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Alternative Water Heater Shopping on the Web:

DESUPERHEATER

The model below is attached to one of FHP Manufacturing's EM/EC geothermal heat pump series units (Zoom page to 400% to see close-up of desuperheater at the bottom of the unit below). The GHP's efficiency is Energy Star level and you can buy the GHP with the desuperheater included. If bought separately - as is the case here - one Web source was charging $376 for it - labor not included. (Not seen on the web lately)

A Hartell desuperheater you can attach to a traditional central air system (and linked to a hot water tank) has been spotted on the web selling for $361.

INDIRECT HEATER

The Burnham model below sells for $661 on the web. Should meet the needs of most families. For details click here.

First Comes The Good News

Over the last 35 years we've held the line on water use, as the chart below shows through 2005 (i.e. the latest figures), even as our population has grown. That can be largely explained by reduced use of water in agriculture and industry and it's all to the good.

However, it's not good enough. Our water supplies our dwindling. A majority of states are facing shortages in the future and, of course, even now there is four-year old draught in the southwest.

What the U.S. needs to do is cut its water consumption and become more energy efficient. The latter may have even more affect on water use than the former. That's because the biggest user of water - nearly half - is in power production and the more efficient the U.S. becomes the less water is needed because utilities are producing less energy.

Household hot water use gives homeowners two ways to win. They can improve their water and energy efficiency with their choice of shower heads, dishwashers, clothes washers and water heating source. The more efficient they are in the amount of water and energy they use, then the amount of water the U.S. needs will go down.

Hot Water, Cool Choices

Four alternatives to the tradtional storage tanks that allow you to cut down or eliminate heating water when it's not needed.

The traditional hot water heater storage tank may be the most inefficient energy user in the house. It's wasting energy constantly by heating up 20 to 80 gallons in a storage tank just waiting to be used.

Using hot water to wash your hands and face, to shower and wash dishes and clothes consume on average a total of 70 gallons, each time refilling to heat a new supply of water and keep heating it to stay hot while you sleep, go to work and just plain don't use hot water. This stand-by energy is pure waste - from Maine to Hawaii all year long.

It doesn't have to be that way though. You have a number of options that waste far less energy and money. However, they will cost more money up front and may not entirely free you from the traditional storage tank, but you may cut your hot water heating bill from 20% to nearly 100%.

You can achieve roughly 10% to 60% savings from choosing from:

• Geothermal
• Indirect
• Solar Thermal
• Tankless

It must be added quickly that 1 and 3 can't go it alone, but if combined with 2 or 4 instead of a traditional water heater can increase savings even more. Take the extreme step of combining all four and you're pretty nearly talking zero energy. Hint: You use almost no fossil fuel and no two systems work at the same time. Puzzle assembled below.

Geothermal Desuperheater

It can be the most affordable and efficient of all the alternatives when, of course, you have a geothermal heat pump providing your space heating and cooling.

The desuperheater is a small relatively inexpensive factory-installed auxillary to your geothermal heat pump and exists solely to recover heat to be transferred to water stored in a tank.

The amount of extra heat in a geothermal system may provide you with enough to produce about 60% of your hot water needs. This is good, but not the same as getting 100% of your space heating and cooling as you do with the rest the system. It means you'll probably need a back-up hot water heater to get the other 40%.

Some times are better than others for gathering heat. Summer is the busy season. All that heat being sucked out of the house is collected by the desuperheater to heat water in a tank instead of being pumped back to the earth. That way, you'll have all the hot water you need to wash clothes (32 gallons) and for anything else during those hot months. Plus you'll improve the A/C efficency (i.e. it's a shorter trip through the desuperheater to a tank than back down to earth).

Chances are your desuperheater will draw enough heat in winter from the earth to heat water while it's heating your home. It's the spring and fall that's the problem. Neither your heating or cooling is on much during those seasons so there isn't a lot of heat to be redirected so you'll need to have your back-up switched on much of the time.

Note: You can also have a desuperheater attached to the central air of a traditional heating and cooling system. In warmer climes you'll have free hot water all summer.

Nothing is stopping you from setting up a separate system where the desuperheater can suck up heat from the earth all year round, but this idea - "triple function" - has never caught on. One reason is that if you have an open loop, as may be the case when you have water heating included with your GHP system, and the water you're using contains minerals it can cause mechanical problems for the system.

Since your geothermal system runs on electricity, your back-up is likely to be an electric hot water heater. This may not be the most efficient way to heat hot water, but it's only working part-time so you should still come out well ahead of relying completely on a traditional hot water storage tank, especially in the south and southwest where there's plenty of heat to go around for at least several months a year and the GHP's A/C mode is working hard to send it somewhere.

Indirect Water Heater

The indirect water heater is a storage tank connected to your boiler and as the boiler heats up water to provide space heating for your home, it's heating up hot tap water too. Again, you can count on solid seasonal savings over traditional storage tanks.

Tip: Whatever kind of tanks you may have make sure they are wrapped with insulation.

When winter ends and you shut down the heating for the house, you can put your indirect heater into a lower heating mode just for hot water. True, you'll be wasting energy as you do with a traditional system, but not all year round. Obviously, this is a solution to be taken more seriously in New England and the upper midwest - where the boiler may be running half the year - than in south Florida. See: desuperheater.

