By Loïc Letailleur, P.Eng.

Four years ago, we used to play a game as a family while driving around – who could spot the next electric car? They were rare and sometimes you would go days without seeing one. Now, they are everywhere, every day, no matter which city or small town you are in. Most people likely don’t realize how many there are because they don’t all stand out (they aren’t just Tesla’s)! 

With the rapid adoption of electric vehicles comes the requirement for charging infrastructure. There are charging speeds (is the limiter of the vehicle or the charger), people’s driving habits and also public expectations. Without getting into the psychology of range anxiety or other concerns, let’s review some of the key points related to electric vehicle (EV) charging.

What are the different levels of Electric Vehicle Charging?

At Falcon, we provide capital planning services for all types of buildings. As a unique engineering firm, we have developed a proprietary costing database. We regularly update this database with our retrofit projects to provide new and existing clients with a detailed capital plan for their upcoming projects. We are even able to break budgets into project phases for comprehensive planning purposes.

  • Level 1 – Basic 120V wall outlet (15 or 20 Amp)
    • This will charge the average EV at approximately 8km/hr.
  • Level 2 – AC charger, 208/240V from 15A to 80A of delivered energy
    • This will charge the average EV at 15-80km/hr.
  • Level 3 – DC fast charger, from 20KW to 350KW
    • This can reach charging speeds over 1,000km/hr.
    • It bypasses the inverter in the vehicle.
    • Vehicles have limits to what they can accept for charge (not many can take 350KW).

What are the Electric Vehicle Charging Standards and how do they differ?

There is one Level 2 charging standard globally and it is the J1772 plug.  All vehicles have this outlet except for Tesla, which comes with an adapter.

Globally, there are three major Level 3 charging standards:

  • Tesla – Proprietary charger plug except in the EU.  The Supercharger network in the USA is slated to be opened to other vehicles, though this will require a special adapter.
  • Chademo – Asian standard, was adopted early by Nissan – many fast chargers will include a Chademo connector. Not many vehicles require this standard.
  • CCS – European standard, has become the global standard. It is the plug included in the majority of vehicles (except Tesla).

When assessing which charging level you will most frequently use, you need to assess the following factors:

  • What is your daily distance travelled?
  • Do you have access to charging at your residence? And what level?

The majority of individuals will drive less than 50 km per day, and their vehicle is parked for a minimum of 8 hrs overnight. This means for those fortunate enough to have access to charging at home, a simple Level 1 charger that will provide 8km/hr (60+ km of range overnight) is sufficient. 

electric vehicle charging map for British Columbia
Image Source – Google Maps

A Level 2 charger at home will allow for more rapid charging or allow for the charging to occur during off-peak hours (maybe not start charging until 0100 – with a time of day utility billing coming soon this may be advantageous).  On the rare occasion that you have returned from a long road trip with a nearly empty battery, you still don’t need to worry as overnight you will charge enough for the next typical driving day. If back-to-back extended trips are required, then a visit to a public Level 3 charger is an easy way to boost up the available range.

For individuals who do not have access to charging at their home, Level 3 charging will be similar to stopping at the gas station and will have to be done approximately once a week depending on the range of the car and the distances covered.

What about at Work?

ev charging system

One of the most frequent questions we are asked by Clients is should electric vehicle charging be provided at the workplace? To answer this, it is important to go back to the previous analysis of daily driving habits.  If individuals have access to charging, then it would be rare that needing to charge at the workplace (or the mall) would be required.  Even for people without home access to charging, the rapid increase in the number of public fast charging stations allows for easy access to charging needs people may have.  I would consider the availability of workplace charging a perk and not a necessity.

The exception to this is for fleet vehicles.

I am a Developer and What Should I Do?

In Part II of Electrical Vehicle Charging our engineering team will discuss the options for both existing and new multi-family and mixed-use buildings. 

Do you have any questions? Contact our skilled engineering team today and we can answer all your electrical engineering questions. 

Need to learn more about our engineering services? Visit our integrated engineering services page.

Want to learn more about electrical engineering? Check out some of our other blogs!

