 Pa and

25 Pa; e.g. using equation (1) with n = 1, the equivalent flows are

3 2 3 2

computed to be 7.5 m /h*m at 50 Pa and 3,8 m /h*m at 25 Pa. It is

well to keep in mind that walls cover larger areas than doors and that

interior walls are probably at least as permeable as exterior walls.

It appears that interior doors which are not specifically designed

with sealing devices will not be capable of meeting the leakage limit of

3

16 m /h*m at 100 Pa which is currently proposed in DIS 5925 Part 1 [11],

Even close-fitting doors such as fire-check doors complying with British

Standard BS 459 would allow a flow rate many times this figure.

10
Finally, as an Illustrative example, the estimated leakage through

a 1 by 2 m "smoke control door assembly" designed to the suggested limit

3 in DIS 5925 Part 1 would be 70 m /h at 50 Pa. At this pressure, the

leakage through the walls of an interior (or "core") stair shaft

measuring 3 by 6 m and constructed of concrete block may be about 120

3

m /h per story. Thus, the advantage of using an effective smoke control

door assembly may be limited if the door is mounted in a wall of normal

construction.

6. DISCUSSION

This report was prepared to provide a review of available measurements of air leakage through Interior door assemblies and a discussion

of future needs and approaches for defining the performance of "smoke

control doors". It has been pointed out that currently used doors

separating each room from the corridor (e.g. , apartment entrance doors),

smoke barrier doors used in corridors, and exit stair doors will not

3

meet the arbitrary 16 m /h*m leakage limit proposed in DIS 5925 Part 1.

Is there a more rational basis for this limit or other limit?

In 1970, McGuire et al [16] suggested that the control of smoke

within a high building could, as a first approximation, be accomplished

by limiting the density of smoke at any point to 1 percent of the smoke

density at the source. This value was based on a review of data on smoke generation, and on visibility in smoke-filled rooms and occupant

tenability. The concept of using a limiting value of 1 percent may also

be extended to air flow through door openings. What would such an approach provide in terms of evaluating the performance of conventional

apartment entrance doors and typical fire-rated stair shaft doors?

For example, what is the likely flow of air past a closed apartment

entrance door if the air flow were limited to 1 percent of the flow

through the open door? Assuming a temperature difference of 10 K, the

convective air flow through an open apartment entrance door according to

3 3 Equation 2 would be approximately 0.48 m /s (1730 m /h) . Thus, 1 percent

11
3 3 of this flow would be 17,3 m /h or approximately 2.9 m /h*m for a 1 by 2

m door. According to Table 1, which is admittedly incomplete and subject

to verification, interior doors, including many provided with seals

along the door frame edges, would be unable to meet this criterion.

In buildings designed with pressurized stairwells, corridors or other selected zones, it may also be of value to use Equation 3 to

compute the air supply necessary to prevent flow of heated air through

3 an open (or partially open) doorway. This flow amounts to 1.6 m /s

(5760 m^/h) for AT = 10 K and 4.8 m^/s (17300 m^/h) for AT = 100 K.

The forced air supply necessary to prevent flow of heated air through a door or other wall opening is about 3 times the flow induced by natural

convection.

7. CONCLUSIONS

Based on a review of the factors governing air flow through closed

door assemblies and of available measurements of air leakage through

interior door assemblies, the following conclusions appear justified:

1) The flow of air past closed door assemblies may be expressed

in terms of a leakage coefficient and a power function of

the pressure difference. The assumption of conventional

values for these factors based on turbulent flow past sharpedged orifices may introduce considerable error. The

appropriate pressure difference should be based on the

maximum anticipated value according to door location,

building design and environmental factors.

2) There is a wide range in the reported measurements of

air leakage rates among different doors, even of similar

construction. As a first priority, accurate and consistent

air leakage measurements on a wide variety of interior doors

according to a standardized and validated test method are

needed. To take account of differences in the design of

I
doors, door frames, and sealing devices, as well as the

effects of the anticipated differences of pressure, many

interior door assemblies will need to be tested with air

pressure applied separately in each direction.

