Abby Normal wrote:
If it is an R2000 home, it has an HRV or perhaps an ERV.
The R2K spec is now mostly performance-oriented. It says what needs to happen
vs how to achieve it. An exhaust fan in a somewhat air-leaky house can be
a lot less expensive than an HRV in a more airtight house. A 2400ft^2x8' R2K
house that leaks 1.5 ACH (480 cfm) at 50 Pa (0.2" of water) might be vented
easily with a small exhaust fan with a one-day damper.
http://oee.nrcan.gc.ca/residential/p...ion.cfm?attr=4
That says "R2000 homes use HRVs." It does not say "R2000 homes must use HRVs."
Some use exhaust fans ("a mechanical ventilation system") instead. They must
have a min capacity and at least two speeds and a manual switch to turn them
on that can override other controls. Some R2K houses in Ontario have had air
quality problems because the owners didn't use the "principal exhaust fan,"
mainly because nobody told tham that was needed.
You might look at the R2K standard itself, and the standards it references...
http://oee.nrcan.gc.ca/residential/p...e.cfm?attr=3D4
5.2.1 Design, Installation and Balancing of Ventilation Systems - Mechanical
ventilation systems shall be designed, installed and balanced in accordance
with CAN/CSA-F326-M91 Residential Mechanical Ventilation Systems...
The National Building Code of Canada 1995 Section 9.32.3.1
Required Ventilation
prescribes that every dwelling unit that is supplied with electrical power
shall be provided with a mechanical ventilation system complying with:
CAN/CSA-F326 or the balance of Section 9.32.3
The following paragraphs describe the types of ventilation systems and their
requirements.
Firstly, all types require the "room count" method of determining a Total
Ventilation Capacity (TVC). Using a combination of continuous (principal)
and intermittant (supplemental) fans, the mechanical ventilation system must
be capable of operating at the TVC.
Type 9.32.3 (NBC95)
9.32.3 requires that a Principal Exhaust fan must provide at least 50% of
TVC. A fan capable of supplying 75% or more of the TVC must have a control
to allow switching to 45 to 55% of TVC.
If this fan exhausts only the kitchen, a vented range hood is not required
but bathroom fans are.
If this fan serves more than one room, a vented range hood is needed in the
kitchen.
Bath fans are required only when the bathroom is not served by this
principal exhaust.
The principal exhaust fan must be capable of continuous ventilation (not a
range hood).
Section 9.32.3.10(5) requires kitchen exhaust be filtered.
Code required range hoods must be capable of exhausting 100 cubic feet per
minute (CFM) and not exceed 3.5 Sones (Noise level). Code required bath fans
must be at least 50CFM and not exceed 2.0 Sones. Be careful with HVI labels.
An HVI label indicates the fan has been tested. It does not mean it meets
the requirements of NBC. Bath fans and range hoods that are not part of the
required ventilation do not have to meet these requirements.
Fresh air equal to 50% of the TVC is required with distribution via ducts to
all bedrooms and all levels without bedrooms. See Section 9.32.3.7. It must
be linked by controls to the principal exhuast fan and tempered (heated) to
12 degrees C before entering the living space. Make-up air is required if
protection from depressurization is necessary.Section 9.32.3.8.
F326 Installations
F326 requires that a ventilation system be capable of providing supply air
(fresh) at least equal to the TVC.
This ventilation system must be equipped with a means to adjust the
ventilation rate to less than the TVC.
The system must provide kitchen exhaust equal to either a continuous 60 CFM
or intermittent 100 CFM.
The system must provide bathroom exhuast equal to a continuous 20 CFM or
intermittent 50 CFM.
Make-up air is required if protection from depressurization is necessary.
Type R2000
R2000 uses F326 as a basis for ventilation capacity and requires the items
listed above plus the following:
-TVC is the higher of the "room count" or F326 total continuous exhaust
(60CFM kitchen, 20CFM bath)
-Kitchen exhaust must be filtered.
-Actual TVC must be within 15% of calculated TVC.
-Low speed operation must be 40-60% of TVC...
Nick