Inverter chiller retrofit brings huge savings in hotel maintenance
Several operating concerns including inefficient energy use and high maintenance costs initiated the need for a chiller replacement at Sun-n-Sand in Shirdi, India. Oil-free Magnasmart Inverter Chiller from Blue Star Ltd. using Danfoss Turbocor® compressors was chosen as a replacement. Operating costs were drastically reduced when this air-conditioning system was upgraded.
Sun-n-Sand is a leading group of five-star hotels which strives to serve both business and leisure travelers. The Mumbai property is the flagship hotel of the Sun-n-Sand group and was commissioned in 1962.
It was the vision of Mr. R. J. Advani and Mr. Jack Voyantz which gave birth to Mumbai’s first five star beach hotel. Five decades of operations and constant innovations have assisted the Sun-n-Sand to understand and master the art of serving guests. Since 1996, Mr. Rajesh Advani (Managing Director) has led the Sun-n-Sand group to leverage its presence as a strategic business and leisure destination in Maharashtra. The group currently operates 5 star hotels also in Pune, Mumbai, Shirdi and Nagpur.
The challenge - Project overview
The Sun-n-Sand in Shirdi is renowned as the home and final resting place of the revered Shri Sai Baba which attracts devotees from all over the world.
A decision was made to evaluate an alternative to cool the building due to the rising diesel costs associated with the operation of two 140TR diesel fired absorption chillers. Chief Engineer Mr. Kenneth of the Sun-n-Sand in Shirdi visited Blue Star Ltd. (BSL) in December of 2011 to explore the potential for the Blue Star Magnasmart Turbocor® 150TR chiller in inverter air conditioning system as a replacement for the diesel fired absorption chiller.
Many aspects were considered by the Sun-n-Sand's Engineering team prior to making the decision for oil-free technology. The first issue was the inverter chiller energy usage as well as following other key aspects.
- Local Service and Support
- Remote Monitoring and easy maintenance
- Noise and vibrations
- Load fluctuation
- Footprint
The solution - Magnasmart chiller with oil-free Danfoss Turbocor® compressor.
After various technical discussions and approval from the Sun-n-Sand´s engineering team, Blue Star Ltd. supplied LCWT1-0515F Turbocor® chiller to Shirdi in January 2012. The chiller is designed for 0.68 kW/TR where as IPLV is 0.359 kW/TR.
The installation and commissioning.
The chiller location on the 7th floor had site constraints such as limited roof space, conversion of water piping from the old chiller to the new chiller with space constraints.
Blue Star Ltd. completed the installation in February 2012. The service engineering was exclusively trained by Danfoss USA. After a full analysis of data retrieved from the inverter chiller and compressor, it was proven that the optimized algorithms for India conditions successfully ran the chiller in its most efficient envelope during low load conditions.
In Operation – The new chiller is not only highly energy efficient.
"Noise and vibrations are critical for hotel applications", said Mr. Rajesh Advani, Managing Director of the Sun-n-Sand Group, and continued, "I am impressed with the 73dBA sound level of the running machine which allowed us to re-occupy the office space directly below the chiller room."
"Blue Star's Magnasmart chiller with oil-free centrifugal compressor technology boosts energy efficiency and cuts operating costs," said the plant operator at Sun-n-Sand. "It provides much better efficiency compared to the old unit, and we are all very pleased with the smooth and efficient operation of the new Magnasmart chiller."
Mr. Shinde, Sun-n-Sands facility manager, added: "Total costs to run the inverter air-conditioning plant decreased drastically. We are saving approximately 200,000 to 250,000 INR (US$3,200 to 4,000) per month". Payback was within 18 months.
| Date | Savings with Magnasmart | % |
| 26-April | 8395 USD | 42 |
| Hotel occupancy(n* of rooms) | +26 rooms | |
| 27-April | 6306 USD | 48 |
| Hotel occupancy(n* of rooms) | +17 rooms |
On top of the energy savings and quiet operation, the staff at the hotel is pleased to see further advantages of the Magnasmart inverter chiller with Danfoss Turbocor® compressor over their old cooling units:
- Considerable smaller foot print of the Magnasmart chiller compared to the absorption machine
- On board inverter reduces the starting current of the compressor to only 2 amps
- Only one moving part - Reliability of chiller is improved due to lower complexity of the system
- Oil-free operation - Removing oil completely from the compressor eliminates lubrication issues. Lubricating oil hinders heat transfer significantly - a chiller with an oil content of 4% loses 9% efficiency
- Remote monitoring enables Blue Star to optimize performance and reliability of the chiller
- The chiller control panel provides the operators and engineers operational information and system parameters immediately available at the unit
- Another sustainable attribute associated with this compressor technology is the potential for converting to an environmentally friendly, non CFC refrigerant – R-134a. This also can help to gain LEED-EB credit
Conclusion
The goals of the project have been met. Comparing energy consumption of two days data log at the same day of 2011 and 2012, the operating costs in 2012 had gone down by 42%, while there was a higher occupancy level in the hotel. Same is for all months and throughout the year.
Danfoss Turbocor® technology brochure
Online Product Catalog - Danfoss Inverter Compressor Solutions