Nice work to Ringo!  He was a top candidate!

The February meeting tour featured University of Guelph- Humber's living wall biofilter.  Following were presentations about Humber College's new "Building L - Lakeshore Commons" on the Lakeshore Campus, and the modifications to the central mechanical plant on the Lakeshore campus.

On the tour, Dr. Alan Darlington, of Nedlaw Living Walls explained how University of Guelph - Humber's living wall biofilter cleans the air that is drawn through it.  Air is drawn through at the rate of 10 to 20 CFM/ft2.  Plants held in pockets in a vertical mat, several stories tall, remove formaldehyde, benzenes and other pollutants, through the process of biofiltration.  Sixty to eighty percent of VOCs are removed in a single pass.  The plants are 6" to 10" ordinary potted plants with all the soil knocked off.  Their roots hold beneficial microbes which feed on the pollutants.  A living wall biofilter is better than an activated charcoal filter in that it is self-cleaning, and does not fill up with pollutants.  This living wall biofilter also includes a louvered bypass section. 

Following, Mr. Scott Valens, Architect / Associate Director of Planning & Construction at Humber College, made a presentation on the architectural history of Humber College's Lakeshore campus, which used to be the Mimico psychiatric facility.  The campus is comprised of the restored original heritage cottages, built in the 1890's, surrounding a quad with the new "Building L - Lakeshore Commons".   Ms. Katherine Sendrowicz, HOK Project Architect presented the design of the four-storey, 110,000 sq. ft. "Building L" which houses classrooms, labs, faculty offices, student project space, learning commons and a new media communications centre. This attractive new building was carefully planned to provide easy circulation for the students inside, as well as comfortable areas to rest and congregate.  Some of the exterior walls of the building are transparent, to show how the building's occupants circulate inside, and to provide a sense of connection to the rest of the campus.  

Mr. Bram Atlin P.Eng., LEED AP, Mechanical Project Manager of Smith + Andersen presented the redesign of the central plant, to remove its components from view of Humber College's Lakeshore campus, and to provide extra cooling capacity.  Two open loop, induced draft cooling towers, which were in plain view before, were changed to a closed loop, glycol system, and buried in a bunker.   The switch to closed loop cooling towers resolved the elevation issue of the chiller being higher than the cooling tower.  As well, the cooling towers are now located further away from sensitive receptors, so that their plumes will not cause interference. The new chiller was over sized to account for the glycol, and was then oversized beyond that, to provide additional capacity to the campus, while staying within the same frame size.

Mr. Bram Atlin also explained the HVAC design of the central commons "Building L".  The Smith + Andersen team minimized the number of rooftop equipment to one hydronic make-up air handling unit, MUA.  Inside the building, compartment units were used, with overhead cooling by VAV boxes.  Studio spaces have radiant panels.  The MUA provides ventilation air to the compartment units, and also allows air free cooling.  Oversized outdoor air and relief shafts maximize the airside free cooling range.  The result of the new campus HVAC design is the provision of the needed extra capacity with more energy efficient equipment.  Equally important, is the virtual disappearance of HVAC equipment from view, at Humber College's beautiful Lakeshore campus.   

Website & Gazette Committee Member

The February technical breakfast seminar featured a presentation on Variable Refrigerant Flow (VRF) systems by Mr. Kevin Farbridge, P.Eng. Principal of Smith + Andersen.  A VRF system uses refrigerant as the heat transfer media.   This energy efficient, decoupled system is comprised of an outdoor (or indoor) condensing unit serving many indoor evaporator units, on a common refrigerant piping network.  Refrigeration control units regulate flow to each evaporator unit.  The variable speed compressors are centralized in this system.  Controls are complex for refrigerant flow and oil management.   A three pipe system enables the system to offer heat recovery, with the third pipe containing refrigerant in the hot gas phase.  

In North America, the Variable Refrigerant Flow system has mostly been implemented in low rise buildings. There are limits on maximum piping length and height difference between the condenser and evaporators. The manufacturer's software should be used in the design/layout process since many factors must be taken into account.

The impact of winter outdoor air temperature must be considered. Without low ambient controls, the system will not provide cooling below 23 degrees F.; something to consider if internal loads such as computer rooms are included in the system. The systems heating output and COP will drop with outdoor air temperature with, currently, -4 degrees F. being considered most manufacturers' low limit for heating.

It is important to follow CSA B52-05 regulations for refrigerant in direct contact with an occupied area. Splitting refrigeration circuits might be necessary to ensure that the refrigerant concentration in any space will not exceed the limitations set by B52 in the event of a leak.

Variable Refrigerant Flow systems are energy efficient and can be beneficial in dealing with challenging building envelopes (e.g. existing buildings, limited ceiling height); phased construction due to VRF's modularity; and heat recovery, where possible. Due to the proprietary nature of the controls and equipment, the same manufacturer would need to be used for all phases and for future adjustments.  More work needs to be done in integrating performance parameters of VRF systems into current energy modeling software.  Mr. Farbridge says that it is good to know about VRF systems, because they are another tool available to the HVAC Engineer.

Website & Gazette Committee Member

Dates Are Set: Am Fri Aug 23 To Noon Sun Aug 25, 2013

Venue: The Fairmont Royal York

We are looking for Chapter Members support in helping us run a successful CRC. We are looking for volunteers to help out with:

Iowa State University

Principal Investigator, Michael Pate

TC 8.9, Residential Refrigerators and Food Freezers