3) Interior doors which are not specifically designed with

special sealing devices will not be capable of meeting

3

the leakage limit of 16 m /h*m at 100 Pa which is

currently proposed in DIS 5925 Part 1. Even many doors

provided with seals along the door frame edges may be

unable to meet a criterion based on limiting flow to 1

percent of the open door flow.

4) An appreciable fraction of air leakage may occur through

Interior walls, including stair shaft walls, according to

published measurements of leakage rates. Thus, the

advantage of using an effective smoke control door assembly

may be limited if the door is mounted in a wall of normal

construction.
REFERENCES

1. NFPA 80-1979, Standard for Fire Doors and Windows, Appendix F

Classification, 1979.

2. Degenkolb, J.G. , "Fire Door Assemblies - What Do the Ratings Mean?",

Building Official and Code Administrator, pp. 61-64, July/Aug 1975.

3. ASHRAE Book of Fundamentals, Chapter 21, 1977.

4. Idel'chlk, I.E. , "Handbook of Hydraulic Resistance", Moscow, 1960.

5. Brown, W.G. and Solvason, K.R., "Natural Convection Through

Rectangular Openings in Partitions", Inti. J. of Heat and Mass

Transfer, _5, p. 859-868, Sept. 1962.

6. Shaw, B.H. and Whyte, W. , "Air Movement Through Doorways - The

Influence of Temperature and Its Control by Forced Airflow", Bldg.

Service Engineer, 42 , pp. 210-218, Dec. 1974.

7. ASTM E 283-73, "Standard Test Method for Rate of Air Leakage

Through Exterior Windows, Curtain Walls, and Doors", Part 18,

Annual Book of ASTM Standards, 1980.

8. British Standards Institution BS 4315:Part 1, "Methods of Test

for Resistance to Air and Water Penetration", 1968,

9. European Standard EN 42:Part 1 (also BS 5368:Part 1:1976), "Methods

of Testing Windows:Part 1. Air Permeability Test", Oct. 1975.

10. ISO Draft International Standard DIS 6613, "Windows and Window

Doors - Air Permeability Test".

11. ISO Draft International Standard DIS 5925/1, "Fire Tests - Evaluation of Performance of Smoke Control Door Assemblies - Part 1: Ambient Temperature Test", Feb. 1980.

12a. ISO 3008, "Fire Resistance Tests - Door and Shutter Assemblies",

April 1976.

b. ASTM E 152-80, "Fire Tests of Door Assemblies", Part 18, Annual

Book of ASTM Standards, 1980.

13. ASHRAE 90-75, Energy Conservation in New Building Design, The

American Society of Heating, Refrigerating and Air-Conditioning

Engineers, Inc., New York, 1975.

14. ISDSI-109, Door Insulating System Index (DISI) for Insulated Steel

Door Systems, Insulated Steel Door Systems Institute, Cleveland,

OH., 1979.

14
15. ANSI/AAMA 1102,7-1977 Voluntary Master Specification for Aluminum

Storm Doors, Architectural Aluminum Manufacturers Assn., Chicago,

IL., 1977.

16. McGuire, J.H., Tamura, G.T. , and Wilson, A.G., "Factors in

Controlling Smoke in High Buildings", ASHRAE Symp. Proc. , "Fire

Hazards in Buildings", Jan. 19-22, 1970.

17. Hobson, P.J. and Stewart, L.J., "Pressurization of Escape Routes

in Buildings", FR Note 958, British Joint Fire Research Organization, Dec. 1972.

18a. Houghten, F.C. and Ingels, M, , "Infiltration Through Plastered and

Unplastered Brick Walls", ASHVE Trans. 33 , p. 377, 1927.

b. Larson, G.L. , Nelson, D.W. and Bratz, C. , "Air Infiltration

Through Various Types of Brick Wall Construction", ASHVE Trans.

16, p. 99, 1930.

19. Tamura, G.T. , "Computer Analysis of Smoke Control with Building

Air Handling Systems", ASHRAE Journal, p. 46-54, Aug. 1972.