Are you wondering how to get the right retrofit for your project?

Our team of interdisciplinary engineers can provide customized niche mechanical engineering solutions for projects ranging from HVAC design to deep energy retrofits. Our team has a proven track record of results on these projects and are well versed in requirements for different client types. We bring a commitment to service that extends through design, construction, and post-construction activities.

Read on as we elaborate on some of our niche mechanical and industrial engineering services that set us apart from other engineering companies:

Capital Planning

At Falcon, we provide capital planning services for all types of buildings. As a unique engineering firm, we have developed a proprietary costing database. We regularly update this database with our retrofit projects to provide new and existing clients with a detailed capital plan for their upcoming projects. We are even able to break budgets into project phases for comprehensive planning purposes.

Mechanical engineering room


Design is an integral part of the engineering and construction phase of your project. We are experienced with tailoring bespoke solutions that best suit

the need of your project’s purpose and building type. Some of our niche design services include:

Lifecycle-Centered Design. Building and engineering represent only a fraction of the overall lifecycle costs of a mechanical project. With this in mind, we take an approach that is not focused solely on the installation costs of a project. We include operating cost considerations like energy efficiency, ease of maintenance, reliability, and planning for replacements at the end of service life. Our lifecycle-centered design approach applies to all our projects.

Heat Pump Thermal Plant Design. We have developed several bespoke heat pump and heat recovery thermal plant designs. These archetypal systems can be adapted and modified to fit the needs of many building types and configurations. The systems have been designed to eliminate unnecessary complexity, undue costs, and to reduce the maintenance burden.


We know that every project has a specific purpose with distinct needs to suit the environment in which it operates. We have expertise in planning, managing, and implementing large-scale mechanical retrofits. We offer retrofits in the following areas:

Deep Energy Retrofits. The goal of deep energy retrofits is to provide systems that not only increase energy efficiency but also renew aging equipment to improve overall effectiveness and reliability. Often this involves the replacement of major components and systems. These retrofits often need to be carefully planned and phased in to keep the facility as operational as possible throughout the process

Conventional Energy Retrofits. If you don’t need a large-scale retrofit, our team is also able to replace building mechanical systems on a component-by-component basis. These could consist of boiler upgrades, terminal equipment replacement, and control system upgrades. We replace aging equipment or systems to optimize lifecycle costs and reliability.

Business showing their mechanical engineering systems

Prime Consulting. Having worked with both private and public institutions, we are experienced in consulting on contract awards for facility upgrades or new system implementation. Depending on the project, we can provide full design services as well as managing tendering, providing recommendations for contract award, and administering the construction contract throughout the implementation phase. Our experience with many different building types makes us well versed in the different requirements for all client types.

Industrial and Clean Facilities

At Falcon, we have developed specialist expertise for industrial buildings. From ventilation systems to specialty water system design, our team will develop the right solution for your facility. Some of our specialized areas include:

  • Precision environmental control
  • Clean-room filtration and contaminant control
  • Laboratory ventilation
  • Specialty exhaust and ventilation systems
  • Specialty process piping systems
  • Compressed air system design
  • Process heating and cooling
  • Process water system design
Mechanical room

Is it time for a retrofit for your facility or building?

We are confident that our team will deliver designs that will add the right components to your facilities’ systems to increase reliability and efficiency. Our engineering professionals are seasoned experts, who know how to create and implement a lifecycle-centered approach to your system upgrade. You can guarantee practical and innovative solutions, designed for your specific needs.

Have questions about a project? Contact us!

Need to learn more about our services? Visit our integrated services page.

Want to learn more about mechanical engineering? Check out some of our other blogs!

There is no doubt that climate change is one of the biggest issues facing our society. Globally, almost 60 billion tonnes of greenhouse gasses are emitted every year, while the current warming trend is proceeding at an unprecedented rate. In British Columbia alone, we have experienced havoc caused by climate change, from back-to-back years of record spring precipitation causing historic flooding followed by hot, dry summers that contributed to droughts and wildfires.

Why Now?

