- Serving The Fraser Valley & Lower Mainland
- Gas – LGA0103126
- Refrigeration – LBP0001017
- Boiler – LBP0204397
24hr Emergency Service
Click to Call Dispatch
Click to Call Dispatch
In the commercial HVAC world, terms like “conditioned air,” “make-up air,” and “tempered air” get used frequently—but they’re not always clearly defined. For commercial facility managers in Chilliwack, Abbotsford, and the surrounding areas of the Fraser Valley, understanding the distinction isn’t just academic. It has real implications for a building’s performance, energy costs, and the reliability with which systems comply with ventilation codes.
This article explains what tempered air means, how it differs from other HVAC air treatments, and why it’s essential for many commercial applications in the Fraser Valley climate.
Tempered air refers to outside air that has been partially heated or cooled before being introduced into a building’s ventilation system. Unlike fully conditioned air, which is brought to a specific temperature and humidity level for occupant comfort, tempered air is adjusted only enough to prevent extreme cold or heat from disrupting the internal environment.
Tempered air is typically delivered by make-up air units, which draw in outdoor air, treat it to a moderate temperature, and distribute it through ductwork to balance indoor pressure and meet ventilation requirements. These systems often include simple heating or cooling elements that provide moderate conditioning without meeting occupant comfort standards.
This approach supports ventilation objectives while reducing the load on central HVAC systems. It ensures a smoother transition between outdoor and indoor conditions, especially in climates with significant seasonal variation.
Quick Fact:
Tempered air isn’t about comfort — it’s about control. It helps systems meet ventilation codes without overburdening heating or cooling equipment.
Tempered air contributes to several operational priorities:
Benefit:
Properly tempered air improves occupant experience while protecting HVAC investments and ensuring regulation compliance.
In regions like Chilliwack and Abbotsford, winter temperatures frequently drop below freezing, while summer months can bring high humidity and elevated heat. These fluctuations create unique challenges for HVAC systems, particularly those responsible for ventilation.
During colder seasons, untreated outdoor air introduced into indoor spaces can cause frost buildup on mechanical components, increase heating loads, and pose health or safety risks if air distribution is poorly managed. In summer, warm, moist air can create uncomfortable indoor environments, especially in buildings where humidity control is critical.
Tempered air acts as a buffer, softening the contrast between outdoor and indoor conditions. It makes compliance with ventilation standards more practical and supports energy-conscious design by reducing the reliance on full-space heating and cooling.
Tempered air systems are used in a wide range of commercial and institutional buildings, particularly where ventilation volumes are high, and full conditioning is not economically or operationally feasible. Examples include:
Insight:
If your facility exhausts large volumes of air, tempered make-up air may be essential to maintain comfort, pressure balance, and system performance.
It is important to distinguish between three key types of air introduction in HVAC systems:
Strategy:
Choosing the right air strategy isn’t one-size-fits-all — it should reflect your building’s purpose, occupant needs, and climate context.
Some facilities may operate with make-up air systems that do not temper incoming air, which can have unintended consequences:
To determine whether a building is using tempered air appropriately, assess how incoming air affects indoor temperatures and energy use. If performance issues or comfort complaints are common, tempering might be underutilized or absent altogether.
The design and installation of tempered air systems must account for several variables:
Design Tip:
System upgrades should include control flexibility, efficient heat sources, and compatibility with existing ventilation paths.
Proper planning supports a system that not only meets current demands but adapts to seasonal and operational changes efficiently.
To sustain long-term system performance, tempered air systems require regular inspection and maintenance. This includes checking burners or heating elements to ensure they are functioning properly, cleaning intake screens and air filters to maintain airflow efficiency, and inspecting duct insulation and seals to prevent energy loss.
It is also important to verify that control sensors are calibrated correctly and responding as expected to temperature and pressure changes. Lastly, ongoing evaluation of system performance against current ventilation and safety standards ensures continued compliance and energy efficiency. Ignoring these tasks can lead to uneven tempering, poor indoor air quality, equipment strain, and unnecessary energy consumption.
Maintenance Alert:
Routine maintenance isn’t optional — it’s essential to preserve efficiency, indoor air quality, and regulatory compliance.
Tempered air serves a specialized but essential function in commercial HVAC systems. It bridges the gap between untreated ventilation and full conditioning, offering a pragmatic solution for compliance, comfort support, and system protection.
In regions like the Fraser Valley, where seasonal weather variation is significant, tempered air supports building resilience and operational consistency. A well-implemented tempered air strategy can enhance overall building performance, reduce maintenance strain, and support long-term HVAC efficiency.
While fresh air intake is mandated, tempering is not always explicitly required. However, it is often the most practical way to comply with ventilation mandates without compromising interior comfort or system performance.
Yes. Modular components and duct-mounted accessories are available to retrofit older systems. These modifications can often be integrated with existing ventilation infrastructure.
Tempered air uses energy for heating or cooling, but it is generally less energy-intensive than full air conditioning. The benefits of improved efficiency and fewer maintenance issues can offset operational costs.
Delivery temperatures vary with outdoor conditions and system design; in winter, they typically range from 10°C to 18°C, and in summer from 20°C to 24°C. The goal is moderation, not full comfort.
Look for components such as duct heaters or make-up air units with integrated heat sources. A system review can confirm whether air is being tempered before distribution.