As the economy slowly re-opens, businesses need to plan for restarting operations. Those who require their staff to work in a common location will need to ensure their employees, customers and partners feel safe and can trust that they will be returning to a healthy and clean work environment, both for the near future and for potential second or third waves of infection.

The spread of COVID-19 is generally understood to be through close proximity – by respiratory droplets and aerosols created when an infected person coughs, sneezes, sings, shouts, or talks,  and surface transmission. Transmission through HVAC systems is not adequately tested or documented, and available resources (such as ASHRAE) appear to favour an abundance of caution in making any recommendations due to this lack of testing. Our engineers and technology strategists have been exploring the impact of COVID-19 on building design. Here are some considerations for building owners and tenants.

As the economy slowly re-opens, businesses need to plan for restarting operations. Those who require their staff to work in a common location will need to ensure their employees, customers and partners feel safe and can trust that they will be returning to a healthy and clean work environment, both for the near future and for potential second or third waves of infection.

The spread of COVID-19 is generally understood to be through close proximity – by respiratory droplets and aerosols created when an infected person coughs, sneezes, sings, shouts, or talks,  and surface transmission. Transmission through HVAC systems is not adequately tested or documented, and available resources (such as ASHRAE) appear to favour an abundance of caution in making any recommendations due to this lack of testing. Our engineers and technology strategists have been exploring the impact of COVID-19 on building design. Here are some considerations for building owners and tenants.

Improving Air Quality In a typical office building, indoor air is comprised of roughly 25% outdoor air. The rest is recirculated and filtered. It will be important to understand what upgrades may be necessary for the building’s HVAC and Building Automation System (BAS), as well as current and emerging technologies to enhance these systems. Simple building operation and system adjustments A first stage of re-entry can include the following, relatively simple adjustments to normal building operation:

  • Assess the amount of additional outdoor air for occupied and unoccupied modes of operation to permit increased air exchange in the tenant areas and disable demand-controlled ventilation schemes.
  • Review the volume of additional outdoor air that could be added to the system based on current system capacity and further open outdoor dampers to eliminate or reduce recirculation. In milder weather, this does not necessarily affect thermal comfort or humidity, but will become more difficult in extreme weather.
  • Assess the site for possible addition of energy recovery units to offset some of the operational costs associated with an increase in outdoor air.
  • Make necessary adjustments to building control sequences and changes to set points, such as humidity, to allow for temporary flushing or extended operation of systems.

Design and selection of various filter options for your air handling systems

  • Investigate solutions to retrofit or add enhanced filter technologies in existing air handling systems such as higher MERV-rated filters, High Efficiency Particulate Air (HEPA) filters, Active Particle Control filters, UVGI, and Bipolar Ionization.
  • Consider portable room air cleaners with HEPA filters.
  • Active Particle Control technology filters are claimed by their manufacturers to create collisions on a sub-micron level. This causes smaller particles to collide and stay together becoming larger, and providing the ability to collect the larger particles within normal MERV 13 or higher filters.
  • Consider ultraviolet germicidal irradiation to safely and effectively reduce bacteria, viruses and allergens, particularly in high-traffic areas such as lobbies, elevators, and cafeterias/kitchens.
  • Bipolar Ionization may also be a beneficial solution to improving air quality. Manufacturer literature states that it inactivates viruses and creates positively and negatively charged ions that attract to other particles and become bigger and heavier. These bigger heavier particles can now be better trapped by MERV 13 or higher-rated filters. Also, many small particles that are generated within a space will drop to the floor quickly, taking them away from where we breathe. It is imperative to understand that the above changes to system operations and addition of certain filter technology will have an associated impact to energy use and cost.

Cleaning of systems

  • Consider probiotic cleaning of existing coils and other components in contact with air streams.
  • Consider swabs of air handling unit interiors after cleaning and instantly test for presence of Covid-19.
  • Consider use of mobile and local air-cleaning solutions in congested areas.
  • Re-start and re-establish safe drinking water supply.
  • Establish process, protocols, and testing requirements for domestic water systems that have been stagnant during the COVID pandemic.

