On Feb 18, 3:01*pm, "Steve B" wrote:
I have two propane appliances. * One is a Bosch range top, fed from an
outside 114 gal propane tank. *The other is a Vermont Castings grill, fed
from a 20# bottle. *Both of the tanks are outside.

At this time of year, when I go to grill, there is barely enough propane
coming out to get the grill to 250 degrees, even with four burners on high.
The grill DOES need cleaning (boy, howdy, it really does), which may be part
or all of the problem.

But, the two feed off tanks that are outside at the same temp. *The cooktop
line, though, comes through the garage and a heated portion of the house, so
gets some heating up along the way, but the regulator and tank are still
outside.

Just how does propane function with relation to outside temperatures, and
when is it just too cold to grill outside? *Temps here during the
questionable episodes were 40-45 deg. F at max coldness, so not down there
around freezing. *There was some wind, and in the past that does blow the
flame around a lot.

After a thorough disassembly and cleaning, what can I expect from propane
use outside in 40ish temperatures?

Steve

here is a useful primer on propane

http://rjmurray.com/serviceBulletins...nsHandbook.pdf

probably more info than you wanted but here's an important
excerpt........

Vaporization Rate
The rate of vaporization of a container is dependent upon
the temperature of the liquid and the amount of “wetted
surface” area of the container.

The temperature of the liquid is proportional to the outside
air temperature and the wetted surface area is the tank
surface area in contact with the liquid. Therefore, when
the outside air temperature is lower or the container has
less liquid in it, the vaporization rate of the container is a
lower value.


The vaporization rate is important because it determines the maximum
energy delivery rate (btu per hour) that you can get from the tank in
a particular cooking situation.

I have similar BBQ but a different mfr & only three burners (~40,000
btu / hr)

If yours is a four burner then you're in the 50K+ range.

I'm guessing the cold weather with a bit of wind is stealing heat from
the bbq.
And you;re suffering from reduced a reduced vaporization rate as well.

here's a better link... it shows the btu's per hr from various tank
sizes at various outside Temps with the tank at 25% full (the
conservative way to estimate tank size required to supply a load).

http://www.generatorjoe.net/html/PropaneNGUse.html

scroll down and read the section

"What does all this mean?"

There are a number of variables at work that can "go against you" when
you're trying to cook in cold temps with LP gas.

One way around the problem is to always use a tank that is closer to
full in cold weather.
Or place the in a large galvanized wash tub with ~4 gallons of 85F
water while you're cooking.
That would be 2 gallons of cold water at 50F and 2 gallons of hot
water at 120F.
YMMV

That will give you plenty of heat input into the tank to vaporize the
propane and make the bbq happy.

cheers
Bob