Resolving the Conflict between Building Preservation and ...
49
Resolving the Conflict between Building Preservation and the Proper Temperature and Relative Humidity Requirements of Collections Marion F. Mecklenburg Charles S. Tumosa November 2003
Transcript of Resolving the Conflict between Building Preservation and ...
Res
olvi
ng th
e C
onfli
ct b
etw
een
Bui
ldin
g Pr
eser
vatio
n an
d th
e Pr
oper
Tem
pera
ture
and
Rel
ativ
e H
umid
ity R
equi
rem
ents
of
Col
lect
ions
Mar
ion
F. M
eckl
enbu
rg
Cha
rles
S. T
umos
a
Nov
embe
r 200
3
“Ess
entia
lly, r
elat
ive
hum
idity
expr
esse
s the
m
oist
ure
cont
ent o
f air
as a
pe
rcen
t of w
hat i
t can
ho
ld w
hen
the
air
is sa
tura
ted.
”[a
t a g
iven
tem
pera
ture
]
The
Deh
umid
ifica
tion
Han
dboo
kSe
cond
Edi
tion
Car
goca
ire
Stan
dard
50%
+/-
5% R
H
“The
stan
dard
spec
ifica
tion
of +
/-4
or 5
% in
RH
con
trol
is b
ased
mor
e on
wha
t we
can
reas
onab
ly e
xpec
t the
equ
ipm
ent t
o do
than
on
any
deep
kno
wle
dge
of th
e ef
fect
of s
mal
l var
iatio
ns o
nth
e ex
hibi
t”.
Thom
son,
The
Mus
eum
Env
ironm
ent (
1978
).
Tulip
Pop
lar,
48%
RH
30 S
econ
d In
c. T
est
00.
002
0.00
40.
006
0.00
80.
010.
012
0.01
402468
Stra
in m
m/m
m
Stress (MPa)
Ultim
ate
Stre
ngth
Mod
ulus,
E
Yield
Poin
t
The
Mec
hani
cal a
nd D
imen
sion
al
Res
pons
e of
Cul
tura
l Mat
eria
ls to
M
oist
ure
•ce
llulo
sew
ood,
pap
er•
colla
gen
bone
, ivo
ry, g
lue
•ar
tists
’ pai
nts
pigm
ente
d fil
ms
•m
iner
als
•m
etal
s•
cera
mic
s
Org
anic
Str
uctu
ral C
ompo
unds
Four
bas
ic o
rgan
ic st
ruct
ural
com
poun
dsT
wo
suga
rs: c
hitin
and
cel
lulo
seT
wo
prot
eins
: ker
atin
and
col
lage
n
Cel
lulo
se
New
Sco
tch
Pin
e, T
he T
hree
Prim
ary
Dire
ctio
ns
020
4060
8010
00
0.00
5
0.01
0.01
5
0.02
0.02
5
0.03
0.03
5
Rel
ativ
e H
umid
ity(%
)
Free Swelling Strains
Rad
ial
Tang
entia
l
Long
itudi
nal
R
L
T
Scot
ch P
ine, T
ange
ntial
Dire
ction
020
4060
8010
00
0.00
5
0.01
0.01
5
0.02
0.02
5
0.03
0.03
5
Rela
tive
Hum
idity
(%)
Free Swelling Strains
Mea
sure
men
t as p
er
Woo
d Han
dboo
k (.0
0044
1 / %
RH)
Inter
med
iate
(30%
to 65
% R
H)M
easu
rem
ent (
.0002
67 /
% R
H)
Cha
nges
in d
imen
sion
are
di
ffus
ion
cont
rolle
dan
d ar
e us
ually
ver
y sl
ow
for w
ood
bloc
ks o
r boo
ks
Radia
l
Long
itudin
al
Tang
entia
l
Tens
ile Te
sts
of B
irch
in th
e 3
Dire
ctio
ns
00.
005
0.01
0.01
50.