Technologies for Infection Control in Buildings  There are various technologies currently in use or emerging in the healthcare sector that could benefit and be applied to commercial real estate buildings. Real-time locating and monitoring systems

  • Hand hygiene compliance–technology such as infrared can be used to better monitor hand hygiene. Can be deployed at hand-washing stations and bathrooms.
  • Contact tracing apps can create a contact history log, based on location. They can allow you to accurately track the interactions between people, the facility and equipment. Knowing this information can help to slow the spread of the infection. However, there are privacy implications involved with contact tracing apps which should be carefully considered.
  • Occupancy sensors provide real-time information on occupancy and location to indicate whether social distancing or occupancy limits are being respected.
  • Building owners and tenants can also send instant communications and alerts through a mobile app to occupants, and provide information to first responders in case of emergencies, including specifying the exact location of the emergency.


  • UV lighting technology has improved to the degree that it can sanitize an unoccupied room in a few hours.
  • Cleaning robots (currently used in some hospitals) may become normal procedure to clean office buildings or hotels in off-peak hours.
  • Occupancy sensors can notify cleaning crews (or the aforementioned robots) that a particular area is vacant and can be sanitized before next use.

Touchless (Hands-free) control

  • To minimize potential infection from contaminated surfaces, occupants could utilize mobile apps (through their smartphones) to control security access/opening doors and elevator call. This could be rolled in with existing space management apps used for boardroom booking and office hoteling – which also play a role in effective social distancing.
  • Automated or proximity sensor door opening technology.

Social distancing

  • To better practice social distancing in the office environment, occupants may prefer to access amenities such as ordering food, dry cleaning notification, building gym occupancy, transit alerts and ride sharing services through an app – possibly one provided by the building owner that integrates in-building amenities and other local services.
  • Automated social distancing alerts through wearable technologies or smartphone apps.
How HH Angus Can Help Whether you are a building owner or tenant, we can help you plan your operational restart strategy. Specifically, we can:
  • Assess your HVAC systems and explore ways to minimize the impact of virus aerosols.
  • Work with the Facilities team to appropriately optimize building systems and controls.
  • Investigate and recommend technologies that can help mitigate the spread of infectious disease through sanitization, monitoring, social distancing and other means.
HH Angus has been involved in the design of healthcare facilities (both new construction, renovation/retrofits, expansions and maintenance) for over 75 years. We are a leader and innovator in all aspects of healthcare design. Our knowledge of hospital design and how to address challenges such as infectious disease control can be effectively leveraged into other sectors such as office buildings, retail, hospitality, educational facilities, airports, transit stations, entertainment centres and more. As well, many of HH Angus’ technical staff are actively involved in committees and associations that are continually developing industry standards for construction and renovation, including the CSA’s HVAC Standard, and the Catastrophic Events section of CSA Z8000 – Canadian Healthcare Facilities. On the technology front, our Angus Connect division is focused technology, including smart buildings technology, and is a leader in providing technology strategy and implementation in healthcare facilities. To learn more contact:

Kevin O’NeillP.Eng., LEED® AP
Commercial Director

High Oxygen Demand

Due to the COVID-19 pandemic, the high oxygen demand by ventilators and related equipment can create high flow rate demands on a bulk liquid oxygen system, in excess of flow rates for which they were designed. This situation has been reported overseas where increases in flow have in cases exceeded 1000% of design capacity.

Bulk oxygen systems are owned by the medical gas supplier. They consist of a storage tank, a vaporizer, and a gas pressure regulator station as well as a reserve supply.

Bulk oxygen is stored as a cryogenic liquid at approximately -183°C, and then is vaporized to a gas by use of ambient air vaporizer(s), which uses ambient atmospheric heat. Due to the cold liquid temperature, ice does form on the vaporizer (from condensation of atmospheric humidity onto the cold vaporizer surfaces) irrespective of the outdoor conditions. 

