ENERGY SAVING/GREEN BUILDINGS


RECOMMENDATION FOR SAVING ENERGY PROFRAM IN 01 HOTEL/RESORT


it is recommendation to apply the following means to reduce the energy consumption and also to enhance the quality and maintain the standard of operation

 

HVAC Services

  • Carry out immediately the cleaning and preventive maintenance to all HVAC equipments and refrigerant pipe system.
  • Special attention needed to be paid on the outdoor and indoor units fin coils to avoid corrosive by salty environment subsequently reduce the efficiency and increase the power consumption of the HVAC equipmens
  • Replace the spoiled insulation on the refrigerant gas pipes by quality closed cell insulation with proper cladding.
  • Replace the main doors with good seals for tightly closing and less energy consumption (and less noise)
  • Adjust the cooling element in every guest rooms.

Laundries

Follow these suggestions whenever possible to keep energy use to a minimum.

  • Use lower temperature settings. Use warm or cold water for the wash cycle instead of hot (except for greasy stains), and only use cold for rinses. Experiment with different laundry detergents to find one that works well with cooler water. By presoaking heavily soiled clothes, a cooler wash temperature may be fine. The temperature of the rinse water does not affect cleaning, so always set the washing machine on cold-water rinse.
  • Turn down the thermostat on your water heater. A setting of 1200F (470 C) is adequate for most hotel needs. By reducing your hot water temperature, you will save energy with either hot or warm wash cycles
  • Load the washing machine to capacity when possible. Most people tend to underload rather than overload their washers. Check your machine’s load capacity in kG, then weigh out a few loads of laundry to get a sense of how much laundry 4.5 or 8 to 9 kG represents. Then use your eye to judge the volume of clothes for a load. Washing one large load will take less energy than washing two loads on a low or medium setting
  • If washing lightly soiled clothes, use the suds-saving feature if it’s available on your washing machine. This saves the water to be reused in the next load. Only use this feature, though, if the second load is to be washed right away
  • When drying, separate your clothes and dry similar types of clothes together. Lightweight synthetics, for example, dry much more quickly than bath towels and natural fiber clothes.
  • Don’t overdry clothes. Take clothes out while they are still slightly damp to reduce the need for ironing – another big energy user. If your dryer has a setting for auto-dry, be sure to use it instead of the timer to avoid wasting energy
  • Don’t add wet items to a load that is already partially dried
  • Dry two or more loads in a row, taking advantage of the heat still in the dryer from the first load.
  • Clean the dryer filter after each use. A clogged filter will restrict flow and reduce dryer performance.
  • Check the outside dryer exhaust vent. Make sure it is clean and that the flapper on the outside hood opens and closes freely
  • In good weather, consider hanging clothes outside and using totally free solar energy to do the drying

Kitchens

Energy-Saving Kitchen Tips

  • Be sure to place the faucet lever on the kitchen sink in the cold position when using small amounts of water. Placing the lever in the hot position uses energy to heat the water even though it never reaches the faucet.
  • Use the automatic, electric ignition system gas oven. An electric ignition saves gas because a pilot light is not burning continuously.
  • In gas appliances, look for blue flames. Yellow flames indicate the gas is burning inefficiently and an adjustment may be needed. Consult your manufacturer or your local utility.
  • Keep range-top burners and reflectors clean. They will reflect the heat better, and you will save energy.
  • Use a covered kettle or pan to boil water. It is faster and it uses less energy.
  • Match the size of the pan to the size of the heating element.
  • Make sure your pan covers the coil of your range. If you can see coil peeping out from the sides of your pan, you are losing energy and you need a bigger pan!
  • If you cook with electricity, turn the stovetop burners off several minutes before the allotted cooking time. The heating element will stay hot long enough to finish the cooking without using more electricity. The same principle applies to oven cooking.
  • Use small electric pans or toaster ovens for small meals rather than your large stove or oven. A toaster oven uses a third to half as much energy as a full-sized oven.
  • Try one-pot cooking. Stews, soups, and other great peasant meals only take one burner to cook and they are so nourishing and satisfying!
  • The less liquid and fat you use, the quicker cooking time
  • Always make more food than you plan to use and freeze it for your own “fast food.”
  • Most of us eat a lot of pasta. Make extra, toss with olive oil, and keep in the fridge so you don’t have to heat an entire pot of water to the boiling point every time you want some.
  • Try using a solar box cooker
  • Perform regular maintenance on all kitchen equipment and repair when necessary

Dishwasher Tips
  • Check the manual that came with your dishwasher for the manufacturer’s recommendations on water temperature; many have internal heating elements that allow you to set the water heater to a lower temperature.
  • Scrape off, don’t rinse off, large food pieces and bones. Soaking or prewashing is generally only recommended in cases of burned-on or dried-on food.
  • Be sure your dishwasher is full, but not overloaded.
  • Don’t use the “rinse hold” function on your machine for just a few soiled dishes. It uses 12 to 27 Litres of hot water each time you use it.
  • Let your dishes air dry. If you don’t have an automatic air-dry switch, turn off the control knob after the final rinse and prop the door open a little so the dishes will dry faster.


