Design Analysis VRV

8/16/2019 Design Analysis VRV

1/47

CHAPTER 4

DESIGN ANALYSIS

4.1 Overview

Design is the creation of a plan or convention for the construction of an object or a

system while analysis is the process of breaking a complex topic or substance into smaller parts

in order to gain a better understanding of it. This chapter will cover on the design of this system

by conducting a cooling load study and perform the analysis.

4.2 Cooling Load Cal!la"ion

Internal and external cooling load is a vital criteria to estimate the building cooling load.

Internal load can be described as heat produce by occupants, machine and lighting.

https://en.wikipedia.org/wiki/Plan_(drawing)https://en.wikipedia.org/wiki/Convention_(norm)https://en.wikipedia.org/wiki/Complexityhttps://en.wikipedia.org/wiki/Plan_(drawing)https://en.wikipedia.org/wiki/Convention_(norm)https://en.wikipedia.org/wiki/Complexity


2/47

4.2.1 Solar Hea" Gain "#r! Gla$$

The area of the house is on 1! north of the "arth#s e$uatorial plane. The house

coordinate is %!&1'( latitude and 1!%&'". )sing window heat gain software, the values of

window heat gain in *tu+hr- unit can be obtained by key in the parameter such as window

orientation, solar heat gain coefficient value /0- and latitude of the location. olar heat gain

is influenced by the gla2ing type, the number of panes, and any glass coatings. olar heat gain of

gla2ing ranges from above 34 for uncoated water5white clear glass to less than 64 for

highly reflective coatings on tinted glass. 7 typical double5pane I0) has a /0 of around

.8. This value decreases somewhat by adding a low5" coating and decreased substantially

when adding a tint. In this project, all windows is covered with tint and assuming clearness and

sunshine percentage is 1 and 14, type of concrete is old surface and /0 value is .66, the

solar heat gain is available in 7ppendix 6 as well as (9: label (ational 9enestration :ating

ouncil). *ase on building survey, all windows are exposing to the sunlight and each of the solar

gain will be calculated accordingly. 9rom 7ppendix 6, the solar heat gain occurring in ;ay at

16? *tu+hr-s$.ft-, 7 = 6.@6 B @.6> = 1@.>6 ft6

/ence

$s = >?B1@.>6 = @,>@&.3 *tu+hr

http://www.commercialwindows.org/reflective.phphttp://www.commercialwindows.org/lowe-phphttp://www.commercialwindows.org/tint.phphttp://www.commercialwindows.org/reflective.phphttp://www.commercialwindows.org/lowe-phphttp://www.commercialwindows.org/tint.php


3/47

;aster *edroom window 1! (orth of "ast-

0iven,

) = >? *tu+hr-s$.ft-, 7 = >.63 B @.%@ = 61.%6 ft6

/ence

$s = >?B61.%6 = 3,>?6.3 *tu+hr

*edroom C6 window 1! outh of Aest-

0iven,

) = >@ *tu+hr-s$.ft-, 7 = 6.1> B %.%3 = 11.3? ft6

/ence

$s = >@B11.3? = &,63.& *tu+hr

*edroom C> window 1! outh of Aest-

0iven,

) = >@ *tu+hr-s$.ft-, 7 = 6.1> B %.%3 = 11.3? ft6

/ence

$s = >@B11.3? = &,63.& *tu+hr

*edroom C& window 1! outh of Aest-

0iven,

) = >@ *tu+hr-s$.ft-, 7 = 1.@& B &.%? = 8.%> ft6


4/47

/ence

$s = >@B8.%> = 6,81.3 *tu+hr

Dining /all window 1! outh of Aest-

0iven,

) = >@ *tu+hr-s$.ft-, 7 = @.%@ B @.3? = &%.6 ft6

/ence

$s = >@B&%.6 = 1@,686 *tu+hr

9amily 7rea window 1! outh of Aest-

0iven,

) = >@ *tu+hr-s$.ft-, 7 = 1.@& B &.@ = 8.%&& ft6

/ence

$s = >@B8.%&& = 6,81%.3& *tu+hr


5/47

4.2.2 Hea" Gain "#r! %all and Roo&

Aalls and :oofs can have an important effect on interior comfort conditions in both the

