REHVA - Experts & Thought Leaders

Eurovent, REHVA, and Nordic Ventilation Group have launched a common proposal on implementing Indoor Environmental Quality (IEQ) requirements introduced by EPBD under revision. These new provisions added by the Commission's and Parliament's initiative, represent an important step forward to ensure healthy and comfortable IEQ in buildings. Guidelines and examples In this document, IEQ substance and requirements are explained just on a few pages In this document, IEQ substance and requirements are explained just on a few pages. It is shown which items need regulatory effort and which aspects can be left for technical guidance documents such as European standards or national technical guidance. Guidelines and examples are presented on how essential IEQ requirements can be implemented on a national level. Article 11a updates Also, some minor, but important changes are suggested to make Article 11a implementation technically and economically feasible. The guidance was prepared in a joint effort by Eurovent, REHVA, and Nordic Ventilation Group. From Eurovent, input was provided by its newly set up Issue Group ‘Indoor Environmental Quality’ (IG-IEQ).

Eurovent is going to be at Mostra Convegno Expocomfort – an Italian exhibition which showcases and provides a global business platform for companies in the HVACR, renewable energy and energy efficiency sectors. The Eurovent Team members Felix, Francesco, Igor, Markus, Massimiliano and Stijn will be at the exhibition. Delicious local dinner The Eurovent Team will be housed at the booth of its Italian Member Association Assoclima / ANIMA (Hall 18, stands A01 & A09), which all MCE attendees are invited to visit. ANIMA will present a series of initiatives at its Hall to represent and promote the environmental comfort sector. Users can find out more about the events, webinars and meetings on the ANIMA website. The Eurovent Certita Certification Team will also be present at the exhibition, and users can find them at booth S18 in Hall 24. All exhibition participants are cordially invited to attend a presentation by PRODBIM titled ‘How to facilitate access to certified data in BIM software’s and exchanges’ which will take place at the REHVA seminar in the Libra room, first floor of Stella Polare Congress Centre at the Expo on Friday, 01 July, 12:55-13:20h. Eurovent will also hold its Product Group 'Residential Air Handling Units' (PG-RAHU) meeting at its regional office in Milan on 27 June 2022. As usual, the meeting will be followed by a social evening including delicious local dinner. For more information and registration, check out the Eurovent website.

REHVA (Federation of European Heating, Ventilation and Air Conditioning Associations) has announced that they will take part in the KGH 51st International HVAC&R Congress and Exhibition: the Serbian HVAC&R Virtual Congress that will be held online from 2nd December to 4th December 2020, confirming the longstanding collaboration with KGH. 51st International HVAC&R Event Following the welcome greetings from the REHVA President, Frank Hovorka, REHVA (Federation of European Heating, Ventilation and Air Conditioning Associations) is slated to present ‘Introducing hybridGEOTABS: Comfort supplied in a Sustainable way!’ seminar session at the 51st International HVAC&R Congress and Exhibition. This is a seminar developed by hybridGEOTABS EU funded project, in which REHVA is a partner. The aim of the seminar is to showcase the development of hybrid technologies based on building-integrated radiant heating and cooling systems and geothermal heat pumps that enable very high energy efficiency and the flexibility of thermal storage, while providing freedom of space and high thermal comfort to the user.

