Optimum Solar Orientation: Miami, Florida

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1 Optimum Solar Orientation: Miami, Florida The orientation of architecture in relation to the sun is likely the most significant connection that we can make to place in regards to energy efficiency. In this diagram that is specific to Miami Florida, the optimal orientation for the long edge of a vertical surface is determined to be on the axis of 250 degrees from due north. Meaning architecture that takes this directionality will have the least solar gain when correctly set in depth for day lighting and shaded correctly from the sun s path across the summer solstice line of declination. Psychrometric Chart: Active cooling overlay, Miami, Florida The Psychrometric chart shown here is specifically relevant to Miami, Florida and is a diagrammatic overlay of the zones or pockets in which intervention of conditioned cooling would be necessary or a combination of evaporative measures and air conditioning and combinations of natural ventilation with conditioning measures. The chart is specific to Dry Bulb Temperature measured horizontally along the bottom of the chart and relative humidity measured along the right hand parabolic slope. What is not shown here is the time of year, which could be derived quickly know that South Florida rarely reaches the comfort zone as defined by ASHRAE of between degrees fahrenheit and a relative humidity below 60%.

2 Thermal Comfort Averages: Miami, FLorida The graphic along the top represents monthly averages of Thermal Heat Gain attributed by the temperature, relative humidity, direct solar gain, and diffuse solar gain. The graphic at the bottom right is representative of the daily heat gain conditions occurring on July 8 th. The daily conditions diagram represents those shown in the monthly averages in addition to wind speed and cloud cover. The red graphic is showing a contour shading of the temperature variations and is the dominant heat gain contributor. Measurements are given in Celsius. Maximum Temperature: A weekly summary, Miami, Florida This graphic is representative of a 52 week cross section mapping assembly measuring 24 hour days. The far right hand of the chart illustrates the mapping of January and the far left of December. The elevated temperature readings in summer, peaking in July, show that the majority of summer is elevated above 100 degrees Fahrenheit.

3 Minimum Temperature: A weekly summary, Miami, Florida This graphic is representative of a 52 week cross section mapping assembly measuring 24 hour days. The far right hand of the chart illustrates the mapping of January and the far left of December. The elevated temperature readings in summer, peaking in July, show that the minimum temperature in July is possible to reach 95 degrees Fahrenheit, while the minimums in the winter months are capable of reaching the low 40 s. Relative Humidity: A weekly summary, Miami, Florida This graphic is representative of a 52 week cross section mapping assembly measuring 24 hour days. The far right hand of the chart illustrates the mapping of January and the far left of December. What is clear from this chart is the consistency of relative humidity regardless of the month of year or temperature. Peaks are between 50 75% relative humidity and valleys between 30 40%.

4 Direct Solar Radiation: A weekly summary, Miami, Florida This chart is a mapping of the sun s energy relevant to a 52 week time frame measured in a 24 hour day. The far right hand of the chart illustrates the mapping of January and the far left of December. The Measurement is W/m2 (Watts per meters squared). This energy is commonly referred to as Insolation, defined as the measure of solar radiation energy received on a given surface area in a given time. It is commonly expressed as average irradiance in watts per square meter (W/m 2 ) or kilowatt hours per square meter per day (kw h/(m 2 day)) (or hours/day). In the case of photovoltaics it is commonly measured as kwh/(kw p y) (kilowatt hours per year per kilowatt peak rating). The challenge is to configure building systems which can harness this energy and avoid the heat gain attributed by such an intense energy. Diffuse Solar Radiation: A weekly summary, Miami, Florida As sunlight passes through the atmosphere, some of it is absorbed, scattered, and reflected by the present air molecules, water vapor, clouds, dust, and pollutants. The sum of the diffuse and direct solar radiation is called global solar radiation. As this chart illustrates, scattered cloud coverage may be evident in south Florida throughout the year, however the diffuse solar radiation is fairly regular.

5 Average Cloud Coverage: A weekly summary, Miami, Florida This chart is a mapping of the cloud coverage relevant to a 52 week time frame measured in a 24 hour day. The far right hand of the chart illustrates the mapping of January and the far left of December. As the chart shows there are two sets of daily peak cloud coverage typical throughout the year. What this chart also begins to explain is the irregularity of cloud coverage throughout the weeks of the year. Average Rainfall: A weekly summary, Miami, Florida More consistent than cloud coverage, the rainfall in Miami appears to work like a clock. With little variation in the levels of precipitation throughout the day, this chart also points out the peak rainy season in July and September. When considering technologies which harvest rainfall, for the general use of the occupants, a calculated level of water should be rationed by the users in order to sustain the natural ecosystems that are being preserved. Rainwater is safe to use for cleaning, bathing, and sanitary devices of low consumption. Drinking water could be generated through the implementation of dehumidifying devices that employ multiple stages of filtration, extracting water from the relatively humid air.

6 Prevailing Winds: Maximum Relative Humidity, Miami, Florida This graphic illustrates the directionality of winds which contribute to high levels of relative humidity. Winds coming from due East and from the North West have the highest values of relative humidity (55 65% & in higher concentration). Winds coming from the North East represent the lowest levels of relative humidity. Prevailing Winds: Maximum Wind Temperature, Miami, Florida This graphic is best seen from afar to perceive the hottest prevailing winds which come from the North West compass directions. Interestingly, the higher ratios of cool air and as seen in the graphic above relative humidity also come from this direction. In combination, these last two charts show that South Florida faces a difficult challenge when attempting to utilize natural breeze patterns which are within or close to the comfort zone.