COVID-19: Dealing with an Airborne Virus

The World Health Organization has acknowledged there is emerging evidence that the coronavirus can be spread by tiny particles suspended in the air. 

The airborne transmission could not be ruled out in crowded, closed or poorly ventilated settings, an official said. See BBC article below:

The Importance of Filtration and Ventilation

Harvard professor and co-author of “Healthy Buildings”, Joseph Allen, wrote an article for the Financial Times citing several cases of viruses being transmitted through the air ducts. One such example of a SARS outbreak that infected 187 people found that the virus was transmitted across the building through the air ducts coming from a bathroom.


A common HVAC system that has proven effective against spreading disease is pressurized outdoor air and pressurized return ventilation to the exterior. This condition will flush out bacteria and dirty particles from the building. Pollutants can enter the building from outdoors or generated inside. The air conducted from the exterior or returning inside must be filtrated. The management team should keep a close eye on the air filtration every month. Recent diseases have proven that it is necessary to clean out the ductwork once a year. Additionally, polluted air can pass through cracks on the exterior walls, unsealed doors and windows. Cracks can also be the source of reduction of pressure—lower pressure will lead to dilution of the air and reduction of the ventilation. Achieving a healthy indoor air environment in high-rise buildings hallways is possible with a careful balance of the mechanical components, air pressurization and ventilation airflow, along with the building materials.

When containing disease, even within rooms, it is necessary to retrofit the HVAC system and maintain air filtration of the whole building in order to achieve healthy indoor air. The solution is simple: ventilation system need to be designed to provide an emergency flush out protocol in cases of airborne disease. Depending on your building, it may be easier to implement than you think.

Urgent Measures to Slowdown Coronavirus in Condos

The Coronavirus COVID-19 has paralyzed the world with its highly contagious virality, and governments have been reacting in a panic to the pandemic for months. There doesn’t seem to be any good way to combat the virus other than quarantine, and even inside the sanctuary of a building there’s a high possibility that you won’t be safe from the disease.


The virus, roughly one 900th the size of a single strand of hair, can be transmitted through the air. In an article published by Heather Murphy at the New York Times, a person can be infected by breathing in viral droplets—a droplet containing viral particles. When the virus becomes suspended within the droplets in the air, it can stay suspended for about half an hour (according to the New England Journal of Medicine). This proves that keeping a social distance is not enough to contain the virus. This path of infection is critical for common areas of the building, such as the lobby, hallways and elevators.

Air should be exhausted faster—better ventilation translates into less life-safety risk and less liability for the board and management. The author was predicating on the last two decades that Indoor Air Quality is more important than energy savings. Today, nearly all of our clients realize this is true. Driven by cost-savings measures, Air Conditioning systems were converted in the last fifteen years to save energy. Many of the buildings we have tested recently showed stagnant air after the conversion.

Stagnant air in common areas, especially in lobbies with high traffic, is a red flag. This unhealthy condition will worsen the indoor air quality during the hot summer months when the humidity increases. Many viruses have shown that they survive longer at high humidity. Emergency testing of air pressurization and ventilation airflow should now be considered an urgent life-safety mitigation measure in common areas of condominium buildings where residents share the same.

RAS is assisting in the fast recovery of South Florida during this terrible epidemic. We are concerned over the rapid spread of the virus through congested communities breathing the same stagnant air without proper ventilation. If you know anyone that lives in a condominium with more than 50 units, contact us for a complimentary visit and recommendations for testing the indoor air. Due to high demand, we are offering this complimentary visit to buildings located in South Florida, east of I-95.

Contact us:

Evaluating your Flood Risk

Flood Season is upon us and there are many details to consider in order to remain safe and keep your building watertight.

At RAS, we want to ensure that you are prepared this King Tide Season and have implemented a five-step program for property managers and owners in flood prone areas.

  1. Recognizing the flood risk of the property. RAS evaluates risky areas of the building by reviewing a current land survey provided by the owner.
  2. Based on risk evaluation a shortlist of the areas subject to flood is created.
  3. Review as-built plumbing and drainage drawings provided by the owner.
  4. Site visit to evaluate flood risk areas including sample testing of underground using radar and thermography scanning.
  5. Flood mitigation plan.