Since its inception, Falcon Engineering has been dedicated to providing efficient, cost-effective solutions to our clients. We have always encouraged going above and beyond Code and Regulatory baselines by showing clients not only the environmental benefits but also the economic payback over the investment of the systems. We have been fortunate to work with progressive forward-thinking clients that have seen the value in these systems, and have been part of projects that set the benchmark for low energy consumption in their respective sectors. As a firm, we wanted to look internally and see what changes we could make to demonstrate our commitment – and not just talk, but walk too!


2021 was a year of extremes in British Columbia, beginning with record-breaking high temperatures in June, which spiked at 49.6°C in Lytton, breaking the all-time highest temperature ever recorded in Canada three days in a row. What followed was a catastrophic wildfire that wiped out the entire village of Lytton, destroying the majority of buildings and killing two people. Massive wildfires burned throughout the Interior of British Columbia in the region’s worst fire season on record, with firefighters struggling to keep control and thousands of residents evacuated from their homes. The cost of wildfire suppression totalled $565 million.

After an incredibly dry and challenging summer, winter bought record-breaking rainfall, which caused severe landslides and flooding, closing off all highways from southwest BC to the Interior. Hundreds of homes were evacuated, while thousands of livestock were killed as the waters rose. The towns of Merritt, Princeton and Tulameen were decimated as their rivers flooded.    

Climate scientists have predicted that extreme weather events, such as those experienced in British Columbia in 2021, will increase in frequency and severity, bringing massive loss and disruption, as well as high costs for governments.

flood photo

climate change certified

As a leader in green, energy-efficient building systems, we are dedicated to providing sustainable energy engineering to meet our client’s needs, and our consulting teams bring skill sets that are unique amongst engineering firms. Our experience with district energy systems (such as VIU’s Mine Water District Energy System in Nanaimo), low carbon heating systems, heat recovery systems, solar photovoltaic and renewable energy generation provide a unique range of energy-efficient design options that can be tailored to our client’s projects. Drawing on our extensive portfolio of successful projects, we work closely with our clients and design teams to achieve innovative and sustainable solutions rooted in established engineering principles. 

With our commitment to helping our clients achieve the most efficient electrical and mechanical systems possible, we looked at ways our company could do more to reduce our carbon footprint. To do this, we enlisted the help of Climate Neutral.   

What Is Climate Neutral?

Climate Neutral is a nonprofit organization working with brands and consumers to eliminate greenhouse gas emissions. It was launched in 2019 and now works with hundreds of companies across more than a dozen industries globally. In just three years, Climate Neutral Certified companies have measured and offset over 2,000,000 tonnes of CO2e, equivalent to over 430,000 passenger vehicles being driven for one year.

Our 2021 Carbon Footprint

We worked with Climate Neutral as we measured and offset last year’s carbon emissions and identified ways to reduce future emissions. The process to become Climate Neutral Certified is a months-long effort to measure, offset, and reduce our carbon footprint:


We measured our 2021 carbon footprint at 169 tonnes. To arrive at this number, we looked at all of the emissions created from delivering our services, including employee commuting, business travel, utility bills, paper, and computer equipment. 


We offset these emissions by purchasing verified carbon credits. These carbon credits supported a portfolio of projects including schemes that will help avoid deforestation, improve forest management, support solar power generation, and encourage bioenergy generation.


Last, but not least, we created Reduction Action Plans to help lower our emissions over the next 12-24 months, and the following are our first steps towards achieving this goal:

  1. We will reduce emissions from air and car business travel

We will write and implement a travel policy to standardize and regulate travel bookings. We will encourage staff to combine multiple projects per trip and reduce the number of in-person meetings by conducting virtual meetings.

  1. We will reduce emissions from employees commuting into the office.

We will be improving the bike storage area so that more staff can cycle to work and store their bike securely. We intend to introduce a bike-to-work incentive/sweepstake to encourage staff to walk, use public transport or cycle.

  1. We will reduce emissions from the use of paper contracts and couriers.

We have signed up with DocuSign to digitally send all our contracts in 2022. This will save paper and reduce emissions by cutting the use of couriers to deliver the physical documents.

