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NATL INST. OF STAND & TECH R.I.C.

A11104 SSblOt

NBSIR 79-1739

Tests on the Performance of

Automatic Fire Detectors in

Health Care Occupancies - A

Preliminary Report

Richard W. Bukowski

Center for Fire Research

National Engineering Laboratory

National Bureau of Standards

U.S. Department of Commerce

Washington, D.C. 20234

April 1979

lonsored in part by:

“QC "' ' " epartment of Health, Education and Welfare

]_QQ Washington, D.C. 20201

,U56

79-1739

NBSIR 79-1739

TESTS ON THE PERFORMANCE OF

HEALTH CARE OCCUPANCIES - A

PRELIMINARY REPORT

Richard W. Bukowski

Center for Fire Research

National Engineering Laboratory

National Bureau of Standards

Washington, D.C. 20234

April 1979

Sponsored in part by:

Department of Health, Education and Welfare

Washington, D.C. 20201

U S. DEPARTMENT OF COMMERCE, Juanita M. Kreps, Secretary

Jordan J. Baruch, Assistant Secretary for Science and Technology

NATIONAL BUREAU OF STANDARDS, Ernest Ambler, Director

AUTOMATIC FIRE DETECTORS IN
.
TABLE OF CONTENTS

Page

LIST OF FIGURES iv

LIST OF TABLES iv

Abstract 1

1. INTRODUCTION 2

2. DESCRIPTION OF FULL-SCALE FACILITY 2

3. EXPERIMENTAL PROCEDURE . . 3

3.1 Automatic Fire Detection System 4

3.2 Evaluation Criteria 6

4. RESULTS 7

5. DISCUSSION ....... ........ 9

6. FUTURE WORK 10

7. REFERENCES ...... 11

iii
LIST OF FIGURES

Page

Figure 1. Corridor/lobby instrument stations

(floor plan) 12

Figure 2. Corridor/lobby instrument stations

(elevation) 13

Figure 3. Burn room - plan 14

Figure 4. Burn room - elevation 15

Figure 5. Experimental arrangement 16

Figure 6 . Detector alarm times 17

Figure 7. Patient rescue times 18

Figure 8. Corridor tenability times 19

LIST OF TABLES

Page

Table 1. Mattress details 20

Table 2. Detector type and sensitivity 21

Table 3. Detector replacements 22

Table 4. Times to untenable conditions 23

Table 5. Device response times (sec) 24

IV
TESTS ON THE PERFORMANCE OF AUTOMATIC FIRE DETECTORS

IN HEALTH CARE OCCUPANCIES - A PRELIMINARY REPORT

Richard W. Bukowski

Abstract

The paper reports the results of the

first series of eight full-scale fire tests

to evaluate the response of automatic fire

detectors in health care occupancies to flaming

ignition mattress fires. Comparisons were made

between three types of detectors (ionization,

photoelectric, and heat) installed in the

patient room versus in the corridors.

For the fire scenario selected (flaming

ignition of bedding and mattress) , the results

indicated that the ionization-type detectors

in the patient room provided the maximum time

for escape. The maximum time period available

for either rescue of a non-ambulatory patient

in the room of origin or for use of the corridor

past the room of origin as a means of escape

averaged only about five minutes. The times

available for escape or rescue were based on

the time provided between detector alarm and the

time that one of several criteria selected for

occupant tenability was exceeded.

Key words: Corridors; escape; fire detectors; fullscale tests; heat detectors; hospitals; ionization

detectors; mattresses; nursing homes; photoelectric

detectors

.

1
1 . INTRODUCTION

The National Bureau of Standards (NBS) , Center for Fire

Research (CFR) is currently engaged in a five year experimental program sponsored by the U.S. Department of Health,

Education and Welfare (HEW) to study fire protection techniques for health care facilities. One of the major segments

of this program includes the conduct of full-scale experiments

to obtain data on the response of automatic detection and

suppression systems to fires in a patient room. This is a report of the results of the first group of eight tests in

this series as pertains to the response of selected detectors

to these fires. It should be emphasized that this is only a report on the results of the first eight experiments of a larger test program. Further reports on other groups of

experiments on detectors and sprinkler systems will be

issued separately. This report summarizes the response of

detectors representative of current technology to flaming

ignition bedding and mattress fires with detection principle

and installation location as key parameters.