residential and non5residential sectors. Aalls and roofs come into direct contact with the exterior

environmental conditions. everal factors can be utili2ed to reduce energy consumption and

improve interior comfort conditions. ight colored exterior walls can help to reduce interior

temperatures by reducing solar heat gain. In addition, shade trees and bushes can reduce this heat

gain. 9or roof, insulation in the attic is important because the attic is a large source of heat gain

from the roof.

Total "$uivalent Temperature Difference T"TD- is used to account for the added heat

transfer due to the sun shining on exterior walls, roofs, and windows, and the capacity of the wall

and roof to store heat. The T"TD is substituted for ∆T in the e$uation for conduction. 9or this

project, a heat transfer software will be used to determine the heat gain through wall and roof.

:esistance value :-, which is thermal resistance of a material that will be used is determine by

the material itself and for this case the wall is common brick type which give :=.3 and roof is

ceramic tile which give : = 6.>1. :eferring to 7ppendix 6, the e$uivalent temperature difference"TD- for all areas occurring at 16pm is and transmission coefficient )- for @ inch thickness of

medium weight concrete, define as below-

:oof< ) = .18

The cooling load calculation for wall that expose to the sunlight is describe as below


6/47

Aall TD

;ain /all 5 Aall 1! (orth of "ast-

0iven,

) = .>? , "TD = 8>%.>

/ence

$s = .>?B8>%.> = [email protected] *tu+hr

Dining /all 5 Aall 1! (orth of "ast-

0iven,

) = .>? , "TD = &81.6

/ence

$s = .>?B&81.6 = 13>.88 *tu+hr

9amily 7rea 5 Aall 1! (orth of "ast-

0iven,

) = .>? , "TD = 13

/ence

$s = .>?B13 = 86 *tu+hr

;aster bedroom 5 Aall 1! (orth of "ast-

0iven,


7/47

) = .>? , "TD = 1686.

/ence

$s = .>?B1686. = &[email protected] *tu+hr

*edroom C6 5 Aall 1! (orth of "ast-

0iven,

) = .>? , "TD = &81.6

/ence

$s = .>?B&81.6 = 13>.88 *tu+hr

:oof TD

;aster *edroom roof

0iven,

) = .18 *tu+hr-s$.ft-, 7 = >.63 B @.%@ = 61.%6 ft6

/ence

$s = .18B61.%6B&@8%.> = 18,1&.11 *tu+hr

*edroom C6 roof

0iven,

) = .18 *tu+hr-s$.ft-, 7 = 6.1> B %.%3 = 11.3? ft6


8/47

/ence

$s = .18B11.3?B&@8%.> = ?&%.13 *tu+hr

*edroom C> roof 1! outh of Aest-

0iven,

) = .18 *tu+hr-s$.ft-, 7 = 6.1> B %.%3 = 11.3? ft6

/ence

$s = .18B11.3?B&@8%.> = ?,&%.13 *tu+hr

4.2.' Hea" Gain "#r! Ceiling and (loor

The transmission coefficient for ceiling and floor can be found from 7ppendix 6. 7ccording

to the transmission coefficient table, the ) value for bottom and top surface is .@1 *tu+hr-

s$.ft- while outdoor and indoor temperature are >! 3@- and 6@! 83.3- respectively. The