To The Future

Falcon Engineering hopes to engage fellow consulting firms, contractors, and others in the industry to join in the commitment to reduce our impact.  The hundreds of brands certifying this year all go through the same process to measure, offset, and reduce their emissions. Together, Climate Neutral Certified companies are working to eliminate more than 1,000,000 tonnes of carbon emissions.  

At Falcon, we know we have to act now to solve a problem that we understand to be an urgent threat. We have committed to reducing our carbon footprint by 50% by 2030 and our Reduction Action Plans will help in achieving this goal. Climate change requires immediate action, and we’re proud to be part of the solution.

Climate neutral certified

If someone asked you to name the elements of a sprinkler system, could you do it? You’ve most likely seen certain elements before; on a basic level, there are sprinkler heads, piping, and valves – but there is so much more! A sprinkler system is designed to control or extinguish fires in the early stages, making it easier and safer for building occupants to exit the building, and for firefighters to extinguish any fire that remains. 

Beyond the importance of having a fire sprinkler system, an efficient layout/design is required to allow for cost control and high performance. The variations in building design, and the coordination needed based on components within the building, make fire sprinklers complicated in design. However, understanding the fundamentals of sprinkler design will provide good insight into the specific needs of the project and the detail required for specifications.

Determining the Water Supply

A fire sprinkler system begins with water and having enough of it to control a fire. Most sprinkler systems are automatic, meaning human intervention isn’t necessary. Because of this, a source is required, which can include city water, ponds, rivers, reservoirs, water tanks, and more. No matter the source, it must have a sufficient capacity.

Factors that determine the capacity include: 

  • Flow Rate (Gallons per minute/GPM)
  • Pressure (Pounds per square inch/PSI)
  • Duration (How long it can maintain the required pressure & flow)
  • Flow Test (provided by nearby fire hydrants)
Picture of a fire hydrant

Water supply is fundamental in the development of a sprinkler system, no matter the building layout. 

Understanding the Building

Picture of a school main entrance

As simple as it sounds, to determine the sprinkler system required, you need to understand the building. Typically, once a contractor has been selected, the contractor then engages their engineer during construction. Unfortunately, this approach can hamper coordination between the sprinkler system and other building elements. Common questions to ask are: Is this a commercial project? Industrial? Or are there specifics required for the building?

For projects where a performance specification is not appropriate, however, our team can provide full sprinkler design services including:

  • Sprinkler head layout
  • Pipe layouts
  • Pipe sizing

Wet, Dry, or Preaction System?

Beyond the capacity and building demands, it’s necessary to determine if a wet, dry, or preaction system is required. Fire sprinkler engineering services offered by Falcon include wet and dry systems, pre-action systems, and specialty gaseous systems for mission-critical infrastructure.

Wet systems, which have pipes filled with water at all times, are the most commonly used system for buildings. Water flows when each sprinkler head reaches its design temperature and the glass element bursts, allowing a plug to drop out.

Dry systems, as the name suggests, don’t contain any water, and are pressurized with air. When a sprinkler head activates, the air is discharged, causing an automatic valve to open and allow water into the piping system. Dry systems are generally reserved for areas with freezing concerns. Lastly, there are preaction systems, where the cost of an accidental discharge would be severe, in places such as data rooms. In this system, water is held back by a preactivation valve and activation relies on a separate trigger, providing another layer of protection or control when activating water.

Fire sprinkler engineering


If there is one point we hope you take away from this, it is that fire sprinkler systems are complicated yet essential. While there are many factors to consider with these systems, evaluation, assessment, and specifications are instrumental to the performance of the system.

At Falcon Engineering, we can offer performance specifications or full design and engineering services, depending on the specific needs of the project. We are committed to providing effective system designs for mechanical projects.

Should you have any questions about how our team can help you with your mechanical projects, including Fire sprinkler engineering, get in contact by using our contact page

Check out our service offerings here

Want to learn more about mechanical engineering? Check out some of our other blogs!

