Where should PVC vent piping not be installed?

PVC vent piping should not be installed indoors primarily due to safety and code compliance concerns. Indoor applications can lead to the accumulation of harmful gases, such as carbon monoxide, which could pose serious health risks. Ventilation systems are designed to expel gases safely from appliances to the outdoors, and using PVC indoors can hinder this process or cause improper venting, potentially leading to dangerous conditions.

Furthermore, local building codes typically regulate the materials that can be used for venting appliances. In certain jurisdictions, using metal or other materials that meet more stringent fire and durability standards is preferred for indoor installations. PVC, while versatile, is not typically rated for the high temperatures and conditions that may exist in indoor environments associated with gas appliances, leading to potential failure or hazards.

In contrast, PVC can be suitable for above-ground, outdoor, or crawl space installations, provided it meets relevant codes and standards, making those three options acceptable for acceptable vent installation.