total of heat gain thru ceiling and floor is as below = 1@.>6 ft6

/ence

$s = .@1B1@.>[email protected] = 81.@8 *tu+hr


9/47

;aster *edroom eiling and 9loor

0iven,

) = .@1 *tu+hr-s$.ft-, 7 = >.63 B @.%@ = 61.%6 ft6

/ence

$s = .@1B61.%[email protected] = ?&.%6 *tu+hr

*edroom C6 eiling and 9loor

0iven,

) = .@1 *tu+hr-s$.ft-, 7 = 6.1> B %.%3 = 11.3? ft6

/ence

$s = [email protected][email protected] = %6.66 *tu+hr

*edroom C> eiling and 9loor

0iven,

) = .@1 *tu+hr-s$.ft-, 7 = 6.1> B %.%3 = 11.3? ft6

/ence

$s = [email protected][email protected] = %6.66 *tu+hr

*edroom C& eiling and 9loor

0iven,

) = .@1 *tu+hr-s$.ft-, 7 = 1.@& B &.%? = 8.%> ft6


10/47

/ence

$s = .@1B8.%>[email protected] = >>.8 *tu+hr

Dining /all eiling and 9loor

0iven,

) = .@1 *tu+hr-s$.ft-, 7 = @.%@ B @.3? = &%.6 ft6

/ence

$s = .@1B&%[email protected] = 1?3.%6 *tu+hr

9amily 7rea eiling and 9loor

0iven,

) = >@ *tu+hr-s$.ft-, 7 = 1.@& B &.@ = 8.%&& ft6

/ence

$s = .@1B8.%&&[email protected] = >>.1> *tu+hr


11/47

4.2.4 Hea" Gain &ro) Peo*le

The heat gain come from people consist of two types which are sensible and latent heat. The

calculation is based on 7ppendix 6. In building survey, the maximum of person that stay in this

house are four &- people. The example calculation as below


12/47

*edroom C6

"stimate number of people will occupied at this area is at a time is 6,

Es= 6B61 = &6

$= 6B1& = 63

*edroom C>

"stimate number of people will occupied at this area at a time is 1,

Es= 1B61 = 61

$= 1B1& = 1&

*edroom C&

"stimate number of people will occupied at this area at a time is 1,

Es= 1B61 = 61

$= 1B1& = 1&

Dining /all

"stimate number of people will occupied at this area at a time is @,

Es= @B61 = 16@

$= @B1& = 3&


13/47

9amily 7rea

"stimate number of people will occupied at this area at a time is &,

Es= &B61 = 3&

$= &B1& = %@

4.2.+ Hea" Gain &ro) Lig#"ing S,$"e)

/eat gain from lighting can be determined using e$uation E=A x >.& x *9 x 9.

7ccording to 7ppendix 6, the fluorescent lamp has typical value of 1.% A+s$.ft. *elow is the

calculation for sensible heat gain by lighting = 1@.>6 ft6

$s = 1.%B1@.>6B1.6%B>.&1= 1&.>% *tu+hr

;aster *edroom

7 = >.63 B @.%@ = 61.%6 ft6

$s = 1.%B61.%6B1.6%B>.&1= 1>8.%? *tu+hr

*edroom C6

7 = 6.1> B %.%3 = 11.3? ft6


14/47

$s = 1.%B11.3?B1.6%B>.&1= [email protected] *tu+hr

*edroom C>

7 = 6.1> B %.%3 = 11.3? ft6

$s = 1.%B11.3?B1.6%B>.&1= [email protected] *tu+hr

*edroom C&

7 = 1.@& B &.%? = 8.%> ft6

$s = 1.%B8.%>B1.6%B>.&1= &3.1& *tu+hr

Dining /all

7 = @.%@ B @.3? = &%.6 ft6

$s = 1.%B&%.6B1.6%B>.&1= 63?. *tu+hr

9amily 7rea

7 = 1.@& B &.@ = 8.%&& ft6

$s = 1.%B8.%&&B1.6%B>.&1= &3.6> *tu+hr


15/47

4.' Sele"ion o& S,$"e)

7fter the entire cooling load has been determined for each area, the next step is to find the

total cooling load for entire house. The total cooling load will help to determine the selection of

F:F model that suitable with the load. This is important due to undersi2e of the system will

cause the desired temperature unable to achieve and oversi2e the system will cause the waste of

energy. Table &.1 show the list of the cooling load for each area and the total cooling load for

entire house.

