Mark
somebody shut me the fark up.
Sorry for the redundancy of this post for those of you that already saw it in my heat shield post but Phil and I thought this discussion important enough to make it a seperate thread.
Water is pretty amazing stuff when you think about it and these properties make it the ideal substance for the water pan. Hopefully, the information below shows why:
The specific heat capacity of sand is less than 0.2 Btu/lb F
The specific heat capacity of water is exactly 1.0 Btu/lb F
This means a pound of water can hold over 5 times the heat of a pound of dry sand. This also means that water is nature's perfect heat sink and will control smoke chamber temperature swings better than anything else.
On top of that, water at 212°F (0 P.S.I. Gage) is changed to steam at the same temperature by the addition of 970 BTUs per pound. This also controls temperature swings.
Finally, water evaporation is assisted by the vapor pressure gradient between the hot, dry smoke entering the smoke chamber and the surface of the water in the water pan.
So while you can use sand or even kitty litter (ugh!) if you want to and may even produce good Q doing so, water will help reduce the variables thus improve your odds of prodicing consistantly good Q.
Hope this helps.
Water is pretty amazing stuff when you think about it and these properties make it the ideal substance for the water pan. Hopefully, the information below shows why:
The specific heat capacity of sand is less than 0.2 Btu/lb F
The specific heat capacity of water is exactly 1.0 Btu/lb F
This means a pound of water can hold over 5 times the heat of a pound of dry sand. This also means that water is nature's perfect heat sink and will control smoke chamber temperature swings better than anything else.
On top of that, water at 212°F (0 P.S.I. Gage) is changed to steam at the same temperature by the addition of 970 BTUs per pound. This also controls temperature swings.
Finally, water evaporation is assisted by the vapor pressure gradient between the hot, dry smoke entering the smoke chamber and the surface of the water in the water pan.
So while you can use sand or even kitty litter (ugh!) if you want to and may even produce good Q doing so, water will help reduce the variables thus improve your odds of prodicing consistantly good Q.
Hope this helps.
