This article is not for the general public. It is not for those who believe air conditioning solves the problem of a hot house, impact windows the problem of exposed openings and insurance the problem of poor construction.
“Hey, listen man. I wan’ be in my house fer Chris’mas. I ain’ gat no time to talk ‘bout that stuff.”
“ I cyan’ afford no architect. They too expensive.”
“My bill ain’ too high. B’sides, BEC say dey comin’ down on they bill soon.”
“Da’ stuff too expensive. I’s a li’l man.”
These people are obviously committed to the idea that they should pay the least for their house, even if it means they are committing to a life of high monthly bills. This article is not for them.
We believe there are a few people out there who realize that their future financial lifestyle is dependent on the decisions they make today, and they are prepared to take responsibility for that future condition. This article is for those who accept the fact that there are no free lunches – everything comes with a price.
“If you think education is expensive, wait until you find out the cost of ignorance.”
This article suggests 10 strategies available to the average Bahamian homeowner to reduce their power bill, not by legislation or lower rates from BEC, but by reducing the amount of energy used by their home. Unlike the rates charged by the utility company or the cost of oil, they are all strategies over which the consumer has complete control.
The list is subdivided. Some of the strategies are usually addressed before the house is constructed, while others may be addressed at any time. Otherwise, the list is presented in no particular order.
Let’s first look at some ways a homeowner may reduce the cost of operating their home while preparing to build.
1. Orientation
There are a few constants in the world. One of them is that the sun rises in the east and sets in the west. Over the years, builders have found that that predictability allows them to organize their buildings to expect certain conditions. For example, in the morning, the sun’s rays are warm and cheerful, making it welcome for greeting the day. But by mid-afternoon, when the earth has warmed up and the angle of entry through the atmosphere is oblique, those rays are fierce and destructive, and must be avoided.
Another constant for the region of the Bahamas is the direction from which the cooling trade winds, or breezes come. Throughout the year, the “good” breezes come from the southeast quadrant – more northerly in winter, more southerly in summer. Winds coming from other directions (e.g. from the north or north-west) are generally unwelcome, bringing either cold winds off the North American landmass or are part of bad weather systems. Designers have learned to orient their buildings so as to welcome the “good” breezes and to avoid the destructive winds. They have even learned ways to cause the breeze to speed up while crossing the building by the ways in which they size the openings.
Together, these two factors suggest the best locations for certain spaces and the arrangement of openings for the creation of maximum comfort without air conditioning and the use of unnecessary energy.
2. Cross Ventilation
This is taken separately because its application is so important. For most of today’s Bahamians, the small house they grew up in was more comfortable than their new dream house is. Most of the reason is that that small house paid attention to the way breezes got across those small rooms. The combinations of openings allowed the breeze to enter one opening and leave through another. This principle of “cross-ventilation” is at the root of the design of a sub-tropical house. Even if there is air conditioning available, buildings in this region only behave efficiently if they allow the penetration of tropical breezes. For example, much of the discussion about “green” design is about air quality. Toxic emissions from modern fabrics and materials combine with the normal stale air in closed buildings to create poor air quality. In some instances, A/C systems are designed specifically to increase the rate at which the air is changed (generally Engineer-designed systems), affecting the cost of cooling the building. Proper ventilation avoids this expense (with the added benefit in the Bahamas of bringing the smells of the garden inside).
3. Vegitation
We have agreed that there is a need to mitigate the effects of direct sunlight on the building, especially on certain sides. The most important aspect of sub-tropical design is the provision of shade from the sun. As noted above, this is most important when the sun is on the south and west sides of the house. There is a need to provide shade for both openings, which allow the sun inside the building and bare walls, which can heat up and act like radiators to heat up the interior. One of the most effective devices for shading the building is vegetation. Well-places shade trees provide shade while creating lively patterns, adding character to both interior and exterior spaces. The type of tree, of course, must be chosen for its location, as trees change character over the year. But the basic idea of shade trees on the west and south sides of buildings in the Bahamas is always a good one.
The sun also bounces off the ground, to be reflected into the building. Ground cover is an excellent way to absorb those rays, and the good designer manages the location of hard surfaces carefully.
Finally, lower trees and shrubs are a way to both filter the air between the building and dust-producing streets and to absorb traffic noise.
