Benefit Of Tankless Water Heater

FROZEN TOES - Breathes there a person with soul so dead who never to himself (or herself has said) - "Good grief that water is cold!" (language cleaned up to protect the innocent). Since most of us don't belong to the Polar Bear Club that blast of cold water as you first turn on the shower is enough to shatter the firm resolve of even the strongest will. All of which brings us directly to the subject of water heaters. The gas or electric tank water heater you are used to has been in our midst since the early part of the twentieth century and has had little change for 25 or 30 years. The first one I remember was about the size of an oversized canister vacuum sweeper and was made by RUDD. I won't say how long ago that was.

THE SIMPLE FUNCTION OF A WATER HEATER - Most current units have elements at the top and bottom. One of them cycles on or off constantly which increases your heating bill. We all like to have all the hot water we want the moment we want it. For that reason most of us have our heater's temperature set on "molten lava" which is both dangerous and costly. Turning on the hot water causes cold water to be added to the bottom of the tank which lowers the temperature in the tank. The element turns on to reheat the water which, of course, uses more electricity. When you are ready for your bath or shower you adjust the faucet to get the water to a suitable temperature which usually results in a lot of wasted water. A 60 gallon tank has 45 gallons of useable hot water. There is a "stand-by" heat loss associated with this. Thus, conventional tanks are constantly losing heat through radiation.

HOW DO YOU GET INSTANT HOW WATER AND STOP WASTING ENERGY? The solution is to install a tankless water heater. It's a compact heating unit that provides hot water on demand. For this reason you will also hear it called an "on demand" system. Unlike a traditional tank type water heater it does not store hot water. In this system when you open a hot water tap water enters the heater, the system senses the demand and an electric or gas heating device heats and delivers hot water at the predetermined temperature. The system has an electronic ignition system. This eliminates the need for a pilot light. When the water flow stops the heating element shuts off. The tankless heaters are energy and money savers since they only use energy to heat water as it is used. Savings are estimated to be 20% to 40% of the energy used to heat the water and NOT of the entire energy bill. None-the-less, on an annual basis that can amount to a tidy sum; especially in these days of high energy costs.

WHEN SHOULD YOU CONSIDER A TANKLESS WATER SYSTEM AND WHAT DO THEY COST? Whether you are interested in a tankless system in order to save on your energy bill, because you are building a new home and have an option as to the kind of hot water system to be used or because your existing tank isn't cranking out hot water as quickly as you want or is showing signs of going to that old water tank junk yard in the sky, the time to think about it and consider all the ramifications of installing one is well before it has to be done. If you would be changing to a tankless system from an existing tank type system there will be plumbing modifications required and you may want a separate tank to hold more water as well. These systems are more limited in the amount of hot water they can produce at one time than regular systems. Also, they cost 2 to 2 ½ times as much as a conventional tank type system. While energy saving should eventually pay for the difference the up front cost is a consideration most people can't afford to ignore. Furthermore, since these systems don't start heating water until it is called for it can take longer for it to be delivered. Fear not! For every problem there is usually a solution. In this case it takes the form of a special pump. The pump helps the system get hot water to you in about half the time it takes a normal system to do it. Keep in mind that installing a tankless hot water system and recirulating pump takes time and you will probably need some permits and/or licenses prior to starting the job.

ANOTHER ADVANTAGE OF VALUE With a tankless hot water system you don't have to worry about a water tank leaking or breaking and causing damage to your home. If this happens when the tank is on the second floor or attic of a home the damage can be very substantial.

KINDS OF TANKLESS HOT WATER SYSTEMS Basically, there are two kinds of tankless hot water heater systems: Whole-House and Point-Of-Use. The whole house system produces from 2 to 5 gallons of hot water per minute and distributes it to the entire home from a central location. Point-of-use systems heat water for only one or two fixtures. These heaters are used when hot water is needed at a considerable distance from the central system such as a guest house sink or shower. A standard tank heater's average life is about ten years while a tankless system can last twice as long - with proper maintenance of course. While these system are relatively new in the U.S. they have been in use in Europe for many years.

