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Envira-North Systems Ltd. is a manufacturer and distributor of energy efficient ventilation products. Our line of fans, turbines and curtains can improve the level of comfort in a building while lowering energy consumption.

Our systems are based on 75 years of combined ventilation expertise. Our products are combined to create a tailor-made system designed specifically for the space in question.

Contact us today to have a system designed to solve your facility's ventilation issues.

| Education

| Heating

In most large buildings, heaters are mounted overhead so as to not interfere with the space. This creates a heat gradient differential of 10 - 20 degrees Fahrenheit from floor to ceiling.

Because heat rises a situation called 'stratification' occurs. The heaters are now heating the top 2/3 of the building, working overtime to force heat down to the floor and at thermostat level.

By thoroughly mixing the air, our fan family can virtually eliminate the temperature differential (or de-stratify) between the ceiling and the floor. Thermostat settings can be reduced without any loss of comfort, resulting in a reduction in heating costs.

| Cooling

Our fan family provides an efficient and cost effective alternative to cooling environments where air conditioning is not feasible or can be unhealthy. This is especially true when non-disruptive cooling is desirable to improve comfort for the interior environment.

The fans do not cool the air. They work as a occupant cooling system. When perspiration evaporates off the body, it feels cool because evaporation moves body heat away from the body. One Altra-Air fan can make a human's skin feel at least 5 - 9 degrees Fahrenheit cooler. The fans also reduce reduce humidity, which adds to the feeling of comfort.

Alternatively, our fan family can work in conjunction with air conditioned spaces. Operating the fans on slow speeds creates a constant moving mass of air inside the space. This limits allows for a higher temperature set point and reduces compressor run time.

Hurricane™ Turbines provide relief and prevent build up of hot, stale air inside the building.

| Ventilation

Envira-North fans and Hurricane™ Turbines work in conjunction to provide ideal and efficient ventilation.

Our fans continuously mix incoming fresh air with stale air, minimizing the total amount of ventilation required to achieve adequate air quality.

Hurricane™ Turbines provide relief of the stale air remaining inside the building envelope and allow for fresh air to be brought in naturally through open doors, windows and louvers.

A naturally ventilated building makes for a comfortable environment and lower utility costs.

| Savings

Our products and systems at Envira-North focus around three major benefits. Environmental benefits from reducing energy consumption, economic benefits from reducing overhead costs, and social benefits from a healthier and more productive working environment.

To determine a cost savings is not easily accomplished considering the variables included in the three major benefits.


The environment is at the forefront around the world. Governments and companies have took action to reduce waste and encourage energy efficiency. The public perception of a company plays an integral part in their business. Promoting your companies accomplishments with our products shows you are doing your part.


The economic benefits are still what motivate managers to purchase our products. To gain a better understanding of the potential savings it is best to analyze the variables. Take into consideration the size and height of the space, r-values of roof and walls, temperature set point, delta temperature, exhaust rates, number of heating days, efficiency of heaters and the cost of heating.


Our technologies make for a more comfortable interior environment for the occupants of the structure. When the occupants of the structure are comfortable they are more productive. Our products have been able to eliminate excessive heat breaks during the summer months and decrease the amount of days lost to heat. During the winter months, occupants are warmer resulting in higher efficiency.

| Glossary Of Terms

| Airfoil Terminology


Reduction in the lift coefficient generated by an arifoil as angle of attack increases. This occurs when the airfoil's critical angle of attack is exceeded.

Spanwise Pumping

The primary cause of of efficiency loss in all rotating systems.

Tip Stalling

When a wing tip stalls before a wing root.

| Ventilation Terms


Hot air rising, creating a heat gradient differential from floor to ceiling.


The elimination of stratification (see above).

Natural Ventilation

This is the process of supplying and removing air through an indoor space by natural driven means. there are two types of natural ventilation; wind driven and stack driven.

Non-Disruptive Airflow

Constantly moving large masses of air (gently) throughout the space, without disruptive breezes negatively effecting the functioning space.


High Volume, Low Speed, refers to the Altra-Air Fans's ability to move a high volume of air, while operating at a very low speed; a classification of fans.

| Terms of Measurement


Cubic Feet per Minute is a measurement of airflow.

Conversion factor for cfh to cfm is 0.0166667.


Litres per Second is a measurement of airflow.

Conversion factor for m3/h to l/s is 0.0277778.

Ambient Temperature

Simply refers to the temperature of the surroundings.