The photo on the left illustrates a partially covered surface of a vaporizer; the photo the right shows a vaporizer fully encapsulated with ice (in the middle of the photo). Both photos were taken at different hospitals in southern Ontario during the week of 30 March 2020, when outdoor temperatures were above freezing.   

As ice build-up increases on the vaporizer, the ice acts as an insulator, thereby reducing the available heat transfer surface area; this reduction in surface area reduces the capacity of the system to deliver gaseous oxygen. Vaporizers are sized to allow for certain accumulation and still supply 100% design flow with some degree of safety but, past this flowrate, ice can incrementally accumulate. 

During periods of unusually high oxygen demand, with reduced heat transfer capacity, this can reduce the production rate of gaseous oxygen and can also cause liquid cryogenic oxygen to be introduced into the distribution pipeline downstream of the gas pressure regulators. When this liquid evaporates in the pipeline, the very large change in volume from a liquid to a gas can create significant pressure fluctuations in the pipeline oxygen pressure. 

Removal of Ice from Vaporizers

At all times, but especially at times of unusually high oxygen demand, it is important to keep vaporizers clear of ice. Contact your bulk supplier who will recommend and oversee specialist cleaning companies to perform this maintenance procedure.

Current High Oxygen Demand During COVID-19

It is recommended that a supplemental management plan during this COVID-19 event be established to monitor ice formation on the vaporizer and for ice removal, and to plan for additional high flow rate demand contingencies: 

  • Discuss with your medical oxygen bulk supplier if the LOX tank is being monitored daily by the supplier; if not, monitor the liquid level gauge at least two to three times a day
  • Discuss with your medical oxygen bulk supplier any necessary requirements to deal with a sudden significant step change in flow demand (e.g. keep clear access to the pad for extra deliveries, be ready to support emergency technical service access, etc.) 
  • Discuss with your medical oxygen bulk supplier how much of the surface area can be covered with ice before the evaporator needs to be cleaned; establish response times from the supplier to have a representative on site when the vaporizer(s) need to be cleaned 
  • Do not attempt to remove ice. Contact your bulk supplier who will recommend and oversee specialist cleaning companies to perform this maintenance procedure 
  • Establish daily monitoring of ice build-up; initiate cleaning response as necessary
  • Maintain the area around the evaporator clear of obstructions to airflow, for approximately 3 m if possible
  • Frequently monitor the medical gas pipeline pressure for significant and unusual pressure fluctuations; this may be indicating liquid gas being injected into the pipeline, meaning inadequate vaporizer performance
  • Locate (where provided) the facility emergency oxygen inlet station on the facility façade and verify the shut-off valve is operational.  While the outdoor air temperature is warming, the amount of moisture in the air is also increasing, which can still pose an ice build-up problem over the next few months.

If you would like to learn more about this topic feel free to reach out to:

Ed Hood, P.Eng.,B.Eng.
Mechanical Technical Leader

Kim Spencer, P.Eng., LEED AP
Principal | Division Director, Health

Voir ci-dessous pour des informations en français

In light of the increasing number of cases of COVID-19 in North America and the announcement by the World Health Organization declaring COVID-19 as a pandemic, HH Angus is taking reasonable precautions to ensure the safety and security of our employees, clients, vendors and guests across all our office locations while maintaining a consistent level of client service. We are executing our Business Continuity Plan that covers maintaining office operations, remote working for all our staff, and delivering service to our clients during weather, natural disasters, and other emergency situations where our offices are shut down for extended periods of time. Our Senior Management Team is meeting daily to respond promptly to the latest conditions and to ensure that we continue as best we can to deliver on our commitments to our clients.

