There are many factors to consider when choosing a water heater. There’s fuel type, water capacity, size, mode of operation, and cost. But one of the more important factors that homeowners are prioritizing more these days is efficiency. The efficiency of your water heater is twofold because it’s not only how much electricity or fuel your water heater uses; it’s also how well it preserves and maintains water that’s already been heated. Here we look at the different types of hot water systems and how they compare in terms of efficiency.
Conventional Storage Tank Water Heaters
Conventional hot water tanks are still the most common option in U.S. homes. Conventional tanks have a supply of between 20 to 80 gallons of hot water on hand ready to use. The tank refills from the bottom with cold water and can be fueled with electricity, gas, propane, or fuel oil.
Because hot water is stored in a water heater tank, energy can be lost from the tank through standby heat loss. Choosing a model with good insulation (thermal resistance between R-12 and R-25) helps to prevent heat loss.
The larger your water heater tank the less efficient it’s likely to be. The water heater tank that costs the least up front can often have the highest running costs and annual expenses, so make sure you consider both the short and long-term costs when choosing your water heater.
Tankless or On Demand Water Heaters
Tankless or on demand water heaters are becoming more popular due to their energy and cost saving capabilities. Tankless water heaters produce hot water as you need it by heating water as it runs through a pipe with gas or an electric element. Because these heaters don’t store hot water, there’s no standby heat loss. However, the flow rate of an instantaneous water heater is limited by its output. This means that running two appliances using hot water at the same time, such as the shower and the dishwasher, might exceed the limits of the tankless system. For households that use 41 gallons or less of hot water a day, a tankless hot water heater can be 24-34% more efficient, while for homes that use a lot more hot water, they can be 8-14% more efficient.
Smart Water Heaters
Smart water heaters are a relatively new addition to the market and are, at the simplest, a combination of the electric water heater, an electronic thermostat, and a digital user interface screen. What makes these water heaters truly smart is that they are able to “automatically [adjust] water temperature according to consumer hot water use patterns to reduce standby heat loss and save money.” Many are also configured with easy-to-read diagnostic and error codes, making quick work of putting in a service call to your plumber.
Power Vent Water Heaters
Power vent water heaters have become popular in recent years because they don’t require a chimney or upright vent for getting rid of exhaust gasses. Instead, an electric fan or blower pushes the gasses through horizontal pipes, allowing for the water heater to be placed anywhere in the house or in homes without chimneys. For some, the added electrical cost of powering the vent fan is a disadvantage, as is the slight noise made by the fan. However, the advantages of its easy installation make the power vent water heater a simple choice for most homeowners – and their plumbers.
Heat Pump And Tankless Coil/Indirect Water Heaters
These heaters use your home heating system or another heat source to generate energy to warm your water. These water heaters are generally very efficient, but it’s important to have a plumber consult with you to determine your needs and the best heater for you.
Choosing the most efficient water heater helps you to save money on your utility bill while enjoying a more consistent and environmentally friendly supply of hot water.