Refrigerator / Freezer Energy Tips

  • Look for a refrigerator with automatic moisture control. Models with this feature have been engineered to prevent moisture accumulation on the cabinet exterior without the addition of a heater. This is not the same thing as an “anti-sweat” heater. Models with an anti-sweat heater will consume 5% to 10% more energy than models without this feature
  • Don’t keep your refrigerator or freezer too cold. Recommended temperatures are 3 to 5 degrees C for the fresh food compartment of the refrigerator and -15 degrees C for the freezer section. If you have a separate freezer for long-term storage, it should be kept at -18 degrees C.
  • To check the refrigerator temperature, place an appliance thermometer in a glass of water in the center of the refrigerator. Read it after 24 hours. To check the freezer temperature, place a thermometer between frozen packages. Read it after 24 hours.
  • Regularly defrost manual-defrost refrigerators and freezers. Frost buildup increases the amount of energy needed to keep the motor running. Don’t allow frost to build up more than 6mm.
  • Make sure your refrigerator door seals are airtight. Test them by closing the door over a piece of paper or a dollar bill so that the paper or bill is half in and half out of the refrigerator. If you can pull the paper or bill out easily, the latch may need adjustment or the seal may need replacing.
  • Cover liquids and wrap foods stored in the refrigerator. Uncovered foods release moisture and make the compressor work harder.
  • Move your refrigerator away from the wall and vacuum the condenser coils once a year unless you have a no-clean condenser model. Your refrigerator will run for shorter periods with clean coils.


Electrical System

  • The % loss percentage of all AC motors from 750W to 7.5kW is 14-35% loss of max load. Therefore, should check all motors if it is low-efficiency motors and replace by the high-efficiency motors. In case of running at low voltage, the motors shall incur the bigger losses therefore it is necessarily to check and renovate your distribution network to maintain the voltage at 380V +/- 5%
  • The % loss percentage of all cable networks is from 1-4% of max load. As per our investigation, the Main Switch Board, Sub-Switchboard and Distribution and the Power Supply Distribution Network in Victoria Phan Thiet has been designed in according to International Standard. However, check again all cable system especially cables in the final outgoings for any undersized cable and improve immediately
  • Improve the phase voltage imbalance in a Three Phase System. Phase to phase voltage imbalances by even 2.5% of the nominal votage can reduce motor efficiency up to 10%. Imbalance of more than 5% should therefore not be permitted.
  • Unequal loads on individual phases, negative and zero phase sequence components cuase overheating of transformer, cables, conductors and motors thud increasing the losses and motor malfunction. The limit of negative phase sequence as per 1EC34-1 is 2% of the voltage.
  • The power factor of the hotel should be maintained above 0.95 for low tension three- phase supply. A high power factor allows the optimization of the components of an installation. Losses in cables are proportional to square of the current and Power factor improvement reduced the distribution losses up to 1% from the exsiting level. By improving the power factor of a load supplied from a transformer, the current through the transformer shall be reduced thereby allowing more loads to be added. Methods of improving the power factor is:
    • Replace the underloaded motors with motors of lower rating
    • Restricting no-load operation of motors
    • As mentioned above, the Main Switch Board with the Capacity Bank & compensation control system of Victoria Phan Thiet has been designed in according to International Standard. However, check again the normal functional operation of the compensation capacitors installed in the Main Switch Board. Carry out the measurement of the power factor and record in a longer period for estimating the average value of power factor in the hotel installation.

Hot water system – Using solar energy to generate hot water

Located in the subequatorial region, Vietnam has good solar resources with solar radiation from 3 to 4.5 kilowatts per hour, per square meter, per day (3-4.5 kWh/m2/day) in winter and to around 4.5 to 6.5 kWh/m2/day in summer time. According to research data, the number of hours of sunshine ranges between 1,800 and 2,700 per year.

In Vietnam, especially in the South Provinces of Vietnam (Nha Trang, Phan Thiet, Phu Quoc…) many resorts use solar heater to produce hot water. The system for local solar heater in each bungalow is simple, easy to be installed and free maintenance operation.

With the availability of at least 5,000 square meter of roof of the building and bungalows, solar water heating system can supply up to 500 m3 at 600C.


Opportunity to save energy from solar water heater system

A simple solar water heating system can be installed in all bunglows to supply hot water for 02 bungalows. The concern is the aesthetic view of the thatch roof after installation. For the Administration Building, solar heater can be installed in the roof to supply hot water for laundry, staff canteen, kitchen and spa…

Total average hot water demand of the hotel is 12 m3/day.

Average electric consumption for hot water by electricity in 01 day as per load calculation above is 710.63 kWh or 259,380kWh/year that costs 480,000,000 VND (23,500USD) yearly.

Therefore, the price to produce 1m3 hot water by electricity is 110,000 VND/m3, which is very high.

  • Investment cost

Let calculate the typical solar hot water system capacity for 4-6 person, the cost of supply and installation can be estimated USD 2,000 x 35 sets = 70,000 USD

  • Payback period

The payback period of general solar heater is 2.97 ~ 3 year

  • Reduction of emission (CO2) from Government Power Plant

Potential of CO2 annual emission reduction is about 70.3 tons of CO2/year.


Lighting system

Lightings consume totally 363.65kWh/day equal 8.3% of total hotel consumption. In this amount, the hotel internal lighting consumes 57% while the external lighting (garden lights that covering the very big garden area, security lighting and tennis court) consumes a major load up of 43%.

Some of lights have been already converted into LED lighting. Nevertheless, below are opportunities to reduce the electricity from lighting

  • Change the low efficiency ballast by high efficiency
  • Change other possible lights to LED lighting fixtures
  • Adjust lighting level to meet the demand
  • Install the timer and motion detector sensors for automatic swiching ON-OFF lighting circuits
  • Cleaning the bulbs regularly