2. DESCRIPTION OF FULL-SCALE FACILITY

Full-scale experiments were conducted in one wing of a building formerly used as a military barracks. The building

corridor was widened to 2.44 m (8 ft) and the burn room and

corridor were fire hardened by lining them with cement

asbestos board over 1.3 cm (1/2 in) gypsum board. The burn

room and corridor were instrumented for temperature, smoke,

air velocity, gas, and heat flux at various locations.

Detailed drawings giving dimensions and instrument locations

are shown in figures 1 thru 4.

The burn room was laid out to represent a small two-bed

hospital room. The test fires were initiated in a trashfilled plastic wastebasket adjacent to a bed frame and

2
mattress. The bed was mounted on a steel platform suspended

on a high temperature strain gage load cell to measure

weight loss during the test. No second bed was used, but

the second bed location was instrumented to give data on

conditions at the adjacent patient location. Flaming fires

were selected for the test scenario since Veterans Administration records [ 1

]

1 indicate that this is the highest life

hazard type of fire in their health care occupancies.

Figure 5 shows the experimental arrangement of the test

bed. For all tests, bedding materials including 50/50

cotton/polyester sheets and pillow case and a cotton-covered

shredded urethane foam pillow were used to provide a typical

bed arrangement. A cotton/polyester bedspread was also used

for the experiments. Prior to ignition, the sheet and

bedspread were folded back as shown in figure 5.

A more complete description of the facility and

instrumentation is contained in a separate report [2]

.

3. EXPERIMENTAL PROCEDURE

The first group of experiments was primarily designed

to identify the most and least severe fire which might occur

from the exposure of four mattresses* representative of types

commonly used in health care facilities to a fire in a waste

container. Descriptions of these four mattress types are

given in table 1.

Identical tests were conducted with each mattress type

in ventilated and unventilated conditions. For the ventilated condition, the exhaust fan shown in the ceiling of

“Numbers in brackets refer to the literature references

listed at the end of this paper.

3
the lobby area was operated continuously during the test.

For the unventilated condition, the exhaust was not operated

and the fan opening was closed by a set of metal louvers.

It should be understood that these represent only two

ventilation conditions and are not representative of all the

different ventilation conditions which might occur. Such

other conditions could have a significant effect on the

detection system performance. For example, if the patient

room pressure is positive with respect to the corridor the

performance of the corridor detectors could be enhanced.

Conversely, if the room is negative with respect to the

corridor (as is done in hospitals for infection control) the

performance of the corridor detectors could be delayed. It

is hoped that these effects can be studied in future tests

in this series.

For this first series of tests, none of the fires were

extinguished until temperatures had peaked and subsided to

low, steady state values. Dry sprinkler heads (tell-tale

sprinklers) were installed in the burn room and were monitored

for their actuation time only. A report on sprinkler operation

is being prepared separately. As explained, the intent was

to determine which of the mattresses provided the most

severe fire. Once this mattress was identified, it would

then be the only mattress type used in the next series of

experiments to determine the effectiveness of an automatic

sprinkler system in control or extinguishment of the fire.

3.1 Automatic Fire Detection System

Three sets of automatic fire detectors were installed

in the facility. Each set of detectors included three smoke

detectors and two heat detectors. Two of the smoke detectors

used the photoelectric principle and one the ionization

principle. The two heat detectors used at each location

4
consisted of one 57° C (135° F) f ixed-temperature heat

detector with a UL 15 m (50 ft) space rating and one 60° C

(140° F) rate-compensation type heat detector with a UL 15 m

(50 ft) space rating. The heat and smoke detectors used

were of the commercial type normally used in health care

facilities and were selected as a representative of current

detector technology. Table 2 gives the types and sensitivities of the detectors used by location.

One detector board was installed in the center of the

burn room ceiling and the other two detector boards were

installed 4.6 m (15 ft) either side of the leading edge of

the burn room doorway on the corridor ceiling. This was

done to provide comparative data on the performance of

detectors installed in each patient room versus detectors

installed on 10 m (30 ft) nominal (33 foot actual separation

for these tests) spacings in the corridors. These are the

two installation schemes most often encountered in health

care occupancies [3]

.

