Estate for years. An estate for years is one which is to continue for a definite period fixed in advance by. agreement between landlord and tenant. The name is somewhat misleading because the period may be for less. than a year, measured in specific days, weeks, or months. Estate from period to period. An estate from period to period (or periodic tenancy) is one which continues for. periods of time (typically year-to-year, month-to-month, or week-to-week) as designated by landlord and tenant. in their agreement. The most common periodic tenancy is the month-to-month tenancy.
You will still require 8.34 BTU to raise the temperature of a gallon of water one degree F. 1  I say approximately because the weight of water varies slightly with its temperature. 2  Water is at its densest at 4 degrees Celsius (39 degrees F). 3  A gallon of water at temperatures above and below that value will weigh less.
At 92% efficiency, that's 14,126 BTU. From above, heating a gallon of water by 1Â°F takes 8.33 BTU. Heating from 68Â°F to 104Â°F would by a 36Â°F rise, or 36 x 8.33 = 300 BTU to heat 1 gallon of water. With 14,126 BTU, we could heat 14,126 BTU Ã· 300 BTU/gallon = 47 gallons. So, our typical 4500-watt electric heater can make 47 gallons of hot water per hour â about a full tank.