Smoke backup open HVAC Register

[RAB1947]

During the installation of a new HVAC system the installers left the ceiling register to the crawl space above open overnight without installing the new duct. When I lit a Duraflame log in the fireplace the smoke went up the open hole instead of up the chimney. The chimney flue was open. Smoke filled the house. I had to put the fire log out with a fire extinguisher which made a heck of a mess of my furniture, walls and ceiling.
The insurance company for the installers is now denying that the open duct would cause the smoke to be drawn up into the crawl space instead of up the flue.They claim it's :"against the laws of physics" .
Is it possible that the open vent hole to my crawl space drafted more smoke than my chimney, causing the smoke to vent up the open ceiling hole?

 

[bholler]

During the installation of a new HVAC system the installers left the ceiling register to the crawl space above open overnight without installing the new duct. When I lit a Duraflame log in the fireplace the smoke went up the open hole instead of up the chimney. The chimney flue was open. Smoke filled the house. I had to put the fire log out with a fire extinguisher which made a heck of a mess of my furniture, walls and ceiling.
The insurance company for the installers is now denying that the open duct would cause the smoke to be drawn up into the crawl space instead of up the flue.They claim it's :"against the laws of physics" .
Is it possible that the open vent hole to my crawl space drafted more smoke than my chimney, causing the smoke to vent up the open ceiling hole?

It is possible yes but it is not their fault or their responsibility to pay for it. They were in the middle of a job and had no reason to suspect it would cause a problem. Submit the claim to your homeowners insurance.

 

[RAB1947]

I just need Fireplace advice, not legal advice. Thank you. The fact is that it is physically possible. Thanks. Now I know the cause for certain.

 

[bholler]

I just need Fireplace advice, not legal advice. Thank you. The fact is that it is physically possible. Thanks. Now I know the cause for certain.

No you dont know the cause for certain. And regardless cause is way different from fault. I would be fighting that claim as well if i was the contractor. But i also would have covered the vent for the night. Not because of the issue you had just so there wasnt an open hole.

 

[maple1]

I just need Fireplace advice, not legal advice. Thank you. The fact is that it is physically possible. Thanks. Now I know the cause for certain.

How do you know the cause for certain? Someone on the internet saying something might be possible is a looong way from saying a certain thing is for certain.