Ta-le 4.1 ummari2ed of ooling oad

(loor Loa"ion

T,*e o& Cooling Ca*ai", /0"!#r To"alCooling

Ca*ai",

/0"!#r%indow %all Roo&

Ceiling

and

&loor Peo*le Lig#"

1

;ain /all @,>@&.3 [email protected] (7 81.@8 6,1 1&.>% 3,?68.%?

Dining /all 1@,686 13>.3 (7 1?3.%6 6,1 63?. 1?,&>.6?

9amily 7rea 6,81%.3& 86. (7 >>.1> 1& &3.6> &,3??.6

*edroom C& 6,81.3

(7 (7

>>.8

>% &3.1&

>,1&6.1

6;aster*edroom 3,>?6.3 &[email protected] 18,1&.11 ?&.%6 8 1>8.%? 6@,?6%.1

*edroom C6 &,63.& 13>.3 ?&%.13 %6.66 8 [email protected] 1&,8&6.%?

*edroom C> &,63.& (7 ?,&%.13 %6.66 >% [email protected] 1&,63.36

To"al 31555.67


16/47

7s per table &.1, total cooling load is ?1,333.@ *tu+hr without considering any safety

factor. afety factor is to be applied to all rooms to cover up the error of the calculation. To get

an ideal and effective air conditioner system, safety factor of 14 is applied. The value after

adding 14 safety factor are called "ffective :oom Total /eat ":T/-. Table &.6 determine the

actual total capacity after safety factor of 14 is applied.

Ta-le 4.2 E&&e"ive Roo) Cooling Load

(loor Loa"ion

To"al Cooling

Ca*ai",

/0"!#r

E&&e"ive Roo)

Cooling Load

/0"!Hr

1

;ain /all 3,?68.%? ?,36.>%

Dining /all 1?,&>.6? 6,?&8.@6

9amily 7rea &,3??.6 %,>3?.16

*edroom C& >,1&6.1 >,&%@.61

6

;aster

*edroom 6@,?6%.1 6?,@18.@1

*edroom C6 1&,8&6.%? 1@,[email protected]%

*edroom C> 1&,63.36 1%,@6?.8

TOTAL ?1333.@ 11,88.&@

7fter safety factor been applied to the existing cooling, the new total cooling load is 11,88.&@

*tu+hr. The selection of the model will be based on comparison of design capacity of that model

versus cooling load re$uired by the house. 7fter some survey and market research, Daikin F:F

system with model number :GE16T/H1"- is suitable since this model provide cooling

capacity up to 11&, *tu+hr and maximum of indoor unit that can be connected is 6.


17/47

Table &.61 shows the specification for Daikin F:F model :GE16T/H1"-. 7s per

below specification, the recommended total pipe length is >,63 ft and the weight for outdoor

unit itself is 13% kg. 7lthough manufacturers routinely increase the maximum allowable

refrigerant pipe run, the longer the lengths of refrigerant pipes, the more expensive the initial and

operating costs. 9or most F:F units, the maximum allowable vertical distance between an

outdoor unit and its farthest indoor unit is approximately 1% ft &@ m-. The maximum

permissible vertical distance between two individual indoor units is approximately &% ft 1& m-

and the maximum actual refrigerant piping lengths allowable between outdoor and farthest

indoor units is up to &? ft 1&? m-. 9or indoor unit, there are & models that need to be used base

on cooling load re$uirement. Indoor units are available in multiple configurations such as wall5

mounted, ceiling5mounted cassette suspended, and concealed ducted types. 9or this project, wall

mounted type has been choose due to flexibility and ease of installation. tarting from 8,%

*tu+hr to >, *tu+hr cooling capacity will be used to cool down from >,&%@.61 *tu+hr up to

6?,@18.@1 *tu+hr cooling load. The list of indoor unit as indicate in table &.6.1.

