In our area (northern West Virginia), municipal water companies
install water meters in the ground in a plastic sleeve or pit. The
sleeve is about 18 inches in diameter and 24 inches deep. When the
water meter and water lines are installed in the pit, the water lines
are about 14 inches below ground level. There is no filling or
insulation placed into this pit, just an air space abouve the meter
and water lines and a metal cover on top of the pit. In our area we
typically bury water lines 18 inches to avoid freezing in severe
winters.
So - why doesn't the meter and/or water lines in the pit freeze in the
winter is there is just air in the pit - no insulation - and the lines
are so close to ground level? What principle am I not understanding??