Calculator Journal Report
The physical basis and algorithm of an ultraviolet germicidal irradiation (UVGI) scientific calculator was made to assist the design of the Covid Clean Isolation System. The algorithm is implemented in the Calculator tab. On the bottom of the page, you will see a link to the calculator journal report. This scientific calculator aggregated the best research and data to facilitate the engineering and design of air-purifying equipment being developed for use in hospitals, commercial and residential applications. The calculations illustrate how different factors of the construction of a UVGI air-purifier may influence the degree of virus deactivation.
We used UV stabilized Polycarbonate for the shell due to its ideal properties. It blocks all of the electromagnetic spectrum under 395nm. Germicidal UV-C light starts at 280nm giving us a large window of safety to use germicidal lights to disinfect the exterior of the isolation system without needing to remove the patient. It allows 90% of the visual light spectrum so lights do not need to be engineered into the system, Near-infrared so a patient can control electronics such as a TV outside of the isolation room, IR lasers at 1550nm to wireless charge electronic devices, radio frequency (RF) so wireless headphones and communication can be used and allows all of the important FCC dedicated medical telemetry signals to transmit so the patients’ vitals can be monitored remotely. This blend of polycarbonate is 250x stronger than glass and has high sound-blocking abilities to provide a quiet space within the room. This blend of PC also has a very high fire rating further increasing safety. It can be mass-produced to supply the world with this solution.
Computational Fluid Dynamics
To understand how the airflow would operate we hired an expert who is the lead designer of the air intake systems of heavy equipment and tractor-trailers for a multi-billion dollar corporation. We ran several rounds of CFD analysis on very powerful supercomputers. With this data, we knew the parameters to balance the air-flow of the room with the irradiation chamber. To our surprise airflow rates had a significant influence on the flow of air over the patient and into the exhaust. We built into the model filter restriction and system geometry. We will need to continue to run CFD for every model variation and parameter change. Once we do we will be able to construct this grid into our calculator and display the simulated airflow path.
The use of Ultraviolet germicidal irradiation has been used for about 140 years to kill microbes and slow the spread of airborne disease. However, it is not utilized to the degree it should be or with the right equipment. Smaller home-based UVGI air-purifiers selling for many hundreds of dollars are almost universally inadequate and systems being sold for HVAC systems are not much better. This is a science that needs to be taken seriously. There is no regulation or oversight so this practice persists. For instance, I have warned Amazon for several months to remove obviously scam UVGI LED products being sold in mass with no effect and the products that were being sold were commanding prices that should be deemed illegal due to the pandemic. Supplies were low since the largest US manufacturers decided to offshore all UVGI production creating several months of transport issues. The US spends 700Billion a year on defense yet the one biggest mitigating factors for one of the largest known risks was ignored. We were able to locate the few US-based manufacturers and talk about production capacity. The irradiation chamber utilizes an extremely reflective material in the UV range. This is a very expensive and rare material. One that very few even in the germicidal industry use and they typically opt for reflective surfaces 30x less effective in their products as if they were not trying at all. With the combination of the correct geometry, chamber size, reflection, and UVGI power we were able to mathematically prove not only our effectiveness but the ineffectiveness of the vast majority of products being sold.
The temporary negative pressure isolation units were designed to be used in a hospital room but can be used in almost any room. The height was determined to comply with regulations within hospitals. Overhead equipment in most states requires overhead equipment to be stowed away above 7 feet. Our systems height clears this. The size of the doors also exceeds the minimum required-entry width of hospitals by half a foot or more. The structure is made of 4x4 wood since it is a common product worldwide and does not need specialized manufacturing ability outside of local communities and will allow for rapid decentralized production. 4x4 was used for its strength to hold up the fairly light structure without needing to be 16” on center as is the case with most wall construction in the US. The larger beam allows the larger spacing between members and simplifies the construction. A few simple cuts and the parts fit together like building blocks then screwed into place. The polycarbonate can also be easily screwed into the wood without the need for a highly engineered product requiring centralized production which would slow down the speed of implementation and increase the cost. Polycarbonate is also a material that handles wood screws extremely well unlike other clear plastics that need special tools to avoid shattering. The system also may utilize a small air-lock entry system providing an additional layer of isolation and protection in both a positive or negative pressure isolation setup. The system is designed for rapid assembly and disassembly for rapid response. Ockham’s Razor roughly means, “The simplest solution is usually the best solution.”