Ta-le 4.2.1 Li$" o& Indoor !ni"

Model Type Cooling CapacityFXAQ07P Wall mounted type 7500

FXAQ09P Wall mounted type 9500FXAQ18P Wall mounted type 18000FXAQ30P Wall mounted type 30000


18/47

Ta-le 4.2.2 S*ei&ia"ion &or O!"door Dai8in 9R9


19/47

Ta-le 4.2.2 S*ei&ia"ion &or Indoor Dai8in 9R9 /(:A;7


20/47

Ta-le 4.2.' S*ei&ia"ion &or Indoor Dai8in 9R9 /(:A;73P


21/47

Ta-le 4.2.+ S*ei&ia"ion &or Indoor Dai8in 9R9 /(:A;15P


22/47

4.'.1 Co$" Anal,$i$

*elow table is total cost to purchase indoor and outdoor unit for Daikin F:F 1J.

Quantity Location

Indoor Outdoor

Model/ Type

RatedCoolingCapacity(Btu/h)

Price(RM)

Quantity Model


Price(RM)

1 Main Hall

FXAQ09P

9500 2,187

1 RXQ12THY1€ 114,000 28,500

Wall mount!t"#

1 $inin% Hall

FXAQ18P

18000 &,000

Wall mount!t"#

1 'it(n

FXAQ07P

7500 1,820

Wall mount!t"#

1*!+oom

4

FXAQ07P

7500 1,820

Wall mount!t"#

1Ma-t+

*!+oom

FXAQ&0P

&0000 4,551

Wall mount!t"#

1*!+oom

2

FXAQ12P

18000 &,000

Wall mount!t"#

1*!+oom

2

FXAQ12P

18000 &,000

Wall mount!t"#

.u/ Total 108,500 19,&78

114,000 28,500

+an! Total n!oo+ 3ut!oo+ RM) 47,878

*elow table is installation cost for F:F


23/47

ITEM DESCRIPTION UNIT QTY

AMOUNTBEFORE GSTRM!

AMOUNTAFTERGSTRM!

A

Supply materal and manpo!er ton"tall ndoor and outdoor #ara$le

%e&r'erant #olume ()! a((e""ore",*ttn'", ppe !or+", (ondut !rn',

$ra(+et and "upport &or Floo" # -all,nn', Famly Area and /edroom 4.

otal re&r'erant ppe len'tappromately 204&t otal

manpo!er " 4

6ot 1 5,133 5,441

/

Supply materal and manpo!er ton"tall ndoor and outdoor #ara$le

%e&r'erant #olume ()! a((e""ore",*ttn'", ppe !or+", (ondut !rn',

$ra(+et and "upport &or Floo" $a"ter /edroom, /edroom 2 and

/edroom 3.otal re&r'erant ppe len'tappromately 71&t otal

manpo!er " 4

6ot 1 4,387 4,50

e"tn' and omm""onn' 6ot 1 1,500 1,590

:rand otal 11,020 11,81

*elow table is operational cost for F:F

odel

Po!eron"umpton

-our"perday

;ner'yon"umpton

per year +!

% peryear

Main Hall

FXAQ09P 30 Watt 9 98.55 21.4

Wall mount!t"#

$inin%Hall

FXAQ18P 30 Watt 9 98.55 21.4Wall mount!t"#

Famil" A+a

FXAQ07P 20 Watt 9 5.7 14Wall mount!t"#

*!+oom4

FXAQ07P 20 Watt 9 5.7 14Wall mount!t"#


24/47

Ma-t+ *!+oom

FXAQ&0P 70 Watt 9 229.95 53.Wall mount!t"#

*!+oom2


*!+oom2


3ut!oo+ nit

RXQ12THY16 9.2


25/47

%epla(e=AS &an$earn'" 10 1 140 337 49

%epla(ere&r'erant 10 8 70 133 220Su$totalrepar)repla(e 1,392

otal%> 3,777

9igure :efrigerant pipes must remain clean, dry, and leak free. Ahen stored prior to

