Raleigh, North Carolina. Thousands shiver in the shower! Is one of these bathers you? You step into the tub turn on the water and then jump to the back of the tub to escape the freezing stream of cold water that blasts out of the shower head. That process is uncomfortable, wastes water and costs you money. Traditional gas or electic tank heaters have been around since the early part of the twentieth century and have been little changed during the last 25 or 30 years. Most have heating elements at the top and bottom. One of them cycles on or off constantly whether you are home or not and so that increases your heating bill. Most of us heat our water to very high temperatures, often times dangerously high, in order to have a maximum amount of hot water available when we want it. When you turn on the hot water faucet the tank adds cold water which, of course, lowers the overall water temperature in the tank. This causes the element to use more power to reheat that water. You, in turn, turn on the cold water faucet and fiddle with both faucets until you can achieve a suitable temperature for your use. Sound wasteful? It is. A 60 gallon tank has 45 gallons of useable hot water. Furthermore there is a “stand-by” heat loss. This is the radiating loss of heat a conventional tank is constantly losing.
What’s the alternative? A tankless water heater. It is a compact heating unit that provides hot water on demand. For this reason it is also known as an “on demand” system. It does not store hot water like a traditional tank-type water heater. When a hot water tap is opened water enters the heater. The system senses the demand and a gas or electric heating device starts heating and delivering hot water at a predetermined temperature. The electronic ignition system eliminates the need for a pilot light. The heating element shuts off once the water flow stops. Since the tankless water heater only uses energy to heat the water as it is used your savings are estimated to be 20% to 40% OF the 20% of your energy bill that goes into heating water and not that of your entire energy bill. None-the-less, on an annual basis that amounts to a bunch of bucks. You are a candidate for a tankless water system if your current water heater has gone to heater heaven (more likely the city dump), it is not providing enough hot water or you want to lower you energy bills. Take a look at the price of oil and tell me if that matters. The time to think about this is before you MUST. You really don’t want to hear ”John the water is freezing and the crawl space is full of water!!” When you change from a “regular” water heater tank to a tankless system your plumbing will have to be modified. Items such as a recirculating loop take time to install and, depending on local ordinances, you may have permits and licenses to deal with. Tankless water heaters have been popular in Europe for many years but are relatively new to the U.S. The down and dirty of these systems is that they are somewhat limited in the amount of hot water they can produce at one time and they cost more than a conventional storage type water heater. Since they don’t start heating water until you call for it, it can take longer for you to get it. However their are specialized pumps are available that, when combined with the waterless tank system can get hot water to you in less than half the time it takes if you turn a faucet wide open using a conventional water heater. Also, you don’t have to worry about a water tank rusting out, leaking or breaking and doing substantial damage to your home; especially if it is located on an upper floor. A building contractor friend of mine has a 9,000 square foot home that has 5 Rinnai units in it. It provides all the water his family needs without limitation. He says that one unit can, generally speaking, handle the needs of a 2 1/2 bath home. He further states that with a recurulating pump and storage tank owners will rave about the system while without them they will rave at it.
So now you are interested in a tankless water heater. Who makes them? Manufacturers include Bosch, Eemax, Noritz, Paloma, Powerstar, Rheem, Rinnai, Seisco, Takagi and Titan. In the U.S. companies such as Eemax and Seisco have taken some innovative approaches to these systems and are worth checking out. Rheem was bought out by Paloma (Japanese) in 1988. None-the-less, Rheem still has a line under its name as does Paloma. There are, of course, electric models, natural gas models and propane gas models. As you might immagine the electric models take longer to heat than the natural and propane gas models. You would do well to look into the ratings of an eletric unit to see you much hot water per minute it produces and calculate how much water is simultaneously use in your abode. Propane units heat quickly and efficiently. However, propane is stored in a tank on your lot and not piped into your home. An air supply is needed to provide for proper combustion and to be certain that the gases combusion produces are safely vented out of your home for both propane and natural gas systems. If you already have natural gas to your home running it to your tankless heater system is no big deal. Again, keep in mind that in most situations a permit will be required and the work will need to be approved by a city or county inspector. Bascially, there are two types of systems: Point-of-Use and Whole-House. A Whole House tankless water heater can produce from 2 to 5 gallons of hot water per minute and are designed to provide hot water to the entire house from a central location. Point-of-Use tankless water heaters are designed to heat enough water for one or two fixtures only. They are used when you need hot water at some distance from a home’s central system such as guest house shower or sink. With normal maintenance a tankless water heating system can last 20 years or more. That is about twice the life of a standard tank heater. More than 7.3 million tank water heaters are dumped into landfills every year so the more tankless systems that go into use the less junk for the dump. Furthermore, the U.S. Department of energy says that if all the tank-type hot water heaters were replaced with tankless units there would be a saving of 290 million gallons of fuel oil per year; 164 million gallons of propane or 6 billion hours of kilowatt electricity. I am not about to suggest what type of unit you should use. The very best advice I can give you is to have a heart to heart with your building and/or plumbing contractor. What units are available in your area and IN PARTICULAR the local plumbing companies that have experience in installing such units are of far more importance to you than one unit vs. another. I can promise you that almost any contractor that handles only gas units will tell you that electric units stink and visa versa - and prove it! When you are doing your homework and if you are interested in electric units I would recommend you go to Google, type in - tankless water heaters - and look for an article by David Seitz called - THE GUIDE TO TANKLESS WATER HEATERS. His credentials are impressive and he certainly makes a strong case for electric vs. gas systems.
