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.
How long does it take to heat my pool? It depends on the size of your pool but a 116 BTU heater will raise 10000 gallons of water about 1.4 degrees per hour. 20000 gallons 0.7 degree per hour.