Hot water expenses can account for a significant portion of monthly energy costs — up to 25 percent of your utility bill can be consumed by water heating. With this much money going to hot water, the efficiency of your water heating system is an important consideration. Here are three factors to consider when sizing your water heater for the best level of efficiency.
Peak hot water demand
Sizing refers to choosing a water heater with a big enough tank and enough heating capacity to produce enough hot water for your household needs.
A major consideration in sizing your water heater is peak hot water demand. This is the amount of hot water needed during the period when your family is using the most hot water at one time for tasks such as bathing, cooking or cleaning.
For example, an average shower will consume about 38 litres (10 gallons) of hot water. Shaving will use about 7.5 litres (2 gallons), food preparation about 15 litres (4 gallons), and dishwashing about 15 litres (hand-washing) or 23 litres (6 gallons) for an automatic dishwasher. Multiply the amount of water used by the number of times these tasks will be performed during the busiest hour to find peak-hour demand. Your hot water heater will need to be able to supply that much hot water.
Correct capacity and tank size
Your water heater will need a tank big enough to hold enough water to meet a normal peak-hour demand. On average, a medium-sized family home with three occupants will need a water heater with a 225-litre (60-gallon) capacity for electric water heaters, 180 litres (48 gallons) for gas models and 135 litres (36 gallons) for oil-based heating.
Unit energy factor
The water heater’s energy factor (EF) is an indicator of its overall efficiency. EF is determined through laboratory testing. Water heaters must meet minimum government standards to be sold in Canada. Look for water heaters with the highest EF possible, since higher EF ratings mean better efficiency.
Calgary-area HVAC customers can trust Arpi’s Industries Ltd. for professional heating, cooling and home comfort services. Contact us today for more information on water heaters and for help with sizing your water heater to meet all your household hot water needs.
Our goal is to help educate our customers in Calgary, Alberta about energy and home comfort issues (specific to HVAC systems). For more information about sizing your water heater and other HVAC topics, download our free Home Comfort Resource guide.
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