A PRESENTATION

ON

ENERGY SAVINGIN BASEMENT AR PARK VENTILATION FORTHE ADMINISTRATIVE BUILDING AT GREAMS ROAD , CHENNAI.1

Tamil Nadu Telecom Circle

ADMIN BUILDING AT GREAMS ROAD, CHENNAI Proposed Hi-Tech Admn. Bldg Consists of 2 Towers- G+8 / G+5 and has a common lower and upper level Basement Capacity of Basement Parking for 157 cars & 97 two-wheelers. Area of Basement (covers Towers 1&2) Lower Basement Upper Basement 4664 sq.m 4437 sq.m

Ceiling height of basements -

2.2 Mtr2

Car Parking area in Basements are fully enclosed. Enclosed Under-ground parking area requires Mechanical Ventilation. In absence of Ventilation, Parking facility presents several Internal Air Quality problems. Most serious is the emission of high levels of Carbon-Monoxide(CO) CO is easily absorbed by Haemoglobin in Human Blood and can Inhibit Oxygen delivery to Body and can cause adverse health effects varying from headache to death3

The NATIONAL BUILDING ODE OF INDIA 2005 Specifies the following parameters for Ventilation: CO level- within 29mg/cu.m (25 ppm) with Peak level not to exceed 137 mg/cu.m.(125 ppm) As per ASHRAE Max Level for CO 8 hrs exposure 25ppm 1 Hour exposure- 35 ppm Air change requirement as per NBC for Basement Car Parking : 9 to 12 ACPH under normal conditions ( For Design purpose 10 ACPH is used) 30 ACPH in case of fire emergency4

DUCTED VENTILATION The Conventional Ventilation System is the ducted Ventilation system. This has: -Provision of Fresh air fan and Exhaust Air Fans with ducting arrangement as per requirement. - To be operated based on timing control. - Full capacity of Fans has to be operated irrespective of Smoke level or CO Concentration.5

DUCTLESS VENTILATIONThe Modern method of Ventilation system is the Ductless Ventilation system in which : - No Ducts are required. - Only Fresh Air Fans, Exhaust Air Fans and Jet Fans required. - CFD(Computational Fluid Dynamics) analysis, is utilised to decide the number and location of Jetfans for effective and optimum performance. - A group of approximately 4 Nos of Jet Fans are controlled by one CO Sensor and Integrated with IBMS. - When the CO level exceeds threshold value, CO Sensors extends signal to IBMS and accordingly the corresponding group of Jet Fans are triggered. - When CO level exceeds threshold value in approximately 50% of CO Sensors per Basement , then Fresh Air/ Exhaust Fans are switched ON through IBMS along with jet fans

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ADVANTAGES OF DUCTLESS VENTILATION No ducts: duct system and accessories are eliminated. Improved air quality and efficient Operation Optimum use of Car Park Space & Optimisation of Head room for Vehicles and Pedestrians. Flexibility in installation,quicker installation Effective smoke management During Fire Conditions, the volume of air to be handled is of the order of 1.25 lakh CFM. Under this situation ductless system fares better compared to ducted system.7

How energy saving is achieved in Ductless Ventilation? Ducts are associated with pressure drop,hence higher size F.A/E.F. are reqd. Jetfans are located using CFD Analysis in a manner that they help FA/EF to suck/exhaust air respectively, hence smaller size(HP) FA/EFreqd. During low traffic in Basement, depending upon CO level concentration, only a group of Jetfans may be switched ON by IBMS to distribute/ dilute CO concentration, while in ducted system higher capacity FA/EF have to be kept ON most of the time.8

JET FAN

9

Construction / Characteristics of a Jet Fan4 3 2 1 5 1 - Casing made of Sheet Steel 5 2 3 4

2- Special silencers at the inlet and outlet side 3- Inlet cone(s) 4- Protection guard(s) 5- mounting brackets for ceiling suspension -Suitable for 300deg C operation for 1 hour - Speed : 1450 / 2900 rpm Dual speed - CFM : 1900 / 3800 - KW : 0.3 / 1.5-Sound level : 53 / 71 dB10

-Area Served by each Fan 280 sq.mtr.(Approx)

Comparison between DCapital Cost of D 1. ted ystem : CFM 38477X1 o 1764X1 38477X3 o os irst Basement Fresh ( mm ir Fan ) ir fan )

ted & DKW . X1 18. X1 18. X3 1 . X3 o. o os os

tless system:Cost 43 6 X1 o X1 o 396 1888 X3 os X3 os

Exhaust (4 mm 2.