Figures 1 and 3 show the detector

board locations.

In addition, one ionization type door closer detector

and one photoelectric type door closer detector were mounted

at the inside top of the burn room door for one experiment.

Since the first series of experiments did not include automatic suppression, extremely high temperatures were reached

during the course of the tests. The detector board on the

ceiling of the burn room was arranged such that, after all

the detectors had alarmed, the board could be physically

lowered to the floor to minimize damage to the detectors.

Since this was not possible with the door closer detectors,

they were destroyed by the test fire.

5
Since this gave only one data point, no conclusions

were drawn about the performance of door closer detectors in

the patient room. Although the corridor detectors were 4.6 m

(15 ft) down the hall from the burn room door, these detectors were also damaged by some test fires and had to be

replaced periodically. When replaced, every attempt was

made to replace the detector with one of equivalent sensitivity. Table 3 gives the sensitivities of replacement

detectors and the times they were replaced.

3.2 Evaluation Criteria

The performance of the detection systems was evaluated

for two situations. The first was the amount of time which

would be available to staff or firefighters to rescue a patient in the adjacent bed of the room of origin. Since

this patient is located in the room of origin, it must be

assumed that he would rescue himself if he were ambulatory.

Therefore for the purposes of this analysis, it was assumed

that this patient was not ambulatory and would require

assistance in leaving the fire area.

This "patient rescue time" was estimated by determining

the time period from alarm of the detector by class and

location to the time at which a patient in the adjacent bed

would be physically incapacitated by the fire. Physical

incapacitation of the patient was considered to be the time

at which the patient had been exposed to a time-rated

concentration of CO sufficient to result in a calculated 25%

carboxyhemoglobin blood concentration, instantaneous 0.25

watts per square centimeter radiant flux on the adjacent

bed, or 0.5 optical density (OD) per meter smoke level in

the upper portion of the burn room. (Data taken from smoke

meter on instrument channel 71 - see figure 4.) The 0.5 OD

per meter value was selected as a level at which rescuers

6
wearing self-contained breathing apparatus (fire department

personnel) would no longer be able to see far enough to

locate the patient. A discussion of these three limits is

contained in reference [2]

.

The second situation considered in assessing detector

performance was the determination of the amount of time

available after detector alarm for staff or patients to use

the corridor past the burn room as a means of egress. For

this portion of the analysis, the limits for incapacitation

were set at 0.25 optical density per meter smoke level at

the five foot level or 0.25 watts per square centimeter

radiant flux coming out of the burn room door (1 m (3 ft)

_ l from floor). The 0.25 OD/m value used here was based on

a value used by the author and others [4,5,6] as the point

where some psychological apprehension might be encountered

in individuals moving down a corridor through the smoke.

Table 4 lists the time to reach each critical tenability

value for the room an£ corridor for each test.

4 . RESULTS

Table 5 gives the device response times for each test.

These times and the tenability times from table 4 were used

to prepare figures 6, 7 and 8.

The range of elapsed times for detector alarm for the

first series of tests are shown in figure 6. The alarm

points are given by detector class and location. The dots

are the numerical average of the response times of either:

-- The one ionization smoke detector in the room array.

-- The two photoelectric smoke detectors in the room

array.

-- The two heat detectors in the room array.

7
-- The two ionization smoke detectors in the corridor - one in the east array and one in the west array,

or — One each of identical model photoelectric smoke

detectors in the corridor - one in the east array

and one in the west array. (The second photoelectric

model pair was not present in all tests.)

The bars indicate the range of values for all of the tests

conducted in phase 1. As can be seen in figure 6, the

ionization detector in the burn room alarmed the fastest for

all tests. The response of the photoelectric detector in

the burn room was essentially equivalent to that of the

ionization detectors in the corridor with the photoelectric

detectors in the corridor alarming later. The heat detectors in the burn room alarmed last. The heat detectors in

the corridors are not shown in figure 6 since the heat

detectors in the corridor did not alarm for a number of

tests

.