Highlights of our plan include:

Remote Working

We have been closely monitoring this situation and have made the decision to instruct our staff to work remotely beginning March 16, 2020 until further notice. We have technology implemented that enables our employees to provide service remotely for all our clients and projects if they are unable to be in our office physically or report to the project site. This includes access to our design software, network, email, audio and video conferencing, and other communications technologies. Our remote working protocols and equipment are being implemented to enable our employees to continue to deliver service to our clients. All our communication channels related to on-going projects remain unchanged. If you have any questions or concerns about a project we are working with you on, please reach out to your HH Angus contact. We will coordinate with you to make arrangements specific to your project including replacing, where possible, in-person meetings with tele/video conferences. If you require information but do not have an existing contact at HH Angus, please email, or reach out to one of the key HH Angus contacts listed at the end of this announcement.

HH Angus has suspended all international and all non-essential domestic travel until further notice. Personal travel is discouraged and any staff returning from travel outside of Canada must self-isolate for 14 days.

We have encouraged our employees to not participate in large gatherings such as conferences or networking events and, where possible, to utilize video/teleconferencing or similar communications technologies for external and internal meetings. Our technical staff will continue to visit project sites but will contact the client in advance to ensure that the site is still open and inquire as to health and safety precautions that are in place to ensure that there are no restrictions preventing their visit. We will assess each site meeting on a case-by-case basis to assess compliance with our firm’s existing protocols to protect the health and safety of both HH Angus staff and client staff.

Office Environment
We have intensified cleaning standards for our offices. We have installed hand-washing signage based on best practices in all washrooms and have increased hand sanitizer stations, where products are available, across our properties in order to help minimize the spread infectious agents.

As mentioned previously, we have asked our staff to work remotely as of March 16, 2020. However, certain staff will be on office premises to facilitate deliveries and perform network maintenance. If you require coming to our Toronto office in person, please speak with Reception by telephone (416-443-8200) in advance. Our Vancouver, Montreal, Dallas and Chicago staff will not be available in their respective offices. Please get in touch with your contact in each region for any inquiries, or call Toronto Reception (416-443-8200).

Reporting procedures
We have established a reporting protocol with our employees, should anyone be exposed to coronavirus directly or indirectly, or is feeling unwell for any reason. Any employee travelling out of the country for any reason is required to self-isolate for 14 days upon return to Canada. We will continue to monitor the situation closely, and adjust our response as required.

For more information, we encourage you to review the following resources:

Health Canada
World Health Organization

We will update this information page as the situation evolves. We are committed to helping our staff, clients and communities manage through this crisis to the best of our ability.

Key HH Angus Contacts:

Paul Keenan, President – | 416 209 4374

Tom Halpenny, Vice President Operations & General Manager – | 416 580 0811

Sameer Dhargalkar, Vice President, Marketing & Business Development – | 416 904 4592

COVID-19 - Réponse de HH Angus

Compte tenu du nombre croissant de cas de COVID-19 en Amérique du Nord et de l’annonce de l'Organisation mondiale de la santé déclarant la pandémie mondiale de COVID-19, HH Angus prend des précautions raisonnables pour assurer la sûreté et la sécurité de nos employés, clients, fournisseurs et invités dans tous nos bureaux tout en maintenant un niveau de service constant pour nos clients. Nous mettons en œuvre notre Plan de maintien des activités, qui assure le maintien des activités de bureau, le télétravail pour l’ensemble du personnel et la prestation de service à nos clients en cas de désastres météorologiques ou naturels, ou de tout autre situation d’urgence, dans les endroits où nos bureaux sont fermés pour des périodes prolongées. Notre équipe de direction se réunit quotidiennement pour répondre rapidement aux dernières conditions et pour s'assurer que nous continuons du mieux que nous pouvons à respecter nos engagements envers nos clients.

