Water Heaters 101

Today you have many hot water heater choices. This guide will cover the various kinds of hot water heaters, their features, and the pros and cons of each type. There are many factors that go into determining what type of water heater is best for you.

Factors to consider when choosing a hot water heater

• Fuel: gas or electric.
• Water Storage: conventional tank or tankless.
• Function: entire house or point of use.

Fuel

Most hot water heaters are fueled by gas or electricity.

Gas

• A little more expensive than electric units.
• Require outdoor venting for safety.
• Some units have sealed combustion and/or power venting which increases safety.
• They are usually more energy efficient.
• Conventional tank units are not affected by electrical power outages.

Electric

• Are usually cheaper than gas models.
• Are more simple to install and maintain.
• They don’t require venting.
• They heat water quickly.
• More expensive models come with high energy factor ratings.

Water Storage

A conventional tank style water heater stores water in an insulated tank until hot water is needed. Tankless models don’t store water. Instead, they heat it on demand by running water through a series of heated coils. Each style has unique advantages.

Conventional Tank Water Heater

A water heater that constantly heats water and stores it inside of an insulated tank.

Economical

• Many installation placement choices: closets, garages, basements, just about anywhere.
• Numerous capacity ranges from 20 to 80 or more gallons.
• Efficiency varies greatly between different models, brands and fuel sources.

Tankless Water Heaters

• They heat water with a gas burner or electric element and do not store heated water.
• They are more expensive up-front.
• They can be hung on wall and don’t require floor space.
• An excellent option for residences that are occupied part-time.
• Are much more energy efficient and can require energy usage by 30% or more.
• Are limited by amount of water required at same time, called the flow rate.
• More units are gas fueled and require ventilation.

Entire house versus point of use

All conventional tank style water heaters are whole house systems. They send water from the tank to all parts of the house. Areas of the home which are very far from the water heater require running the water for a longer period of time in order to receive hot water.

Tankless water heaters can be either whole house or point of use. Point of use systems are installed at each point in the home where hot water is needed. This requires the installation of several units, but each individual unit is less expensive than one whole house unit. There are numerous advantages to a point a use on demand water heating system. If one fails, you still have hot water at other points in the house. Because they are installed near where hot water is required, they often produce hot water faster, as hot water doesn’t have to travel a long distance to you. By running a smaller unit at the point of use, it is even more energy efficient and requires less fuel to produce hot water.

Small tankless systems are also a great choice for remote locations or seasonal residences. They are near maintenance free.

Solar Hot Water Heaters

A solar hot water heater is a variation on a conventional tank system. Instead of running on gas or electric, it is powered by a solar energy source.

Capacity

Once you’ve decided on tank or tankless, gas or electric, and whole home or point of use, the final consideration is capacity.

Tank Water Heater Capacity

A typical 3 bedroom 2 bathroom American home usually requires a 40 gallon hot water heater. Larger homes with more people and use scale up from here. A small apartment or condo with only one or two people can get by with a 30 gallon hot water heater.

Tankless Water Heater Capacity

Tankless systems are sized differently. They are sized based on the amount of concurrent hot water required and are sized based on their flow rate.

A whole house system will need to be big enough to provide hot water to all areas of the home that require concurrent hot water. Think shower, washing machine, and dishwasher all running at the same time. If you get a unit that is too small, the system will not be able to provide hot water to all points in the home at the same time. Most American 3 bedroom, 2 bathroom homes will require a tankless system that can provide a flow rate of at least 6 gallons per minute. Depending on how big your home is and how many people live there, this number will increase from here.

With point of use systems you have more flexibility. If your dishwasher requires 0.75 gallons per minute, you install a 1 gpm unit near the dishwasher. If your shower and bathroom sink together require 3 gpm, you install a 3.5 gpm unit in the bathroom, and so on. Each unit individually turns off and on as hot water is required at each point in the home.

Dimensions

Once you know the capacity for your water heater, the final consideration is the unit’s dimensions.

If you are installing a tankless water heater, be sure your installation location meets its ventilation requirements. An ideal location is on an exterior wall that is near a water supply line, gas supply line, and electrical power source (Gas tankless systems still require electricity for their electronic ignition). This is the most cost-effective and easiest way to install the unit and run its venting.

Hot water heaters should have 1/2" clearance on the sides, 12" on the front and 18" above the floor.

Energy Efficiency

Your water heater is probably the third largest consumer of energy in your home, after your HVAC unit and refrigerator/freezer. Gas units are almost always more energy efficient than electric units. Newer units are becoming more and more energy efficient each year. All new units carry an energy factor (EF) rating which is clearly printed on the unit. This is a rating that measures how efficiently a water heater converts energy into heat. For optimum efficiency, choose a water heater with an EF factor as close to 1 as possible.

Conclusion

All Trades here in Las Vegas, Nevada repairs, installs, and services all hot water heater types. If you have any additional questions or require service, please contact us today. If you have a water heater emergency, we offer fast, same-day service.