Arkansas HVACR NewsMagazine April 2018

reduces the available and necessary combustion air. Now we should ask, “Why did anyone participate in a furnace install where there would be insufficient combustion air?” Well, ignorance and carelessness are two options. As one that suffers from IC (ignorance and carelessness), I do not want to appear to cast stones. Our purpose is not to name names, cast blame, or to embarrass anyone. Our purpose is always about education and protecting the health and safety of the public. With that in mind, let’s again ask the question, “Why did this happen?” Here are a few scenarios. 1. The HVAC contractor did not know that the crawl space would be encapsulated. 2. The HVAC contractor did not know that encapsulating a crawl space would reduce the necessary combustion air for the furnace. 3. The crawl space encapsulator did not know that a furnace would be installed in the crawl space. 4. The crawl space encapsulator did not know that encapsulating a crawl space would reduce the necessary combustion air for the furnace. 5. The designer / engineer / remodeler / construction contractor did not know the inter-relationship between encapsulation and combustion air. 6. The designer / engineer / remodeler / construction contractor did not convey the necessary information to the HVAC contractor.

You can check the box that you think is the most likely reason for this mistake. Frankly, I think you can check more than one. Regardless of where you think the ignorance or carelessness needs to be assigned, the result is the same. Oh yes, what was the result? Well, after the installation of the furnace and the crawl space encapsulation, the Governor smelled gas. He called the appropriate folks who called the appropriate folks and they determined there was indeed a problem; however, they could not find a gas leak. (Just a note—don’t you like the way I am going out of my way not to name names; i.e., appropriate folks called appropriate folks?) Anyway, two different and credible companies checked for gas leaks and could not find one. So, how did the Governor smell gas? Here it gets a little complicated and some of the following is the result of educated guesses / assumptions. 1. The unit was being starved of air because of the crawl space encapsulation. 2. The flame was burning rich so not all the gas was being consumed. (This is important because, if the gas was consumed, the added ordorants which make natural gas smell would have been consumed.) 3. The exhaust pipe was B-vent but was connected to the furnace with flex pipe snaking around the unit to get to the solid B-vent.