Member Meetings

Presented by David Hill, President, Eneready Products

Relative humidity is a measure of moisture content in the air compared to the maximum that air could hold if it were fully saturated (i.e. steamy bathroom).

Absolute moisture, a less used but still important term, is a measure of weight in 'grains of water' contained in 1 pound of dry air.

Maintaining the correct relative humidity (RH) is important for the health of:

a) the residence itself and
b) our ultimate customer, 'Ms Smith' its owner/occupant.

Although the 2 ideal RHs levels are slightly different, the difference between them is small and in good buildings, a compromise will satisfy both. HVAC systems are a part of the solution, but unfortunately only 1/2 of that required for effective RH control. The builder's attention to detailing of the air barrier and insulation layer is critical, but that is not always done well.

Due to ground breaking research at the Vancouver Test Hut, (read Leaky Condo Research Project) Mark Gauvin (builder) and Dr. Joe Lstiburek P.Eng. (researcher) have shown that wood frame homes, an inherently affordable method of construction can satisfy both and provide decades of good service if they are:

a) externally insulated,
b) have an effective (sealed) air barrier and in when located in coastal areas
c) have a ventilated rain screen (cavity) incorporated beneath the exterior cladding.

In a building devoid of either or both a) & b) above, if we were to forcibly raise the relative humidity in aide of Ms Smith's lung health, the risk of damage to the house is real and will likely show up with:

a) excess moisture in the attic and/or
b) mildew/moisture in cool dead corners of closets and basements ultimately compromising respiratory health.

In defence of adding RH is winter, Dr. Stephanie Taylor's recent research has shown that our natural human immunity against infectious bacteria and viruses increases when relative humidity levels rise above 40% in a well-built home, a good HVAC system will have an effect and can:

- Lower RH using ventilation in the winter and A/C in summer and
- Raise RH with humidification. While in winter this will increase the moisture stress across the exterior wall and ceiling this can be done, in moderation without risk

David Hill will share his experience and first-hand knowledge on this often misunderstood topic.

Presented by Jeremy Young, TECA Board Member and Quality First Instructor

Jeremy Young presents an overview of currently available technologies for residential hydronic heating, chilled water cooling and domestic hot water using air-source heat pumps. The presentation includes details on suitable applications, strategies to enhance efficiency and reliability, as well as defining the common mistakes made by experienced designers and installers who come from backgrounds with fossil-fuel based hydronic heat sources and how to mitigate those risks.

Presented by SAEED DANESH, Technical Project Specialist - Building Technology, REHAU

This TECA presentation covers the principles of radiant heating and cooling systems, highlighting how they function and integrate within modern building design. Key benefits such as improved thermal comfort, enhanced energy efficiency, and alignment with electrification and carbon-reduction goals are discussed. Real-world project references are also shared to demonstrate practical applications and performance outcomes.

Presented by: Micah van der Heide, RSE/Technical Support & Training Manager, Refrigerative Supply

Micah will present on Low GWP / A2L refrigerants and discuss some of the important upcoming changes that will impact the HVAC industry. The transition to refrigerants with lower global warming potential (GWP) is driven by worldwide initiatives to decrease greenhouse gas emissions.
The U.S. Environmental Protection Agency (EPA) mandated a switch to refrigerants with a GWP of 700 or less by January 1, 2025.

The Canadian government enacted the Regulations Amending the Ozone-depleting Substances and Halocarbon Alternatives Regulations, which set a phasedown of HFC consumption. This means the HVAC/R industry is phasing down the production and consumption of Hydrofluorocarbons (HFCs) refrigerants and is transitioning to lower GWP refrigerants such as R-454B and R-32.

Todd Backus presents his approach to use CSA F280 guidelines to model cooling in a single living space in order to meet the requirements for maintaining a 26°C indoor air temperature in one living space which is outlined in section 9.33.3.1. of the BCBC. The CSA F280 standard was not designed to model a single room, therefore, some assumptions are required to generate an accurate model.

Todd discusses appropriate strategies and design considerations to meet code minimums and improve the thermal comfort of the occupants when determining which areas should be cooled. Todd also identifies how the internal loads of a building are calculated and why buildings with low summer design temperatures still generate a significant heat gain load.

Several challenges for proving that active cooling is not required are also highlighted and the information that would be required to make the argument that active cooling is not required to meet the intent of the code are also discussed.

Presented by Todd Backus, P.Eng.
TECA Manager & Programs Development

TECA's Hydronic Systems Design manual with Hydronic & Combo Guidelines forms the basis of our Registered Designer program. Trains those working with hot water heating to properly design a residential hot water heating system to meet the guidelines established by the Residential Hot Water Heating Association of BC. Quality First Registered Hydronic Designers receive a numbered certificate, wallet card and stamp for submitting system drawings from the Guidelines to inspection authorities. These Guidelines are used in conjunction with the TECA Hydronics Systems Design Manual when designing systems. The drawings in these guidelines are approved boiler room and system layouts and are used by many BC authorities having jurisdiction for inspections of hydronic installations.

Quality First Registered Hydronic Designers receive a numbered certificate, wallet card and optional stamp for submitting system drawings from the Guidelines to inspection authorities.

What the mechanical contractor needs to know about the new building envelopes and how they affect the work we do. Discussion is on the changing regulatory and policy context that is driving changes in building enclosures and cascading effects on design and construction practices. What will these changes mean for mechanical systems design and installation? Topics include operating and embodied carbon emissions, performance metrics, Step 5 - airtight and low-thermal demand buildings, emerging building science risks and mitigation strategies, etc.

Presented by: Nico Pellegrino - Technical Specialist, Thermo 2000

Topics covered in this video include:

- Do I need a buffer tank with a heat pump system?
- Do I need a back up system for a heat pump system?
- The different ways to utilize a buffer tank heating or cooling
- Do I need full back up or just to get me some heat?
- What is the trend for buffer tanks and electric back up boilers for heat pump systems?

Scott Miller, Director of TECA (Thermal Environmental Comfort Association of BC) discusses heat pumps in this presentation.

Content:
1. Overview of Heat Pumps: Philosophy
2. Principals of Heat Pumps: How it works ... the Vapor Compression Cycle
3. Categories of Heat Pumps: Ducted, Ductless, Multizone
4. Best Practices: Location, supports, code standards
5. Thermal Properties of Heat Pumps: Capacities, ratings, sizing
6. Electrical Requirements
7. Rebates