MCP15‐80
00
Septtember, 201
11
THE
T
TECH
T HNICA
AL TI
TIMESS The
e Atherrion Adv
vantage
IEER
I
- Effic
ciency & Performanc
P
ce Designe
ed for Toda
ay and Tom
morrow
D
Did you know that the current min
nimum DOE
E
Department of
o Energy) effficiency requ
uirements forr
(D
pa
ackage coolin
ng equipment are based on standards
s
pu
ut forth in AS
SHRAE 90.1-2
2007? Did you
y know thatt
th
he DOE currrently only addresses
a
minimum EER
R
(E
Energy Efficie
ency Ratio) ra
atings? Do yo
ou know whatt
an
n IEER (Integrated Energ
gy Efficiency Ratio) rating
g
iss? Do you know
k
the diffe
erence betwe
een EER and
d
IE
EER? Did yo
ou know the DOE does not currently
y
ad
ddress minim
mum IEER ra
atings? Did yo
ou know thatt
A
ANSI/AHRI 340/360-2007
7 has sta
andard testt
prrocedures to determine both
b
the EER and IEER
R
pe
erformance for
f cooling eq
quipment? Did
D you know
w
th
hat there arre more stringent ASHR
RAE building
g
effficiency stan
ndards than ASHRAE 90
0.1, such as
s
A
ASHRAE’s gre
een building standard ASH
HRAE 189.1-20
010? If yo
ou can’t answ
wer yes to all of these
e
qu
uestions you
u are going
g to find the
t
following
g
in
nformation verry informative
e.
H
How are unit ratings
r
deterrmined and certified?
c
In
ndependent certified and
d accredited third party
y
te
esting laboratories (such as
a ETL, UL, etc.)
e
are used
d
to
o conduct the perform
mance tests defined in
n
A
ANSI/AHRI (fo
ormerly ARI) Standard 340/360-2007.
Equipment cerrtified by these approval agencies will
ear the certification label of that agenc
cy. Modine’s
s
be
A
Atherion unit is
s tested and independentlly certified by
y
ETL to ANSII/AHRI Stand
dard 340/36
60-2007, and
d
be
ears the ETL Listed Mark from
f
Intertek.
W
What is EER?
?
EER (Energy Efficiency Ra
atio) is a me
easure of the
e
ull-load energy efficiency ratio
r
of cooling equipment.
fu
It is a measu
ure of the ratio
r
of the input energy
y
equired to pro
oduce the output cooling at
a 100% load
d
re
co
onditions.
EER = Cooling out (Btu/Hr)
Energy in (watts)
For example if it takes 24 kW (24,000 watts) of
electtricity to produce 20 tons ((240,000 Btu)) of cooling
the e
energy efficiency ratio wou
uld be 10.0 Bttu/Watt.
EER
R = 240,000 B
Btu = 10.0
24,000 Wa
atts
The EER is dettermined by applying the
e standard
ANS
SI/AHRI 340//360-2007 p
performace rrating test
cond
ditions which
h are 95 oF DB outdoo
or air (air
ente
ering the cond
denser) and 8
80 oF DB/ 67 oF WB air
ering the evap
porator coil an
nd operating tthe cooling
ente
em at its ma
aximum capacity (100% lo
oad). The
syste
resu lts are meassured and do
ocumented. The total
measured (in watts), and
d the total
enerrgy “in” is m
cooliing capacity o
output is mea
asured (in Btu
u/Hr). From
this d
data the EER
R is calculated
d.
The EER rating of an air conditioner onlyy tells you
whatt the efficienccy of the unitt is when it iss operating
at itts maximum capacity an
nd under the
e standard
ratin g conditions defined abo
ove. We all know that
nt is sized and
d selected to assure the
cooliing equipmen
userr that the equipment can m
maintain interiior building
temp
peratures a
and humidityy levels tto design
cond
ditions under worst case cconditions (th
he average
hotte
est day expe
ected based on historica
al weather
data
a). But how o
often is the eq
quipment eve
er operated
at th e worst case design condiitions?
ather data forr the US show
ws that on the
e average,
Wea
the 1
100% design load conditio
on is only reacched about
2% of the time. The averrage percentt full load
ditions and du
uration breakd
downs are ass follow.