TYPES OF TANKLESS HOT WATER SYSTEMS The types of tankless hot water systems are natural gas, electric and propane gas. Most of what you read and hear about electric models is that they take longer to heat water than their natural gas and propane gas counterparts and use more energy to do it. To quote from a Rinnai, a manufacturer of natural gas and propane units, "Electric tankless water heaters can only produce a relatively small amount of hot water. This is because they require a large amount of electrical current to produce a significant amount of hot water. For example, in order to have the same capacity as our smallest unit you would need to provide about 120 amps of power to an electric tankless unit. This represents over half of the amperage capacity of a typical home and 5 times the amperage of a typical central air conditioning unit." Some sources refute the superiority of gas units and later on I will suggest a source you might want to read concerning this. Of course, if your home or area does not have natural gas available to it and/or there is difficulty in getting and maintaining propane tanks that becomes a moot point. None-the-less, I suggest that you check the ratings of electric units to see how much hot water per minute they produce and determine how much water is used at any one time in your home. The "down and dirty" on propane units is that they are efficient and heat quickly. Propane is stored in a tank on your lot and is not piped into your home.

To assure proper combustion and to properly vent combustion gases out of a home, for natural gas and propane units, a good air supply is needed. Many manufacturers offer units that use the combustion air that is in the home. Others, such as Rinnai, don't think that is the way to go. They feel that tankless water heaters have a large gas capacity and need a lot of combustion air and that most homes don't have the free space needed to install a tankless system to code. Rinnai says, "Even if you do have the huge open space necessary to install a system with interior combustion air, that unit will be drawing thousands of cubic feet of conditioned air from inside your home each day and will discharge it outdoors. To replace this, outdoor air will be drawn back into your home through infiltration and will need to be warmed or cooled by your HVAC system. To us, this is an unacceptable waste of energy." The Rinnai interior units are sealed combustion and they utilize what is called a power draft system. Their pipe within a pipe concentric vent sucks in combustion air from outside and expels the flue gas back outside through a single penetration in the roof or a wall. This system is exclusive to Rinnai. Furthermore, the tankless water system heating vent system is cool to the touch.

Since the vast majority of water heaters are placed within the home it is hard to think in terms of systems that can be mounted outside. Again, material from Rinnai addresses this when it says that their unit is designed to operate properly down to outdoor temperatures of minus 30 degrees - F. They go on to say that exterior units will not freeze up as long as they have electrical power and gas. However the water connection to an exterior unit must be properly insulated to prevent them from freezing.

To determine what kind of unit you might want to use I would suggest that you talk to a building or plumbing contractor. Above I mentioned that electric units take longer to heat and that not everyone agrees with that. I would point you to an article by David Seitz that's called - THE GUIDE TO TANKLESS WATER HEATERS. He makes a case for electric units rather than gas units and his credentials are substantial. To find it go to Google and type in - tankless water heaters. You can find it from there.

LOCAL AND NATIONAL LONG RANGE BENEFITS OF USING TANKLESS HOT WATER SYSTEMS More than 7 million tank water heaters are hauled to landfills around the nation every year. A switch to tankless systems would be a substantial help to landfill managers and the number of landfills needed. Finding places for landfills is a very difficult problem for many communities. Any major items that are put in them that can be eliminated, or at least substantially reduced, is of major benefit to them and, in the long run, to you as well. Switching totally to tankless systems in this country would also produce annual savings of 290 millions gallons of fuel oil, 6 billion hours of kilowatt electricity and 164 million gallons of propane.

WHERE DO YOU PUT TANKLESS HOT WATER HEATERS AND WHAT SIZE ARE THEY? They can be installed in a laundry room, a garage or just about anywhere that's convenient - including, as just mentioned, outside. For quicker and better distribution of the heated water, when mounted inside, a location in the central part of a basement or crawl space is preferable. A regular 40 gallon hot water heater tank is about 20" in diameter is about 47" high and weighs in at about 250 pounds. A wall mounted Rinnai tankless hot water system (for example) is 14" x 24" x 9" and weighs 46 pounds. It has a digital control that allows users to select the desired water temperature. If you want to change the temperature from wherever you are in the home you can use wireless or wall-mounted digital controllers.