20. Butcher, G.C. and Parnell, A.C., "Smoke Control in Fire Safety

Design", E. and F.N. Spon, Ltd. publishers, 1979.

21. Tamura, G.T. and Shaw, C.Y., "Air Leakage Data for the Design

of Elevator and Stair Shaft Pressurization Systems", ASRAE Trans.

81, 1975.

22. Poulsen, P.E. , "Smoke Control Doors Test Report", Danish National

Institute for Testing of Materials, 1979, (ISO/TC 92/WG 3 N 218).

23. Report of ASTM E 283 tests conducted by commercial laboratory

for sponsor, 1973.

24. Tests reported by Hans Strom, Jl-Te AB for Mr. Jackman

(TRADA), June 1979 (ISO/TC 92/WG 3 N 236).

25. Tests reported by Timber Research and Development Association,

June 1979 (ISO/TC 92/WG 3 N 236).

26. Air Leakage Test Chamber for Smoke Control Doors (SMP,

Dortmund) 1979 (ISO/TC 92/WG 3 N 228).

27. Thorogood, R.P. , "Resistance to Air Flow Through External Walls",

BRE Information Paper 14/79, 1979.

28. Tamura, G.T.

,

"Measurement of Air Leakage Characteristics of House

Enclosures", ASHRAE Trans. 81 , 1975.

15
29. Carruthers, J.F.S. and Newman, C.J., "The Repeatability and

Reproducibility of Test Results on Windows and Wall Span Elements

and the Expected Results", BRE Current Paper, CP 49/77, 1977.

30. Data from Figs. 4.39, 4,40 and Fig 4.41 of Japanese report.

31. Data from Building Research Station (1971) and Princess

Risborough Laboratory (1972), referenced in [14].

16
Table 1. Values of exponent in Equation 1

Building Component Exponent n Reference

Brick Walls 0.87, 1.0 17, 18

Leakage Openings 0.77 3

Exterior Walls 0.67 19

Window Gaps 0.62 17, 20

Door Gaps 0.5 17, 20

Air Supply and Return Openings 0.5 19

Shaft Walls; Floors 0.5 19

17
Table 2. Measured and estimated air leakage rates for doors

Type Description

Leakage

Rate ^ m^/h'm

Pressure Difference

Pa

Interior stair door Gap width 2. 0 mm 38 25

Interior stair door Gap width 4 • 6 mm 92 25

Elevator door Gap width 4« 8 mm 100 25

Elevator door Gap width 6.8 mm 140 25

Installed office door with catch, singleleaf

Computed gap width 1.9 mm 29 25

Installed door without catch, singleleaf

Computed gap width 3.7 mm 55 25

Installed double leaf door Computed gap width 3.2 mm 48 25

Installed elevator

door Computed gap width 5 . 9 mm 88 25

Interior wood door 30 min. fire rating; without

avg. rebated clearance 0.6

seals;

Tnm 8 25

Interior wood 60 min. fire rating; double seals 0.5 25 (acoustic door) along four edges

Interior steel door 60 min. fire rating; single seal 16 25 all edges except bottom

Exterior steel door Weatherstrlpped on four edges and special bottom comer seal0.2 to 0.8 75

Interior wood door Threshold with 7 mm stop, no sealing strips

>15 25

Interior wood door Same, with sealing strips In door frame5 25

Interior wood door Same, with sealing strips In door frame and threshold0.3 25

Interior wood door Hung as In use >40 25

Interior wood door Same, with 25 mm stop >40 25

Interior wood door Same, with 25 mm stop and smoke

seal

20 25

Interior wood door Same, with 25 mm stop, smoke seal and threshold taped

1.3 25

Interior door 90 min. fire rating; without seals 30 25

Interior door Wired glass In aluminum frame; seals along four edges of door and frame7 25

Interior door Wired glass panels (2) In steel frame

seal on all edges except bottom

24 25

Per unit crack length

Reference

21

21

21

21

17

17

17

17

22

22

17

23

24

24

24

25

25

25

25

26

26

26

18
Table 3. Measured and estimated air leakage rates for building components

Component Description

Leakage Rate

11 ^ /h m^ m^/h m

Pressure Difference Reference

Buildings

School Precast concrete panel walls;

gasket Joints; plasterboard

lining.

