ENERGY ANAlYSIS OF A RETROFITTED SCHOOL BUILDINGWITH A SOLAR AIR HEATER

Sukhbir Mahajan, California State UniversityLanfranco Soma and Simonetta Fumagal 1i

ENEA, FARESergio Zabot, Regione Lombardia, Serviz;o Edilizia Scolastica

Ashok Kumar Bhargava, Ramjas College, Delhi University

ABSTRACT

A low cost methodology is used to evaluate the thermal performanceof a retrofitted school with a solar air heater~ The main aim of theanalysis is to determine with a reasonable accuracy the performance of thevarious subsystems and to make suggestions for improvements~

Hourly data f·or weather variables, indoor temperatures, fuelconsumption and heat delivered to the building (both from auxiliary and solarheater) are collected using an automatic Data Acquisition System (DAS)~

The infiltration rate was determined using tracer gas techniques andoverall conduction heat loss was determined using night time data during along cloudy period (5 days)* A constant temperature difference (betweenindoor and outdoor) was maintained throughout this period& The ambienttemperature was nearly constant during this peri ode Using these measuredquantities and hourly data, the passive solar gains are calculated. Asubtractive approach is used to obtain these quantities~ The results of 12day periods (7 to 18 March and 14 to 25 November 1985) are reported~ Forthese periods, the passive and active solar contributions make up 39% and30% re~pectively of the total heat load~ Suggestions for improvements toenhance these contri ions are presented.

The ana 1ys is of the data presented here, i nd i cate that the·methodology is simple and reliable for large scale monitoring using shorttime peri ods (10-15 days)t)

MAHAJAN ET ALo

ENERGY ANALYSIS OF A RETROFITTED SCHOOL BUILDINGWITH A SOLAR AIR HEATER

Sukhbir Mahajan, California State UniversityLanfranco Soma and Simonetta Fumagal 1i

ENEA, FARESergio Zabot, Regione Lombardia, Servizio Edilizia Scolastica

Ashok Kumar Bhargava, Ramjas College, Delhi University

I <= INTRODUCTION

The passive solar gains in bUildings are difficult to calculate~

Available models predict very different numbers for slightly differentclimatic conditions0

For policy making purposes and to encourage investment in solar(passive and hybrid) design, it is necessary to have a reliable method and atransparent procedure to determine solar contributions to the total heatingload&

In order to achieve this goal, a methodology 1,2,3 has been developedGUsing this methodology one can calculate the passive gains and evaluate thethermal performance of the various subsystems~

This methodology 4 has been tested on the Elementary School ofMontorfano (Como, Italy)~ The results show that the methodology is simple,reliable and that it is possible to arrive at a definite conclusion aboutlong term performance using short term data@

If performed in real time, a closed loop network model can be usedto drive various systems for controlling the energy performance~

II -- AND

The ada Elementary School ;s located 20 kme north of the city ofSondrio in Regione Lombardia (see Fige 1)@ It is at the end of ValMalenco (a side valley of Valtellina), below the Bernina Range -- in theAlps~ Winter and spring seasons are sunny and cool@ Summers are moderatelywarm@

The school is a masonry building made with massive stones, internallyvered with bricks (average thickness 70 cm~)0 The school has a compact

shape with all the classrooms facing south0 It is a three story buildingwith a small gymnasium at the lower levele

MAHAJAN ET ALe

Figure 2 shows the floor plan and a section of the building. In orderto decrease energy consumption, the following major retrofit measures wereinstall ed in 1983:

o Increased envelope insulation on North side

o Double glazed all windows on North side

o Insulated the ceiling

o Instal led solar air heaters on South facade connected witha venti 1ation system

Table I lists the physical parameters of the school~

III - METHODOLOGY AND DATA COLLECTION

A methodology is developed to determine the passive gains and toevaluate the solar air heater thermal performance~ All the energy sources,like auxiliary heater, solar air heaters and internal gains are monitoredClUsing this monitored data, energy balance for the whole building isperformed@ The fol lowing equation is used to determine passive solar gains:

Qpassive =Qloss - Qauxiliary - Qinternal - Qcollector

Qloss is made up of three parts:

Qloss = Qconduction + Qinfiltration + Qventilation

(1)

(2)

The infiltration rates were measured with tracer gas technique$ Thedetail of this technique is presented at the end of this section@ Theventilation rate is calculated by subtracting injected air from aspiratedair. The data on aspirated ~ir are obtained from the ventilation unitplaced at jower level; 3025 m Ih of air is aspirated through the stairwelland 1200 m /h is reinjected through the ventilation openings@

Due to the heating system desiqn it is difficult to determine theconduction heat loss coefficient (UA) with the coheating methode Thereforean indirect method has been used~ During a long cloudy period the indoor­outdoor temperature difference was held constant~ The auxiliary deliveredat night (10 hours) and temperature differences during this period weremonitored0

The measured infiltration heat losses are subtracted to obtain theconduction losses& The conduction losses are then divided by inside-outsidetemperature differences to obtain the overall conduction loss coefficient(UA)~ The average value for 5 nights is assumed as the true UA value. Itwas found that the UA value is 34% lower than the calculated value (Italian

MAHAJAN ET AL.

Standard UNI-CTI). Table II shows calculated and measured UA valuestbAuxiliary is calculated from the measured outlet and inlet watertemperatures and water flow rates. Solar col lector contributions aresimilarly obtained from air temperatures and air flow rate.

For internal gain calculations, 75 Wper student during the lessonhours is assumed~ The heat gains from lighting are also added to internalgains. Steady state conditions are assumed throughout the calculations.The tgerma 1 time constant of the wa 11 sis of the order of a few days (130hours ), and initial and final conditions should be considered in order todeal with short periods of time. For periods greater than 10 days thethermal mass effects are small. For seasonal performance evaluations theerrors due to thermal mass effects should be negligible.

The data collection was limited to a level adequate for assessingperformance evaluations of subsystems. A complete list of measuredquantities is given in Table III~ All probes were calibrated in thelaboratory before field"installation. The Solartron Schlumberger ORION isused for data logging. It allows some conversion on probes, counters unitand measures of eventsCl It is a high accuracy system and has manypossibi 1ities for programming and interfacing with oth,er systems~ The datawere recorded on a cassette tape and later transferred on to the VAX 11/750system via modems and telephone line.

During back-up operations, logger operations were interrupted. Therewere a lot of disadvantages by working in this mode. However, there were noother options available.

Tracer Gas Measurements

The tracer gas measurements were done at 4 places: classroom andcorr; dor at fi rst floor, classroom at second floor and gymnas i um at lowerleve13 The tracer gas (SF 6) was injected in the rooms, corridor andgymnasium~ After waiting for half an hour, four to five air samples fromeach of the spaces were taken at 15 minute intervals~

The concentr i on of SF 6 was measured us i ng gas chromatography\$ Fromthe 6 concentration decay rates, the air exchange rates were obtained~

The se mea sur em en t s we red one wit h fan 0 f f l& I n Tab 1e I V the air ex chan 9erate values for three different parts of the school are listedo

MAHAJAN ET ALe

IV DATA ANALYSIS

The main objective of the data analysis ;s to calculate the total heatlosses, auxiliary energy used, internal gains and solar energycontributions$ The solar energy contributions consist of two parts: theenergy provided by the solar air heater and passive solar gainse A shortdescription of the procedure used to calculate these quantities is describedbelowe

Total Heat Loss

The heat loss from the building occurs through conduction, infiltrationand ventilationo All these loss calculations assume steady conditions. Asmentioned earlier, this assumption is valid for periods longer than the timeconstant of the building&

The conduction heat losses were calculated using the value of conductionloss coefficient (UA) as determined above and the measured indoor-outdoortemperature differenceso

* T * t (3)

The infiltration heat losses were calculated using the infiltration ratedetermined from tracer gas measurements and indoor-outdoor temperaturedifference@

Q;nfiltration

::: Air Infiltration Rate for the j th space

::::: Temperature difference between the j thspace and outdoor

::::: Densi of air

::: Specific Heat Capacity of air

::: Duration

where v" =J

R~J

Tj

= V~*R9*P*C *~Te*tJ J Ja a J

Volume of the j th space

(4)

The ventilation losses are calculated using the ventilation rate as'e determined above (difference between aspirated rate and injected rate) and

indoor-outdoor telnperature differences. An equation very simi 1ar to Eq. (3)is used to calculate ventilation rate for the fan on periods.