Figure 7 shows the available rescue times for patients

by detector class and location. The maximum rescue time was

provided by the ionization detector in the patient room,

averaging just less than five minutes and ranging from a little more than two and a half minutes to more than nine

minutes. The heat detectors in the patient room gave the

least rescue time, averaging a little over one minute and

actually ranging negative; indicating that the heat detectors operated after conditions had been reached which would

likely prohibit rescue of the patient. As was seen with the

alarm time data, the ionization detectors in the corridor

were essentially equivalent to the photoelectric detectors

in the patient rooms.

8
When examining the results in figure 8 for the time

available to use the corridor as an escape route the same

order of rank holds. The ionization detectors in the

patient room again provided an average of somewhat less than

five minutes of tenability time ranging from about three and

a half minutes to almost seven minutes. Again, the ionization detectors in the corridor demonstrated essentially

equivalent performance to the photoelectric detectors in the

room and the heat detectors in the burn room provided the

least time.

5. DISCUSSION

The results of the phase 1 experiments indicated that,

with a flaming fire involving a bed in the patient room, the

maximum time for escape and rescue was obtained with the

ionization- type detector installed in the patient room. The

performance of ionization detectors in the corridor and

photoelectric detectors in the patient rooms was essentially

equivalent, but would provide nearly one minute less time.

However, a more fundamental point derived from this series

of tests is that maximum time provided was an average of

slightly less than five minutes of escape or rescue time.

Given the likely typical reaction time of the staff to a fire situation, this time seems quite short. This would

suggest the need to use other approaches to increase the

amount of time available for escape and rescue or to better

manage the time available through preplanning and training.

To the extent that additional time could not be provided,

some consideration should be given to decreasing staff

reaction time or to better direct their rescue and other

fire safety activities to make optimum use of the time

available. Conceptually, one method of doing this would be

to connect the detectors in the patient room to the nurse

9
call system in addition to the fire alarm system. It is

reasonable to assume that after the initial alarm, as much

as 30 seconds or more might be lost to the staff trying to

remember the appropriate procedures to be followed in case

of fire. If, however, the fire detector were connected to

the nurse call system such that an emergency mode nurse call

was generated with the detector alarm, the instinctive nurse

reaction would be to proceed immediately to that room.

After the patients in the room of origin were rescued, one

need only glance at the nurse call master station to determine the subsequent rooms for rescue or evacuation as those

would be in the emergency signaling mode when the detectors

in these rooms operated. Therefore, this interconnection

would graphically indicate the fire spread or smoke contamination in each individual room in the wing. This cross

connection is attractive primarily since most newer hospitals

have this type of nurse call system already installed and

the connection into the nurse call system from the detector

could be easily done using the detector supplementary alarm

contacts connected into the bedside station or bathroom call

button. This would typically require no additional equipment other than the length of wire connecting the systems

within the patient room. Also, since this would be a

supplementary signaling feature, its implementation would

not require any changes to current installation or approval

laboratory standards [7,8].

6

.

FUTURE WORK

In the next series of tests, only the worst case

mattress (M-02, polyurethane innerspring) determined from

the first series will be used. The 74° C (165° F) , 1.27 cm

(1/2 in) sprinkler will be connected to a water supply

sufficient to flow 102 £pm (27 gpm) . Tests will include

10
three types of privacy curtains around the bed of origin.

These are mesh top, solid top with plastic hangers, and

solid top with metal hangers.

Future tests will investigate the effects of room

ventilation in the burn room, smoldering ignition of the

bedding, and fires in free standing wardrobes.

7 . REFERENCES

[1] Bright, Richard G., Private communication.

[2] Babrauskas, V. , Combustion of mattresses exposed to

flaming ignition sources, Part 1. Full-scale tests and

hazard analysis, Nat. Bur. Stand (U.S.), NBSIR 77-1290

(September 1977)

.

[3] Life Safety Code, NFPA 101, paragraph 10-2.3.3.6,

National Fire Protection Association, Boston, MA (1976)

.

[4] Budnick, E. K. , Fire spread along a mobile home corridor,

Nat. Bur. Stand. (U.S.), NBSIR 76-1021 (July 1976).

[5] Bukowski, R. W. , et al, Detector sensitivity and siting

requirements for dwellings, NBSGCR 75-51 (August 1975)

.

