作为CAN/CGA-B149修订版于1992年发布的通风孔尺寸表的前言。1-M91天然气安装规范，CAN/CGA-B149。2-M91丙烷安装规范，包含I类设备的新通风标准。这些相同的表格（不变）包含在后续版本的代码中（即CAN/CGA-B149.1-M95和CAN/CGA-B149.2-M95），并已被所有省份采用。这些表格附带的一般通风要求包括一项要求（#14），其中规定“如果所需通风高度和通风接头上升和/或横向位于表格条目之间，则允许线性插值计算允许的设备输入额定值。 超出表格条目的推断是不可接受的。“”为了响应使用这些表格的人的请求，已发布了所附的插值。这些表格旨在为用户提供一种方便的方法来确定通风系统的尺寸。请注意，应参考完整的B149安装规范、任何适用的省级法规以及设备制造商的安装说明，以正确安装设备和相关通风系统。

PrefaceThe vent sizing Tables, published in 1992 as Amendments to the CAN/CGA-B149.1-M91 Natural Gas Installation Code, and CAN/CGA-B149. 2-M91 Propane Installation Code, contained new venting criteria for Category I type appliances. These same Tables (unchanged) were included in subsequent editions of the Codes (ie. CAN/CGA-B149.1-M95 and CAN/CGA-B149.2-M95) and have been adopted by all provinces.The General Venting Requirements accompanying these Tables includes a requirement (#14) that states ""if the desired vent height and vent connector rise and or lateral are between the Table entries, linear interpolation is permitted for calculation of the permissible appliance input ratings. Extrapolation beyond the table entries is not acceptable."" In response to requests from those using the Tables, the attached interpolations have been published. These Tables are intended to provide the user with a convenient way to size vent systems.Please note that reference should be made to the complete B149 Installation Codes, any provincial regulations that apply, and the appliance manufacturers' installation instructions, to properly install the appliance and associated vent system.