SELECT A NEW WATER HEATER

Do not underestimate the value of doing your homework when it comes to selecting the right equipment to heat your hot water. Energy costs have gone up and it will pay you to spend a little time before you make the buying decision. Of course, you can pay us to make the decision for you if you desire! You want to find a water heater that gives you what you need and costs you as little as possible over time.

Don’t wait until your water heater is leaking or dead to do your research. Not all equipment is sitting on the floor on any particular day. Some models must be ordered from the factory or a remote distributor taking sometimes as long as a month to get delivered to you. Determine what type of water heater best suits your needs: gas or electric, storage or tankless, stand-alone or add-on to your heating system, etc. Then determine the right size for your family.

How to size your water heater: It is important that your water heater be sized correctly to provide the maximum amount of water used at the busiest time of the day. A storage type tank water heater “1st hour rating” is indicative of your maximum use from a dead start (such as first thing in the AM or after the tank has had time to heat up before you start your tub or shower – typically about an hour). After that quantity of water has been used then the recovery rate is all you get. The tankless 0r demand type of water heater must be sized according to how many gallons per minute at maximum use. For example: If you want the water heater to keep up with two showers being used at the same time occasionally you must calculate how much water per minute each shower uses (1.8 gallons per minute is typical). Measure the water coming out of your shower or tub spout if you must (get a 5 gallon pail and measure the time it takes to fill it up). In the case of our two shower example being taken as the most water being used then you will need a tankless heater that can deliver at least 3.6 gal./min. Solar water heaters are tricky and should be calculated by a pro.

Which fuel? Here we use gas if you have it. It is typically the least expensive fuel cost compared to electric or oil.

Sealed combustion chambers with power venting water heaters are typically much more efficient than atmospheric types (flue pipe goes into the chimney) (they are also safer in some circumstances). Sealed combustion means that outside air is brought in directly to the water heater and exhaust gases are vented directly outside. The combustion chamber is separated from the house air.

Power-vented equipment (but without closed combustion chamber) can use house air for combustion (single pipe flue), but flue gases are vented to the outside with the aid of a fan. In air-tight houses, drawing combustion air from the house and passively venting flue gases up the chimney can sometimes result in back-drafting of dangerous combustion gases into the house.

WATER HEATER EFFICIENCY
The energy efficiency of a storage water heater is indicated by its energy factor (EF), an overall efficiency based on the use of 64 gallons of hot water per day. The first national appliance efficiency standards for water heaters took effect in 1990. New standards, which took effect in January 2004, increased the minimum efficiency levels of water heaters.

The most efficient gas-fired storage water heaters have energy factors ranging from 0.60 to 0.65, corresponding to estimated gas use below 250 therms/year. Condensing water heaters have energy factors as high as 0.86. The most efficient electric storage water heaters have energy factors ranging between 0.93 and 0.95, resulting in estimated annual energy use below 4,725 kWh/year. There is little difference between the most efficient electric resistance storage water heaters and the minimum efficiency standard. Fortunately, heat pump water heaters using less than half as much electricity as conventional electric resistance water heaters are becoming commercially available. If you use electricity for water heating, consider installing a heat pump water heater. Otherwise, look for the most efficient electric resistance unit in your size range.

With demand water heaters, the manufacturers provide different specifications: the energy input (Btu/hour for gas, kilowatts [kW] for electric); the temperature rise achievable at the rated flow; the flow rate at the listed temperature rise; and so on. In comparing different models, be aware that you aren’t always looking at direct comparisons, especially with temperature rise and flow rate. For example, while one model might list the flow rate at a 100°F temperature rise, another might list the flow rate at 70°. Until there are industry-standard ratings for temperature rise and flow rates, it will be difficult to compare the performance of products from different companies. Some companies are beginning to publish energy factor ratings for these products and this information should make for easier comparisons.

COMPARING THE TRUE COSTS OF WATER HEATERS

When comparing the cost of various water heating options, keep in mind that there are two types of cost you need to look at: purchase cost and operating cost. Life-cycle costs, which take into account both the initial costs and operating costs of different water heaters, provide a much more accurate representation of the true costs of the water heater than the purchase price alone. Life-cycle costs for the most common types of water heaters under typical operating conditions are shown in the table here. When both purchase and operating costs are taken into account, one of the least expensive systems to buy (conventional electric storage) is one of the most costly to operate over a 13-year period. An electric heat pump water heater, though expensive to purchase, has a much lower cost over the long term. A solar water heating system, which costs the most to buy, has the lowest yearly operating cost among electric systems.

UPGRADING YOUR EXISTING WATER HEATER

Even if you aren’t going to buy a new water heater, you can save a lot of energy and money with your existing system by following a few simple suggestions.

• Insulate Your Existing Water Heater: Installing an insulating jacket on your existing water heater is one of the most effective do-it-yourself energy-saving projects, especially if your water heater is in an unheated basement or space. The insulating jacket will reduce standby heat loss—heat lost through the walls of the tank—by 25–40%, saving 4–9% on your water heating bills. Water heater insulation jackets are widely available for around $10. Some newer water heaters come with fairly high insulation levels, reducing (though not eliminating) the economic advantages of adding additional insulation. In fact, some manufacturers recommend against installing insulating jackets on their energy-efficient models. Always follow directions carefully when installing an insulation jacket. Leave the thermostat(s) accessible. With conventional gas- and oil-fired water heaters, you need to be careful not to restrict the air inlet(s) at the bottom or the draft hood at the top.
• Insulate Hot Water Pipes: Insulating your hot water pipes will reduce losses as the hot water is flowing to your faucet and, more importantly, it will reduce standby losses when the tap is turned off and then back on within an hour or so. A great deal of energy and water is wasted waiting for the hot water to reach the tap. Even when pipes are insulated, the water in the pipes will eventually cool, but it stays warmer much longer than it would if the pipes weren’t insulated.
• Lower the Water Heater Temperature: Keep your water heater thermostat set at the lowest temperature that provides you with sufficient hot water. For most households, 120°F water is fine (about midway between the “low” and “medium” setting). Each 10°F reduction in water temperature will generally save 3–5% on your water heating costs.
• When you are going away on vacation, you can turn the thermostat down to the lowest possible setting, or turn the water heater off altogether for additional savings. With a gas water heater, make sure you know how to relight the pilot if you’re going to turn it off while away.