Getting in Hot Water

Domestic hot water… how does it work in your home? That is an interesting question as there are so many different ways of heating water. These range from the more traditional tank type water heaters to the tankless and on-demand systems. Here is a brief guide to the various types of water heaters most commonly found in our area.


Conventional Storage Tank: This style of unit features a tank that holds water to be heated. This means that the capacity of the tank determines how much hot water you have available at once. The tank is insulated so that when the water heats up, it remains warm until it is needed. These water heaters can be electric, gas-fired, or oil-fired. These are the most common types of water heaters in residential homes. The capacity of the tank and the way it is heated determines how much each water heater can produce. As an example, a 50 gallon electric water heater will produce approximately 67 gallons of hot water, first hour draw. A 50 gallon gas-fired unit will do about 86 gallons and a 50 gallon oil-fired water heater can produce upwards of 200 gallons, first hour draw.


Tankless Water Heater (On-Demand): As the name implies, a tankless water heater has no tank. Instead, the cold-water flows through a heat exchanger that flash heats it. These allow for a nearly endless supply of hot water. Tankless water heaters run primarily on either electricity or gas. Like most other water heaters, these units come in different sizes based on output flow rate. It’s critical to size the system properly and based on the needs of the home. Be careful not to confuse these systems with a tankless coil boiler. Though they both do not use a tank, the tankless coil boiler is an inefficient way of creating hot water as it requires the boiler to maintain temperature 24 hours a day.


Heat Pump Water Heaters (Hybrid): This is typically a tank type water heater that uses heat in the air to heat water. This means that electricity is only used to move heat from the air to the water, instead of the alternative where electricity is used to generate heat. Heat pump water heaters can use up to 60 percent less electricity than traditional styles of water heaters. The downside of these units is that they require more space to accommodate the compressor on the top and they do make a bit of noise. In addition, since they are pulling latent heat out of the air, the area around the water heater (in the basement) can be fairly cold. A 50 gallon heat pump water heater will produce approximately 69 gallons, first hour draw.


Indirect Water Heater: This style of water heater uses a storage tank and the heat from your boiler to provide your home with abundant hot water. In an indirect system, water is heated up by the boiler and is then passed through a heating coil or heat exchanger to heat the water in the tank. Like a conventional tank type water heater, these tanks are well insulated to store the hot water. When paired with a high efficiency boiler, these units can create large amounts of hot water for less money. A typical 50 gallon indirect can produce more than 200 gallons, first hour draw. The obvious downside is that you must have boiler in your home.


The water heaters, discussed above, are merely a snapshot of the various options available. There are so many to choose from with various capacities and efficiencies. When looking to replace your water heater, contact your plumber or mechanical company and they can offer you options to properly take care of your needs.