We’re excited to announce the launch of our brand new website and brand. In planning for this redesign, we took a step back to figure out what’s most important to our clients and how we can serve them best. As it turns out, we had much to ponder! All this internal dialogue led to an exciting new step in the evolving Falcon Engineering timeline.

The roots of Falcon Engineering run deep through the City of Kelowna and throughout Western Canada. We made a name for ourselves by focusing on strategic value propositions centred around resourcefulness, long-term efficiency and attention to detail. Our brand and online presence must reflect these commitments because our clients rely on them. Below are brief descriptions of our new website pages, so you know what to expect.


Our services page makes it clear what we offer. We pride ourselves on being a multi-discipline engineering firm with a complete systems approach to design and construction. We’re home to nearly 50 staff, including 14 engineers with diverse skills and a talented group of support staff that ensure continuity and consistency.

We collaborate, deliberate and arrive at solutions as a team, ensuring the client’s goal is always top of mind. Our core engineering services include:

• Mechanical – HVAC, life cycle cost, plumbing, fire sprinkler, capital planning and more.

• Electrical – Lighting, power, emergency, life safety, communication and more.

• Energy – energy options analysis, energy modeling and design, implementation of renewable energy infrastructure and more

Kal Tire Place engineering project

To find out more about our services, click here.


Over the years, our team has enjoyed working on a wide array of construction projects. We collaborate with project managers, architects, city and capital planners, business owners, among many others. Our commitment to resourcefulness and teamwork extends to all service providers we work with, ensuring a successful long-term project. With effective in-house and outward collaboration, we all win.

To view some of our latest projects, click here.

About Us

Like any successful construction project, our team is only as strong as the sum of its parts. And we not only attract proficient engineers to our team; we cultivate them.

Kelowna engineering company

In this section, we spotlight our history, culture and principal engineers. Our extensive history hasn’t limited us from continuing to reach for new levels of proficiency. Renowned mentoring and
training programs bring every team member up to speed, equipping them for tomorrow’s engineering challenges with the right tools and skills. It’s history in motion, and we’re proud to share it with you.

To navigate to the About Us page, click here.


It’s not just about proficiency; it’s about continued learning. Professional engineers must always stay nimble in the face of new challenges, regulations and standards. Head to our blog page, where you’ll find a continually updated series of articles, trends, project spotlights and other helpful information. 

Example of an engineering project

We look forward to sharing what we know with you, and we hope you enjoy exploring our new site. Let us know if you have any questions by using our contact page!

Written By Jeff Quibell, P.Eng.

Many of the systems Falcon designs are inherently hidden from public view. The adage “out of sight…out of mind” certainly applies to much of our work. As a result, there isn’t generally much public awareness about the types of systems we deliver.

Changing Times

Times are changing. We’re in the midst of a remarkable shift in the way society in Canada, and indeed around the world, perceives the use of various forms of energy. Along with this shift is an emerging new appreciation for the value of energy.

Consequently, more and more attention is focused on energy systems of all kinds, whether for our cars, homes, or the public buildings we fund and occupy. In this new era, energy systems may still be out of sight, but with greater awareness of de-carbonizing goals, energy systems increasingly become top-of-mind features.

Aerial view of Kelowna

Engineers and scientists are leading the way toward implementing effective, practical, and affordable methods to conserve energy resources and reduce energy emissions without compromising reliability or performance. Our profession is responsible for sharing progressive information and some of the challenges we face to achieve such progress.

Accordingly, we feel an obligation to engage with our clients and the greater public. We wish to relay and share information about what’s being done now and what’s to come so that we can tackle some of our time’s biggest challenges.

What Falcon is doing

A few examples of the efforts Falcon is supporting to engage in BC communities:

UBC Okanagan, Kelowna, BC.  In collaboration with UBC – Okanagan, Falcon has delivered a series of guest lectures for 4th-year mechanical engineering students as they prepare to launch their careers. The lectures focused on practical (beyond the textbook) aspects of delivering high-performance HVAC energy systems.  Falcon’s Don Poole, Hayley Shearer, and Jeff Quibell gave a lecture series focused on practical aspects of HVAC design, practical applications of energy modelling, and a hands-on discussion of the merits and limitations of geoexchange energy systems.

