Lalu... bagaimana kalau ruangannya lebih besar dan membutuhkan kapasitas pendinginan yang lebih besar?
OK selain type split wall, juga ada type split duct, type cassete (2,5 sd 4,5 PK), type ceiling suspended (2,5 sd 4,5 PK), floor standing (5pk). Hal ini tergantung kebutuhan dan ketersediaan ruang yang ideal.
Contoh:
Sebuah kantor memiliki 4 ruang, A=4x4m2; B=3x5m2; C=6x6m2; D=4x5m2
menggunakan AC sentral dengan ducting didalam plafon.
Jawab:
A = 4x4x550 BTU/h = 8.800 BTU/h
= 8.800 BTU/h/30 = 293 CFM
B = 3x5x550 BTU/h = 8.250 BTU/h
= 8.250 BTU/h/30 = 275 CFM
C = 6x6x550 BTU/h = 19.800 BTU/h
= 19.800 BTU/h/30 = 660 CFM
D = 4x5x550 BTU/h = 11.000 BTU/h
= 11.000 BTU/h/30 = 367 CFM
Total E = A+B+C+D = (8.800 + 8.250 + 19.800 + 11.000) BTU/h = 47.850 BTU/h
= 1.595 CFM
sketsa instalasi AC Ducting
-------------h--------------g
| --a--A --b--B
---- / /
| E |---f---|-----e----|
---- \ \
| -d---D --c--C
--------------j--------------i
Supply
Diffuser A = 8.800 BTU/h:293 CFM = 7"
Ducting a = 8"x9"
Diffuser B = 8.250 BTU/h:275 CFM = 7"
Ducting b = 8"x9"
Diffuser C = 19.800 BTU/h:660 CFM = 12"
Ducting c = 15"x9"
Diffuser D = 11.000 BTU/h:367 CFM = 9"
Ducting d = 10"x9"
Ducting e = B + C = 935 CFM = 24"x10"
Ducting f = A + B + C + D = 1.595 CFM = 25"x13"
Ducting return g = 293 CFM = 11"x10";
RAG-B = 10"
Ducting return i = 660 CFM = 19"x10";
RAG-C = 14"
Ducting return h = A + B = 293 + 275 = 568 CFM = 16"x10"
RAG-A = 293 CFM = 10"
Ducting return j = C + D = 660 + 367 = 1.027 CFM = 19"x13"
RAG-D = 367 CFM = 10"
Fresh Air duct
= vol ruang x pertukaran udara/jam x 35,31 (angka keramat) 261 x 2 x 35,31
--------------------------------------------------------- = ---------------- x 1/60 = 307 CFM
60
FAG = 10" dg ducting 11"x10"
atau gampangnya adalah 20% dari total CFM
tabel besaran diffuser, grille dan ducting menyusul atau lihat di sini:
www.hartandcooley.com/flex/Air%20Duct%20Calculator.xls
ketik di paman google :"DUCT_SIZING" filetype:XLS
