Hello guys, I am starting an Energy Saving Series with an explicit energy conservation tip on one of the high energy consuming units in a household. But before I kick start on that, let me convince you on why you should be actively involved in the energy saving practice.
Why save energy aside the money returns it brings?
We get electricity from various generation plants. It could be hydro, thermal, nuclear, wind, geothermal (heat emanating from earth crust), solar, etc. According to the International Energy Agency (IEA), thermal power generation of electricity which is powered by coal, oil or natural gas forms a whopping 67.3% of the total power generation plants in the world. All these sources of fuel for powering thermal plants stand the chance of going extinct after long continuous use. It will, therefore, be unwise on our part to accelerate the extinction time by not conserving the energy we use in our homes. Furthermore, Power utilities often shed load automatically at some designated areas using a device called “automatic under frequency load shedding relay”. When the power being used is higher than the available generation capacity, the frequency of the power system goes down beyond the normal thereby making the power system unstable. The aforementioned device automatically cuts off the power supply to the places where they‘ve been positioned in other to stabilize the power system. So next time you are overusing your electricity, think of it that you might actually be depriving some other people of electricity supply.
Let’s now dive straight into business. I will be taken you through all there is to know on saving energy on your air conditioning units.
Air conditioner (AC) consists of two main units, Indoor unit which is the Evaporator and the Outdoor Unit which is the Compressor & Condenser. The power consumed by the evaporator (30 to 80 Watts) is very less as compared to the compressor (1500 to 5000 watts). The great chunk of power consumed by the AC is from the compressor & condenser (outdoor unit). The power of the evaporator (indoor unit) is nearly equal to a ceiling fan. During the daily working time of the AC, the outdoor unit doesn’t stay on all the time but cuts off as and when the room temperature is in equilibrium with the set temperature. Therefore if you switch your AC on for 9hrs a day, it doesn’t presuppose that it runs 9hrs at its rated power.
With this background information, let’s now look into how we can save energy on your air conditioners.
1. Make the right purchase.
An air conditioner is an appliance that can significantly blow up your electricity bills and serious care should be taken while buying one. It’s a unit you will use for a long time say up to 10 years at least so you need to make the right purchase or you will live with huge bills for the next ten years. Do yourself a big favor and compare wattages and energy efficiency ratings (energy stars you see on appliances) of available ACs in other to make an optimum choice. There is an app on the android play store called certified appliance app that can help you make meaningful comparisons and make the right purchase. Never buy an AC without having to know its rated power and energy efficiency rating.
2. Use it wisely with this trick.
You can actually have your AC on for a long time and save almost 40% of the energy if you follow this trick I am about to show you. With earlier information, we now know that if we keep the compressor & condenser (outdoor unit) running the whole time, we will end up paying huge bills. When you set the AC to a temperature of 18 degrees Celsius, your outdoor unit is most likely to run all the time that the AC is on because your room temperature is not likely to reach 18 degrees Celsius to attain equilibrium. Instead, set your AC at 24 to 25 degrees Celsius and switch on your ceiling fan to maintain a cool temperature in your room. You can also use the turbo/hi-speed function (increase in the fan) of your AC. At this set temperature, the compressor & condenser will run 60% or less of the time the AC is put on and help you save big time on your bills.
3. Pay attention to the outdoor unit.
The AC is generally a unit that collects heat from inside the house and dumps it to the air outside the house with the help of the compressor & condenser (outdoor unit). The outdoor unit has been engineered to remove the heat by having a designed amount of air flow around. If less air flows over it, less heat is dumped outside. That means the whole heat removing process will take a longer time to complete. If the temperature around the outdoor unit is also high, it will result in the same thing. The outdoor unit must, therefore, be placed properly to avoid your home taking a long time to cool, raise in your energy bills and increase in the likelihood of your AC breaking down.
Here are a few guidelines to help in its proper placement.
- The outdoor unit should always be placed outside where it has unlimited access to outdoor air and less exposure to the sun. There should not be any large obstructions within at least 3-4 feet of your unit.
- If your home has multiple outdoor units, they should be placed far enough away from each other that they do not hinder one another’s airflow.
- Avoid building a fence or deck around your outdoor unit. If for security reasons you choose to do that, there should be enough openings in the surrounding structure to allow air to flow in and out.
- You can plant a shade tree nearby but it must follow the 3-4 feet “no obstruction rule”.
4. Pay attention to the room hosting the AC.
The room where the AC is placed should be well sealed to prevent the cooling air from escaping. Doors leading to the kitchen, bathrooms or any other room with open windows must be all closed while using the AC. Use window blinds or thick curtains to prevent the sun’s rays from entering the room. In the absence of all the aforementioned, the outdoor unit which consumes the great chunk of the power will run throughout the time of use and bloat your electricity bills.
5. Make periodic maintenance of AC a priority.
The AC has got filters which get dirty with use so there must be a periodic replacement at least once every quarter of the year to accelerate the smooth and efficient operation of your AC. You can save between 5 to 15% of energy with regular filter replacement. Also, get your evaporator coils checked for efficiency.
Having AC at home or office can be a huge financial burden depending on how you purchase, install, manage and maintain it. Always get professional help to install your AC and do periodic audits and maintenance of your AC unit and avoid the headaches that come with huge electricity bills. For those in Ghana, Novich Electric (www.novichelectric.com) can help you with a comprehensive energy audit.
What are your energy saving hacks on ACs, share with me?
Prince John Abakah,
MSc. High Voltage Power Engineering.
Managing Director, Novich Electric
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