3.119

r~AHAJAN ET AL 0

Auxiliary Energy

Auxiliary energy is provided by hot water radiators~ The energysupp 1i ed by the hot water was ca 1cu 1ated from the i nformat i on on in 1et­outlet water temperature differences and water flow rates, and the time forwhich the pump was on&

Qauxiliary

\'1here

:: F * fw * c *w T * t (5)

F :: Water Flow Rate

fw :: Density of Water

Cw :: Specific Heat Capacity of Water

T :: Inlet-Outlet Water Temperature Difference

t :: Time for which Pump is On

Internal Gains

The information on the number of occupants, time of occupancy and thelighting level was used to calculate internal gains@

Boiler Efficiency

The burner flow rate and the burner on ....off time gi ve the tota 1 oi 1burned and finally the oil burned along with the auxiliary energy deliveredgives the heating system efficiency~

Solar Contributions

The measured values of the air flow rate through the col lector, theinlet-outlet air temperature difference and the time for which the fan ison, are used to calculate solar contributions provided by the solar aircollectors~ An equation similar to Eq~ (4);s used for this calculationeFinally the passive solar contributions are calculated subtractively usingEquation- (l)@ However, any errors made in the calculation of Qloss and Qauxare lumped into the passive contributions$

~ V - AND DISCUSSION

Two 12 day periods were analyzed~ These two periods are representativetypical spring and fall cl;mate~

MAHAJAN ET AL.

During the twel ve day period in Fall (November) six days were sunnyand six days were overcast. In March, eight days were sunny and four dayswere overcast. The average ambient temperature is nearly the same duringthese per i 0 ds • The ins 0 1at; 0 n val ueson collec tor p 1 ane, i nd0 0 rtemperatures and outdoor temperatures are plotted in Figures 3 and 4 for athree day period (November 7-8-9 1~85). This is a relatively clear periodwith insolation peaking at 850 W/m 0

The bar chart in Figure 5 shows the hourly auxiliary delivered to thebuilding and the solar energy incident on the collector plane for the samethree day period@

There were considerable temperature variations in different parts of thebuilding primarily due to the stack effect: classrooms at lower floors havelower temperatures~ The increased ceiling insulation decreased the heatloss at the second floofe This means the radiator system needs to berecalibrated~ The corridors have generally lower temperatures than adjacentclassrooms due to the fact that corridors do not have direct gain (corridorsface north) and have higher infiltration rates0

In Figure 6 the average temperatures in different parts of the buildingare graphed for a twelve day period in November 19850 The heat balancecalculations are performed for the whole building~ The results for the 12day periods in March and November 1985 are presented in Table V and TableVI respecti y

Only values andive) are listed inthe tota 1 1oad~

15 of Q]oss~ Qin' Qaux and Qsol (both passive andis table~ The listed percentages are with respect

The ilyener balance has 11 le meaning, because of differentshifts in the various contributions due to the transient effects through thethick walls, twelve day ods presented are nearly free of thermalmass effects. ildi coll a considerable amount of solar ene29Y:the south facade has of direct 9ai~ aperture (windows) and 130 m ofcol lector area out a total 380 m of the south facade area$ Thecollector icien in e periods doesnit exceed 30% and 20%

ivel is low ici is mainly due to the low flowrate of ~ot

air remov from the collectors~ e measured air flowrate is 1200 m /hleaving the collectors versus 3200 m3/h (3025 from inside plus 175 from

ide) of air into collectors by the fan and pushed through~ Thedesigned value is 5 m3 jh with 60% efficiency~ The discrepancy is

ibuted to the fol lowing factors:

o collector trimmings

o Cracked Ducts are made polistyrene and thecracks are due either to vibrations from fan-engine andaccidental breaking of

