It is a fact that most current energy-saving solutions seem too expensive and payback periods are sometimes impractical. Unfortunately most people ignore or simply refuse to consider this context, but whether we like it or not energy saving is now a must!
As a matter of fact Malta already has in place a Building Energy Efficient Directive (2002/91/EC). There are various stages as to how to save on energy; the ideal one being, of course, the planning stage before actually building a new structure.
These energy-saving possibilities are very effective. There are also retro-fit ideas one can use if the structure is already built - subject to existing conditions, a subject to be discussed in another article. The idea behind energy saving is simple - rather then turning totally green and trying to save 35 per cent of energy, which very possibly means altering drastically a comfortable lifestyle, it just falls down to saving what is at most times wrongly used and wasted. There are proven ways of how to save energy by changing wasteful habits and methods - all we need to do is simply implement them.
Thus, the scope of this article is to inform and explain how simple saving on energy and resources is - the upside is less waste, a better environment and fewer bills. There are many practical tips on how one can save energy. Most are simply corrective measures on widespread wrong use. To start with, I suggest switching off all appliances that aren't being used now!
Water usage
Are we aware that nearly 50 per cent of our water consumption is taken up by flushing? Consider using a half flush rather than a full one - if your flushing unit does not host this half-flush option, I suggest you change it before the next water bill - you will be saving 25 per cent on all future water bills!
As for bathing - it is much more economical to have showers as much less water is used - better have two showers at different times of the day than one bath! Don't let water run continuously while shaving, washing your teeth or hair.
Lighting
Lighting absorbs 30 per cent of the total energy consumption, so saving here helps substantially. How many times do we leave lights on unnecessarily? Before switching on the lights, see if you can open a blind/curtain to let some natural light in.
Before leaving the room do you switch off the lights? We generally tend to use artificial lighting, which can be easily replaced by free natural lighting. What about energy savers and electronic dimmers? These devices substantially reduce the amount of energy consumption.
Water heaters
It is a very common habit to leave water heaters on all the time - this is wrong! This is because water heaters available on the market are not designed to efficiently keep the water at high temperatures - 500 C-600 C. Heat simply leaks out and the unit constantly switches on and off (this is the reason why units used in such situations wear out much quicker) and mixing hot with cold water to produce the right temperature simply wastes energy. The idea on how and when to heat up these units is relative to size and number of users. Twenty litres are normally enough for the needs of one person.
Case 1: Family of two: 40-litre unit: Time to heat up is approximately 30 minutes. Experimenting with temperatures, one can find the ideal temperature to bathe directly with the hot water supply, rather than mixing with cold water, thus leaving hot unused water in the water heater. After use, the unit can be switched off.
Case 2: Family of four: 80-litre unit: Time to heat up is approximately one hour. If the family members bathe after each other, the unit can be switched off once ready. If, on the other hand, they don't, but the time lapse between baths is a few hours, the water heater may be left on. If it's more than six hours, then it's better to switch it off and on again an hour before use.
Once the temperatures and using time when to switch on and off are noted, a suitable timer can be used to avoid manual switching.
Space heating, cooling and humidity
Another wasteful habit is when we heat or cool a room/area. People have the tendency to first fit in necessary furniture and other appliances in an area. It is only then that we start worrying on how to heat or cool the place. This is a very wrong design; unfortunately most of us do this when we should be doing it the other way round. The aim here is to make good use of such heating/cooling appliances once installed (design will be discussed in later articles).
We normally use air-conditioning in summer to cool down places due to hot temperatures; on the other hand in winter we heat the rooms due to cold temperatures. But if the levels of humidity are controlled, it will be much more cost-effective to heat/cool afterwards, and on most days we might not need to heat or cool at all. We thus need to change mentality and adapt to our environment.
Before switching on heatrs and air-conditioning units, one has to try and make oneself comfortable by wearing adequate/suitable clothing related to temperature. After that, one has to consider efficient heating/cooling and use economic appliances. The average comfortable temperature with adequate clothing is 20-23.50 C for winter and 23-260 C for summer. An average of 40 to 60 per cent humidity all the year round is considered ideal.
Heating: Heat rises by natural convection, so the lower the source is, the better. Before heating an area, close door/s and window/s and always try to keep the cool temperatures out. In addition, allow the winter sun in to naturally heat the rooms.
