7/23/2019 Transmission Coefficient u Final

1/8

Najran Court Complex

Calculation of

Transmission Coefficient ( U )

.

7/23/2019 Transmission Coefficient u Final

2/8

Transmission Coefficient U

Btu/hr. Ft2. F

Heat Gain (Btu/hr) = Area x U x t (out!oor tem". # in!oor tem".)

$etermine the %esistance (%) of the structure

R = R1+ R2+ R3+ .. Rn

Then:&

U=

%

1- Masonry Parttons

2- Masonry !xposures

3- "lat Roo# $th Roo# % &e'( )nsulaton

*- Transmsson Coe##'ent #or $no,s.

.

7/23/2019 Transmission Coefficient u Final

3/8

&' asonr *artitions

2mm ollo, /lo'( 0r2

2mm an Plaster 0 r1 ( 2mm an Plaster 0r3

Masonry Parttons stru'ture

Masonry Parttons stru'ture Materal:

2mm ollo, /lo'( ,th /oth ses san plaster 2mm as sho,n n ta4le 25

0Transmsson 'oe##'ent % masonry partton Part 1 loa estmatn6 Carrer an4oo(.

U = +.,&

.

7/23/2019 Transmission Coefficient u Final

4/8

2 ' asonr -x"osures

2 mm 'on'rete 4lo'( 0R3 7 mm nsulaton 0R*

2 mm an Plaster 0R2 17 mm 'on'rete 4lo'( 0R7

)nse sur#a'e resstan'e 0R1

8utse sur#a'e resstan'e 0R9

8utse Masonry $alls tru'ture

st o# outse ,all materal:

1. )nse ur#a'e Resstan'e R1= .59

2. 2 mm an Plaster R2 = .17

3. 2 mm ea;y Con'rete /lo'( R3= 1.*

*. 7 mm !xtrue polystyrene R*= 9.9* a#ter 7 years o# nstallaton

7. 17 mm ea;y Con'rete /lo'( R7= .hr. #t2. ?"

R 11.

7/23/2019 Transmission Coefficient u Final

5/8

ote0 1all construction as "er architectural !etails.

All %'alues are 3ase! on A4H%A- Fun!amentals Ch. 25 an! local manufacturers6 s"ecifications.

3 - Roo# ,th Roo# % &e'( )nsulaton

.

2 mm tles

7/23/2019 Transmission Coefficient u Final

6/8

Roo# stru'ture Materal

Con'rete th'(ness s 2* mm ,th 5 mm nsulaton on top o# e'( as sho,n a4o;e

Roo# &e'( Materal R ;alues:

1. 8utse sur#a'e resstan'e R1= .27

2. Tles san 'ement an mortar R2= .37

3. 7 mm !xtrue polystyrene R3= @.* a#ter 7 years o# nstallaton

*. * mm ,ater proo# mem4rane R*= .127. 7 mm slope s'ree R7= 1.7*

5. 25 mm hea;y,e6ht 'on'rete R5= .

7/23/2019 Transmission Coefficient u Final

7/8

U = +.+75 Btu/hr. Ft2. F

ote0 %oof construction as "er structural an! architectural !etails

All %'alues are 3ase! on A4H%A- Fun!amentals Ch. 25 an! local manufacturers6 s"ecifications.

8 ' Transmission Coefficient for 1in!o9s

&ou4le 6lass ,no, 5mm 6reen + 12mm ar 6a4 + 5mm 'lear 0Al. #rame ,thout

thermal 4rea(

A''orn6 to ARA! "unamentals 'hapter "-31 0Ta4le *:

.

7/23/2019 Transmission Coefficient u Final

8/8

U = +.:7 Btu/hr. Ft2. F

A''orn6 to ARA! "unamentals 'hapter "-31 0Ta4le 13 solar heat 6an 'oe##'ent

BC = .29 #or e = .7 on sur#a'e 2

han6 Coe##'ent:

C = BC>.9< = .32

.