r~AHAJAN ET AL @

There is a definite need to improve the collector performance*

o The ventilation unit should be moved to the attic andthe externalair intake should be closed0 Theairwouldbe aspiratedfromthe collectors and the fresh air wouldthen be taken from col lector leakse

o Thedistribution ducts should be redesigned and protectedfrom accidental damages@

o A better cal ibration of the air distribution system isalso needed@

The total solar contribution (30% in November and 39% in March) isquite good and with the modifications suggested~ should easily reach 35-45%of the total load. The collector contribution will increase ~f the existentventilation unit is moved to the attic@ It has been shown that for lowpressure solar air heaters, the leaks do increase the efficiency althoughoutlet air temperature decreases slightlY$

Average boiler efficiency for the 12 day period in November is 68%0 Itlooks good, considering that no retrofit measures been performed onauxiliary heating system0 In Table VII the daily iciency for November1985 is presented0

The operationa 1 logic seems qui adequate~ e huge mass of thebuilding is used as thermal storage for the heat coming from the collectorsand on sunny days this considerably reduces the auxiliary energy needs~

A comparison between March 83 energy use and March 85 energy6presented in TableVIII~ For the two month peri ,there is over 45%reduction in oil consumption0 Besides there is an increase in passive solarcontribution, due to improved insulation of the building~

Inc 0 nc 1us i on the ret r 0 fit measures are ad equa tel y des i 9ned and w; t hslight modifications the performance the solar air heater can improveconsiderably~ This will lead to a further reduction in oil consumption@

Acknowledgments

The authors are thankful to Dr0 Giuseppe Rizzi and Dr~ Eric Aranovitchfor many helpful discussion and criticism of the manuscript@ They aregrateful to ENEA and the Joint Research Centre for providing a pleasant

~ research environment and their generous hospitalityo

3.122

- MAHAJAN ET AL.

REfERENCES AND FOOTNOTES

1~ Palmiter L& Hamilton, Holtz Me BIlow Cost PerformanceEvaluation of Passive Solar Heating and Cooling ll

•

2. Mahajan S, Shea M, Newcomb C and Mort D0nperformance of Passive Solar and Energy ConcerningHouses in California u

0

SERI report STR-254-2017~

3@ Shea M, Mort 0, Mahajan S and Newcomb C~

"Documentation of Data Processing Procedures andExtension of Class B Data Analysis u

$

SERI report STR-254-2055@ September 1983

4e Zabot $, Mahajan S, Bhargava A K, Soma Land Fumagalli 50IRA Low Cost Methodology for Thermal Performance Monitoringof Public Schools in the Regione Lombardia"@Ispra - August 1985

5~ CNR - Progetto Finalizzato EnergeticaURepertorio delle Caratteri iche Termofisiche deiComponent; Edilizi Opachi e Trasparenti@UCNR-PEG Roma, May 1983

60 The 1983 energy use was obtained from the daily fieldpresently measured boiler efficiency0 The UA value wascalcul ed and then uc by 34%~ This percentagedifference was obtained for the measured and calculated UAvalues retrofi

~

NM

*M

N

SECTION A-A

AI

Ground floor

rt;\

r,.--J,.~,~,.\

--, . .,.....,

i\~ .f' A~ 1'- ., 'i!Ji .., .-'

'_, /J.'C!.l 'l:'~ -, ", ("_,,.1, \::1\ ". <:1,\ l.......

". ' ' "j ,0,,')\$'~~\ I',J ~ ,~\';"0 ,(-'" ';,,1-..;,·,:,,1,\ " •. J

',_, ~-t-'(~.,-- .<-(w?o:(-.i;JJ'1; \,J".,~;:1~~JJ' . . r < '.. .~ ~3~. u- :.'\

r ,,~...l~' -" I• ". '-'>. "

~t ;\<'~\ L.,-.~ .-:. I.OJA~\

~y.

"- "" ... , J ) I (----... ,-----"'- "'" r" I ;*-'\,j_../.--/r.-- .. . ">__"'-'-1°"'· .

"-)

(

Figure 1. Site location map,.Figure 2. School building floor plan and a section.

