By Jonny Lupsha, Wondrium Staff Writer
California’s San Quentin State Prison is under fire for spiking COVID-19 cases and deaths, Fast Company reported. The disproportionately large number of cases in the facility may partially be due to poor architectural design and ventilation. Proper air circulation is vital to any residence.
According to Fast Company, the number of COVID-19 cases among prisoners and guards at San Quentin State Prison is abnormally high. “More than two-thirds of the prison’s roughly 3,200 inmate population has been infected with the virus, and 25 people there have died, including one guard,” the article said. “According to experts, a major reason the outbreak has been so extreme in San Quentin and at other prisons is their design.”
The article went on to state that two of San Quentin’s biggest facilities each house 800 men in “tiered blocks of single- and double-occupancy cells five levels high,” which—when coupled with the barred doors—mean lots of recirculated air with little to no ventilation.
Air circulation and ventilation are rooted in a building’s heating system. There are three main types of residential heating: the furnace, the boiler, and the heat pump. The furnace is the most common.
The Furnace: Heating
“The gas furnace has four main components—the burner, electric blower, heat exchanger, and control system,” said Dr. Stephen Ressler, Professor Emeritus from the United States Military Academy at West Point and a Distinguished Member of the American Society of Civil Engineers.
“When your thermostat calls for heat, the control system opens a valve, sending gas to the burner, where it’s ignited by a pilot light. Outside air is drawn by natural convection through an intake pipe to provide oxygen for combustion.”
Dr. Ressler said that the resulting hot gases flow upward through the heat exchanger and are exhausted out through a stack. Crucially, he also pointed out that two streams of air move through the furnace. The first is combustion air, which originates outside the home and feeds the flame, and is then exhausted through the stack. The second stream, circulating air, originates from and returns to the occupied areas of the home. The heat exchanger transfers heat from one stream to the other without the streams mixing.
The Furnace: Cooling
A furnace being involved in cooling may sound like a paradox, but furnaces use forced air for circulation and they share duties with the air conditioning.
“A central air conditioner [is] called a split system, because the compressor, condenser, and expansion valve are located in a stand-alone unit outside, while the evaporator is indoors,” Dr. Ressler said. “And note that, in an integrated system, the evaporator is actually placed inside the supply plenum, just above the surface.
“Thus, when the air-conditioning system is operating, cool air is circulated through the same ducts used by the heating system, and is propelled by the same blower.”
Dr. Ressler said it’s an efficient setup that accounts for a lot of the popularity of forced-air heating systems in climates that require both heating and cooling.
Having properly circulating air in any living space—whether it’s a house, apartment, hotel, prison, or otherwise—makes a big difference. Not only does it matter for comfort but also for breathing in fresh air. Otherwise, tragedies like the COVID-19 cases and deaths at San Quentin and other prisons run rampant.
Dr. Stephen Ressler contributed to this article. Dr. Ressler is Professor Emeritus from the United States Military Academy at West Point and a Distinguished Member of the American Society of Civil Engineers (ASCE). A registered Professional Engineer in Virginia, he earned a BS from West Point and an MS and a PhD in Civil Engineering from Lehigh University, as well as a Master of Strategic Studies from the US Army War College.