5 200 27

House Timber-frame panels; flberboard

sheathing; plasterboard lining.

10 200 27

Walls

Factory

(windowless)

Profiled steel cladding;

quilt Insulation; plasterboard

lining.

30 200 27

Warehouse

(windowless)

As above. 20 200 27

Elevator

Shaft Cast-ln-place concrete 4-15 75 21

Elevator

Shaft Concrete block or clay tile block. 30-35 75 21

Stair Shaft Cast-ln-place concrete; concrete

or tile block. 0.5-4 75 21

Wood Frame Insulated 1 and 2 story 3-23 75 28

Wood Frame Shingles; sheathing; bldg, paper; lath and plaster (3 coats) 0.1 75 3

Brick 8.5 In. thick, unplastered. 7 75 3

Brick 8.5 In. thick, plastered 0.06 75 3

Windows

Household Weatherstrlpped 2.2-13.8 100 29

Non Weatherstrlpped 6-25 100 29

Fixed 0.006-0.08 75 30

Wooden Sash 5-25 75 30

Metallic Sash 0.5-30 75 30

Household, Nonweatherstrlpped, avg. fit wood double-hung

5 75 3

Household, Weatherstripped, avg. fit wood double-hung

3 75 3

Pivoted 5.8 (1-20) 25 31

Pivoted and weatherstrlpped 0.8 (0.1-6) 25 31

Sliding 2.2 (0.5-9) 25 31

Per unit area; per unit crack length

19
Figure

1.

Discharge

coefficients

for

orifice

flow

PQ 1N3I3IJJ303 39)IVH3Sia

20

REYNOLDS

NUMBER

N
NBS>114A (REV. 9-78)

U.S. DEPT. OF COMM. 2.C0^t Accession No, BIBLIOGRAPHIC DATA

SHEET

1. PUBLICATION OR REPORT NO. NBSIR 81-2214

Reciptenf$ Accessloii No»

4. TITLE AND SUBTITLE

A Review of Measurements, Calculations and Specifications

of Air Leakage Through Interior Door Assemblies

5. Publication Date February 1981

S. Pedorming Organization Code

7. AUTHOR(S)

Daniel Gross

8. Performing Organ. Report No.

9. PERFORMING ORGANIZATION NAME AND ADDRESS

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, DC 20234

Ift. Proiect/Task/Work Unit No.

11. Contract/Grant No.

12. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS rsrreor. City, state, ziP) 13, Type of Report & Period Covered

15. SUPPLEMENTARY NOTES

I I Document describes a computer program; SF-185, FIPS Software Summary, is attached.

16. ABSTRACT (A 200*word or less tactual summary of most significant information* If document includes a significant bibliography or

literature survey, mention it here*) A review was made of measurements eind calculations of air leakage through door

assemblies in order to evaluate their effectiveness as barriers to smoke flow.

It was noted that typical "fire doors” are not capable of meeting proposed

limitations of air leakage at ambient temperatures and that significant air

leakage may also occur through interior walls. It was concluded that first

priority should be given to developing and validating a standardized test

method for air leakage measurements.

17. KEY WORDS fsfx twelve entries; alphabetical order; capitalize only the first letter of the first key word unless a proper name;

separated by semicolons)

Air leakage, buildings, doors, fire doors, fire tests, infiltration, orifice

flow, smoke control, smoke movement.

18. AVAILABILITY ^Unlimited

I I For Official Distribution. Do Not Release to NTIS

I I Order From Sup. of Doc., U.S. Government Printing Office, Washington, DC

20402, SD Stock No. SN003-003- ^Order From National Technical Information Service (NTIS), Springfield, VA. 22161

19. SECURITY CLASS

(THIS REPORT)

UNCLASSIFIED

20. SECURITY CLASS

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UNCLASSIFIED

21. NO. OF

PRINTED PAGES

24

22 . Price

$5.00

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