cond
MCP15‐800
M
Modine Manufacturing Company ‐ Septtember, 2011 2
2% of the time
e the equipment is at 100%
% of full load
6
62% of the tim
me the equipm
ment is at 75%
% of full load
2
24% of the tim
me the equipm
ment is at 50%
% of full load
1
12% of the tim
me the equipm
ment is at 25%
% of full load
Equipment designed to maximize the energy
y
g
effficiency ratio at only the maximum operating
co
ondition may be far less efficient at the
t
part load
d
co
onditions, th
herefore pro
ojected operrational costt
sa
avings using only the EER
R ratings cou
uld be greatly
y
m
misleading. The
T HVAC ind
dustry has recognized this
s
ph
henomenon and hence established
d the IEER
R
m
method of test to address partial
p
load rattings to betterr
re
eflect the actu
ual performance of a unit over
o
the entire
e
co
ooling load range. (Integ
grated Energ
gy Efficiency
y
R
Ratio (IEER)) –New pa
art-load ratin
ng effective
e
1//1/2010).
W
What is IEER?
?
IE
EER (Integratted Energy Efficiency
E
Ra
atio) is a testt
m
method used to define an
nd estimate the average
e
effficiency of a product over
o
a range
e of varying
g
op
perating cond
ditions.
efficiiency under part load co
onditions. A parallel to
this iis; should a ccar’s maximum
m mileage pe
er gallon be
desig
gned and ad
dvertised at a driving spe
eed of 120
mph , or would it be better to maximize it a
at 65 mph,
eds? Most
som ething closerr to average driving spee
drive
ers aren’t pla
anning to spe
end much driving time
cruissing around a
at 120 mph, so
o the obviouss answer is
to m
maximize the m
mpg at a poin
nt where the ccar is most
likelyy to operated most of the ttime. The same can be
said with air cond
ditioning units.
ow shows wh
hat the EER ratings at
The graphs belo
d conditions might look like for a
vary ing part load
100% load
typiccal air conditioning unit. If only the 1
EER
R was conside
ered, and the EER was ma
aximized at
the 1
100% load co
ondition the re
esult might loo
ok like Fig.
2.1. In this case the 100% loa
ad EER is aro
ound 12.5,
but tthe average o
overall IEER is only 11.46.
ure 2.1
Figu
EER
R Maximized at 100% Loa
ad Conditions
EER is a weig
ghted calculattion of the un
nit’s efficiency
y
IE
att four load po
oints –100%, 75%, 50% an
nd 25% of full
co
ooling capac
city. The formula for ca
alculating the
e
IE
EER is;
IEER = (0.0
020 * A) + (0.6
617 * B) + (0.238 * C) +
(0.125
5 * D)
W
Where:
A = EER at 100% net ca
apacity at AH
HRI standard
d
ating condition
ns
ra
B = EER at 75% net capa
acity and redu
uced ambientt
81.5oF for air-cooled)
(8
C = EER at 50% net capacity and reduce
ed ambient
(6
68oF for air-co
ooled)
D = EER at 25% net capacity and reduce
ed ambient
65oF for air-co
ooled)
(6
A
As the data at
a each ratin
ng point is collected
c
and
d
w
weighted to the percenttages above
e, it is nott
un
ncommon to find that the unit efficiency
y at part load
d
co
onditions (IEER) exceeds
s the value of the 100%
%
(E
EER) capacity
y level. In ad
ddition, the eq
quipment can
n
be
e deliberatelly designed to reach its maximum
m
effficiency at something
s
less than full load to take
e
ad
dvantage of the fact tha
at the maxim
mum load will
prrobably only be
b reached 2%
2 of the time
e. This being
g
th
he case, it is preferable
e to maximiz
ze the unit’s
s
P a g e | 2 How
wever, if more
e emphasis iss put on maxiimizing the
part load EERs, the results could look like F
Fig 2.2.. In
R at the 100%
% load condittion is only
this case the EER
und 10.3, butt the IEER iss 12.6 or 10.3% better
arou
than the first casse (12.6 ÷ 11.46). This shows the
act of maxim
mizing the effiiciency of a product at
impa
the point of gre
eatest use, n
not at the w
worst case
ditions.
cond
ure 2.2
Figu
EER
R Maximized for Part Load Conditions
s
MCP15‐800
M
Modinee Manufacturing Company ‐Septtember, 2011 coilss, condenser fans driven by variable frequency
drive
es, Parallel F
Flow microch
hannel condenser coils,
high efficiency fa
ans and mottors, and low
w pressure
p high efficiency filtration, e
etc.