02020406080100
120
140
Stra
in (m
m/m
m)
Stress (MPa)
Col
lage
nous
Mat
eria
lsgl
ues,
gela
tins,
skin
s, pa
rchm
ents
, le
athe
rs
Gel
atin
s hav
e be
en u
sed
exte
nsiv
ely
for c
entu
ries a
s gl
ues.
The
gela
tin is
from
rend
ered
ani
mal
skin
s and
bo
nes.
A p
artic
ular
ly st
rong
glu
e is
from
stur
geon
swim
bl
adde
rs. G
elat
ins a
re fo
und
in fu
rnitu
re, s
izes
for c
anva
s pa
intin
gs, i
mag
e em
ulsi
ons f
or p
hoto
grap
hic
prin
ts a
nd
film
s. It
is o
ne o
f the
stro
nges
t of t
he c
ultu
ral m
ater
ials
.
Wal
rus
Tusk
, Tan
g./ R
adia
l Dire
ctio
n
020
4060
8010
0-0
.02
-0.0
10
0.01
0.02
0.03
Rela
tive
Hum
idity
(%)
Free Swelling Strains
.000
205
Stra
in/%
RH
It w
ill ta
ke a
20%
RH
cha
nge
to d
evel
op a
mec
hani
cal s
train
of
0.0
04 w
hen
rest
rain
ed. T
his
is th
e sm
alle
st y
ield
poi
nt.
10 Y
ear O
ld H
ide
Glue
(Gel
atin
)
020
4060
8010
0-0
.03
-0.0
2
-0.0
10
0.01
0.02
0.03
Rela
tive
Hum
idity
(%)
Free Swelling Strains
0.01
The
gel
atin
s eve
n w
hen
rest
rain
ed
can
easi
ly b
e cy
cled
from
50%
RH
+/
-15%
RH
with
out d
amag
e.
20th
Cen
tury
Pho
togr
aphi
c M
ater
ials
The
allo
wab
le e
nviro
nmen
t for
20th
cent
ury
phot
ogra
phic
mat
eria
ls. T
his
incl
udes
the
imag
e em
ulsi
on la
yers
, th
e pa
per a
nd p
last
ic su
bstra
tes,
and
the
dyes
and
silv
ers.
A
CD
B 1 2 4 10 30 100
500
010
2030
4050
6070
8090
100
-30
-20
-100102030
Rel
ativ
e H
um
idit
y
Temperature, C
Gel
atin
Abo
veT
g
Art
ists
’ Pai
nts
This
cat
egor
y ca
n in
clud
e oi
l pai
nts,
acry
lic
emul
sion
pai
nts,
alky
d pa
ints
, egg
tem
pera
, an
d ot
hers
. Low
tem
pera
ture
is a
far g
reat
er
prob
lem
than
low
rela
tive
hum
idity
Whi
te L
ead
in C
old
Pres
sed
Lins
eed
Oil
020
4060
8010
0-0
.03
-0.0
2
-0.0
10
0.01
0.02
0.03
Rela
tive
Hum
idity
(%)
Free Swelling Strains
20 Y
ear O
ld Y
ello
w Oc
hre
in L
inse
ed O
il
020
4060
8010
0-0
.03
-0.0
2
-0.0
10
0.01
0.02
0.03
Rela
tive
Hum
idity
(%)
Free Swelling Strains
Even
with
a d
esicc
atio
nfro
m 6
0% R
H to
30%
RH
the
chan
ge is
only
0.0
05
Napl
e's Y
ello
w, E
quil.
Stre
ss S
train
Tes
ts
00.
005
0.01
0.01
50.
020.
025
0.03
012345
Stra
in
Stress (MPa)
48%
RH, 2
3C
5%RH
, -3C
5%RH
, 23C
Relat
ive H
umidi
ty St
ress
es
Ther
mal
Stre
sses
20 Y
ear O
ld Y
ello
w Oc
hre
Alky
d Pa
int
00.
005
0.01
0.01
50.
020.
025
0.03
0.03
505101520
Stra
in
Stress (MPa)
22.5
C, 5
8%RH
22.5
C, 5
%RH
-5C,
5%
RH
Burn
t Sie
nna
Acry
lic E
mul
sion
Pain
t
00.
