Energy Conservation Measures in the Hotel • Due to competition and aggressive marketing strategies, hotels have to gear up with new activities and additions, latest illumination, new technology, and to meet demands by guests. • This has set a trend of increase in the energy consumption, compared earlier periods. Also energy cost has increased considerably. This phenomenon has necessitated various energy conservation measures to reduce the energy bill, to be a profitable business.
Following measures are generally initiated by hotels, on energy saving.1.Energy Audits.2.Review of Benchmarks.3.Action Plans
Action Plans 1) Deployment of Energy efficient machines.2) Auto – controls for A/c systems (BMS)3) Efficient chilled water distribution system4) Variable speed secondary pumping system5) Change of cooling tower blades – metallic to FRP.6) Double skin AHU – supply return ducts7) Room automation – key card system, (Key switches)8) Utilization of cool atmospheric air9) Use energy wheel recovery of cooling effect.10) Offline dedicated filter for cooling tower11) Efficient lighting system, use of energy saving bulbs/CFL.12) Use of Dimmers13) Electronic Ballast / energy efficient tube (T-S)14) Voltage reducer for lighting circuits.15) Lighting circuits on BMS/Auto Controller
16) Energy efficient motors.17) Timers for remote lighting/Security lighting18) Efficient Elevator machines. VVVF19) Boiler insulation – Front/Back covers.20) Burner modulation.21)Fuel additives.22)Reclaiming heat from boiler flue.23)Waste heat from condensate – waste heat recovery24) Use A/c machine with De – super heater.HOTEL CASE STUDY
CASE STUDY(5 Star Hotel) • Air conditioning- Chilled water distribution system. • Pumps – Efficiency /Sizing • Lighting system. • Cooling Towers
System Before Modification • Chilled water tanks ( Primary / Secondary) are located at building terrace at the height of 37 mtrs. • Open loop pumping system, was used earlier. • 4 nos primary pumps of 25 HP each were connected in parallel from secondary stage tank on terrace to primary tanks on terrace through the chillers in basement plant room. • (5 + 5) secondary pumps for 05 zones were connected from Primary tank on terrace to secondary tank on terrace through the AHUs / FCUs.
DISADVANTAGES • Loss of 10F between chiller outlet to suction of secondary pumps. • 4 nos primary pumps with higher capacity were used for pumping chilled water to terrace tanks. • Since primary pumps were not dedicated for each machine, additional pump was used for additional machine • Secondary pumps were sized for maximum flow required with constant speed, resulting in loss of power during low demand. • Less efficient Primary/secondary pumps.
RECOMMENDATIONS & ACTIONS • Removal of primary and secondary tanks from terrace. • Converting this system to close loop pumping system. • Replacement of 4 nos 25 HP old primary pumps by 7.5 HP high efficient grundfoss pumps dedicated to individual plant. • Replacement of secondary pumps with high efficient grundfoss make pumps. • Installation of variable speed drives for secondary pumps to control the flow as per demand in respective circuit. • Each AHU in these circuits were provided with return Air Temp. controlled, modulating valve.
INVESTMENT • Cost of replacing pumps – Rs. 10.00 lacs • Cost of modification of pipelines insulation, controls, – Rs 15.00 lacs • Cost of variable speed drives – Rs. 5.00 lacs
COMPARISION OF P0WER CONSUMED Saving in running cost @ 16 hrs / day and 300 days / year - 72.7 kw (97.5 HP) x 16 hrs x 300 days @ 5.5 Rs / Kw = Rs.19.20 lacs
SAVING AND PAY BACK. • Total Investment made = Rs. 30 lacs • Saving per year = Rs. 19.20 lacs • Pay Back period = 1.56 year. = 19 months
Introduction • At the hotel, water having high TDS (more than 950 to 1100 ppm), R.O. plant is used for laundry, dishwashing, boiler and water blended with softener and RO water is used for cold and hot water in the hotel. This requires multiple pumping system for storage, transfer and distribution of total water system. Several pumps are used for this water distribution system including S.pool and cold storage cooling system.
Important Pumping Systems Are Comprising of : • R. O. hot primary and booster • R. O. cold primary and booster • Soft cold primary and booster • Cold storage condenser circulation. • Swimming pool /water bodies circulation. In all systems the Beacon and Jyoti make pumps were used of various capacities from 3 HP to 15 HP
Observation & Recommendations • Average operating efficiency of the pumps is 43.1%, • Since the operating efficiency of the pumps is low. It is recommended to replace the pumps with cost effective more efficient Grundfos pumps.
Potential Saving in Pumping System • Energy Saving Potential : 143544 Kwh • Cost of Saving : Rs. 811023 • Initial Investment : Rs. 619200 • Pay – Back Period : 09 months
LIGHTING SYSTEM • The visual comfort in the Hotel is provided by suitably designed lighting schemes in the guest, public, external and services areas of the hotel. • The lighting connected load is approximately 635 kw , which is 17% of the total connected load of the hotel.
Observation On Lighting System • Lighting supply voltage level measured was higher than specified. In night it used to reach up to 260V against 230V, resulting in higher power consumption and fusing of lamps. • Public Toilets and common passage / service areas lights used to remain ON during “No Occupancy” time specially at night.
Observation On Lighting System • Presently tube lights used in service area, laundry, kitchens, corridor and atriums, consume total 56 wt each, which is much higher. • 60 /100 W GLS lamps are used in admin / guest corridor / guest rooms.
Recommendation • Voltage reducer ( ES-25) to be used on lighting circuit to reduce voltage to 205V – 208V to save power and avoid failure of lamps, without loss of illumination • Occupancy sensors to be used in toilets and passages in service areas to switch off lights when areas are not in use. • 28W, T-5 energy saving tube lights to be used with electronic choke, against 56W tube lights with copper wound choke, to save power. • CFL 11W / 9W to be used against GSL lamps.
SAVING / PAY BACK Pay back time - 33.35 / 29.40 = 1.14 year
Cooling Tower–old setup • Three in number cooling towers of capacity 300 ton each were located at 1st floor level. These cooling towers were connected in parallel and are feeding to 3 nos AC plant of capacity 300 ton each. • In normal case 2 Nos. 300 ton chiller, and 3 nos. 300 T cooling towers were operated to get desired condition
Observation • Due to space problem cooling towers were located very close to each other and also close to building wall resulting in poor efficiency, operation of 900tons cooling towers caters to 2 nos of AC plants i.e 600 tons. • Due to poor efficiency of cooling tower, hotel is unable to operate two AC plants of 300 ton each on full load resulting in switch “ON” of third plant of 300 ton to meet the demand. • High power consumption resulted due to fixed speed and old design. • Causes noise pollution in the guest rooms.
Recommendation – New setup • Relocate existing cooling tower, away from the building to have more fresh air and space between them so as the efficiency increases and eliminate noise problem. • Replacement of 3 nos x 300 ton cooling towers by 2 nos x 500 ton each. • Installation of variable speed drive on both cooling towers. Hence flexible output.
Investment • Cost of Cooling Towers : Rs. 10.0 L • Civil work on new site:Rs 6.4 Lacs • Modification of pipe line Rs. 2.5 L • Cost of V.F.Ds : Rs. 2.0 Lacs
Potential saving • Energy saving potential (Kwh) 1.85 lacs / Annum • Cost of Saving : Rs. 11.1 lacs • Initial Investment : Rs. 20.90 lacs • Pay back period : 2 years.