installation, the edges of refrigerant pipes need to be sealed. (itrogen gas must be used during

welding to prevent oxidation of the interiors of refrigerant pipes. 7 detailed installation manual

must be followed. The installer should be familiar with the control options available for F:9

systems. "ach individual indoor unit can be controlled by a programmable thermostat or a

multiple indoor units serving the same 2one can be controlled by the same thermostat.

*elow table is total cost to purchase split aircond

Quantity Location

Model

Brand Indoor


Pricebefore

!T (RM)

Price after !T (RM)

1 Main Hall

*.Q09*8A5

9500 &,82 4,05Wall mount!t"#

1$inin%Hall

Pana-oni(

P:18H'F

18000 4,01 4,257Wall mount!t"#

1Famil" A+a

AR07&.*4

7500 &,179 3,370Wall mount!t"#

1*!+oom

4

AR07&.*4

7500 &,179 3,370Wall mount!t"#

1Ma-t+

*!+oom

.&07H;&

&0000 7,255 7,90Wall mount!t"#


26/47

1*!+oom

2

.120H6;

12000 &,788 4,015Wall mount!t"#

1*!+oom

&

.120H6;

12000 &,788 4,015Wall mount!t"#

Total 9,500 29,0&1 &0,77&

Total Price after !T +,-..+

Installation cost for plit 7

ITEM DESCRIPTION UNIT QTY

AMOUNTBEFOREGSTRM!

AMOUNTAFTERGSTRM!

A

Supply materal and manpo!er ton"tall ndoor and outdoor Splt unt()! a((e""ore", *ttn'", ppe !or+",(ondut !rn', $ra(+et and "upport &orFloor 1 -all, nn', Famly Area and/edroom 4.otal manpo!er " 4 %150)ead

Wrn' %250)unt

6ot 1 3,850 4,081


27/47

/

Supply materal and manpo!er ton"tall ndoor and outdoor Splt unt()! a((e""ore", *ttn'", ppe !or+",(ondut !rn', $ra(+et and "upport &orFloor 2 a"ter /edroom, /edroom 2and /edroom 3.

otal manpo!er " 4 %150)eadWrn' %250)unt

6ot 1 3,100 3,28

e"tn' and omm""onn' 6ot 1 1,500 1,590

:rand otal 8,450 8,957

Kperational cost for plit 7

Model B"andPo/e"

Con%*&ption 0/!

1o*"%

pe"day

Ene"gyCon%*&ption pe"

yea"0/2!

RM pe"yea"

Main "all

*.Q09*8A5

2.8 9 9198 2,005Wall mount!t"#

#ining

"all

P:18H'F

Pana-oni(

5.28 9 17344 3,780

Wall mount!t"#

$a%ily&rea

AR07&.*4

2.1 9 898 1,503

Wall mount!t"#

Bedroo%'

FXAQ07P;


28/47

*elow table is total cost for repair and maintenance for plit 7

Co%t Ite&%

Pe"iodyea"% Qty'

(a)o"Co%tRM!

Mate"ial Co%tRM!

Ann*alCo%tRM!

Maintenance %epla(e ar*lter"ndoor

0.5 7 35 154 504

e(+)(lean

&an (ol(onden"ate"y"tem"

1 7 105 280 393

%epla(e ar*lter"outdoor

1 7 84 175 27

Su$totalmantenan(e

1,14

Repair/Replace Fan (ol

motorrepla(ement 10 7 490 3000 392

%epla(e(apa(tor 10 7 35 315 37%epla(etermo"en"or 10 7 35 140 19

%epla(ere&r'erant 10 7 105 980 118Su$totalrepar)repla(

e 57 otal%> 1,730


29/47

CHAPTER +

DISC=SSION

+.1 In"rod!"ion

It is important to know how much the total of the cooling load of a project so that a good

selection can be done and to avoid waste. Aith the availability of calculation and formula, the

cooling load of each area can be determined. Knce the total of cooling load has been discovered,


30/47

then only searching activity for the suitable system can be done. "very manufacturer will provide

information such as cooling load capacity of a model. Ahen the differentiation between cooling

load re$uirement and cooling load capacity is executed, then only the specific model can be

selected by choosing the lesser of the differentiation so that the efficiency can be maintained and

optimi2ed.