Do HVAC systems help with the spread of COVID-19? No one is entirely sure, but it seems very likely. Especially in the case of enclosed indoor spaces. As soon as the COVID-19 pandemic began, fingers pointed to air-conditioning systems as culprits, and scientists now believe a super-spreader event traced back to a restaurant in Guangzhou, in China, which could have started with an asymptomatic person who just happened to cough close to an HVAC fan. Scientists also believe something similar happened on the Diamond Princess cruise ship, which made headlines over the world, in February 2020. Especially because cruise ships have elaborate inter-connected HVAC systems, which could have aided the coronavirus as it ripped through the cruise population. HVAC systems Role in COVID-19 spread And because air-conditioning units typically function indoors, and because the coronavirus (COVID-19 virus) can float about for a little while on respiratory droplets in the air, it should be no surprise at all that HVAC units have come under scrutiny. In response to this, over the last year, the REHVA (European Federation of Heating and Ventilation Engineers) group actually set out guidelines on what to do, in order to make HVAC units safer. Actually, they went further than that, because on the contrary, properly configured air-conditioning units can actually help to fight the coronavirus, rather than aid its spread. How AC units can limit viral transmission By making sure there is a fast and constant exchange of air, AC units can actually wash away virus particles Despite the apparent doom that HVAC units can kick start super-spreader events, the answer is not to do away with air-conditioning systems. In fact, REHVA recommends the opposite. Instead, what we actually need to do is to reconfigure our AC units so that they can stop coronavirus particles from loitering about in the air, and then settling down. When virus particles ‘settle’ on a surface, they can be infectious for a time. The technical term for this is a ‘fomite’ and an area that is infectious to touch. By adjusting the settings on AC units to increase the amount of outside air they pull in, and the rate to which this fresh air is distributed indoors, we can make indoor environments much safer. By making sure there is a fast and constant exchange of air, AC units can actually wash away virus particles and prevent fomites from occurring. What about just opening the windows? Before modern HVAC units, there was, of course, the humble open window. And sure, open windows is a great way to make sure that air from the inside is quickly and constantly being exchanged with the air from outside. But as we all know, opening the windows is seldom the ideal choice. For example, it isn’t desirable in cold or in air-polluted or noise-polluted spaces. Open windows can even be a hazard if there is a risk of injury or falling. If you can work in an environment with open windows in a way that’s feasible and manageable, that’s great. They will likely offer similar protection against lingering coronavirus particles. But even if you can, the evidence suggests that a properly configured HVAC system is still safer (not to mention more comfortable, given their ability to regulate temperature) than the age-old open window option. AC units with high-efficiency particulate air filters Arguably the most proficient AC units today are those equipped with high-efficiency particulate air (or HEPA) filters. Although, you will struggle to find any outside of surgical theatres and airplanes, where getting the right amount of air exchange is primarily a health and safety issue and not just an issue of comfort. But as the pandemic has revealed to us, having better optimized HVAC units in public indoor spaces is a health and safety issue. With that being said, could HEPA filters become the norm throughout major public indoor spaces? HEPA filters HEPA filters are so reliable because they are made up of thousands of layers that trap all types of particles HEPA filters are so reliable because they are made up of thousands of layers that trap all types of particles, from dust to viruses. And they operate with an astonishing speed, being able to completely turn over a room’s air up to 30 times per hour. It would almost certainly make sense for HEPA filters to at least be considered for widespread use, but there are some technical issues to work out before their deployment becomes feasible. Cost aside, these filters can cause ‘dragging’ when attached to traditional AC units, among other issues. But if we are serious about tackling all forms of viruses, including influenza which hospitalizes and kills thousands every year, perhaps the widespread deployment of HEPA filters should be at least thought about in our approach to the ‘new normal’. Protecting people with proper air conditioning Whatever the fate of the HEPA filters, we do not have to sit around and wait for a revolution in the HVAC units to keep the general public safe. We can do that right now by equipping and configuring our current systems to properly exchange the rate of air in indoor spaces — to blow away lingering particles and keep surfaces free from fomites. Fortunately for us, the COVID-19 virus finds it hard to spread outdoors. But that means almost all of the spreading must happen indoors. So, it is crucial that we do all we can from an HVAC perspective to limit the spread of the coronavirus, and indeed all the other infections (including flu), which collectively can infect and hospitalize thousands of people every year. New infectious diseases emerge, and old ones come and go all the time. With the guidelines that REHVA has put together and some vigilance, our actions could indirectly save many people from falling ill every year. In summary, it’s not rocket science. To make an indoor area safer from the coronavirus, turn your AC unit up. Blow away the germs and stop them from settling down with a frequent exchange of air at all times.

The amount of carbon dioxide (CO2) in a poorly ventilated indoor space depends on the number of people who exhale their breath in that space. And aerosol virus contained in exhaled breath is a common way that COVID-19 germs are spread. Therefore, might the CO2 level in a given space serve as an approximation of the likelihood of coronavirus spread? Broadly speaking, poor ventilation of indoor spaces can increase the likelihood of aerosol transmission, and a higher CO2 level is an indicator of insufficient ventilation. In indoor spaces, the CO2 concentration should not exceed 1,000 parts per million (ppm), which is higher than the 400 ppm concentration in the fresh air. Deployment Of CO2 Sensors Measuring aerosols in the air is complex and expensive. However, measuring CO2 is inexpensive. Using low-cost and compact CO2 sensor devices can help to warn against high concentrations of CO2 in the air, and by extension, the likely higher levels of aerosols and greater virus spread. Seeking to provide a warning of high CO2 levels (and thus a likely higher concentration of aerosols) points to a need to increase deployment of inexpensive CO2 sensors in a variety of applications. The simplest implementation might be a CO2 traffic light that signals air quality changes with red, yellow, and green lights. Data Analysis, Remote Access, & Monitoring CO2 sensors tied to the cloud for data analysis, remote access, and monitoring and linked to other IoT devices CO2 sensors can also be tied to the cloud (along with other sensors) for data analysis, remote access, and monitoring. They might be linked to other Internet of Things (IoT) devices such as air purifiers and thermostats. CO2 sensors that are the most accurate tend to be bulky and expensive. However, using a microelectromechanical system (MEMS) technology, a CO2 sensor based on photoacoustic spectroscopy (PAS) can analyze CO2 concentration in parts per million. It provides precise results in a small format. CO2 Levels Proxy For COVID-19 Transmission Each person in a building will exhale approximately 8 liters of air per minute. The air has been in contact with lung tissue and contains tiny liquid droplets (aerosols) that can float in the air. Exhalation air also has a concentration of about 40,000 ppm of carbon dioxide, which increases the CO2 levels in a room. In effect, CO2 levels can be used as a proxy for COVID-19 transmission risk. Evidence shows that long-range aerosol-based transmission routes play an important role in transmitting the SARS-CoV-2 coronavirus. Therefore, analyzing aerosol concentration provides an indicator of the safety of an indoor space. Because of the close link between indoor CO2 concentration and aerosol density, using CO2 sensors to monitor an indoor environment can help to monitor possible indoor spread. CO2 Monitoring The Federation of European Heating, Ventilation, and Air Conditioning Associations (REHVA) in Germany has published guidelines for schools to use CO2 monitoring, including the use of a traffic light indicator. In addition to CO2 levels, other factors should also be considered when determining infection risks, such as the number of infected people in a region, activity type, air filtration, and mask-wearing. Activities such as talking, singing, or shouting can increase risk. Ventilation using outdoor air dilutes both CO2 and virus concentrations. Germany’s Federal Environment Agency’s general guidelines for health assessment of carbon dioxide in indoor air include advice relevant to COVID-19. The guideline classifies any CO2 concentration between 1,000 and 2,000 ppm as questionable; anything above 2,000 is unacceptable.