Evaluating your flood risk is essential in South Florida providing you with the tools you need to ensure your property is protected.

Contact us today to schedule a complimentary flood risk evaluation.

Economic Sense of Backup Windows – Thermal Heat

“RAS Engineering is helping unit owners understand the benefits of the new revolutionary backup window. Providing testing and results clearly showing the savings and benefits.”

In this episode we discuss the benefits and savings gained from the reduction in thermal heat with backup windows installed. The testing performed to calculate these savings is a heat test measuring the rate of heat conduction through a brand new standard window and a backup glass frame. We will then calculate the savings based on the difference of heat conducted through both windows. During the test we installed heat flux sensors and two temperature sensors one on the glass and one on the frame on the interior side of the windows. We then applied heat flux sensors on the exterior side of the window and attached the equalizing chamber for both windows. Once we attach the chamber and the sensors are applied to the interior and exterior we apply heat to the chamber using a heater to simulate the exterior temperatures. This allows us to see the heat conducted between the interior and exterior. The heat flux sensors measure the heat that is passing through the glass in watts per hour per square foot. this will help us find the resistant value of the assembly or the conductance.

Ep.3 Thermal Heat Testing Results-3

The testing results show that the standard window conducts more heat requiring 50.30 watts per hour to cool the air. The backup window reduces the conductivity significantly requiring only 6.58 watts per hour for cooling the air. We will use these results to project our findings into a real building with 3 rooms using 3 6’x4′ windows in Miami, FL.

Ep.3 Thermal Heat Financial Chart-5

In this example, the area is larger than the area we used during the test. The differential temperature is about the same parameters. With this projection 452 watts per hour is required to cool the room with the standard windows and only 59 watts per hour on the room with the backup glass frame installed. As you can see there is a significant decrease in watts per hour when using the backup window. If we multiply these numbers by 6,480 hours per year at the cost of 10 cents per kilowatts, we get the energy loss spent cooling a room with standard impact windows at $293 per year versus only $38 a year for a room with backup glass frames installed. The overall savings comes to $255 by installing backup windows over the existing windows. Reducing the thermal heat reduces the required energy needed to cool the interior air resulting in large savings. Not only will you save money but you can become a green leader using green solutions and products.

Economic Sense of Backup Windows – Pollution Control

“RAS Engineering is helping unit owners and tenants become green leaders and take control of their indoor air quality. At RAS we stand behind this new product for its innovative design and many benefits.”

In this episode we discuss the benefits and savings gained from the reduction in the number of pollutants infiltrating the window. We also show the testing performed in the video, explain testing results and savings. We performed a Particle infiltration test measuring the penetration of contaminated air between both a standard window and a backup window.  Once completed we then reviewed the savings based on particle infiltration using the results of the testing. You can see the test being performed in the video above. The results of the testing showed that a large number of contaminants passed through the standard window contaminating the indoor environment. The number of contaminants is significantly reduced with the backup window greatly improving the indoor air quality. Improving the indoor air quality can save you money but it can also increase comfort, decrease adverse health effects, decrease absence rates from school or work, and increase performance in the school or work place. This system is great for Condominium owners that cannot replace their existing windows due to community regulations or approval. It also benefits, office buildings, and schools reducing absent rates and increasing performance.

IAQ Improvements-4

As the particles increase in size the infiltration rate decreases with the backup window, with 5.0 micrometer particles being reduced up to 99% greatly improving indoor air quality. Based on the substantial improvement in indoor air quality we are going to evaluate the savings.

IAQ Improvements

By reviewing the chart above you can see that by adding the backup window you increase the time of replacing the air filter from 11 days to 36 days reducing the annual cost spent on air filters. In a contaminated environment we assume there are 10 sick days per year. In a healthy environment we assume only 2 sick days per year. The loss of revenue due to sick days is estimated at $960. Because living in a contaminated environment increases the number of sick days per year, it also increases the number of visits to your physician and in a healthy environment we assume only one visit per year saving you up to $240 alone in healthcare costs. In total by improving the indoor air quality you can save up to $1,775 per year. The benefits of a healthy indoor environment are more than monetary, increasing comfort, decreasing adverse health effects, decreasing absence rates from school or work, and increasing performance.

