Notice to anyone building a home under the new BC building code.
There have been some significant changes in the BC building code particularly in the ventilation requirements. All homes now require fresh outside air to be distributed in each bedroom and living area. All homes require an exhaust system to continuously exhaust air 24 hours a day and the amount of air (CFM) required for exhaust is based on living space and number of bedrooms. There is 4 different ways this can be achieved each having different results in energy efficiency and installation costs.
1. Ventilation through Forced air system – When a forced air heating system is chosen, the air distribution fan is required to run 24 hours a day in conjunction with an appropriately sized exhaust fan running 24 hours a day. In addition the forced air heating system must have a 4” rigid or 5” flexible fresh air intake no less than 10’ and no more than 15’ from the return air side of the forced air system.
2. Ventilation through an HRV (Heat Recovery Ventilator) system – An HRV system can provide ventilation 24 hours a day while recapturing a significant amount of heat that would otherwise become lost from exhaust fans. The HRV system must have an exhaust port on the uppermost floor and every bathroom. The fresh air from the HRV can be distributed through out the house on its own distribution system or work in conjunction with a forced air heating system. If the HRV is tied in with the forced air heating system the fan of the heating system must run 24 hours a day as well. An independently distributed HRV system is the most energy efficient choice of the 4 available ventilation options.
3. Ventilation through a CRV (Central Recirculating Ventilator) system – The CRV system is a very basic fan system that has the ability to draw fresh outside air and living area air to a common duct. This mixture of inside/outside air is then distributed to each bedroom. This is a cost effective way to meet code requirements however an extremely in efficient system for the end user. This system runs 24 hours a day and must work in conjunction with an adequately sized exhaust fan operating 24 hours a day as well.
4. Ventilation through passive inlets – Passive inlets the most basic and cost effective of the ventilation options. This system is only allowed in dwellings less than 1600 sq ft and they must be a single story per dwelling. This system requires an exhaust fan running 24 hours a day and each room must have a fresh air intake with an intake area of no less than 4 square inches.
What does this mean for Temprite? At Temprite we have made a few changes to our policies to ensure our quality of work and our reputation as qualified professionals protects our customers best interests when making decisions on ventilation.
The changes to policy are:
1. Temprite Climate Solutions ltd. will only take responsibility and sign off on a mechanical ventilation checklist if all exhaust fans (except the range) are sized and installed by our staff. We now have this policy in place because with exhaust fans operating 24 hours a day it is essential the fans are sized to cover the minimum ventilation requirements without excessively ventilating the dwelling.
2. Temprite Climate Solutions ltd. will only be supplying and installing variable speed fans with our forced air systems. Now that forced air systems are required to operate the fan 24 hours a day only a variable speed fan can run on a low continuous speed ensuring minimal air noise and draft when the system is not heating or cooling.
Other notable code changes:
1. Any ducting carrying conditioned air like heating and HRV ducts must be insulated to a value of R-20 to any outside wall. This means extra attention in planning the conditioning difficult areas like bonus rooms at the earliest stage possible. Any air moving though ducting for exhaust or intake can still be insulated to the standard R-4 value.
2. All crawlspaces require some form of return air or air exchange to the living space of the house. The design of the crawl space air exchanges changes with the type of ventilation system.
Temprite Climate Solutions ltd. has TECA (Thermal Environmental Comfort Association) certified technicians on staff. They are rigorously trained to the new BC building code standard. This means you have the comfort in knowing we can design, sign off and stamp the right ventilation system for your new home. The earlier we can be involved with the building process the less chance of any unexpected or additional cost in bringing the ventilation system to meet standards of building today. If you have any questions or would like to know more about the BC ventilation code please call us at 250-465-2490.