Instantaneous Water Heaters

From YourSITE.com

Interior
Instantaneous Water Heaters
By John R. Schneider
Feb 12, 2005, 23:15

I live in a small house, and need to change my water heater. It’s old, and does not heat the water enough. I was considering installing a tank-less water heater, but I don’t really know how they work. Are they worth the expense? And, is gas or electric best? Also, what manufacturer is rated best? It has been difficult to gather information from local home improvement centers or house remodeling magazines - help!
P. M., Pacifica

Installing an instantaneous (also called tank-less) water heater is probably one of the most energy efficient, and overall cost effective devices you can install, when comparing it to a standard water heater tank. The benefits of a tankless water heater are that it heats water instantaneously (only when called for by the user), it is smaller and lighter, and easier to install.

Unfortunately, your comment that information is not readily available to the consumer is correct. Tank-less water heaters have been used for years in most foreign countries because of their efficiency, yet the consumer in the United States knows little about alternatives to the standard water heater tank we use in our homes. Until late in this century, we really never had to worry about our energy costs, but now it makes sense to conserve and install environmentally friendly appliances.

A standard water heater tank is big, and requires a substantial amount of space to install. The main disadvantage of using one is that all the water in the tank (40, 50, or 75 gallons) is being heated at one time, and it is being kept hot, 24 hours a day. This happens whether or not someone is in the house. If you think about it, heating water this way not only represents a substantial percentage of the monthly utility costs, but is extremely inefficient in terms of its costs of operation. In addition, a standard tank has a relatively short life span of usually 8 to 12 years, and often cannot be repaired.

A tank-less water heater is different in that it heats water automatically, on demand. As soon as someone turns on the hot water faucet, the tank instantly heats the water as it travels through the tank. In this manner, only the water that is used is heated, and the tank shuts off immediately after that. These units are extremely cost effective to use. They are also lightweight, and small enough to fit into a small closet or cabinet, and designed to be used with electricity, gas, or propane.

Before you choose to buy an instantaneous water heater, it is important to understand that their ability to provide hot water is greatly dependent upon the rate of water-flow through the unit, the temperature of the incoming water, and the distance the unit is away from the fixtures it serves. Most of these units provide 1 to 5 gallons of heated water a minute, and are sized and designed to accommodate different temperatures of incoming water. You will need to know the number and type of fixtures (sinks, tubs, appliances) you will be serving to determine you needed flow rate to determine which tank will work best for you.

Whether you use gas, propane, or electric will depend upon your specific needs and location of the unit. A gas unit usually has a higher heat output, but they require a flue or vent to the exterior of the building, and openings for combustion air. This limits where they can be installed. An electric unit can be installed virtually anywhere, and besides the water lines, only requires a 110 volt or 220 volt circuit to operate.

Although the initial cost of an instantaneous water heater is higher than a standard water heater, the energy savings will be seen in the reduced energy costs over the life of the unit. These units are also built for long-term reliability with many having a life expectancy of 20 to 30 years, with warranties of 15-20 years. However, because of all the differences in the units, it is important that you do as much research as you can.

One of the best looking units on the market is an instantaneous water heater manufactured by a company called Envirotech, located in Arizona. They have a unit called the ESI 2000, that is the size of a briefcase, operates off of a 30 amp, 220 volt electrical circuit, and supplies five gallons of heated water a minute. This is enough hot water to supply hot water to two people taking showers at the same time. It monitors, and constantly maintains the desired temperature, even if the water flow increases or decreases. It has a digital display the tells you the amount of water being used, the temperatures of the water, and allows the user to change the settings. It even has a lifetime warranty against leakage or failures.

If you would like more information on this type of water heater, you can contact Envirotech at (800) 251-6612, or visit their website at www.tankless.com . Typing in this website will also get you a list of other manufacturers that sell or distribute them, however, you will not necessarily get the specific information you need.

For specific information on other units and manufacturers, I recommend that you check out Jim Dulley’s website at www.dulley.com. Jim is another columnist in this paper that researches and compares specific products for the home. He has a download with a listing of 13 other manufacturers that make tankless water heaters, which can be obtained for less than $3.00.

John R. Schneider is a licensed general building contractor and an ICBO certified residential code specialist. He is president of All About Homes, a residential inspection company, and has been performing code and construction consultations since 1985. Readers may address their comments to John Schneider, 24326 Mission Blvd., Suite 7, Hayward, CA 94544, Fax number: 510-537-8666, or on the web at www.allabouthomes.com . Schneider will answer questions of general interest in the paper. He reserves the right to edit the letter for brevity and clarity. Readers are encouraged to contact a competent contractor or code consultant for specific information regarding questions they may have about their home.