Comfort cooling for a 200,000 square feet yoga hall!
Lying at the feet of Lord Shiva's hills, i.e., Shivaliks, in Uttarakhand (India) is the ancient city of Hardwar. Legend has it that the Suryavanshi prince Bhagirath performed penance here to salvage the souls of his ancestors who had perished due to the curse of sage Kapila. The penance was answered and the river Ganga trickled forth from Lord Shiva's locks and its bountiful water revived the sixty thousand sons of king Sagara. In the tradition of Bhagirath, devout Hindus stand in the sacred waters here, praying for the salvation of their departed elders.
'Baba Ramdev's' ashram in Hardwar called Patanjali Yogpith is the spiritual destination of large numbers of Indian and foreign devotees. The Yog Hall, where thousands of people practice YOGA in the presence of celebrated YOGA GURU - BABA RAMDEV, is a mammoth hall with an area of 200,000 square feet, large enough to accommodate 30,000 people. It is 115 m/377 ft wide, 165 m/541 ft long and 13 m/42.6 ft high. While air conditioning the hall would perhaps give to the yoga practitioners physical comfort commensurate with the spiritual bliss they experience there, it would be rather an expensive proposition. But the salubrious climate of the holy city offered an affordable solution. Rather hot and dry in the summer, but moderate in the winter, the climate is ideally suited for evaporative cooling. Therefore, the Patanjali Yogpith Trust that runs the ashram, decided to install an evaporative cooling system in Yoga Hall. We received the order to execute this project.
Shyamsundar Rao has been with Symphony Limited since 2002. He is currently handling the large industrial air cooling projects business in India. His area of experience has been providing innovative air cooling solutions to various industries. Though an mechanical engineer, he is keenly interested in sales and marketing. He has been instrumental in securing some prestigious orders for Symphony from customers like Nestle India, Maruti Suzuki, Asahi Glass, Hero Group and many others in India. Shyamsundar Rao is working as a Sales Manager for Symphony Limited based in Ahmedabad, India.
Outdoor design conditions in Hardwar can be quite severe in the summer at 44[degrees]C/111[degrees]F with very low humidity. During the monsoon, RH goes up to 85% at 32[degrees]C/89.6[degrees]F. The winter temperature is 12[degrees]C/53.6[degrees]F minimum, and one can do without heating. There is no feasibility of ducting in the space. Due to the large width, air throw of 55m/180 feet would be required. Peak occupancy would be 25-30,000. The indoor design temperature to be achieved was specified at 26[degrees]C to 28[degrees]C/72.8[degrees]F to 82.4[degrees]F during summers. We considered 30 air changes per hour.
We used 22 evaporative coolers, eleven on each side of the hall. Each cooler is ducted into a plenum in the hall. We achieved 85% efficiency of the coolers by using 20HP motors for each unit. We could have gone up to 95% using 25HP/18.75 KW motors, but the performance was found satisfactory with 20HP/15KW motors, so we decided to save energy by leaving it at that. Each cooler has a 40" centrifugal blower, forward curved with 50 mm /2 inch static, with powder coated automotive steel body and stainless steel water tank. The air filters for each unit comprised of 2 wet sections of 12 inch/30.5 cm thick paper cellulose.
We placed 21 diffusers in each plenum, out of which 15 are spot type diffuser of 2200 cfm/3800 m3/hr for long throw and adjusted for even distribution of air in the hall. Six diffusers are jet type, to handle short throws and to balance the air.
The biggest challenge of the project was to ensure that air reached the centre of the hall without any ducting. The width of the hall is 110 m/361 ft. and there was no space to run the duct inside the hall, we calculated all the parameters and designed the plenum to deliver air up to 55 m/180 ft. In fact, we reached beyond 60 m/197 ft. The plenum was not acoustically lined.
Since we used pre-fabricated structure with hot air trap in the middle, we created a positive pressure of cool air so that hot air rises and is naturally exhausted from louvers placed at the centre and sides of the hall. The structure, with hot air trap of 6 inch/12.5 cm width at the centre, running 160 m/525 ft with false ceiling of gypsum board tile of 24 inch/61cm x 24 inch/61 cm above the false ceiling, is insulated with 1 inch/25 mm thick fibre wool placed in polythene bags. The side walls are panelled with wooden board. Sixty percent of the wall has windows along the two sides for ventilation. The total power consumption, with all the units running, would be 328 kW. The indoor noise level is 64 dB.
The following spare parts have been provided to enable quick service in the event of a breakdown:
* Two motors of 20 HP each.
* Two pumps.
* One wet section complete set, comprising stainless steel water tank, two sets of 12 inch/30.5 cm rigid media, water connections etc.
By far this is the biggest air cooling project in India for such a vast area where there is minimal ducting or I can claim absolutely no ducting for air cooling such a large area. It was a great learning experience for the team as this kind of installation was never implemented and has given us confidence to execute large projects with minimal ducting thereby reducing input costs, load on the building, maintenance costs and installation costs.
|Printer friendly Cite/link Email Feedback|
|Date:||Jul 1, 2013|
|Previous Article:||Energy implications of in-line filtration in California homes.|
|Next Article:||Overview of hybrid ventilation control system and full scale monitoring.|