The current domestic energy crisis facing many households across the Island is due in part to the increasing fuel costs driving the unit of electricity, the kilowatt hour increasing ever skyward. However, the real issues are lack of public education about energy consumption and that the built environment in Cayman is not sustainable as it currently stands and when this is combined with the affects of climate change increasing ambient air temperatures and longer periods of drought between seasonal rains. This will leave Cayman’s housing stock at risk from the long term recurrent costs of maintaining them leading to debt repossession or long term social services subsidises.
The root problems of Cayman’s built environment stems from the lack of public education or denial about living in a high energy cost location. The trend to move away from the traditional Caymanian designed house, which were very environmentally sustainable, and the pursuit of the North American dream of desire for wealth and materialism instead of the Traditional Caymanian way of life has also contributed to this.
Since WW2 in North America there has been a marked change in the architectural design with the move away from passive cooling through the use of building designs and the landscape surrounding them, which was almost free, to the use of air conditioning, which is the most expensive part of your utility cost apart from pool pumps. The North American building product market, which is based on low fuel costs and competitive pricing, meant that the air conditioning systems were cheap to build and energy inefficient but this did not matter when fuel prices were cents and the replacement cost not much more.
Combined with the American average house has increased from 1950s to present day in its size every year and while Cayman came later to this market, the trend is the same. Commercial housing developers only looked at the bottom line of the capital costs of houses they built without any consideration of the running costs of these units by selecting cheapest AC units, which were lower SEER rated. The same went for the selection of appliances with not any concern for the energy usage as long as the devices look attractive.
This also is true in Cayman with the most common question asked is how much a SF does the building cost to build and not how much does this cost to run each month as the recurrent cost over the design life of a building can be more expensive than the building costs.
Now the last issue is the owner’s lifestyle issue. In Cayman for many years traditions were based on the Scottish Presbyterian ways of life and this has been slowly eroded away to follow the North American model of rapacious desire of wealth and over the top displays of vanity with building bigger and more materialistic orientated homes combined with the over consumption of utilities to create something to make their peer group envious or compete with them by matching it or have better. As Cayman’s tiger economy grew from the late 1970s, so did its confidence and increasing salaries fuelled this housing expansion as people had to access bigger loans from the banks to pay for their American dream house, which was more exciting than the Presbyterian frugal and non-pretentious way of only spending what you had to and saving money for a rainy day.
The family home is the largest capital purchase and the one building that the family will spend longest duration. Therefore the hidden consequences are that the end product cost a fortune to run on a monthly basis as the boring components such as insulation in the roof or walls, double glazed windows, the energy star appliances and even the energy efficient light bulbs, which missed out as they would not make a good impression unlike a granite counter tops, stainless steel appliances and solid wood kitchens to visitors.
For the last 25 years Cayman has been booming and despite high energy bills these were accepted as normal because the economy had not known a real recession unlike the more developed countries and so Cayman was blessed and continued to grow. The design of the home that had served the country well for 400 years was replaced with open plan kitchens, large expansion of glass on the south side of the building with no overhang shading, stone rear patios, clear southern views with no shade trees to block the views and grass not sand gardens all because the inspiration for the new homes came from buildings designed for more northern climates where heat gain is important for cold winter months and there is no need for shade in the gardens to lower the air temperature because the sun is not such a great issue.
The traditional Caymanian house, on the other hand, uses less energy because its overhanging porches shade the walls and windows from the sun, the raised floor allows the window to blow beneath a house conducting the heat away from the floor. The kitchen was outside or in a separate room so this heat did not spread to the rest of the house and then have to pay to cool it. Small windows and solid doors to the exterior prevent direct heat gain into the house yet allowed light into the rooms. Cisterns for collecting water in the rainy season and that could be used later, in the dry season, instead of using fresh drinking water for non potable uses. These houses could be built with reasonable sums of money that does not cause the owner to have a lifetime of debt. Gardens had fruit trees to provide shade without the need of teams of gardeners to make the place pretty. All of this was forgotten with the new wealth to the Island and desire for something better from the other side of the fence.
