Syntel's Pune campus is spread over 40 acres and houses more than 9000 employees. To provide cool the 350,000 square feet area of the current phase of the Pune campus, it was estimated that a capacity of 100,000 CFM would be required. Cooling this huge amount of fresh air with a conventional HVAC with DX or CWC would incur heavy operating expenses. HMX helped Syntel resolve this dilemma through heat recovery by capturing return air and using it to pre-cool fresh air.

1. Group
Challenge
Case Study
Company Background
Syntel is a leading U.S.-based multinational in the business
of IT outsourcing, IT consulting, BPO, enterprise business
solutions and collaborative client partnerships. Syntel's
Pune campus inaugurated in 2002 is spread over 40 acres,
and is the company's global development centre. Today, this
centre houses more than 9000 employees and has achieved
SEI CMMI level 5, the highest level of an industry-standard
model used for defining and measuring the "maturity" of a
software company's development processes.
Other options considered
The current phase of Pune campus was planned in early
2012. Renowned consultant Refrisynth Engineers, Pune,
was entrusted with the task of HVAC design. They decided to
go with energy saving VRF technology for office air
conditioning. The total fresh air requirement for air
conditioning was estimated to be 100,000 CFM for more
2
than 350,000 ft of floor area. These fresh air calculations
were based on industry standards such as ASHRAE and
LEED considering 10 CFM per person. They realized that to
cool this huge requirement of fresh air, conventional HVAC
using DX or chilled water coil would require very high
investment along with huge operating expenses. So they
decided to go for heat recovery and capture the return air
which was being exhausted and use it to pre-cool fresh air.
Initially heat wheels and heat pipes were considered. Heat
wheels were rejected due to problems of cross-
contamination which occurs due to mixing of incoming and
outgoing air during the rotation of the wheel. Moreover, the
heat exchange matrix in the heat wheel is made from fibrous
materials or with hygroscopic coatings that are susceptible to
damage and degradation by fouling. Maintenance of heat
wheel is very difficult and it is impossible to effectively clean,
when dirty. Heat pipe technology was also rejected on
account of poor efficiency and difficulties in installation.
Solution
The tests conducted after the commissioning of the HMX -
PCU-Rs at Syntel confirmed that all the units are
performing in line with design performance. Even though
ambient temperatures reach more than 40°C, the HMX -
PCU-R consistently maintains fresh air temperature in the
range of 21-26°C. The performance of the PCU-Rs at
Syntel is also monitored through a remote monitoring
system axisLOG-Mini supplied by EcoAxis, a business
unit ofA.T.E. Enterprises.
It was then decided to reduce the fresh air tonnage using
indirect evaporative cooling (IEC) and also recover
exhaust heat. After detailed evaluation, Syntel opted to go
in for 10 nos. HMX-PCU-R (ranging from 3,000 CFM to
16,000 CFM) to pre-cool and supply the required 100,000
CFM fresh air. HMX-PCU-R uses HMX's new generation
heat exchanger or 'DAMA' to precool fresh air using
indirect evaporative cooling. It also recovers energy from
the cool air being exhausted from the building. DAMA(Dry
Air Moist Air) is a patented technology and is a cross flow
plate type heat exchanger built out of an engineering
polymer.
Result
Flow diagram for a typical HMX-PCU-R
Syntel, Pune, opts for HMX-PCU-R – the cost-effective solution for fresh cool air
Figure1:Freshair,supplyairandreturnairtemperaturesover7continuousdaysforthe
16,000 CFM PCU-R installed at Syntel, Pune. The PCU-R consistently delivered cool
airduringthisperiodofoperation.NotethePCU-Risswitchedoffduringweekends.
HMX-PCU-R

2. Customer quote
In the words of Mr Keshav Kulthe, Administration Manager,
at Syntel, Pune, “Syntel is very happy with the performance
of HMX-PCU-R, there have been no problems whatsoever
till date and we are satisfied with the cooling”.
T | +91 - 80 - 2372 1065 / 2372 2325
E | ambiator@hmx.co.in
W | www.hmx.co.in / www.ateindia.com
A.T.E. ENTERPRISES PRIVATE LIMITED
(Business Unit: HMX)
About HMX
HMX, a business unit of A.T.E., designs and manufactures unique, energy-efficient, and eco-friendly products for
space and process cooling for the industrial and commercial sectors, using its patented and highly successful DAMA
technology. The product range includes the HMX-Ambiator, and the fresh air pre-cooling units, HMX-PCU-F and HMX-
PCU-R. With an installation base of 19 million CFM covering more than 3.7 million sq. ft. all over India, HMX is making
fast strides in providing eco-friendly cooling solutions for people and process comfort.
Installation photographs
HMX-PCU-R at Syntel Pune General arrangement of HMX-PCU-R
Total hours in a year: 365 x 24
HMX-PCU-R operational hours from 8 am to 6pm: 10 hours per day
Hours when HMX-PCU-R is in operation (when ambient DBT is greater than 19º C and
precooling with help of room return air, WBT less than 19º C using industry data)
Approximate annual TR savings for 3597 hours when HMX-PCU-R is in operation
(based on our calculations)
Approximate savings in kW/TR with respect to conventional AC: 0.83-0.48
Cost of electricity in Pune
Approximate annual savings in Rs. (402768 x 0.35 x 6)
8760 hours per year
3650 hours per year
3597 hours per year
402768 t/h
0.35 kW/TR
Rs. 6/kW/h
Rs. 845,813
Figure 1 on the first page, shows the operation of HMX-
PCU-R over 7 successive days. The outside air
temperature varies in the range 22-36 °C, but the PCU-R
consistently cools the fresh air to 20-25°C. The specific
energy consumption of PCU-R 0.48 KW/TR, which is 40%
less than a conventional air conditioner system (0.83
KW/TR is considered).
Based on the initial performance results, we have done an
CS3-Sept2014