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Green Hospitals and Energy Efficiency

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Hospitals are known to consume vast quantities of energy and resources. A well planned hospital building must therefore incorporate careful design that will ensure efficiency in the heating, ventilation and air conditioning (HVAC) system; use natural light as far as possible without compromising on illumination; and have energy efficient housekeeping and waste disposal systems. The architects must plan the building so that its design and infrastructure have the optimum energy efficiency. All equipment must be procured only after ascertaining that they consume minimal energy; retrofitting existing equipment must also be considered in this regard.

The time is right for hospital managements to consider effective cogeneration of power, and invest in thermal storage analysis and cooling analysis systems. Staff must be taken on board and motivated sufficiently to internalize green planning in all their activities. Energy saving protocols must be strictly adhered to, and accountability laid right at the start. The hospital administration system must include timely monitoring and evaluation of the establishment’s environmental performance. Green Hospital concepts have started to play an important part in the healthcare sector around the world. Dr.G C Datta Roy of Dalkia Energy Services Limited (DESL), New Delhi highlights the opportunities that exist universally for reducing energy cost in hospitals.

Hospitals are like mini industries requiring energy for diverse applications and based on different energy resources like electricity, fuel and of late renewable resource like solar. Typical application areas are:

  • Electricity

Lighting, Medical equipments, HVAC Systems, Water pumping, Hot water generation, Laundry equipment, Lifts, Kitchen & Canteen equipments, Computers & Printers, Communication facilities and UPS

  • Hot Stream – HFO, LDO, HSD, LPG, NG & Solar

> Autoclaves, Hot water generation,

Typical Profile

Laundry equipment (washers, dryer & press), Kitchen & Canteen

  • Cold Stream

> HVAC

  • Compressed Air

>Medical purpose

>Technical Purpose

The ratio of consumption of different resources for different applications varies mainly depending upon the use of medical equipment and the coverage under air-conditioning system.

Energy consumption in hospitals

Broadly, the ranges are:

Lighting : 30 – 40%

HVAC : 30 – 65%

Water Pumping : 10 – 12%

Others : 05 – 15%

The two figures shown represent the cases of two hospitals—one a Government hospital, which is semi air-conditioned and the second, a speciality hospital with large intensity of sophisticated medical equipment and central air-conditioning system for the entire complex.

Energy consumption in different types of facilities

Apart from the installed load, the consumption pattern also varies widely due to usage factor and composition of idle load. This would be seen from the following benchmarking carried out by DESL based on two different indices. These have been developed on the basis of audit of about 20 hospitals in different cities in India carried out in the years 2008-2010.

Benchmarking energy consumption

From the above, one can draw macro conclusion about potential opportunity for reduction of energy cost.

Potential Opportunities

Energy cost and consumption can be reduced by undertaking several intervention measures like:

  • Resource substitution-changing fuel mix and electricity source
  • Technological improvement

>  Lighting Energy Consumption

>  Steam and Hot Water Systems

>  Pumping Systems

> HVAC System

> Deployment of cogeneration/trigeneration

> Waste heat recovery

> Renewable energy

  • Solar
  • Waste to energy
  • Usage behavioral improvement

Resource substitution

As already indicated, most of the hospitals use both fuel and electricity for meeting the total energy system. Fuel and electricity scenario are undergoing rapid change in terms of both availability and price. Many hospitals use electricity for generation of hot water and steam. Sometime, it may look economical to do so as the cost of alternative fuel, particularly based on liquid fuel may look more expensive. The table below shows the savings achieved from implementation of a centralised fuel based hot water system in a private hospital in Delhi.

Technological improvement

Some of the case examples of technological interventions carried out in a few hospitals areas follows.

Lighting

The table shows the savings from improvement of the lighting system in a hospital. These savings were verified jointly with hospital authorities with direct involvement of their technical and financial personnel in the measurement and verification (M&V) work carried out post project implementation.

Reduction of lighting energy cost

Along with energy savings, illumination levels were improved in all the areas.

Steam & Hot water system

Several projects were implemented for reduction of fuel consumptions. These included providing more efficient burner with burner management control system and retrofit of economiser for waste heat recovery.

The steam systems in the hospital consisted of two 2 TPH IBR boilers fired with LDO and two Hot Water Generators. While the steam boilers were used to meet the laundry demand and other requirements at the old block, the hot water generators were used for the bathing and winter space heating requirements of the new block. The exhaust gas temperature from the steam boilers was measured to be about 280oC and that of the hot water generators at 547oC. The boiler system efficiency was estimated to be about 70% and that of the hot water generators at 58%. The following recommendations were made and implemented.

  • Installation of an economizer to recover the waste heat from the exhaust gases in the steam boilers.
  • Extension of steam pipe lines upto the new block to generate hot water in the hot water storage tanks, thus avoiding the operation of the inefficient hot water generators.
  • Installations of a hot water tank at the roof of the laundry blocks and supply the hot water at regulated temperature for the use at the washing machines.

Savings: With the installation of the Economizer at the steam boilers, the efficiency of the boiler has gone to 85%. After the use of steam to meet the new block hot water requirements and eliminating the use of hot water generators, the combined efficiency of the steam systems has gone to 85% from the earlier combined operational efficiency of 65%. The steam consumption is considerably lower due to the controlled use of steam at laundry by generation and use of hot water at controlled temperature. The estimated savings due to the modifications in the steam systems, based on the improved efficiency of the system and usage of fuel in 2006 is `34.7 lakhs per annum.

Air-conditioning system

Air-conditioning system provides opportunities in many different ways. These include modification of building envelopes, use of efficient chilling and air handling units, providing VFD/VAV system for usage control, efficient maintenance of cooling and air filtration and WHR systems etc. In one case, we had implemented an innovative project of using the waste heat from the Chillers to preheat the boiler water. Twin advantages are derived, reduction of energy consumption due to WHR and less power consumption in cooling tower and less water consumption due to prevention of evaporation. Cumulative savings from the intervention is shown in the following table.

Interestingly, in this case there was huge savings in capital cost in addition to annual savings in operating cost.

Overall savings

A large number of projects were implemented under performance contract in a hospital in Delhi. The savings from the project were measured and verified during different periods in the year to reflect the true savings under all conditions. It is seen that reducing the energy consumption by over 20% on annual basis in most of the hospitals is eminently feasible with very attractive financial return.

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