14-15-16 November 1985TEMP

6

4

2

a-2

-4

W -6/ 1Boem2 9Be

gOO700600SOB40030B200100

0

B 6 12 18 24 36 36 42 48 54 6B 66 72

time

Figure 30 Solar radiation and ambient air temperature profiles for a three day period (Nov' 14-16, 85)0

14-15 16 november 1985

21

5 10 15 20 25 30 35 40 45 50 55 60 65 70

2

2

t 15emp 10

ra 5tur Be

-5

-10

B

time

Figure 4~ Indoor and ambient air temperature profiles for a three day period (Nov 14-16, 85)6

450

400

350

300

({)

<0 250

(f)w..J

200:'>0J

150

100

50

0

14-15-16 NOVEMBER 1985

III

1. It

Lit/'1 ~ljl ill ll~1 UJJ~Jrtl'ij ,WII

li1'6 12 18 24 6 12 18 24 6 12 18 24

Q.AUXILIARY f2ZlJ TOT.INSOL. ON COll.

Fisure 5. Auxiliary energy used and solar radiation incident on col1ector~

IN r ERN/d. I\VL!V\GE [TMPERI\ TURE DIS 1 f< 1BUl ION (14 - 25 Nov. 19B'J)

18.1

Figure 60

Average internal air temperatures~

SECTION A-A

Table Ie Building parameters~

'-jOLUMEM·····3

FLOOF: HF:EA1"1"':2

GLt=1ZING1"'1"":2

CLASSF:OOI"1S 894 271 48 (South)

COF:F:IOCRS 720 218 15 (North) ~ 6 ,:East) • 6 (West)

G,{~lNASrUM 294 90 16 (South)

TOILETS '""""C" 68 24 (East) 6 (i'Jcrth)";''':'..,J~

OTHEF:S 464 110 8 (SoLlth)~

21 (t'lorth)

I NSULI':; T I 0 ~ J ( Aft e r- F: Eo t r 0 f 1 t

NOF:TH FACriDE 5 em. Polystirene ').:::\pCLlr 8art"" i er

GLAZING

ATTIC

DOLlb 1 e P.=\ne Gl.:\ss on i'larth '31 de

5 em. Polystlt""sne

Table II~ UA Values (W/C) of various part of build;ng~

CALCULATED VALUES (!TALIAN UNI-CT 7~57)

SURF:~CE

M"':::BEFOF:E

L1J/CAFTEr:;:I;.J/C

WALLS

wINDOl;J5

DOOF:S

F:OOF

GPOUr-1D

FLOOR

758

270

88

742 519

880 701

~8 16

316 153

50 50

305 305

TOTALS

r1E;"SUF:ED ')~LUES

AFTEF: r.ETFOF I

165:

NO') 18NO l

) 19NO'/ .::»NO'..' : 1~JO')

117.~

11 :'9115,)124(>1'): 1

11

{.1J/C

1744

AVERAGE VALUE ~SSUMED 1145 L>J/C

Table 111 0 List of measured quantities5 Table Vs Energy use for the month of March 1985~

N.PF:OBE DE3CF I F'r I ON

TI;'1ESC;"N

ST~IS

or'J T,;FE

~.\WFCH 1'9:! ~3.500 i •

':':1

4

6

M

00Nrot

1818 17

h:m QOI.J~

1514

Qint

1.:3

[ZJ

1210 i i

c.;:] Qc:ol!

98

Qpo~

7

fZZ]

0.500

0.000 1/",/1 L'./I 1/,/1 !/J11/./II",,'II,,/·j 1//' 1/,/11//'11/,/' !',"

3.000

2.500

CD

(

2 2_000

~

U1w 1.500-1:::l'0...,

1.000

11:' tliln.

1 1) tTIl n ..1.) :nl n.~ ,) tTlln.sec.

sec.:iee.'.5ec.