+.2 Co)*ari$on o& Ca*i"al Co$" -e"ween 9R9 and S*li" AC

(ig!re +.1 < apital ost omparison


31/47

9igure %.1 is comparison chart between F:F and plit 7 for total capital cost. 9or

initial cost, the F:F capital cost is 164 or :; %,@? higher than plit 7 due to the price of

outdoor F:F it is expensive. /owever the final decision for system selection will be based on

operational cost and :eturn on Investment :KI-.

+.' Co)*ari$on o& Re*air and >ain"enane Co$" -e"ween 9R9 and S*li" AC

(ig!re +.2 Re*air and >ain"enane Co$" Co)*ari$on


32/47

9igure %.6 shows a comparison of repair and maintenance cost between variable

refrigerant volume and split air conditioner. The information is obtained from Daikin and 0

/F7 website 6J. (ormal maintenance for a F:F, similar to that of any DG system, consists

mainly of changing filters and cleaning coils. The large number of compressors in a F:F may

create a higher probability of compressor failure, although the redundancy also leads >J. *oth

systems will be schedule to service every @ month and annually based on the preventive

maintenance schedule. In this case, the service cost for F:F is :; @1 higher than split 7 due

to price of material and labor cost as F:F is more high technology than split 7. 9or repair cost,

the recommendation is to replace every 1 years and the amount has been divided accordingly so

that 1 year of service cost can be figured out. This comparison is applicable for 1 year of service

and :KI will be calculated for 1 years of service to determine which system is most profitable.

+.4 Co)*ari$on o& Energ, Con$!)*"ion -e"ween 9R9 and S*li" AC


33/47

(ig!re +.4 Energ, Con$!)*"ion Co)*ari$on

The energy efficiency of F:F systems derives from several factors. The F:9 essentially

eliminates duct losses, which are often estimated to be between 14 to 64 of total airflow in a

ducted system.> F:F systems typically include two to three compressors, one of which is

variable speed, in each condensing unit, enabling wide capacity modulation. This approach

yields high part5load efficiency, which translates into high seasonal energy efficiency, because

/F7 systems typically spend most of their operating hours in the range of &4 to 34 of

maximum capacity >J. 9rom figure %.&, it is very obvious that the indoor F:F unit consume

very less energy compared with split 7 and this give a maximum saving in electricity. The F:F

outdoor unit may consume more energy, but it#s still much lower than split 7.

+.+ Co)*ari$on o& O*era"ional Co$" -e"ween 9R9 and S*li" AC

(ig!re +.+ Kperational ost omparison

9igure %.% shows a comparison of operational cost between F:F and split air conditioner

system. The total operating hours in one year is estimated as >6& hours including public


34/47

holidays and weekends. In this case, F:F system has a lower operational cost compared to split

air conditioner. Kperational cost of F:F for one year is :; 8,68 while operational cost for split

air conditioner in one year is :; 16,&%. In one year, cost saving of :; %,&6> could be

generated if F:F system is been used.

+.6 Co)*ari$on o& Overall Co$" -e"ween 9R9 and S*li" AC

(ig!re +.6 Overall Co)*ari$on Co$" &or 1 Year


35/47

In many cases, the initial cost of a F:9 system is higher than that of a split air

conditioner system. 9igure %.@ is comparison chart between F:F and plit 7 for overall cost in

one year operation. The F:F system is spending approximately :; 6>,%> higher than split air

conditioner and this is normal due to the F:F system depend on payback period in order to gain

saving. This overall cost is calculated for 1 year period, including capital cost which gives an

advantage to split air conditioner system. 9or long term standpoint and to gain back the F:F

investment, an :KI analysis is re$uired.

