How can I remodel my oceanside property for maximum energy efficiency?
I am about to begin a major renovation and extension of my oceanside property. We want to create an inside/outside feel by using large sliding glass doors, but we also would like to minimize the need for air conditioning.
Can you provide energy efficiency tips for our situation? Also, can you recommend any window/door manufacturers? We need to have hurricane resistant glass and also consider security.
There are several ways to slow heat gain in a building and reduce the need for air conditioning while still creating spaces that are sunlit and open to the elements.
The first step is to evaluate your site and the factors that affect temperature: sun, wind, vegetation, and water.
GLAZING AND SUN SHADES
As you are located at a low latitude in the northern hemisphere, the summer sun is very high in the sky and most of its impact is on the roof and the east/west walls. Glass in these areas should be minimized or fully shaded.
Design sunshades and roof overhangs to block the higher sun’s rays in summer, but to allow sunlight to enter in the winter when the sun is lower in the sky. A combination sunshade/light shelf can provide daylight as well as shade.
The type of glazing you use on windows and doors can alleviate some of the problems of heat gain. Dual glazing will reduce heat transmission through the glass, while reflective coatings or low-emittance (low-E) glass will reduce heat gain caused by the direct impact of the sun's rays. Reflective glass will not give you the inside/outside transparency that you want, so you may prefer low-E coatings, which block significant amounts of radiant heat transfer through the use of barely visible, microscopically thin metal or metallic oxide layers.
Properly installed insulation in the roof, walls, and floor is also important in reducing heat gain. Finally, consider landscaping: in your climate, trees that shade the roof are very desirable.
AIR MOVEMENT AND VENTILATION
Properly placed openings will help you take advantage of cool breezes from the ocean during the day—and maximize your ocean view. During the design process, draw diagrams showing the airflow through and around your home. This will uncover any spaces that have no air movement and show you where you need to add openings for cross-ventilation. You might also consider using an elevated, lightweight floor system that takes advantage of the air circulation below. Landscaping should also be planned to best direct breezes into and around your house and to buffer against hurricane-force winds.
Openings high in the house will evacuate heat while openings in the lower portion of the house will draw in cooler air. Ceiling fans throughout the house will create air movement.
HURRICANE-RESISTANT WINDOWS AND DOORS
You will want to select windows and doors with a finish that won't degrade with the salt air. Wood will require a fair amount of upkeep, and anodized aluminum is not a good choice due to the potential for corrosion.
A very good American-made brand that I recommend is Marvin aluminum-clad wood windows and doors. The extruded aluminum cladding on the exterior has an extremely durable, factory-applied Kynar finish that protects the window from corrosion. The wood on the interior can be painted or stained. They also have a good quality finish on their screens. You will also want to invest in marine-grade hardware (stainless steel versus a coated steel).
Marvin has a StormPlus system that is designed for hurricane forces; it is available for impact zones 2, 3, or 4. Special features include laminated glass to protect against impact from debris, reinforced sash framing and locking points, and hardware reinforcements that secure the sash to the frame. The laminated glass will also address your security concerns.
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