Economic Sense of Backup Windows – Improving Air Quality

“RAS Engineering strives to test the performance of building elements used during restoration of buildings to provide high performance results with the belief that testing and discovering energy efficient solutions with high payback is not only possible but makes financial and economic sense.”

RAS Engineering is introducing the revolutionary backup glass frame system, manufactured by GreenB. This system gives unit owners the freedom to choose their window features, without replacing the existing window. It’s a great solution for unit owners that want and need to replace their windows but are prohibited by Association or Code Regulations. The backup glass frame system allows for exactly what you want in a window and much more.

The envelope of a building which is the exterior surface of a building is the shield protecting the occupants from the environment. In addition, elements like windows have a great impact on air conditioning performance and drastically affect the energy efficiency of a building. An innovative product on the market called a backup glass frame is a sustainable solution to restore the envelope saving expenses in various ways. The revolutionary glass frame has several distinctive features: first, it allows for high impact. This is valuable in the event of hurricane winds preventing breakage or blast explosion. The backup window also has extra sealant and insulation inside on the frame, meaning there is no contact in between the metal of the window with the exterior. This prevents thermal bridging that transmits the heat from outside onto the metal, reducing transmission of heat, sound, infiltration of moisture and pollutants. Also, airflow is blocked by the backup glass frame preventing pollutants and air leakage.

In this video, RAS performed an air infiltration test on a backup glass frame and a standard window in order to show the benefits and savings in comparison. A standalone wall with two window frames, referred to as a Mockup, was constructed to test windows. The top window was fitted with the backup glass frame system, while the bottom window was left as a standard brand new window. A blower is connected to the air chamber by flexible ductwork. The chamber is attached to the wall using the clamps for a tight seal. The blower is turned on and the pressure gage is set at 50 Pascal’s to test the upper window with the backup window installed. The testing tablet attached to the mockup automatically calculates the annual cooling cost for this window with the backup glass frame: which comes out to $5 per year per window.

The chamber is then disassembled and reassembled to test the bottom standard window. The pressure gauge is once again set at 50 Pascal’s as the blower is turned on.  The difference is almost an extra 300 cfm passing through the bottom window into the interior of the room. This airflow was blocked by the backup window on the first test. The results of the testing show the annual estimated cost of air leakage is $37 per year in cooling alone for a small window of this size, and of course the cost of wasted cooling air and energy will rise on windows of an even larger size.

We are now going to place the results of the test into a chart.

The perimeter of the standard window is 86 inches, and the test concluded that the annual infiltration rate came out to be 37.6 cubic feet per minute. If we divide the infiltration rate by the perimeter, we find that there is about 0.44 cfm per inch of caulking. The cost of air leakage per year results in 43 cents per inch of caulking. Reviewing the annual infiltration rate from the backup window, the infiltration was only 4.5 cubic feet per minute, which in this case divided by 76, which is perimeter of the caulking on this window, we reach 0.06 cfm per inch. The cost of air leakage per year in this case comes down to 5 cents per inch of caulking.

Ep. 1 Improving Air Quality Test Chart-3Now we will use an example of backup windows installed in 3 rooms in Miami, FL with a size of 6’x4’ approximately.

The caulking perimeter of the standard window would be 1,222 inches and in the backup window, which has less caulking than the standard, it would be 720 inches. We are going to apply the calculated value of cost of air leakage from the first chart for each window, and, assuming 10 cents per kilowatts hour, we see an annual cost of $526 for the rooms with standard windows. In comparison, the rooms with the backup windows would only cost 36$ per year. This gives us a savings of $490 per year on the infiltration of air for just 3 rooms.

Ep.1 Improving Air Quality Financial Chart-3

While the results are impressive. this is only one of eight demonstrating the economic benefit of high-performance buildings. The payback on this innovative product is about one year. Additional benefits will be revealed in future episodes: Pollution Control, Thermal Heat, Solar Radiation, Waterproofing, Air Humidity, Hurricane Impact, and Financial Payback, in addition to Sound Insulation (which cannot be quantified in dollar amounts).