4. Porches and Verandahs
Keeping the sun away from openings that would cause the heating up of the building is one of the designer’s goals. In sub-tropical climates, the most effective tool has been found to be the cover created for space that extends the inside living space, as in the creation of porches and verandahs. These devices provide shade from the direct sunlight as well as reflected sunlight, keeping the interior cooler, providing valuable tropical living space and giving regional character to the buildings.
5. Shutters
In tropical and sub-tropical climates, the use of shutters to provide protection from the effects of storms and hurricanes is a norm. In the Bahamas, the push-out shutter (called the Bahama Shutter in the US), is perhaps the most effective window protection in existence. It provides shade as well as protection when needed. Generally, these are used over exposed windows, while their side-mounted cousins are used under cover or in protected areas.
The second part of our list consists of strategies more appropriate for the existing building, although their application during the design process is still a great idea, where possible.
6. Energy Monitor
The first suggestion for the person concerned about their energy use is to know what energy is in fact being used. Most people have no idea either how or how much energy is used by their building on a daily basis. They wait for the utility company to tell them at the end of the month how much they have used, and hope it is less than the previous period. Studies have shown, in fact, that given a way of monitoring the energy use in the house, a device with real-time information, the average home-owner will reduce their energy consumption between 8% and 16% WITHOUT THE ADDITION OF ANY NEW TECHNOLOGY! Simply knowing how you are using power makes you more sensitive to its use. Obtaining a good energy monitor is an excellent first step in the process of reducing consumption.
7. Room Sensors
Turn off the lights! One of the silent consumers of power is lighting left on unnecessarily. For example, the lights in a bedroom left on all day, while the family is in the garden or on the porch. Commercial operations like hotels and warehouses have used room sensors to automatically turn off lights when the room has been empty more than a preset period of time. The State of California, for example, has made getting a building permit contingent on the provision of room sensors for rooms not used often. Residential sensors are now common, and should be part of any energy-reduction plan, whether for existing buildings or for new construction.
8. Energy Efficient Lighting
With the advent of the fluorescent lighting, the inefficiency of the popular, old incandescent light began its exit from the commercial scene. However it has remained popular for domestic purposes, mainly because it is inexpensive and easy to find. To understand the reason the fluorescent lighting replaces the incandescent lighting, it is necessary to understand that the lighting gotten from a bulb results from an amount of muscle (voltage from the utility company) times the effort needed to make light at that voltage (amps), expressed in watts. The light produced by a 60 watts incandescent bulb is provided by 13 watts of fluorescent lighting. This increased efficiency is further enhanced by the fact that the 60 watt bulb will last only approx. 1000 hours, while the compact fluorescent alternative will last at least 50,000 hours. Now comes the more efficient LED lighting, which gives the same amount of light with the consumption of only 6 to 8 watts and lasts up to 90,000 hours. In the near future, residential induction lighting (already in use commercially) will provide even more efficient lighting in bulbs that last 100,000 hours. Replacing most of the light bulbs in the home reduces its consumption of energy, as well as the cycles of replacement.
9. Solar Water Heaters
Heating water for domestic purposes accounts for approx. 1/3 of power use in the home. Replacing electric water heaters with simple solar water heaters is both easy and inexpensive. For less than $3,000, most homes would reduce their energy consumption sufficiently to pay off the cost of the investment within two or three years. From then, hot water is virtually free for the next two decades, at least. Many solar water heaters are fitted with electric back-up elements for those afraid to go “cold turkey”, in case the sun refuses to shine for more than a couple of days (in the Bahamas!). The units are virtually maintenance-free and the only concern in application is the orientation.
10. Solar Pumps
There are two types of pumps in popular use in Bahamian homes. They are the circulation pump for pressurized water systems within the house (either City water or well water), and a pool pump. Both burn a lot of energy as they recycle endlessly. Placing them on time switches reduces their energy consumption, but as they are needed, they still use energy unnecessarily. Installing a simple solar pump eliminates the power needed to run these two systems without compromising either comfort or convenience.
These 10 strategies provide the concerned homeowner with the tools for achieving a significant reduction in their monthly power bill, regardless of the Government’s or BEC’s success in reducing the rates charged for its use. If and when they succeed, the benefit would just increase.
In the words of an old activist friend of mine “Power To You”.

September 21, 2013

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