Number of Briquettes wasted using Water Pan

[Derek O]

Just to quantify what everybody already knows, you use more charcoal if you put water in a water pan.

My assumptions are as follows:

2 gallons of water are put into the water pan @ 80F (I will discuss what heating up the water can do below)

All of the water is boiled off during the cook (may not be appropriate for short cooks)

Kingsford Briquettes have a heating value of 9,700 BTU/lb

There are 10 Briquttes/lb (I have not actually measured to see how accurate this number is)

Based on these assumption it requires 18.9 additional briquttes when putting water in the water pan.

If you preheat the water to 150F it decreases the number of briquettes used to 17.7 briquettes.

If you use and boil off only a gallon of water (80F) you use 9.4 briquttes.

If you use 2 gallons (80F) and only boil off half then you have used 10.6 briquttes.

IMO heating the water saves you very little in fuel usage, it does save in time to heat up the cooker though.

The amount of water boiled off is the key to how many extra briquettes were needed.

Calcs:

Mass (lb water)= Gallons of water x 8.34 lb/gal
Energy Required to heat water to 212 (BTU) = Mass (lb water) * 1 (BTU/lbF) * (212 - Water Temp)
Energy Required to Boil off Water = Mass of water Vaporized (lb) * 970.33 BTU/lb

Total Energy = Boil Off Energy + Heating Energy

lb of charcoal = Total Energy (BTU) / 9700 BTU/lb charcoal

# of Briquttes = lb of Charcoal * 10 Briquette/lb Charcoal

Sorry got bored today...

 

[Ronnie F]

nice calculations, looks like a practical way to apply physics to everyday use. one of my old engineering professors would throw out random questions like this in class.

 

[Russell Y]

But doesn't the water keep the meat moist?(not really jk-just kidding)

So.... since I am saving money not using water in the pan, how long will it take, in charcoal savings, to pay for my ATC(assume $200)?

I already have one but for others this could be a convincing argument (with SO or wife) on buying one.

 

[Derek O]

<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Russell Y:
But doesn't the water keep the meat moist?(not really jk-just kidding)

So.... since I am saving money not using water in the pan, how long will it take, in charcoal savings, to pay for my ATC(assume $200)?

I already have one but for others this could be a convincing argument (with SO or wife) on buying one. </div></BLOCKQUOTE>

Well assuming charcoal is $0.41/lb (which may be high depending on if you get charcoal on sale or not). If you waste 1.89 lb charcoal per cook, it would take 258 different smoking sessions....few years to say the least.

 

[RichPB (richlife)]

WHAT! 258 cooks is less than a year!

I just wanted an excuse to use that smiley

Rich (with all of 1 smoking session a month for 6 months)