[6] Heskestad, G., Escape potentials from apartments

protected by fire detectors in high rise buildings,

FMRC SN 21017, Dept, of HUD contract no. H2034R (June

1974) .

[7] Standard for local protective signaling systems - 72A,

article 270, National Fire Protection Association,

Boston, MA (1975)

.

[8] Standard for control units for fire protective signaling

systems - UL 864, paragraph 27. 2D, Underwriters

Laboratories Inc., Northbrook, IL (1975).

11
12
13

Figure

2.

Corridor/lobby

instrument

stations
4- LOAD CELL • THERMOCOUPLE -GAS

O THERMOCOUPLE- SURFACE

HEAT FLUX METER

-e GAS PROBE

® DETECTORS

(D TELL-TALE SPRINKLERS

ALL DIMENSIONS IN METERS

Figure 3 Burn room - plan
©<

’“-i-

.03 TC02

0.61

01

A

00© (f)p7,G*<§) 09

.04,06

©01,11 ©32

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nes^ 61^21

SS£«s S^33

72ffl^- 62^22

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42

^

®

- us 2.0 #

730^ 4“ i7 ®

18 53^4,53-^

1 ®V5

•

l9

,031,52,57

®o

»* II II II H II II II II II •1 ll II II II H ii 4^* 'L

2.44

05j

SYMBOLS

© THERMOCOUPLE -GAS

O THERMOCOUPLE- SURFACE

HEAT FLUX METER

VELOCITY PROBE

SMOKE METER LIGHT PATH

GAS PROBE

DETECTORS

(D TELL-TALE SPRINKLERS

ALL DIMENSIONS IN METERS

Figure 4 . Burn room elevation

15
LOAD

CELL

X

X

to to £ cu O o

i— hi—o

CO

16

Figure

5.

Experimental

arrangement
DETECTOR ALARM TIMES

ALARM POINT (minutes)

0 1 2 3 4 5

i r- 1—

—r~

ION - ROOM

ION - DOOR

9

PHOTO - ROOM

I O 1

ION - CORRIDOR

! ® 3

PHOTO - DOOR

©

PHOTO - CORRIDOR

h— —

I

HEAT - ROOM

I © - ——

|

i _i i i i i i 0 50 100 150 200 250 300

ALARM POINT (seconds!

Figure 6 . Detector alarm times

17
PATIENT RESCUE TIMES

TC: SMOKE=0.5 OD/SVf

MINUTES

-1 0123456789 10

ION - ROOM

I • 1

PHOTO - ROOM

I • 1

ION - CORRIDOR

I •- 1

PHOTO - CORRIDOR

I • 1

HEAT - ROOM

I • 1

I I I

1 I -100 0 100 200 300 400 500 600

SECONDS

Figure 7. Patient rescue times

18
CORRIDOR TESTABILITY TSI¥SES

TC: SMOKE=0.25 OD/M

MINUTES

01 23456789 10

1 1 1 1 1 1 1 1 1

ION - ROOM

I -a I

PHOTO - ROOM

I e

ION - CORRIDOR

I 9 —I

PHOTO - CORRIDOR

HEAT - ROOM

I • i

0 100 200 300 400 500 600

SECONDS

Figure 8. Corridor tenability times

19
Table 1. Mattress details

Type

Mattress

No.

Test

No. Ticking Core

Institutional MO-1 10,13 PVC PIJ Institutional MO2

3,5 PVC PU over springs

Commercial MO5

7,14 Rayon PU

Commercial MO6

6,12 Polyester Cotton over springs

20
Table 2

.

Detector type and sensitivity

Type Clock Location

Smoke Detector

Sensitivity

Heat Detector

Sensitivity

P 1 B 0.016 OD/m

P 2 B 0.033 OD/m

I 3 B 0.026 OD/m

H 4 B 60° C

H 5 B 57° C

P 6 E 0. 037*OD/m

P 7 E 0.040 OD/m

I 8 E 0.022 OD/m

H 9 E 60° C

H 10 E 57° C

P 11 W 0 . 043*OD/m

P 12 W 0 . 033*OD/m

I 13 W 0.023 OD/m

H 14 w 60° C

H 15 w 57° C

* Not used in all tests.

Legend

Type - P-photoelectric , I-ionization, H-heat.

