Documenting summer heat stress in multi-unit residential

buildings in Hamilton

Dan Thompson, Ph.D. Matt Thompson

Tools● USB temperature/humidity dataloggers

– 1) south face of concrete apartment building– 2) attic of older brick multi-unit detached house– Two other replicates of attic apartments

● Hourly measurements of air temperature and humidity

● June 1st to Sept 17th, 2013

Rationale● Hamilton's unique geography, built

environment

– Mountain, harbour– Low to medium-income

population living in large tower blocks but also in older detached homes in the lower city

– 74,000 in Hamilton live in apartments ≥ 5 stories

– 37,000 in < 5 story buildings, including multi-unit detached houses

– Beasley: 46% (≥ 5); 16% (<5); seniors

Background

2003 European heatwave (Fouillet et al., 2007):– 50-80% increase in mortality for those >75 years

during heat wave; no change for those <35● Housing type, income not considered in analysis

Teuling et al 2010 (Nature Geoscience)

Background cont'd

● The American Society of Heating, Refrigerating, and Air Conditioning Engineers (ASHRAE) Standard 55-2010:

"Thermal environmental conditions for human occupancy" recommends 20°C to 26°C at 50% relative humidity as comfortable for sedentary work

– An air temperature of 26°C at 50% relative humidity corresponds to a humidex of 29.

● Humidex > 30 used here as threshold for heat stress.

Hourly observations of indoor temperature and humidex

Jun 01 Jun 16 Jul 01 Jul 16 Jul 31 Aug 15 Aug 30 Sep 14

5

10

15

20

25

30

35

40

45Tower BlockAtticYHM

Air

tem

pera

ture

(C)

Jun 01 Jun 16 Jul 01 Jul 16 Jul 31 Aug 15 Aug 30 Sep 145

10

15

20

25

30

35

40

45

Humidex

Cumulative Heating Event

Attic

25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 400%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

YHM

Tower block

Attic

Humidex

% o

f tim

e ex

ceed

ing

hum

idex

val

ueCumulative heat exposure in residences

● Need to know the nature of heat stress: – Is 6 hours at 36 twice as bad as 30?

1150 hours of apartment heat stress

975 hours

25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 400%

10%

20%

30%

40%

50%

60%

70%

80%

90%

YHM

Tower block

Attic

Humidex

% o

f nig

ht-t

ime

hour

s ab

ove

thre

shol

dNight time heat exposure

● Apartment units experience 4-5x more frequent night heat stress hours (>30) compared to the airport.

● ~50% of heat stress hours occur 7pm-6am

550-600 hours > 30

Hot Nights

● Airport cools off quickly: likely a poor indicator of night-time heat stress.● At night, humidity reaches maximum; fans alone less effective.● In attic, peak occurs at 7-8pm

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 00

10

20

30

40

50

60

70YHM

Tower Block

Attic

Hour of the day

Num

ber

of d

ays

with

Hum

idex

> 3

0 in

hou

r gr

oup

5-6 hour lag

Air quality interactions with heat stress

2013

2014 Activities

● Expand observations to six locations● Better understanding of how residents are

currently cooling off– Publicly-accessible spaces (community centres,

Jackson Square)– Cooling in place– Beasley will conduct a cooling survey, key informant

interviews and focus group – Reach out to City Housing Hamilton

Questions

● Can we build a data-driven heat emergency policy:– Excess mortality study for Hamilton

● Age● Building type● Air quality● Night-time cooling

● Can we extend of hours of services to consider heat lag of buildings● In-house cooling strategies for large apartment blocks?

– Chicago common rooms a potential model– Explore cool room program with Horizon (one A/C room available 24/7 per

building)● Summer angels? Social health accountability program

Hamilton's Urban Heat Island

Source: NASA MODIS satellite surface temperaturehttp://daac.ornl.gov/MODIS/