[A/S] How cold would it be...

["Maurice Riggins" <maurice.riggins@xxxxxxxxxxxxxxxx>]

I'm looking at some numbers... a gallon of propane has about 91,500 
btus, so a 30 lb (7.1 gal) tank has a 649,650 and a 40 lb (9.4 gal) 
tank has 860,100.  

A 25,000 btu/hr input furnace, running continuously in a 25' A/S for 
example, could use a 30 lb tank every 26 hours.  And running a 5.5 
amp furnace fan for 26 hours would be 143 amp-hours.

A 34,000 btu/hr input furnace, running continuously in a 34' A/S for 
example, could use a 40 lb tank every 25.3 hours.  And running a 7.5 
amp furnace fan for 25.3 hours would be 190 amp-hours.

Now I know the furnace doesn't run continuously unless its really 
cold.  But how cold would it have to be so that it did with these two 
A/S examples?  I guess that would also depend on what the thermostat 
was set on... it would go continuous at a lot less cold of a 
temperature if the thermostat was set on 70 than it would if it was 
set on 50.  Lets use 60 degrees.  Anyone have a guess?  10 below 
zero?  20 below?

Think there would be enough heat from the furnace at that outside 
temperature to keep the tanks from freezing?
--
Maurice
WBCCI 5446