For space heating, the ideal form of heating is underfloor heating, but we are here considering only installed appliances. The best and most economic method are gas heaters - in adequately ventilated areas.
If Lm10 worth of gas are consumed, Lm9.50 will be converted into heat. On the other hand, if Lm10 of electricity is purchased, only Lm3 arrives in our homes, as Lm7 are wasted in transmission losses.
If these Lm3 are fed to resistance heaters, we only get around Lm2.50 worth of heat energy. If air-conditioning is used to heat, it will use the Lm3 of electricity to extract Lm9 of heat from the outside, thus being more efficient for the consumer, but Lm7 are still lost in transmission between the power station and home. Thus gas is the most cost effective way for heating.
One last tip is to switch an electric blanket only half an hour before you go to bed and always switch it off before you get in bed.
Cooling: Keep the sun and hot temperatures out and use a lot of shading - external shading is more effective than internal shading. Most of us think that air-conditioning units or fans are the ultimate resource, we tend not to consider natural ventilation techniques. Natural ventilation is obtained by creating a draught inside the living environment. It can be simply created by having two openings in the same room/building - the further away from each other, both horizontally and vertically, the better the effect.
Windows should be opened to favour the wind direction. If one considers using fans, ceiling ones are more efficient than standing models. If the latter is not possible, try putting a fan close to a window on a summer evening, when the outside temperature is cooler; this will force a cool breeze inside the room, cooling down the room's temperature.
The forced breeze is also much more comfortable than the cold blowing air from an air-conditioner. When using air conditioning, it is best to use combined ceiling fans to gain an extra 30 C drop in temperature on our bodies - this is know as evaporative cooling. Allow natural ventilation to both cool and remove excess moisture in summer.
Common household appliances
Fridges and Freezers: Most of us put the fridge/freezer near the oven; this is wrong as they should be far from each other. Fridge/freezers should be two separate units, and the best freezers are the chest type. Always check that the on/off cycles are working well. Check their seals. Use the maximum temperature possible, but keep them free of ice - use manual defrosting. Don't put hot foods directly inside, let foods cool down first and keep food in closed containers. Organise food storage (transparent and labelled drawers) to avoid long re-opening times.
Cooking: Ideal cooking appliances are gas hobs and electric cookers. Microwave ovens are even more efficient; stay away from them when on, due to harmful microwaves. Ideally the same (serving) plates are to be used when using Microwave ovens. When cooking, thaw frozen food before; use small ovens and pans - use lids especially for longer cooking times; pans should have flat bases; avoid frequent opening of oven doors and overcooking; turn off electric burners beforehand and use minimum pre-heat times; for toasting bread use small toasters, not grills; use electric kettles for small amounts of water and fill up the kettle with the required amount only.
Dishwasher: Did you now that automatic dish washing can be more economical than manual dishwashing!
• Load the dishwasher to full capacity before running
• Do not use heat air dry options - simply open the door and let the items dry
• Do not pre-rinse, but if necessary use cold rinses
Washing machine: horizontal axis ones are ideal as they consume less water. 'A' rated units use jets and consume less water.
• Do not use too many detergents
• Use ECO settings as much as possible
• Use detergents directly on soiled spots
• A full load is more efficient than two half-loads
• Low temperatures should be used - high temperatures are only necessary to sterilise or for heavy soiled clothes
• Use cold water unless you have a solar water heater
Tumble dryer: To start with, we should hang clothes to dry in favourable weather, if this is not possible, only then use tumble driers and
• Use full loads
• Use maximum speeds available/practical.
• Use auto drying and do not over dry
• Separate the clothes and don't add wet clothes to a partial load
• Clean the dryer filters and exhaust
• Use the lowest possible temperatures
• Dry various loads in a row to optimise residual heat
Driving: Yes driving can be economical too:
• Be early, plan the shortest route and take it easy
• Plan descents and ascents in advance
• Avoid over/under revving 2000 rpm and sudden accelerations/braking; plan your stopping
• Check tyre pressure and avoid unnecessary loads
• Keep to the original settings
• Avoid traffic and take long paths - much more economical
• For short drives, if there is a choice, use a vehicle with a warm engine
• If possible try and keep windows closed and keep cars garaged
• Open windows and cool the car before switching on air conditioning. In traffic open the windows and switch the air-conditioner off.