Which size holes are drilled in the front and rear economizer vestibules to alleviate gas leaks?

The correct hole size drilled in the front and rear economizer vestibules to alleviate gas leaks is 3/8". This size is specifically chosen because it strikes a balance between being large enough to effectively relieve gas pressure and prevent buildup, while not being so large that it compromises the structural integrity or performance of the economizer itself.

In practical applications, smaller holes may not provide sufficient relief for gas escape, potentially leading to dangerous pressure accumulation or inefficiencies in the system. Conversely, a hole that is too large could lead to excessive loss of combustion gases, which may impact overall efficiency and performance. Therefore, 3/8" is the optimal size to ensure safety and operational effectiveness in the economizer vestibules.