Tankless Water Heater

This can be the solution anywhere and the back-up for desuperheaters and indirect water heaters. As is obvious from the name, there is no tank so there isn't any stand-by heat to lose. Energy only starts to flow and water gets heated only when you start the water flowing. A heating element - gas or electric - heats the water in the pipes before it gets to you.

Patience is a virtue with tankless systems since most of them fall short of traditional heaters in the speed in which they delivers hot water. The phrase shower with a friend takes on real meaning because you may not get enough hot water to provide for two people taking two separate showers at the same time. Nor may you be able to take a shower and run the clothes washer at the same time. Check the flow rate against the temperature of the water. That is, the faster the water flows the lower the temperature. You want to check to see what the flow rate is at 120 degrees (i.e. hot). 2-3 gpm is good for most water usage.

The bright side to lower flow rates in tankless heaters is that you'll save water as well as energy.

The solution to having enough hot water with a tankless heater is to buy one each for the dishwasher and the clothes washer and for every sink and shower or spend perhaps evey more on a single home unit that will accomplish the same thing. Here's why.

The average tankless heater for the entire home may reduce your hot water energy use by a third if you use only 41 gallons a day, but about the only homeowner that is going to meet that level is one who lives alone. A couple uses 48 gallons daily just by showering and washing at the sink once each day. Add the use of a dishwasher and clothes washer; wash some food with warm water; maybe shave and you're going to leave that savings far behind. At 86 gallons a day you're down to about 10% savings and a family of four is likely to use more than that. What is needed is a tankless water heater for each shower, sink, the dishwasher and the clothes washer. These are known as point-of-use heaters, as opposed to one tankless system for the entire house. Either that or spend far above the average for whole home tankless heater. In either case, you may then save 50% on your hot water heater portion of the bill.

One other point: Gas is a more efficient power source than electric. Compare gas versus electric in your area, then, if you settle on gas, check out efficiency. Some gas heaters have pilot lights, others don't. The latter is more efficient choice.

Solar Water Heater

It'll knock the most off your bill, saving anywhere from 60% to 95%, but the cost is likely to be the highest of any of the other alternatives to traditional storage tanks.

Also, like the desuperheater and the indirect solutions, solar heaters are part-time heaters. Obviously, a solar collector only gathers heat when the sun is shining and how much that is varies with the season (i.e. summer beats winter) and the location (i.e. Arizona beats Maine).

The upfront costs of several thousand dollar makes this a difficult choice makes for a difficult investment when the utility bills savings is likely to be less than $300 annually. However, there may be incentives, like tax benefits and rebates. You also may completely eliminate all carbon emissions traced to hot water heating.

Not to go crazy here, but let's just work out the puzzle if you haven't already. You don't have any natural gas fuel costs in the summer (credit: geothermal) and winter (credit: geothermal and indirect) so you're down to half already.

With a tankless hooked up, you can count on cutting another 25% in spring and fall. Finally, the solar cuts that last 25% nearly in half in those two seasons. That gets the savings up to around 85%. It's rough math, but whatever the number you get down low enough to wipe out your energy consumption with your solar electric system's output.

If we were to go crazy we would add a recirculating pump to go with every water user in your home.. That way, the cool water that most people let rush down the drain before the warm kicks in is recirculated back into the line to be heated instead of wasted. After all, conserving water ultimately conserves energy too.

A Market for a Fifth Option?

An air heat pump water heater tank can be the perfect solution for a relatively small number of home owners. Not to be confused with the heat pump, it is a separate unit that works well and provides considerably savings only where it is never too hot (i.e. above 90) or never too cold (i.e. below 40). That way they always have a source of relatively accessible heat to pump into the water stored in the tank.

Home owners also need a separate space to store the heater, like a garage or an unused basement. This is because the pump tends to throw off cool air, which is not something you want in your house from fall to spring.

Given these conditions, they haven't been big sellers. However, General Electric is going to be introducing a model soon. So maybe next year an air heat pump water heater tank may attract more national interest.

From top to bottom you'll see that the higher the price the more places you'll get all the hot water you need:

The Stiebel Eltron electric point-of-use tankless hot water heater has a flow rate (.75/1.00 gpm) that's best for a bathroom sink, possibly kitchen too and sells on one web site for $149 - at the low end for tankless water heaters. (Up $11 over last few months.) For details click here.

The Bosch natural gas point-of-use tankless water heater below has a flow rate (2.6 gpm) that's within range of any water use (i.e. shower, dishwasher, clothes washer) and had sold on a web site for $299. Now price is "unlisted". For details click here.

Bosch whole house "single use" natural gas tankless water heat (below) - meaning one shower, dishwasher or clothes washer running at a time. Energy costs, ad says, cut in half. Price: $920. For details click here.

Average efficiency Bosch whole house natural gas tankless water heater (below) that allows you to turn on the hot water in more than one place at a time. Price: $1,067. For details click here.

SOLAR HEATER

SolarRoof.com offers a variety of solar hot water heating systems. Prices range from around $2000 to around $5000. Their solar collectors seen below. For details click here. Tanks not included.

An 80-gal solar hot water tank was selling on the web $1,138 (below).

A complete system, including 80-gallon tank, from Alternate Energy Technologies is available for $2,938. Click here for details. Photo below