What can we do as a society to improve our physical environment and make our homes greener?
Those who are recent residents of the city of Miami don’t know what it was like to live here or in the Caribbean in the 1950s or 1960s. My family vacationed here in the 1960s. We had come from Cuba. in 1961 and moved up north, but have come here once or twice a year on vacation.
In the 1950s or early 1960s, no one had central air conditioning. Most people would have window or wall A / C units in their homes. And many houses did not have air conditioning at all.
So how were houses designed then? Well, most homes were designed for good cross ventilation. They had jealousy or awning windows. Either of these allowed the entire window to be opened to let in the breeze, unlike single-hung or horizontal sliding windows that only open halfway. The ceilings were high and often had ceiling fans. Although most homes lacked insulation, between the high ceiling and cross ventilation the summer heat was bearable. In places like Cuba where there were always cross winds from the ocean, the summers were even more pleasant.
I remember when I lived in the Georgia Tech sorority house in Atlanta while I was in architecture school, there was no air conditioning in the house. We made do with an exhaust fan for the whole house on the second floor, and honestly most of the time that took most of the heat out of the house, making the sorority’s house quite livable, even for a while. Atlanta’s sweltering summer days.
Another detail that good architects took into consideration was the orientation of the house and the protection of the walls and windows. In our part of the Southeastern United States, the sun is hardly ever in the north, except for a few days in winter. The sun rises in the east and sets in the west and moves a little south as it crosses the sky from east to west from sunrise to sunset. This means that the east, west and south exposures of a house require overhangs. Windows to the west should be avoided as the western sun is the hottest of the day. In addition, the sun casts deep shadows. Being by these windows is very uncomfortable in the afternoon. The windows on the eastern exposure are the most popular because the early morning sun is very pleasant.
How are most homes designed now? They ignore all of this.
Air conditioning is the biggest consumer of electricity in any home. The second biggest user is the water heater. If we are to make a real dent in what the typical homeowner uses for electricity, then there are things that need to change in the design of the house. Basically, we have to go back to the future.
Back to the future
There are some simple things we need to change to improve the energy consumption of a typical Miami home:
- Plan the house as if it isn’t going to be running the air conditioning all the time 24/7. This means making sure the house is oriented correctly with good cross ventilation. Consider designing a house around a yard. Plan for high ceilings and large windows. Provide ceiling fans in every living space of the house. Then do not run the air conditioner 24/7. Open the windows and enjoy Miami’s natural winter environment.
- Strongly insulate the attic (R-30 minimum). Heat enters a house primarily through the roof. Only about 3% pass through the walls. For Miami, this means that modest insulation in the walls is sufficient (R-6 according to the Florida Building Code (FBC) of 2007).
- If possible, place the air conditioning ducts in an air conditioned space. This will maximize the efficiency of the air conditioning. The 2007 FBC, which is the code that was adopted by the City of Miami and is enforced statewide, requires R-6 insulation for ductwork in non-air conditioned spaces.
- If the house is to have a water heater with a tank, make sure the water heater is installed with a timer so that it does not run all day. Miami is hardly ever cold, so the water heater can produce excellent hot water in 15 minutes. It is not necessary to run the water heater all day.
- Make sure the house has overhangs where needed. In the Miami area, this means in the south, east and west exposures. Sometimes shading devices, such as louvers and screens can also be added.
- Consider putting several trees near the house to provide shade. It is a very effective way to reduce the exposure of the roof to the sun. This in itself will reduce the temperature around and in the house by several degrees. And, if at the same time we can use landscapes native to the Miami area that are drought tolerant, then water use can be reduced as well.
- Finally, consider installing covered decks, trellises, pergolas, and / or porches around the house for use in the winter in South Florida. As everyone freezes up north, you can tell yourself how awesome you are for choosing Miami as your home!