~2C. sec':::'1) .5t-:?t-='. :;'1) sec::'i> ~el= 011 9 1) =-,='':

:=-:' ='2':: 1(I :TIl n:;t2 t:: III 1.) :111 n

:-.J :nl n. :;<1 Inl n

5 :nl n. :J<' iTIln

:.: tTlln. ~\:l Inl nc: inl;-, • 2>1) :TIl-J

:J ,01 n. '::J') mIn~ In::. n. ~I,) '111n

- :TIl n. :J',) Inl n5 tTIln. ~(1 min:s :nl n. .~I.) ,n1 n5 ;111 n. tnl n

': nl n. ::J'.I :nl n

bU

60,~I)

.S.::'

5

2 i )

39

1')

111:21-=:1 -~

151.::'

171a1 .~

Al r Tl?:np. out of ColI C?ctQrAir Temc. Hole Second FloorAlr Temp. Hole First FlocrAir T.::?iTlp. Inl'2t of Collectc~r

ON-C:FF Fur-naceON-GFF W8ter PumpCI'I-iJF;:: F.::in LO~'J-Speed

orl--OFF F an Hi t:;Jh-Spe~dAu:: 11 i ar./ vJater Flovl F:2tteVJ':I t 2 r T 8 m~. I] U Tvj,~ I: '2'''- T t"?!Ttp. [r·J

S'Ji:::.. r Ins':::'l. on C;"Jllector- l~I!""1'.:?

S c; 1 :.. 1"- tn·:::; \:I 1. on Her i :: 0 n t .:::\ 1 F' '- d r. elJJa 1 I T:?ITIc'-2r =1 t Ut- '2

[un"- i dc,r r 2:np • at Lc,w.:;.r Le'/I? 1(:'::J ,:\1 C'"2PCiS 1 t r t::f1p.F:ccm Ted'tp. Secon.d F10C,t­FC':tn T,?,np. Fir ':; t F 100'­G';,Tina': ~ \..l.tO r'?lf:p.

Ccr:--:. ·:::·=r T."'?,no. 2ecl"Jnd F l GCJrCorrlder Temp. Fir~t Fl~or

~ t: :. 1 c T -einp •

Gr :Jurto.J T2tnp.:: 'l ~tr.i:. ~ :-?,n I:. T ..;?,no.

::1

Table IV. Infiltration rate measurement results.

" A:R ':H~:'lGES ~ER HOUR

':::L ..\SSR()O~,'S

:CRRIDCRS

OCCUPIED

0.60

2.00

UNOC;:UPIED

0.41

1 .86

Lan=ada Elementary School - 11ARCH 1895 [ JOULES * 10"'6 J

-----------------------------------------------Qsolar pas int sol

DATE Qloss Oint Dau:: ColI. Pas? % ., %

---------------------fhu 7 1637.2 200 .. 0 1205.8 4 .. 5 2::6 .. 9 14% 1~.•,

O~~

i 8 1802 .. 1) 200,,0 1329.8 .-. .......... 250.0 14 ~~ 11 i: 1'"~..:. . .:.. I ..

Sat 9 2002.8 200 .. 0 1029 .. 7 448.7 ::::24,,4 16% 1 (I:~,..... ......... ·1....:.. .... ,.

Sun 10 :2021.4 0,,0 959,,1 4:24.9 637 .. 5 32% (Ii~ 21%t'lon 11 214B.B 200 .. 0 895.U 192 .. 3 861. ·1 4(l:~ 9'" 9'"Tue 12 2081 .. 4 200 .. 0 11:0 .. 5 68.7 692 .. 3 33% 10% 3%t·Jed 13 196£L3 21)0 .. 0 940,,4 433" 1 394 .. 8 :O~~ 1O~·~ 22%Thu 1 ·1 2118.5 2(lc).O 9(lI).4- 534 .. 7 483.5 23:~ 9% :25%Fri 15 18'i9.0 200.0 923.1 210 .. 565.5 30% 111. 11%

Sat 16 2(193.1 200 .. 0 1059.1 6 .. 0 828 .. 0 40% i (li~ l)~~

17 ::::62. I) 0 .. 0 1068.4 -~G6" 3 81)7.3 36~~ (Ii: l'

° l

18 :::078 .. 8 200 .. 0 118U.4 1 1 1 " (l ~87 .. 4 28:~ 1 (II.. "J, ..