How do you determine your needs and the unit you should use? The following information about this is from Chili Pepper Appliances. Since, without the proper pump, you have to let the water run longer to get your water there can be water wastage. They produce pumps that are used to solve this problem. They say the first thing you need to do is 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 desired flow rate for the water heater. Once you know this, THEN go looking or have your plumber or contractor look for the unit you want. Water flow for various appliances 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 (bring it on!) shower 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 otherwise, assume that the incoming potable water temperature is 50 degrees F (10 degrees centigrade). For most uses you will want your water heated to 120 degrees F (49 degrees C) for most uses and 140 degrees F (60 degrees C) for dishwashers without internal heaters. 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 closest to 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 throudh 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, if at all, depending on the amount of solar gain that day. Thank you Chili Pepper Appliances.
A tankless hot water heater can be installed in a garage, laundry room or just about anywhere that is covenient, even outside. Size-wise the Rinnai tankles hot water heater, for example, has a wall mounted unit is 14″x24″x9″ vs approx. 20″ in diameter x 47″ high for a 40 gallon tank while the weight is 46 lb. vs. about 250 lbs. The system features digital controllers that allow the user(s) to select the desired water temperature. Using wireless remotes or wall-mounted digital controllers, users can change the temperature from wherever they are in the home.
I was able to find an independent study done by the Okaloosa Gas District in Valparaiso, Florida which measured a Rinnai system against both a gas fired, and an electric 40-gallon hot water tank. It measured three key factors: hot water recovery time, energy efficiency and economic savings. The testing procedure guidelines were developed, in part, from the Federal Register which provides a standard for fair comparison between energy efficiency, energy use and the operating cost of each water heater under the same testing conditions. Hot water was drawn from each heating system every 30 minutes each weekday from 7 am to 3 pm for a total of 360 draws. Before starting the tests each was set to output water at 135 degrees Fahrenheit. Also, the energy meter readings and cumulative water drawn were recorded at the beginning of each draw. Results showed that the Rinnai provided consistent 135-degree water. The electric and gas heaters could not maintain that temperature. The Rinnai operating costs were considerably lower that both of the others. The monthly average cost with the Rinnai was $21 less than the electric 40-gallon tank and about $6.50 less thatn the gas-fired 40-gallon tank. With regard to energy consumption, the electric 40-gallon tank used 332.9 kilowatts per hour while the Rinnai used only 0.6 kilowatts during the same test period. When measured against the natural gas-fired tank, the Rinnai saved an average of 6.6 therms of natural gas. As recovery time, the test evaluated the time it took each unit to reheat water to a desired temperature. It took the electric tank system approx. one hour to fully recover while the natural gas-fired tank took thirty-three minutes. The Rinnai was not part of this test since the unit doesn’t store water. It is directly connected to water line and heats water only when a hot water outlet is tapped. This allows owners the luxury of using several sources of hot water at the same time without any loss of temperature consistency.
In this day and time we all need to be concerned about the best way to do anything and everything. I hope you find this information to be of use.
John Fish (919) 696-3474 Email: Marvmax@mindspring.com Website: www.JohnFish.com