Replies

1. 
   Trevor_Lambert | May 18, 2021 10:43am | #1

   Not sure exactly where in that section you got that, but no. You have a dedicated HRV system, see table 9.32.3.5 for the required rate. Whether you have A/C or not is not relevant. Having said that, it is never a bad idea to have excess capacity in your ventilation system for boosting during cooking, showering or parties.

1. 
   jason_v | May 18, 2021 10:49am | #2

   thank you. its directly from

   9.32.2. NON-HEATING-SEASON VENTILATION
   9.32.2.1. Required Ventilation
   1) Rooms or spaces in dwelling units shall be ventilated during the non-heating season by
   a) natural ventilation in accordance with Article 9.32.2.2., or
   b) a mechanical ventilation system conforming to Subsection 9.32.3.
   2) Where a habitable room or space is not provided with natural ventilation as described
   in Clause (1)(a), mechanical ventilation shall be provided to exhaust inside air from, or to
   introduce outside air to, that room or space at the rate of

   a) one-half air change per hour if the room or space is mechanically cooled during the non-
   heating season, or

   b) one air change per hour if it is not mechanically cooled during the non-heating season.

1. 
   Trevor_Lambert | May 18, 2021 12:23pm | #4

   That looks different from what I remember. Note however that the requirement only applies if you don't have natural ventilation (aka a window) in the area, or adjacent area connected by a minimum unobstructed opening per the table below the text. There's no way anyone is installing mechanical ventilation of 1ACH for the whole house. That would be upwards of 400cfm for a modest sized house, up to more than 1000cfm.

1. 
   jason_v | May 18, 2021 02:36pm | #5

   thanks

2. 
   Jon_R | May 18, 2021 11:06am | #3

   Note that heating system L/s is a minimum, so I don't see any contradiction. If I did the math right, it's more like a 4:1 ratio between seasons.

1. 
   jason_v | May 18, 2021 02:39pm | #6

   for our house, we come up with 60 L/s for continuous operation (via room by room addition of rates), if we go with 1/2 air exchange per hour the math works out to 250 ish cfm, which is 117 L/s