Vancouver Island University, Nanaimo, BC. In collaboration with Vancouver Island University, Falcon teamed up with the Earth Science Department of VIU to engage with students and the public. For the past four years, Jeff Quibell has delivered annual guest lectures to upper-year geology students and a public lecture on the topic of Vancouver Island University’s unique Minewater Geoexchange System low-carbon district energy system.

Okanagan College Kelowna

Okanagan College, Kelowna, BC.  Falcon’s Don Poole is a born teacher. When not mentoring young engineers and technologists at Falcon, Don can be found at Okanagan College as a liaison instructor. He’s currently on hiatus from the College now as he doubles down on his teaching at Falcon. He specializes in conveying lessons learned “the hard way.”

NEAT, Energy Explorer’s Workshops. The Northern Environmental Action Team (NEAT), based in Ft. St. John, BC, does outstanding outreach work engaging with grade schools across northern BC and Alberta on environmental awareness topics. They invited Falcon’s Jeff Quibell to carry out several sessions introducing geoexchange heating to nearly all the Grade 7 classes in Fort St. John. Jeff delivered the first of these sessions in person before Covid-19 struck. Encouraged by the success of the first initiative, Jeff accepted a subsequent invitation to deliver several more sessions to Grade 5 classes (this time via Zoom, due to Covid-19). Using Zoom, NEAT drew school classes from several northern cities into the program, including Whitehorse, YT, Spruce Grove, AB, Ft. McMurray, AB, Drayton Valley, AB, Prince George, BC, and Fort. St. John, BC. In total, NEAT delivered 21 sessions to nearly 500 students. Following the sessions, Jeff commented, “the questions many of these Grade 5 students ask are so insightful”. It is so encouraging and rewarding to see such avid curiosity amongst the generation to come.

Classroom of engineering students
In pre-Covid times, Falcon’s Jeff Quibell conducts a session on Geoexchange Heating for Grade 7 students at the NEAT Energy Explorer’s Workshop, Fort St. John, BC.

Two Way Street

The above engagements are not just an opportunity for Falcon to convey information about technology; they’re an opportunity for a two-way dialogue for us to listen to concerns, uncertainties, and wide-ranging feedback. We may not hear this type of feedback if we remain insulated within our design teams. 

Engaging genuinely in the broader public sphere and learning to respond to such a wide range of views in a respectful, meaningful setting helps us become more effective communicators and better, more well-rounded designers.

Want to talk about your project? Contact us!

Written By Don Poole, P.Eng.

Falcon Engineering frequently performs surveys on existing buildings prior to an HVAC upgrade. Sometimes the equipment is ageing, or sometimes occupant comfort complaints trigger the upgrade. Here are the most common and effective means to improve comfort if air systems are being used to heat and cool spaces (if the terminal equipment is correctly sized). 

1. One Unit for One Zone

Similar loaded rooms can be combined into one zone.

My mentor, Doug Joorisity, and I sorted this one out years ago when the smallest rooftop unit that was available was 5 tons. We would often design two classrooms to be served by a single rooftop unit. The classroom with the thermostat was always comfortable, while the classroom without suffered significant temperature swings. Applying Variable Volume Variable Temperature (VVT) systems to this situation did not end satisfactorily. Once the 2½ ton rooftop unit became available, you could implement an appropriate solution.

A group of offices, such as a group of councilors rooms, can be considered a single zone if they: 

  • Share an outside wall
  • Have the same window size 
  • Have the same floor space

The room temperatures can be very similar in each room. The only problem might be that the occupant may want different temperatures.    

2. Ducted Low-Level Return

Reduces stratification and short-circuiting, improves ventilation effectiveness and saves energy.

When I was in high school, I noticed in winter that the woodshop mezzanine where projects were stored was always significantly warmer than the main floor. I didn’t think much of that until I became an HVAC engineer and noticed that the return air in these woodshops was at ceiling level. In an upgrade to one of these woodshops, with School District 23 in Kelowna, we installed a ducted return air grille at the floor level. Matt Garbelya at the District helped us figure a way to get a filter into the low-level return to keep fine sawdust out of the return duct. By using infrared temperature measuring devices, we could see the hot air, which would have been stratified to the ceiling, drawing down to the floor. 

