Fall 2013 Re-Making the Future Annie Ranttila Hazelwood Climate Analysis
Pittsburgh Pittsburgh, Pennsylvania is located in southwest Pennsylvania s Allegheny County. With a population of approximately 300,000 in city limits, Pittsburgh is built in and around the intersection of the Allegheny, Monongahela, and Ohio Rivers. Because of the proximity to rivers, much of the city was built around the steel industry. The topography is hilly with many green spaces left by unbuildable inclines. The climate is between the humid continental and humid subtropical climate on the Koppen scale and 5A on the ASHRAE Climate Zone Definition (cool-humid). Summers are hot and humid and winters are cold and snowy. The four seasons are visible each year. According to NOAA, there are 5829 annual HDD (65) and 726 annual CDD(65), meaning that while there are four distinct seasons, Pittsburgh is a heating dominated climate. The City of Pittsburgh has adopted the following codes for conformation: International Building Code (2009), International Mechanical Code (2009), International Fuel Gas Code (2009), International Residential Code (2009), National Electric Code (2008), International Property Maintenance Code (2006) (image from Google Earth)
Utilizing the program Climate Consultant, Pittsburgh has a climate that does offer a range of opportunities for passive strategies for heating and cooling. This can minimize the operation of mechanical climate control and reduce energy consumption. (image from Climate Consultant) The psychometric chart shows that the majority of the hours in the year require heating but that much of the warmer hours can be dealt with passively through the use of natural ventilation, sun shades, evaporative cooling, etc. Utilizing strategies like increasing envelope insulation, insulating blinds, selecting windows with a low U-factor and selecting a high-efficiency furnace can help lower the environmental impact during heating months while maximizing operable windows, installing ceiling fans and utilizing solar shades can help reduce the impact during summer months.
(image from Climate Consultant) The daylit hours show that while there is a lot of solar access in the summer months, there is not as much in November, December and January. This can be interpreted that relying on solar gains for heating may not be as effective as super insulating the envelope, but there is also the human factor to consider. Windows remain important even they do not offer heat gains during the winter because they increase occupant satisfaction.
(image from Climate Consultant) The diurnal averages show a much broader swing during winter months because of lower humidity. In summer, the diurnal swing is less because of the moisture in the air, making night flushing a strategy with limited effectiveness. (image from Climate Consultant) The temperatures during the year show a fairly typical range for the region; hot summers with unsteady but reasonable spring and autumns with cold winters.
Hazelwood Hazelwood is a Pittsburgh neighborhood that lies along the east bank of the Monongahela River, bordered by the Squirrel Hill and Greenfield neighborhoods. It was originally boomed because of the railroad, later flourishing with the operation of the Hazelwood Coke Works. When the steel industry began to fade, many steel towns faced closing businesses and population decline. Even though the Hazelwood Coke Works was the last Pittsburgh steel mill to close in 1989, Hazelwood also suffered from this transition. Currently, the site of the Coke Works is planned for a mixed-use development and the main business district of the neighborhood is in transition. Because of the flight after the mill closed, there are many abandoned structures, with 20% vacancies. According to PGHSNAP, the 2010 population was 4,317, down 19% from 2000. The community in 2010 was 54% White, 41% Black, 2% Asian, 2% Hispanic, and 1% other. (image from Google Earth)
5015-5017 2 nd Avenue 5015 2 nd Avenue is a former grocery store that is currently empty. 5017 2 nd Avenue is a 3-flat building on the corner of 2 nd Avenue and Tipton Street. The 3-flat building has three floors above grade with the first floor previously used for commercial, while the top two floors were residential. The first floor is ADA accessible. The grocery store is a single story infill structure with glazing along the street frontage. The rear of the buildings is partially below grade, as the hill slopes up from 2 nd Avenue. The grocery store and 3-flat are built to a zero lot line, extending fully to the alley. Because the grocery store is a tall single story, the third floor of the 3-flat has exposure on all three sides. (image from Google Earth) The 3-flat is a solid masonry building oriented with the long axis running east and west with a pitched roof. The majority of the windows are on the south side with exposure on all three floors because of the corner lot location. Solid masonry walls built to a zero lot line pose some challenges when considering retrofit strategies. Because of the freeze thaw cycle in combination with dew point location, insulating from the interior of a brick wall can cause moisture and mold problems. Ideally, a brick wall would be insulated from the outside to prevent freezing within the brick wall. An un-insulated brick wall uses heat from the interior
to prevent moisture retention. By adding insulation to the interior, the heat from the interior can t flow through the wall like it did previously, changing the moisture balance and keeping the bricks colder, longer. This can cause interior insulation to retain moisture and can possibly cause mold. Ensuring proper interior insulation installation can help prevent this as well as specifying a realistic amount of insulation for the job. By building a stud wall to the interior of the wall and using a closed cell spray foam insulation that can act as a moisture barrier can help prevent some of the challenges seen with interior insulation on this wall type. The windows should be replaced with a more efficient unit, but without sacrificing the operability. Regardless of the program, users of the building will be more comfortable and less likely to use mechanical climate control if they can open the windows. Windows on both sides on the top floor can also help with night flushing when appropriate. The pitched roof facing south offers a great location for solar hot water and photovoltaic systems installation. Because there is no adjacent obstruction, the systems can be utilized effectively. The grocery store is exposed on three sides: the street, the roof and the alley wall (half height due to grade change). By using adjacent structures for adiabatic conditioning, maximizing the envelope is most important on those three remaining sides. Being that it s a grocery store with lots of solar access and fairly simple pedestrian access from the alley, a roof garden can offer higher levels of insulation, the chance to minimize heat island, and increase evapotranspiration while offering the possibility for community engagement, job training and fresh food to be sold in the market. Replacing the glazing on the street frontage is another way to increase the envelope effectiveness.