LETHAL R-134a concentrations from evaporator failure

[Stephen H. Westin]

ghg at worldserver.com writes:

> LETHAL R-134a CONCENTRATIONS IN PASSENGER COMPARTMENTS MAY OCCUR
> FROM EVAPORATOR FAILURE

<snip>

> The specific Volume of R-134a vapor at "normal" pressure (from the NIST
> Standard Reference Database 23 "NIST THERMODYNAMIC PROPERTIES OF
> REFRIGERANTS AND REFRIGERANT MIXTURES") is 3.69 cubic feet per pound
> (cf/lb).  If you blow off a 1 lb can of R-134a into am empty garbage bag
> (sealed), it will occupy 3.69 cubic feet.
> 
> 	     SPECVOL134a CF   R-134a CHG lb         1        1,000,000 parts
> conc. (ppm) = -----------   X -------------  X   --------  X
> ----------------
> 		  lb                            Int.Vol CF   per million
> 
> 1998 CAR		Interior(CF)	lb R134a  pass.conc ppm  Times
> lethal
> Ford Escort		87		1.75	  74,224	  18.6

I don't know where your interior volumes come from; I believe you're
using the SAE volume (also published by the EPA), which is a highly
abstract estimate of roominess for passengers. The actual air volume
inside the vehicle would be significantly greater.

Frankly, this post seems like a scare tactic, based on an unlikely
scenario (a sudden, massive evaporator leak) to try to sell your own
product.

-- 
-Stephen H. Westin
Any information or opinions in this message are mine: they do not
represent the position of Cornell University or any of its sponsors.