Les points saillants de notre plan comprennent: 

Travail à distance 

Nous suivons de près cette situation et avons pris la décision de charger notre personnel de travailler à distance à partir du 16 mars 2020 jusqu'à nouvel ordre. Nous avons mis en œuvre la technologie qui permet à nos employés de fournir un service à distance pour tous nos clients et projets s'ils ne peuvent pas être physiquement dans nos bureaux ou se présenter sur le site du projet. Cette technologie donne accès à notre logiciel de conception, aux lecteurs réseaux, aux courriels, aux conférence audio-vidéo, de même que d’autres technologies de communication. Nos protocoles et équipements de travail à distance sont mis en œuvre pour permettre à nos employés de continuer à fournir des services à nos clients. Toutes les voies de communication relatives aux projets en cours demeurent les mêmes. Si vous avez des questions ou des préoccupations concernant un projet sur lequel nous travaillons avec vous, veuillez contacter votre contact HH Angus. Nous vous aiderons à prendre les dispositions propres à votre projet, notamment le remplacement, si cela est possible, des réunions en personne par des conférences audio-vidéo. Si vous avez besoin d'informations mais n'avez pas de contact existant chez HH Angus, veuillez envoyer un courriel à, ou communiquer avec la personne-ressource de HH Angus donnée à la fin de ce communiqué.

HH Angus a suspendu tous les voyages internationaux et nationaux non essentiels jusqu'à nouvel ordre. Les voyages personnels sont déconseillés et tout membre du personnel qui revient de l’Étranger doit s’isoler pendant 14 jours.

Nous avons encouragé nos employés à ne pas participer à de grands rassemblements tels que des conférences ou des événements de réseautage et, dans la mesure du possible, à utiliser la vidéo / téléconférence ou des technologies de communication similaires pour les réunions internes ou externes. Notre personnel technique continue de visiter les sites de projet, mais doit d’abord communiquer avec le client pour s’assurer que le chantier est toujours ouvert et s’informer des mesures de prévention mise en place pour la santé et la sécurité afin de s’assurer que rien n’empêche la visite. Nous évaluerons chaque chantier au cas par cas afin de vérifier la conformité aux protocoles existants de notre firme en matière de protection de la santé et de la sécurité du personnel de HH Angus et du client.

Environnement de bureau
Nous avons intensifié les normes de nettoyage de nos bureaux. Nous avons installé une signalisation de lavage des mains basée sur les meilleures pratiques dans toutes les toilettes et avons augmenté les postes de désinfectant pour les mains, où les produits sont disponibles, sur nos propriétés afin de minimiser la propagation d'agents infectieux.

Comme mentionné précédemment, nous avons demandé à notre personnel de travailler à distance à partir du 16 mars 2020. Cependant, certains membres du personnel seront dans le bureau pour faciliter la réception des livraisons et l’entretien du réseau informatique. Si vous avez besoin de venir à notre bureau de Toronto en personne, veuillez parler à la réception par téléphone (416-443-8200) à l'avance. Nos employés de Vancouver, Montréal, Dallas et Chicago ne seront pas disponibles dans leurs bureaux respectifs. Veuillez communiquer avec votre contact dans chaque région pour toute demande de renseignements ou la réception de Toronto (416-443-8200).

Procédures de signalement
Nous avons établi un protocole de signalement avec nos employés, si quelqu'un est exposé directement ou indirectement au coronavirus, ou se sent mal pour une raison quelconque. Tout employé voyageant à l'extérieur du pays pour n’importe quelle raison que ce soit est tenu de s'isoler pendant 14 jours à son retour au Canada. Nous continuerons de surveiller la situation de près et d'ajuster notre réponse au besoin.

Pour plus d'informations, nous vous encourageons à consulter les ressources suivantes :

Santé Canada
Organisation mondiale de la Santé

Nous mettrons à jour cette page d'information à mesure que la situation évolue. Nous sommes engagés à aider notre personnel, nos clients et les collectivités à traverser cette crise au meilleur de nos capacités.

Personne-ressource de HH Angus :

Mohamed Kamel, Directeur du projet – | C 514 863 9202