-------------------~------------------------------------

24113 .. 4 200(1 .. 1) 12611.7 2El·l2.8 6658.9 27% 8" 1""'"I.

Table VI~ Energy use for the month of March 1985& Table VIle Boiler efficiency.

mNr-I"

o

M

71.2":

If). C:;M.

61.S::

68. S":

67 .~::

72. \)~:

wo. _'·8

62 .. S~:

62" :~:

67.,Y:

·:=:3 .. -::::::

68. -:::::.:

Er-F I C I Et'lC'r"'

417

4,)6

4-::::34 ' .....,c_

4: 1:,

4':'6.1C=­"'1"....J _,

45845444(J

4:54\)7

5181

Q,;;..u::

TOTriL[kLxJh J

FUELDATE BUF.:I'lED

[L.t'JhJ

-------------------Thu 14 C=-,.

-J/

Fri 15 60Sat 16 64Sun 17 61""1,~n 18 656Tut? 19 ,:S8:t1Jed 20 669Thu 21Fri -..:.. 639SC\t "-t~

O"':'...c.

Sun 24 5'76t10n :::5 -:S15

------------------TOTALS / ....17";'

2?24.23

~ QOU1o{

222120

~ Qint

191817

lS:Sl 01:011

1B1S14

rz:zJ Opes

2.500

0.500

1.000

0.000 1/./11/1/11/,/11/,/1 1/

1[' '(1" '/,/1 I/Ifl 1/, ...·, 1/,/1 ;",/1 '/,/1

3.000

3.500 I NO'/EJ.fEEP 19~5I

(0

(

o 2.000

'*U1~ 1.50()::Jo..,

Table VIII~ Performance comparison (before and after retrofit).

M€·.:\sur-es in JCULES *" 11) ,~

Ti-Te Oloss

5167 54857

5167 ::::S8 1)

16508

7::.:+5 17:: 1)=

Qsclar­Call FaS5Qau:~Oint

62:29::

7653::4

85

!'I,:1F:CH

Lanzada Elementary School - NOVEMBER 1895 [ JOULES * 1 (V" 6

-----------------------~-----------------------Qsolar int sol

D?~TE QI05S Oint Qau~: Call .. Pass .. % I ..

--------------------------------------_._------------------------Thu 14 2602.4 200 .. 0 1461 .. 8 337.3 603.2 23:1;. 8% 13i~

Fri 15 2814.4 200.0 1560 .. 5 318.6 735.3 26:~ 7·' 11%

Sat 16 2758 .. 3 200.0 166 11.5 237.9 656 .. 0 24';: 7"' 9%/.

Sun 17 2781.0 0 .. 0 1~10 1 .. 1 207 .. 4 1072 .. 5 39% (l:~ 7%

t10n 18 25,:"7.6 200 .. 0 1461.2 1 .. I;> 904.5 35i: 8%

Tue 19 25(;~5. 3 200 .. 0 1629 .. 2 36 .. 8 637 .. 3 .a:..:.....J/qJ 8% 1·'

Ned 20 22-!.4.6 200 .. 0 1649 .. 7 18 .. 0 366 .. 9 16:'~ 9·' 11../.

lhu 21 2247.7 200.0 163~:' .. 1 0 .. 0 tl14 .. 7 18:~ 9% O~~

Fri ""'~ 2204.6 200.0 158.3.4 0 .. 0 4'21 .. 2 1Ci% 9% (Ii~~.:..

Sdt 23 2132.8 200.0 15:-~\(J. 4 11.6 390 .. 8 iEl:: 9°/ 1 ~~

Sun ~'l 2'29.3.7 0 .. 0 1465.5 171.1 657.1 29% o:~ 7%

tlCJn 25 271E3.B ~OO .. O 1511 .. 8 250 .. 6 756 .. 3 28:~ 7·' 9'1.

------ - - - - ----- - - - - _... - - - - - - - - - - _... - - ---- - - -.. - -- - - - - - --- - - - - - - - - - _.. - - - --29859.2 2000.0 18652.u 1S':;'l .. 1l 7615.8 ~5:~ 7·/ 5%