10.
20.
30.
40.
50.
605101520253035
Stra
in
Stress (MPa)
23.5
C, 5
%RH
11.1
C, 5
%RH
5C, 5
%RH
-6.6
C, 5
%RH
23.5
C, 4
3%RH
Gla
ss T
rans
ition
Tem
pera
ture
•A
cryl
ic p
aint
s +5
C•
Oil
pain
ts-1
0 C
•A
lkyd
pai
nts
-15
C
Pain
ts c
an su
stai
n fa
irly
larg
e sw
ings
in
rela
tive
hum
idity
. T
ests
indi
cate
s tha
t 40%
RH
+/-
15 c
an
be to
lera
ted
easi
ly. L
ow te
mpe
ratu
res
are
a bi
gger
thre
at to
the
stab
ility
of t
he
pain
t film
s.
Com
pute
r M
odel
ing
of C
anva
s Su
ppor
ted
Pain
tings
Mod
els i
nclu
de a
ll la
yers
of t
he
pain
ting,
line
n fa
bric
, glu
e si
ze, o
il gr
ound
and
the
oil d
esig
n la
yers
.
Env
iron
men
tal S
ettin
gs to
Red
uce
Bui
ldin
g M
aint
enan
ce
Mol
d G
row
th
Eff
ects
of h
igh
rela
tive
hum
idity
can
be
loca
lized
; by
lack
of a
ir c
ircu
latio
n an
d/or
by
cond
ensa
tion
Inap
prop
riate
rela
tive
hum
idity
ca
n ca
use
salts
to m
igra
te to
the
surf
ace
of c
eram
ics o
r to
acce
lera
te
reac
tions
at t
he su
rfac
e of
obj
ects
.
Met
al c
orro
sion
from
salt
depo
sits
re
actin
g w
ith a
mbi
ent m
oist
ure
So…
.. W
hat I
s the
Rig
ht V
alue
?
Rec
omm
enda
tions
An
appr
opria
te m
useu
m e
xhib
ition
en
viro
nmen
t wou
ld b
e:W
inte
r; 40
% R
H +
/-5%
RH
Sum
mer
; 55%
RH
+/-
5% R
HTe
mpe
ratu
re; b
asic
vis
itor c
omfo
rt
FY 1
993,
Sm
ithso
nian
Ene
rgy
Cos
ts
HM
SGR
ENAI
&SI
CH
NM
AHQ
&FN
.G. M
SCN
ASM SE
RCN
MAI
AAPG
NM
NH BA
R HPR
I.RES
. SH
01234565.
34.
6
2.89
2.74
2.72
2.57
2.5
2.13
1.97
1.7
1.65
1.46
1.23
0.75
0.85
40.
48
Build
ing
Energy Cost/Sq. Ft ($)
Elec
trici
tyG
as, S
team
, Oil
NG
AN
AS
M
NM
AH
Ren
wic
k
Free
r/Qua
d
SA
AM
/PG
Priv
ate
Res
iden
ceS
ilver
Hill
HS
GM
HS
GM
NM
NH
FY 1
993,
Sm
ithso
niam
Ene
rgy
Cos
ts
05
1015
2025
300123456
Ann
ual R
H, R
ead
50%
RH
+/-
Energy Costs per Square Foot
New
Sm
ithso
nian
Env
iron
men
tal
Gui
delin
es
“For
gen
eral
col
lect
ions
and
pub
lic sp
aces
….
70 +
/-4
degr
ees F
and
Rel
ativ
e H
umid
ity a
t 45
+/-8
%.“
Oct
ober
200
3
Mar
ion
F. M
eckl
enbu
rgm
eckl
enbu
rgm
@sc
mre
.si.e
duC
harl
es S
. Tum
osa
tum
osac
@sc
mre
.si.e
du
(301
) 238
-370
0 x
118
Smith
soni
an C
ente
r for
Mat
eria
ls
Res
earc
h an
d Ed
ucat
ion