DETERMINING YOUR NEEDS AND THE UNIT YOU SHOULD USE Chili Pepper Appliances is the source of the following information. May I first say that the following information is probably only going to be read and/or put into operation by the kind of person who is handy with tools and enjoys being "Mr. or Mrs. Fix It." But, whether you go directly to a plumbing contractor or not it is always good to have an idea of what they are talking about so that you don't get sold the proverbial "bill of goods" and so that you can ask intelligent questions and end up with the system that best suits your needs. Chili Pepper Appliances produces pumps that are used to solve the problem of water waste cause by letting water run to get the desired hot water. The first thing they say to do is to list the number of faucets and shower heads you expect to have open at any given time and add up their flow rates. This equals the flow rate for the heater. Once you know this, THEN go looking for one that can produce it or have you plumbing contractor look for it.

Water flow for various faucets and shower heads is - Faucets: 0.75 gallons (2.84 liters) to 2.5 gallons (9.47 liters) per minute. Low-flow showerheads: 1.2 gallons (4.54 liters) to 2 gallons (7.57 liters) per minute. Standard shower (thar she blows!) heads: 2.5 gallons (9.46 liters) to 3.5 gallons (13.24 liters) per minute. Clothes washers and dishwashers: 1 gallon (3.79 liters) to 2 gallons (7.57 liters) per minute. Unless you know to the contrary, assume the incoming potable water temperature is 50 degrees F (10 degrees centigrade). For most washing machines you will want your water heated to 120 degrees F - 49 degrees C and for most dishwashers (without internal heaters) 140 degrees F - 60 degrees C. To determine how much of a temperature rise you need, subtract the incoming water temperature from the desired output temperature.

Most tankless hot water heaters are rated for a variety of inlet water temperatures. Select the model that most closely meets your needs. Chili Pepper gives the following example: Assume one hot water faucet open with a flow rate of 0.75 gallons (2.84 liters) per minute. One person in the shower using a shower head with a flow rate of 2.5 gallons (9.46 liters) per minute. Add the two flow rates together. If the inlet water temperature is 50 degrees F - 10 degrees C, the needed flow rate through the heater would need to be no greater than 3.25 gallons (12.3 liters) per minute. Faster flow rates or cooler inlet temperatures will reduce the water temperature at the most distant faucet. Some systems are thermostatically controlled. They can vary their output temperature according to the water flow rate and the inlet water temperature. This is useful when using a solar water heater for preheating the inlet water. If, using this example, you connect this same tankless water heater to the outlet of a solar system, it only has to raise the water temperature a few degrees more, it at all, depending on the amount of solar gain that day. Thank you Chili Pepper Appliances.


COMPARISION OF A RINNAI SYSTEM TO GAS AND ELECTRIC 40 GALLON HOT WATER TANKS I have referenced the Rinnai system several times. I found an independent study done by the Okaloosa Gas District in Valparaiso, Florida that measured a Rinnai system against both a gas and electric fired 40-gallon hot water tank. The three key factors it measured were: hot water recovery time, energy efficiency and economic savings. The Federal Register developed, in part, the testing procedure guidelines used by the Okaloosa Gas District. The Federal Register provides a standard for fair comparison between energy efficiency, energy use and the operating cost of each water heater under the same conditions of testing. Before starting this test each unit was set to output water at 135 degrees F. What they did was draw hot water from each heating system every 30 minutes each weekday from 7 am to 3 pm for a total of 360 draws. The energy meter readings and cumulative water drawn were recorded at the start of each draw. The results showed that the Rinnai provided consistent 135-degree water. The electric and gas heaters couldn't maintain that temperature. Furthermore the operating costs of the Rinnai was considerably lower than both of the others. With the Rinnai the average monthly cost was $6.50 less than the gas-fired 40 gallon tank and $21 less than the electric 40-gallon tank. With regard to energy consumption, the electric 40-gallon tank used 332.0 kilowatts per hour while the Rinnai used just 0.6 kilowatts during the same time. Measured against the natural-gas fired tank, the Rinnai saved, on average, 6.6 terms of natural gas. With regard to recover time the test evaluated the time it took each unit to reheat water to a desired temperature. The natural gas-fired unit took thirty-three minutes to full recovery while the electric tank system took approximately one hour. The Rinnai wasn't involved in this test since it doesn't store water. It is connected directly to the water line and heats water only when a hot water tap is opened. This, of course, allows Rinnai owners the luxury of using several sources of hot water at the same time with no loss of temperature consistency.