After that, we employed a low-level return system at a large secondary school in Prince George. The existing system was multi-zoned, using the ceiling space as a return plenum and the return air grilles were merely egg crates mounted in the T-Bar ceiling. The upgrade replaced the old multi-zone systems with new ones, with low-level ducted returns employed in each classroom. The results? A school considered chronically cold in the winter became comfortable. The management noticed significant gas bill savings, and students were no longer wearing their winter jackets all day.  

School gymnasium with students playing sports
One low-level ducted return can eliminate stratification in this whole gym.

3. Positive Building Pressures

Minimizes drafts.

Rob Bruce, a sage and experienced commissioning agent, taught me that slightly positive pressure in a school significantly improves comfort. He spent many years in northern Alberta and knew how much difference it makes. 

The point of pressurizing a building during the occupied mode is to eliminate drafts through the building envelope. We deployed methodology on a significant HVAC upgrade at a school in the Okanagan Valley. Prior to the upgrade, the receptionist in the central office near the main entryway was always cold. They even had an electric heater under desks to warm their feet. When interviewed after the building was positively pressurized, they reported that they didn’t need the heater all winter, and they were considering removing the heater completely!   

4. Dedicated Relief Exhaust

Enables full economizing. 

I completed an HVAC update at a school in Vernon. It was an older school, and I assumed that the building was leaky enough that a relief system wouldn’t suffice. That was at a time when we started to use demand control ventilation, so we measured CO2 levels. We noticed that CO2 levels in one room, in particular, would sometimes spike way beyond the limit. We experimented with the teacher – one full-class day with the door to the room closed and one day with the door open. The trend logs showed that, with the door open to form the relief path, the CO2 could be maintained at acceptable levels. We introduced a dedicated relief exhaust system and solved the CO2 problem. In addition, we achieved full free cooling (also known as economizing). Without the relief exhaust, such function was severely hindered. 

The moral of that story is “You can only shove air into a pop bottle for so long”! 

HVAC Vent on a roof
Dedicated relief exhaust with a gravity backdraft damper, used to serve a large portion of the school.

5. Tempered Outside Air

Natural ventilation isn’t effective when it is -18°C (0°F) outside

A new college building in the Interior was designed to employ natural ventilation for the outside air source. We deemed the stack effect insufficient, so we introduced large fans to create a negative pressure in the atrium. Some of the outside air was tempered, but the bulk of outside air entering the building leaked through building envelope cracks. The design resulted in awful cold drafts. 

We introduced a make-up air system to reduce the negative pressure, and it helped, but nearly every single office in the whole building had a plug-in electric heater. Whatever energy the original designer hoped to save with the natural ventilation system was more than lost with the electric heaters. It was unfortunate that so many people suffered needlessly. 

tempered outside air outlets
Down blast air outlet was so bad that it was necessary to install a sheet metal deflector.

6. Air Outlet Velocity in the Occupied Zone is Less Than 0.25m/s (50 feet per minute)

A school hired us to investigate a problem in which classroom occupants complained of drafts. Linear diffusers were initially installed at the perimeter (presumably to wash the wall), but they were installed about 2 meters off the wall. The air outlets were too noisy with the outlets aimed horizontally, so the air outlets were left pointing downward. The cooling mode produced intolerable drafts. We replaced the linear diffusers with standard cone-style diffusers, solving this draft problem.


Configuration of the supply and return air systems in a classroom will significantly impact occupant comfort. This is especially true for areas experiencing extreme outdoor temperatures for both heating and cooling. We have seen significant comfort improvements in deploying the above strategies, so it’s well worth the time and effort to keep these tactics in mind during the initial HVAC design. In some cases, we see significant energy savings as well.

Let us know if you have any questions by using our contact page!

Want to learn more about mechanical engineering? Check out some of our other blogs!