Energy efficiency starts with good design. Of course the efficiency of nearly any home can be improved, but designing for energy efficiency is always going to yield the best results. Depending on the status of your project, there are priorities to consider that will have an impact on the energy performance of the structure.
1. Property Selection - View lots are the most common to create challenges with home energy use. Ideally southern views are going to be beneficial and western views the most detrimental. Additionally the shape of the lot can affect the length axis of the home with positive or negative effects on energy use. The preference is that the front of the home faces north but clever design may offer alternatives otherwise. 2. Solar Orientation - Once property has been selected, the structure should be oriented to capitalize on the seasonal arc of the sun. In the northern hemisphere it's preferred to orient windows to the southern exposure and prevent heat gain on the east and west elevations. Because the summer son is high in the sky, overhangs can be designed to shade the windows while still allowing the sun to enter during the winter months when the sun is lower. West-facing windows are difficult to shade from the harsh afternoon sun. 3. Passive Solar Design - The sun can heat our homes in the winter and even help keep us cool in the summer - for free, when passive solar design techniques are used. In this approach, the building itself or some element of it takes advantage of natural energy characteristics in materials and air created by exposure to the sun. Passive systems are simple, have few moving parts, and require minimal maintenance and no mechanical systems but they need to be considered early in the design process. 4. Reduce Energy Demand - Some of the most effective methods to reduce energy use include: increased insulation values and weathertightness; HVAC zoning and programmable thermostats; LED lighting and energy-efficient appliances. Here in Florida, air conditioning is the largest energy user of most homes. Solutions that include dehumidification, increase air movement and reduced radiant heat exposure, will allow you to feel more comfortable with a little higher setting on the thermostat. 5. Reduce Solar Heat Gain - When you walk across a black asphalt parking lot and then get in your black car after it's been sitting in the sun, you are experiencing two different types of solar heat gain. Dark colors absorb heat while light colors reflect it. Additionally, old-school construction techniques that trap hot air in the attic put huge demands on the AC system and insulated envelope. AC ducts in a conventional attic are very inefficient.
6. Increase Efficiency - Increased energy efficiency is available for a number of building systems. This is where cost-benefit analysis becomes important. Depending on the success of the above strategies, there may be a point of diminishing returns from the investment in higher performance products. Windows and HVAC systems are the main items to fall into this category. 7. Solar Thermal Heating (and Cooling) - Solar hot water heating is a type of thermal heating strategy but did you know that thermal solar collectors can also be used to heat the inside of the house? This is called hydronic heating and is actually quite comfortable and can be affordable. Additionally, in the right application solar thermal panels can actually be used to cool your home in the summer time. 8. Alternate or Renewal Energy - The final upgrade to consider is the addition of an alternate energy source like photo-voltaic panels or a renewable source like a micro-hydro generator. Recent industry articles indicate the cost of PV (photo-voltaic) over their lifetime, is getting close to power purchased from utility companies. Additionally, if PV panels are amortized over a 15-year mortgage period, the cost saving and interest tax deduction may exceed the cost of purchased power. Let us help you make the calculations.
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