drop
IE
EER – What it Means in Dollars
D
A
Annual operating cost can be
b relatively easy
e
to
esstimate using the following
g formula:
Cooling Ou
utput
(Btu/hr))
IEER x 10
000
x Ele
ectric Rate ($
$/kWh) x Cooling
Hrs
C
Load
d Hours Map
Figure 3.1 – Cooling
ce of maximizing part lo
oad efficiency
y
The importanc
an be demo
onstrated using the exam
mples in the
e
ca
prrevious sectio
on. Given th
hat the examples were 20
0
to
on units (240
0,000 Btu/hr)) located in Atlanta, GA
A
(1
1,484 averag
ge cooling hours),
h
with an average
e
ellectricity rate
e of $0.13/kW
Wh, how do
o these units
s
co
ompare?
costt
costt
The savings am
mounts to approximately $365
$
per yearr
w
with the unit th
hat has the higher
h
IEER, even though
h
th
he EER on tha
at unit is lowe
er.
ses Energy Efficiency
E
How the Atherion Address
h been designed to ma
aximize IEER
R
The Atherion has
atings to allow
w the users to
o minimize th
heir operating
g
ra
exxpenses overr the entire ra
ange of coolin
ng conditions,,
no
ot just at worst
w
case conditions.
c
Driving this
s
effficiency was the carefful selection
n of system
m
co
omponents su
uch as tandem modulating
g digital scroll
co
ompressors, optional mo
odulating hott gas reheatt
P a g e | 3 g
guide
the
 A
ASHRAE 62.1
1 - Ventilation
n and Accepta
able Indoor
A
Air Quality
 A
ASHRAE - 90
0.1 Energy Standard forr Buildings
E
Except Low-Riise Residentiial Buildings
 A
ASHRAE 189..1 – Standard
d for the Desiign of High
P
Performance Green Buildiings (Exceptt Low-Rise
R
Residential Bu
uildings).
 T
The USGBC’’s (U.S. Gre
een Building
g Council)
L EEDS Rating
g System for g
green building
gs.
ge cooling ho
ours in
Figure 3.1 shows the averag
d States.
diifferent areas of the United
 The unit with 11.4
46 IEER would
ely $4,040 pe
er year to ope
erate.
approximate
 The unit with 12.6
60 IEER would
ely $3,675 pe
er year to ope
erate.
approximate
Mod ine used sseveral stan
ndards to
deve
elopment of th
he Atherion p
product:
ASH
HRAE 90.1 iss used by the
e DOE (Dep
partment of
Enerrgy) as a guide to establishing federally
man dated minimum efficiencyy standards ffor various
products. Ass mentioned e
earlier, the
appl iances and p
E currently on
nly mandatess minimum E
EER levels,
DOE
altho
ough there arre ongoing effforts through
h ASHRAE
and others to lea
ad the DOE tto consider u
using IEER
herion units e
exceed the
ratin gs in the futture. All Ath
ASH
HRAE 90.1 minimum EE
ER requirem
ments (and
there
efore exceed the DOE min
nimum require
ements).
be complacen
nt with meetin
ng just the
Not wanting to b
ASH
HRAE 90.1 rrequirementss, Modine in
nvestigated
newe
er technolog
gies and sett out on a course to
desig
gn, produce, and distributte a product that would
exce
eed the mo
ost stringent efficiency standards,
whetther those sttandards are federally ma
andated or
not. That led us to target the more aggresssive IEER
ommendationss put forth in ASHRAE
E 189.1 reco
ndard for the Design of Hiigh Performance Green
Stan
Build
dings. This d
direction make
es the Atherio
on product
more
e attractive to designerss and ownerrs seeking
LEE D certification
n of green bu
uildings. We
e have met
products at
all off our design goals, have ccertified the p
an E
ETL independ
dent test lab
boratory (to A
ANSI/AHRI
340//360) and can
n now offer a product tha
at exceeds
all off the minimum
m IEER efficiency recomm
mendations
put fforth in ASHR
RAE 189.1-2010.