1764X3 os

econd basement Fresh ( mm ir fan ) 388 7X1 o . X1 7. X1 4. X1 o. o. o. 43 6 X1 o

1 3 4X1 o 61 3X1 o

1 311 X1 o 11116 X1 o

Exhaust air fans ( 4 mm )

388 7X3

os

18. X3 . X3 . X3

os os os Tot ost

396

X3 os

1 3 4X3 os 61 3X3 os

1 311 X3 os 11116 X3 os s. s. ,9 ,68 . , , .

Cost of ducting and electrical panel ,cabling i/c cable tray, etc Grand total of Capital cost

s. 70,9 ,68 .

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Comparison between Ducted & Ductless system: Ducted system Operatin Cost : Assumption : All Fans Operation for 2 Hours (Peak Hour), for Balance 6 Hours (Lean Period) Half an Hour ON & Half an Hour OFF. So, Total operating time=5 hrs/day. Total unit consumption assuming 5hrs operation/day =134.7 KW x 5 hrs = 673.5 KWH/day. Running cost per annum assuming Rs.7/- per unit rate = 673.5 x 25 days X 12 months X Rs.7/= Rs 50 - per annum.12

Comparison between Ducted & Ductless system:Capital Cost for Ductless ystem : . irst asement aust ir fan mm . econd basement res ir fan 38857X1 No 12354X1No 6103X1No aust air fans 25 mmSP) 38857X3 Nos 12354X3Nos 6103X3Nos 18.5X1 No. 7.5X1 No. 4.0X1 No. 15.0X3 Nos 5.5X3 Nos 2.2X3 Nos 396000X1No 153110X1No 111160X1No 396000X3Nos 153110X3Nos 111160X3Nos C os 64X3Nos .0X3 os 9.3X3 Nos Capital Cost 396000X3Nos 635X3Nos

40 mmSP)

Total Cost Rs. 43,43,985.00 Cost of res ir fans & aust ir ans Cost of providin 32Nos. jet fans dd cost of CO sensors, wirin control systems lectrical Panel & Cablin Total Capital Cost =Rs. 43,43,985.00 =Rs.31,99,680.00 =Rs.15,00,000.00 =Rs. 90,43,665.0013

Comparison between Ducted & Ductless system: Ductless system Operatin cost : I.Peak 2 hrs - All jet fans, fresh/exhaust fans ON. a) Jet fans(32X0.3KW) =9.6 KWX2hrs = b) Fresh air and exhaust fan =77.0 KW X 2hrs = 19.2 units 154.0 units

II. For balance 6 hrs (Fresh air & Exhaust fan OFF) a)25% (2 groups i.e. approx. 8 fans ) jet fans ON for 2 hrs =9.6KWX25%x2hrs = b)12.5% (1 group i.e. approx. 4 fans ) jet fans ON for 2 hrs = 9.6KWX12.5%x2hrs= c) For 2 hours (consisting of 4 durations of hr. each) all Fans are OFF = . Total units/day = Energy cost/annum

4.8 units 2.4 units Nil . 0. 0 units

= 180.40X 25 days X 12 months X Rs.7/= Rs. , , 0.00 5,000.00 Maintanence Cost for Jet fans p.a = Rs. Total Operatin Cost per annum = Rs. ,5 , 0.0014

Calculation of Payback periodDucted. Fresh air & Exhaust fans 2. Ductin and electrical panel and cablin , cable tray,CO sensors. . Jet fans Total cost Capital cost for ducted System Capital cost for ductless System Additional capital cost Sa in s in Operatin cost/ Annum by pro idin jet fans Pay back period = Rs. 50. 0 lakhs Rs. 20.00 lakh NIL Rs. 0. 0 lakhs

DuctlessRs. Rs. Rs. Rs. . lakhs

5.00 lakhs 2.00 lakhs 0. lakh

Rs. 0. 0 lakhs Rs. 0. lakhs Rs. .5 lakhs

.5 . 0 = 2 . months

= Rs. ( , , 50/- - ,5 , 0/-) = Rs. , 0,5 0/- per annum. x 2 months

Or Say 2 months15