# Indy neighborhood gas explosion: 3 charged

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• 12-22-2012, 11:02 PM
junkhound
approx 4 million btu per ton of tnt

approx 1000 btu per cu ft, so 4000 cu ft of NG per ton tnt

about 9-1/2 cu ft of air per cu ft NG, right?

so, 42,000 cu ft of house for a ton of TNT for NG blast (aka air-fuel bomb)

Say big house, 8 ft ceiling, 4000 sq ft house including basement, etc = 32/42 approx 3/4 Ton of TNT equivalent.

at 50 ft away, about 8 psi overpressure or wind speed like a Fujita F4 tornado ripping thru the neighborhood which is what the damage indicated.

To actually plan for the level of damage seen and to acheive the stochiometric mix at ignition would imply an intelligence way above what the perps obviously are lacking .. stupidity is no defense for murder, esp when evil intended.... concur with charging sentiments of previous posters
• 12-23-2012, 09:40 AM
ch4man
Quote:

Originally Posted by junkhound
approx 4 million btu per ton of tnt

approx 1000 btu per cu ft, so 4000 cu ft of NG per ton tnt

about 9-1/2 cu ft of air per cu ft NG, right?

so, 42,000 cu ft of house for a ton of TNT for NG blast (aka air-fuel bomb)

Say big house, 8 ft ceiling, 4000 sq ft house including basement, etc = 32/42 approx 3/4 Ton of TNT equivalent.

at 50 ft away, about 8 psi overpressure or wind speed like a Fujita F4 tornado ripping thru the neighborhood which is what the damage indicated.

To actually plan for the level of damage seen and to acheive the stochiometric mix at ignition would imply an intelligence way above what the perps obviously are lacking .. stupidity is no defense for murder, esp when evil intended.... concur with charging sentiments of previous posters

great post, i too was tring to do the math. i cant speak for tnt equivelent but having a background as a "gas guy" i seen many vidios and the results of houses purposfully blown up and the data these tests reveil.

its harder than youd think to reach a level between LEL and UEL in a house esp one that large.

the creeps that did this were either very smart or very lucky.....

from the reports it sounds like the 2lb regulator was removed and bypassed and a valve in the gas fireplace missing. so gas at 2 psi through probably 1/2 or 5/8" copper for 7-8 hours to bring a 3 story 4000 sq ft house with minimal air changes to between 5-15% gas.
before thr microwave was set to start the ignition source.

someone did a lot of research.....

i hope they fry.
• 12-23-2012, 10:42 AM
hvacvegas
Hang um high.
• 01-02-2013, 12:46 AM
jdblack
This is local for me. possibly a gas leak at the furnace in the attic.

http://www2.wspa.com/news/2013/jan/0...r-5277653/?v=2

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• 01-02-2013, 01:25 AM
chaard
The idiots changed the digital tstat to a mechanical tstat that can generate a spark.
Stupid. Why not just program the stat to call for heat at a certain time. The ignition of the furnace would ignite the gas filled house.
• 01-04-2013, 10:58 AM
motoguy128
Quote:

Originally Posted by chaard
The idiots changed the digital tstat to a mechanical tstat that can generate a spark.
Stupid. Why not just program the stat to call for heat at a certain time. The ignition of the furnace would ignite the gas filled house.

Because that's not what they've seen in the movies or read on the internet. Could have been a sealed combusiton furnace too. None of my gas appliances communicate wit hthe air inside the home unless, on 2 of them, you were to leave the service door off sicne the combustion air is a free draw from inside the cabinet.
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