ASHRAE – Treehouse Writers

On May 15, ASHRAE — the association of engineers who work in heating, air conditioning, and ventilation — set out its Proposed Standard 241P, Control of Infectious Aerosols.

They are soliciting comments on it until May 26 from the public. Links and instructions for comments can be found here.

This standard, which was put together over six months — lightning speed for ASHRAE, which often takes years to develop new standards due to its painstaking process — was built on years of work by the organization on indoor air quality and included some input from public health experts.

According to ASHRAE:

The standard will address long-range transmission of infectious aerosols and provides minimum requirements for:

Equivalent outdoor air (combined effect of ventilation, filtration, and air cleaning) for use during Infection Risk Mitigation Mode

Room air distribution to reduce risk

Characterization of filter and air cleaner effectiveness and safety

Commissioning, including development and implementation of a Building Readiness Plan

System operation in Infection Risk Mitigation Mode during periods of high risk

Maintenance tasks and their minimum frequency

Residences and health care facilities

ASHRAE issued some recommendations early in the pandemic that provided guidelines for the kind of filtration that should be used in buildings to minimize transmission of airborne viruses. Those guidelines, though very good, were based on ongoing work on indoor air quality and did not include the kind of comprehensive work they brought to this new standard.

These standards, once incorporated into building codes and other regulations for buildings, will be a major step forward in making sure that the indoor air is safe to breathe. In a world in which many people spend most of their time indoors, that is a crucial element of public health.

These standards will minimize the transmission of airborne diseases including, but not limited to, Covid. Continue reading “Fixing the Air We Breathe Indoors”…

The pandemic buzzword these days is “endemic,” which is being used to mean Covid’s going to stick around so we might as well just go back to normal lives.

That is not what endemic means, of course. Endemic means an illness that constantly exists at a baseline level of some amount in an area without being brought in from elsewhere. The common cold is endemic in most places. So are a few more dangerous illnesses — the plague, for example.

The other key thing about endemic disease is that the illness doesn’t spread at an epidemic pace. Covid’s clearly not close to endemic. Here’s a piece in Nature that explains that better than I can.

Also, just because an illness becomes endemic doesn’t mean everything is rosy. In the Nature article, Oxford Professor Aris Katzourakis points out:

A disease can be endemic and both widespread and deadly. Malaria killed more than 600,000 people in 2020. Ten million fell ill with tuberculosis that same year and 1.5 million died.

I recall a doctor who was working for a pharmaceutical company telling me years ago that no companies wanted to work on TB drugs because there wasn’t any money in it. That’s why those people are dying.

Coming back to the virus at hand: what endemic does not mean and should never be used to mean is letting people die so we can get back to “normal.”. But in many corners of the U.S., people are using the term to mean precisely that. Continue reading “On Not Tolerating the Intolerable”…