Location - B-burn room, E-east hall, W-west hall

21
Table 3 . Detector replacements

Clock

Asn

.

Type

Replaced After

Test No.

New

Type

New

Sensitivity

1 P 4 P 0.030 OD/m

6 P 4 P 0.033 OD/m

11 P 4 P 0.025 OD/m

11 P 9 P 0.013 OD/m

6 P 10 I 0.048 OD/m

11 P 10 I 0.035 OD/m

7 P 10 P 0.044 OD/m

12 P 10 I 0.026 OD/m

5 H 10 H 57° C

10 H 10 H 57° C

15 H 10 H 57° C

4 H 13 H 60° C

22
Table 4 . Times to untenable conditions

Time (seconds) to untenable conditions - adjacent patient

Test 0 . 5 OD/m 0.25 W/cm 2 25% COHb

N3 570 NA 870

N5 200 350 1430

N6 180 570 1550

N7 300 NR NR

N10 230 660 1860

N12 360 NR NR

Nl 3 250 670 1740

N14 390 NR NR

Time (seconds) to untenable conditions - corridor

Test 0.25 OD/m 0.25 W/cm2

N3 240 360

N5 250 1430

N6 250 1550

N7 290 NR

NlO 330 740

N12 390 NR

N13 260 730

N14 420 NR

NR - Not reached during test

23
Table 5. Device response times (sec)

\Test

C1ock\

no . \ 3 5 6 7 10 12 13 14

1 59 113 43 61 90 54 69 81

2 54 116 38 56 97 50 65 45

3 20 30 23 19 24 18 23 20

4 113 170 186 100 277 346 407 297

5 110 179 194 102 310 172 226 134

6 106 154 105 103 152 89 147 81

7 106 153 109 94 151 88 154 80

8 90 103 78 74 82 62 84 60

9 266 282 494 298 580 455 613 420

10 257 283 482 298 577 469 609 426

11 108 295 135 126 123 115 177 98

12 104 152 111 94 142 63 81 60

13 89 95 70 71 68 57 76 52

14 237 259 453 277 528 444 596 429

15 247 271 478 293 552 445 590 394

Ion Door

Closer 53

Photo

Door

Closer 100

24
' l4A IRC V. S-TI) EPT. OF COMM. 1 1. PUBLICATION OR REPORT NO. BIBUOG^RAPHIC DATA NBSIR 79- 1739

3. BwHpiwtf* Accession No.

:

• !. •

. 1 4. title and subtitle

TESTS ON THE PERFORMANCE OF AUTOMATIC FIRE DETECTORS

IN' HEALTH CARE OCCUPANCIES - A PRELIMINARY REPORT

5. Publication Date April 1979

7. AUTHOR! S) Richard W. Bukowski

3. Performing Organ. Report No.

9. PERFORMING ORGANIZATION NAME AND ADDRESS

NATIONAL BUREAU OF STANDARDS

DEPARTMENT OF COMMERCE

WASHINGTON, DC 20234

t'...75?8377

11. Contract/Grant No.

'-2. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street. City, state, ZIP) Department of Health, Education and Welfare

Washington, D.C. 20201

13. Type of Report & Period Covered

15. SUPPLEMENTARY NOTES

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

IS. ABSTRACT .4 200-word or leaa factual summary of moat significant information. If document includes a significant bibliography or

literature survey, mention it here.) The paper reports the results of the first series of eight full-scale fire tests

:o evaluate the response of automatic fire detectors in health care occupancies to

flaming ignition mattress fires. Comparisons were made between three types of

detectors (ionization, photoelectric, and heat) installed in the patient room versus

in the corridors.

For the fire scenario selected (flaming ignition of bedding and mattress) , the

results indicated that the ionization-type detectors in the patient room provided

the maximum time for escape. The maximum time period available for either rescue

of a non- ambulatory patient in the room of origin or for use of the corridor past

the room of origin as a means of escape averaged only about five minutes. The

;imes available for escape or rescue were based on the time provided between

detector alarm and the time that one of several criteria selected for occupant

tenability was exceeded.

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

separated by semicolons)

Corridors; escape; fire detectors; full-scale tests; heat detectors; hospitals;

ionization detectors; mattresses; nursing homes; photoelectric detectors.

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