Whilst from a vanity point of 72” plasma TV is cool and so what if we only have radiant barrier in our roof space; but as climate change takes affect now with increased air temperatures and longer spells of drought combined with increasing fossil prices; the folly of this false pride and energy gluttony starts to show. 60% of heat gain is through the roof and 40 per cent through the walls so if the owner had not spent the thousands on that TV but instead on R30 roof insulation or as the solar institute in Florida recommend for over 10 years – R48 then may not be suffering so badly today.
Air conditioning is the largest use of electricity in the built environment and is normally oversized so the house cools quicker but due to this does not run long enough to dehumidify the house and therefore the thermostat is lowered to remove the damp and in turn costs the owner huge amounts of money as the condenser motor constantly is starting up and using more power or having to work harder to cool the building against high exterior air temperatures.
The sustainable and environmentally designed house or high performance building does not mean that you will lose any of the standard of living that you are accustomed to and the final capital will be about the same as the building is designed to be smaller, this will offset the slightly higher capital cost of construction but the long term financial savings will recover this expenditure well before the end of the mortgage period and this ‘green’ mortgage is increasingly being offered by banks as the homes retain their value better and owners can repay mortgages quicker from the savings in utility costs. The added benefit of these high performance homes are that being better designed this makes them resist extreme weather better and thus lowers the risk to the insurance industries, which in turn lowers insurance premiums as seen with the fortified building code as used in North America giving house owners cheaper insurance and higher resell prices.
The first comment usually made about environmentally designed homes is how little tonnage is required to maintain comfortable and dry interior air. This is because the AC is designed by profes
sionals and the building is well insulated to avoid excessive exterior heat gain and so the AC is effectively undersized to allow it to run for long periods and dehumidify the air thus making it feel cooler because the body can naturally sweat. The AC unit lasts longer because the condenser is not forced to stop and start as much and the fan coil is not the expensive part of the running cost as well as less tonnage, which is cheaper to purchase as well as using less power combined especially if a high SEER rating is selected.
In addition to the design and construction of the home by the use of designed landscape and orientation of the building in its environment; passive cooling and lighting will not only save energy but will enhance the interior living space for its occupants. By the use of solar hot water heaters and letting the sun to dry your clothes; for a relatively low investment large financial returns can be seen. Cayman is one of the few places where even solar power makes economic sense and as the global community starts to use more panels, the prices will dramatically drop and become more affordable to the average homeowner. Using manufacturer’s data and Energy Star spread sheet modified with 34 cents per KwH for Cayman, the following examples will show the potential savings. The average clothes drier uses 4.5 KWs per hour of use or $1.53 per hour – this cost can be totally eliminated by using a clothes line, a load of clothes usually dries in under 30 minutes in Cayman in the sun. In addition your clothes will last longer as they are not cooked by the high temperatures generated in the dryer. Over a year this will save a family $250 upwards.
A passive 40 gallon solar hot water heater costs about $4,000, which may seem a lot compared with $500 to have an electric heater installed but based on just three hours of full heating load per day it costs in power $236 per month or $2,833 per year and so it’s paid off in less than two years and the rest of your life you’re saving this amount every year. So the larger your family the quicker the return is going to be.
Now if we consider AC costs, which are the largest component of your CUC consumption – based on two three-tonne units cooling to 78F on an annual basis and then compare 16 SEER (which as our baseline cost) with 13 SEER, which is standard spec for newer Cayman typical homes, and 10 SEER, which was standard on homes older than 10 years and sadly even after it was banned in US still sold in Cayman, maybe even today. The saving on the capital cost of the units over 16 SEER is about $2,000 for 13 SEER units and $2,600 for 10 SEER units to purchase for the two three-ton units. (Six tonnes)
Based on the same house construction and size with a set temp of 78F using a 16 SEER system over 13 SEER unit savings can be seen around CI$200 per month or CI$400 per month over a 10 SEER unit. So assuming the AC units last about six years the savings over 13 SEER are $14,000 and for the 10 SEER is $28,000. So suddenly the 72” TV and the cheapest cost per SF price do not seem so cheap now!
A quick saving tip is to raise the AC from 78F to 80F; this is predicted to save between 4 per cent to 10 per cent of the cooling bill annually.