+.6 Re"!rn on Inve$")en" anal,$i$

ROI 3 #, Yea"%


36/47

(ig!re +.6 Re"!rn on Inve$")en"

:eturn on investment :KI- is the benefit to an investor resulting from an investment of

some resource. 7 high :KI means the investment gains compare favorably to investment cost. 7s

a performance measure, :KI is used to evaluate the efficiency of an investment or to compare

the efficiency of a number of different investments &J. 9igure %.@ shows that F:F is able to

return back the capital investment in 1 years and generate tremendous saving after the said

period. The saving is calculated based on operational cost saving minus the maintenance cost.

Ahen the net cost saving is obtained, it will accumulate every year and :KI is achievable at 1

years. Aithout doubt, the efficiency of F:F system is proven by generating an operational cost

saving every year.

+.< Sele"ion o& Air Condi"ioning $,$"e)

Kbservation from table &.1, the total cooling load is ?1,333.@ *tu+hr and the total

effective cooling load is 11,88.&@ *tu+hr in order to provide cooling for a 6 storey terrace

house that have a built up 1 s$+ft. 9rom the table it can be seen also that the heat gain

through the wall has the highest value due to material of the wall is poured concrete 3 lb+ft> with

thickness @ inches. The most important factor in finali2ing the selection is to make the cost

comparison. Knce the specification of a model has met the re$uirement of the project, purchase

cost can be obtained by doing internet survey or directly contact with the supplier.

Ahen the purchase cost for F:F and split unit is available, the cost of installation can be

obtained by engaging the $ualified contractor that has experience installing this system. Ahen all

the costs are available, comparison can be made by checking which system has lowered cost and

suitable with this project. *ased on the analysis performed, the most suitable air conditioning

system for this project is variable refrigerant volume because is more cost effective compared to

split air conditioner. The F:F is capable to save :; &,366 yearly, return back the investment in

1 years and generate :; &3,66 cost saving after 6 years of operation.

https://en.wikipedia.org/wiki/Investmenthttps://en.wikipedia.org/wiki/Investment


37/47

CHAPTER 6

CONCL=SION AND RECO>>ENDATION

F:F systems offer controls that match the space cooling loads to that of the indoor coil

over a range of operation. Fariable speed compressors and fans in the outdoor units modulate

their speed, saving energy at part5load conditions. Kutdoor sections should be si2ed to match

building peak loads, not the sum of the peak load for each 2one, reducing the capacity of outdoor

units when compared to a conventional unitary system. The system offers designers and

occupants the ability to choose multiple individuali2ed 2ones, which improves system


38/47

controllability. The system capabilities and limitations should be evaluated carefully to determine

the suitability of the F:F for a project and to optimi2e its design.

APPENDI: 2

olar heat gain table for cooling load calculation


39/47


40/47

etting for window orientation at 1! (orth of "ast

olar /eat 0ain value from Lanuary to December for 1! ( of " orientation


41/47


42/47

etting for window orientation at 1! outh of Aest

olar /eat 0ain value from Lanuary to December for 1! of A orientation


43/47

: Falue for ommon *rick

oftware for /eat Transfer through ;aterial


44/47

Transmission coefficient of ommon *uilding ;aterial

: Falue for :oofing


45/47

Thermal onductivity )- for 7sbestos5cement :oof

Transmission oefficient for eiling and 9loor


46/47

:eference

1J http???@a-+a@o+%>Fil20i/+a+">!o(i/>@@@>20070&27B%otCl+@#!D

&J https


47/47

Design Analysis VRV

Documents

Transcript of Design Analysis VRV