By designing the Atherion to have a cooling
ormance tha
at exceeds ASHRAE 90.1 and
perfo
ASH
HRAE 189.1, tthe annual op
perating cost of a unit is
less than that achieved byy simply me
eeting the
ndards.
minim
mum efficienccy guidelines in these stan
MCP15‐800
M
Modinee Manufacturing Company ‐Septtember, 2011 g table dem
monstrates the
t
Atherion
n
The following
dvantage ove
er the existing
g ASHRAE sta
andards.
ad
mmary – He
ere are some
e of the fea
atures and
Sum
tech nologies thatt put the Ath
herion out frront in the
enerrgy efficiency race.
e of the artt tandem dig
gitally contro
olled scroll
State
comp
pressors for m
maximum IEE
ER ratings an
nd reduced
cost of operation.
PF micro-channel conde
enser coil
All aluminum P
gned to be lig
ght weight, co
ompact, highlly efficient,
desig
corro
osion resista
ant, and all with a low
w air side
presssure drop fo
or maximum efficiency a
at reduced
refrig
gerant charge
es.
able frequenccy drive spee
ed control of condenser
Varia
fans for compre
essor head pressure co
ontrol and
ximum part loa
ad performance.
maxi
formance sele
ected belt drivve system witth standard
Perfo
auto
o-tensioner to
o maintain prroper belt te
ension and
prevvent drive efficciency degrad
dation over tim
me.
W
Where Does ASHRAE
A
62.1
1 Fit into ths Picture?
In
n concert witth and in the
e spirit of ASHRAE 62.1
1
M
Modine has also looked on
nto the future
e with respectt
to
o ever tighten
ning indoor air
a quality standards (IAQ))
an
nd designed a product that can address filtration
n
ch
hallenges as high as MERV 16. With th
he application
n
off advanced filter designs, Modine can
n offer a high
h
qu
uality optiona
al IAQ filter systems thatt includes 2””
M
MERV 10 pre--filters in com
mbination with 4” MERV 16
6
fin
nal filters, alll fitting in a total depth
h of only 6”.
Additionally, th
his new filterr technology allows for a
otal pressure
e drop acros
ss the filterr system (att
to
m
maximum rated
d capacity) off only 0.41” W.C.
W
A
Again
in compliance with
ASH
HRAE
62.1
1
re
ecommendatio
ons the Atherion is offered
d with the full
ca
apability to meet
m
all of the minimum ou
utside air, and
d
ecconomizer sc
chemes of ASHRAE 62.1.
en designed to accept an
n
The Atherion has also bee
ptional total energy reco
overy modulle. Looking
g
op
ah
head the reco
overy wheel was
w designed
d to meet the
e
ne
ewly publishe
ed ASHRAE 189.1-2010 standard
s
and
d
ha
as a minimum
m effectivenes
ss of 60% at maximum airr
flo
ow. Much higher effecttiveness is achievable
a
att
re
educed air flows. This design feature
e presents a
ad
dditional opp
portunity to earn extra LE
EED points in
n
grreen building designs.
P a g e | 4 Full profile evapo
orator coil to maximize he
eat transfer
efficiiency over a broad range of air flows. Allows the
use of a 4 row co
oil with lower air side pressure drops
than
n comparable performing 6 row coils.
hly efficient ba
ackward curvved airfoil sup
pply fans to
High
redu
uce system ho
orsepower an
nd reduce the
e fan noise
often
n associated with other typ
pes of air movvers.
The unit cabinet size hass been opttimized to
ommodate hiigh efficiencyy filtration wiith low air
acco
side pressure d
drops for im
mproved IAQ at lower
RV 16 rated
operrating costs. Up to and including MER
filters
rs.
urfaces includ
ding the roof, walls, and
All cconditioned su
floorr are construccted of fully in
insulated 2” d
double wall
shee
et metal to reduce heat ga
ain, or heat lo
oss through
the e
exterior of th
he unit. Inne
er liners are completely
seale
ed to preven
nt moisture migration be
etween the
doub
ble wall panells.
with Modine’s factory
All units are provided w
prog
grammed and
d installed pre
ecision controll system to
assu
ure maximum
m operationa
al and comfo
ort control,
and system com
mpatibility.
This contro
ol assures
prop
per system fu
unction underr all load cond
ditions and
maxi
ximizes the energy efficiiency of the
e Atherion
cooliing and ventillation unit.
MCP15‐800
M
Modinee Manufacturing Company ‐Septtember, 2011