234 Laurier Header Photo 1 1

Case Study

234 Laurier

Working with JL Richards and Associates, Longhill Energy helped to solve a unique air handling challenge at 234 Laurier Ave here in Ottawa, Canada. Our design not only allowed the client to have one of the highest efficiency air delivery systems available, but also provided the client with nearly double the volume flow rate of the antiquated system. We also managed to locate the new systems within the same mechanical space as the old systems without any requirements for architectural demolition. Furthermore, we were able to simultaneously provide two different mixed air solutions to different areas on the same floor at the same time.

About the Project

Category: Construction

The Challenge:

Find a solution to replace 23 existing air handlers of varying cfm with a new air handlers of approximately 9000 CFM with 12.5% fresh air and 1.1”w.c. ESP, AND approximately 4200 CFM with 43% fresh air and 1.1”w.c. ESP. The new air handlers must also fit into the existing tight spaces; be able to fit through 32″ doorways, and be hoisted only using the freight elevator.

The Challenge 1
The Challenge 1

Recognizing that air is not an efficient heat transfer medium, a hydronic loop is used to heat and cool zones
independently with one energy system. This is accomplished by 97 CGC Bulldog© hybrid heat pumps. Heat pumps allow efficient control of the building’s sensible loads by transferring heat from zones requiring cooling to zones requiring heat. In some conditions the building can satisfy simultaneous cooling and heating demands without an external energy input. Unlike traditional heat pumps, CGC’s Bulldog© heat pump can provide heat without operating the compressor to minimize electrical power consumption. Striving for LEED Platinum, the Engineer utilized this unique design feature to operate the hydronic loop at optimal temperatures and reducing energy use from reduced
compressor operation.

TowerTech’s ground-breaking cooling tower design adapts this 100 year old technology for the future

The Design:

Working with Ventrol Air Handling Systems to design the system, Longhill Energy provided two separate air handlers inside a single box.
Both using FANWALL Technology, we were able to adjust the aspect ratio of the system to accommodate the space constraints on site.
We were also able to adjust fan sizes and motor horsepower to account for the different air flow rates and external static pressure requirements of each subsystem. Using incremental horsepower motors we were able to closely match the brake horsepower system requirements creating an air handling system that runs at the highest peak efficiency at all times. Traditional motor and fan selections simply cannot compete with the FANWALL Technology. Once the systems were designed for performance, the knockdown construction design began, allowing each piece of the puzzle to fit through each doorway, corridor, elevator, and every other obstacle on site.

Ventrol custom air handling showcases FANWALL TECHNOLOGY®

The Execution:

Working in collaboration with Modern Niagara Ottawa, on site technicians were brought to the Ventrol Air Handling Solutions plant located in Montreal, QC, to review the air handlers. Using actual air handlers from the project before they were shipped to site, the on-site technicians were factory trained to efficiently construct each air handler to Ventrol’s specification.


Working with an engineer with great vision, a contractor and site foreman with phenomenal skills and abilities, and great factory support,
this project came to completion without hesitation or delay. The result is another success story for our firm.

Longhill Energy has unparalleled access to many of the world’s leading HVAC manufacturers and their unique technologies.