Tankless Systems
In order to understand how a tankless water heater works, it’s important to know how a standard tank heater operates. In a traditional heater system, there’s a large tank that holds and heats water. In order to give you hot water when you need it, the tank continually heats the water to maintain a constant temperature. The energy used to keep the water hot even when it’s not being used is called standby heat loss. Tankless systems avoid standby loss by heating incoming only as you need it — they’re also referred to as “on demand” water heaters for this reason. The elimination of the standby heat loss is what makes a tankless system more efficient.
In order to get you that piping-hot shower when you want it, a tankless water heater uses a powerful heat exchanger to raise the temperature. A heat exchanger is a device that transfers heat from one source to another. There are heat exchangers in your air conditioner, refrigerator and car radiator. In this case, it transfers heat generated by electric coils or a gas-fired burner to the water that comes out of your faucet. This exchanger is activated by the incoming flow of water. So when you turn on your hot water tap, the incoming water circulates through the activated exchanger, which heats the cold water to your preset temperature.
To find out about the costs involved with having a new one installed. Check out the next post at the bottom of this post.
Tankless water heaters: how much are they?
Tankless systems come in two varieties –
1. Point-of-use heaters and whole-house heaters. Point-of-use sytems are small and only heat water for one or two outlets — say, your kitchen sink. Because of their size, they can fit under a cabinet or in a closet. They’re beneficial because they can be installed closer to your outlet and avoid water loss due to lag time. Lag time is the amount of time it takes for the hot water to reach your faucet. In large houses, the lag time can be significant, sometimes as long as a full minute. This means that while your water heating bill may be going down, your water consumption will be going up.
2. Whole-house systems are larger, more expensive, but can operate more than one outlet at a time.
With tankless water heaters, you can choose from electric, propane or natural gas models. Point-of-use models are generally electric, while whole-house systems are usually powered by either natural gas or propane. Which model to go with and what heating source you should use depends on many different factors. Your plumber will take a closer look at those factors during our appointment so you can make an educated decision when it comes time to purchase your tankless heater.
How tankless water heaters work: video
Tankless Water Heater Specifics-
Deciding what kind of tankless water heater to go with depends on a couple of things:
The flow rate, or amount of water you’ll need heated at one time
Temperature rise, or the difference between your groundwater temperature and the desired output temperature
The Federal Energy Policy Act of 1992 set flow limits at 2.2 gallons per minute (GPM) at 60 pounds per square inch (PSI) for household water fixtures [source: U.S. Dept. of Energy]. Some people also use aerators to further limit the flow of water.Tankless manufacturers size their units based on the temperature rise needed for a given flow rate.
To calculate your flow rate, add up the GPM for the household water fixtures you’ll need at one time:
Bathroom faucets – low-flow faucets use 0.5-1.5 GPM. Standard post-1992 fixtures are set at 2.2 GPM. Faucets before 1992 fall between 3.0 and 5.0 GPM.
Kitchen faucets – pre-1992 fixtures use between 3.0-7.0 GPM. The post-1992 standard remains 2.2 GPM, and kitchen faucets don’t use aerators, so there are no low-flow numbers.
Showers – low flow rate is between 1.0-2.0 GPM. The 1992 standard remains 2.2 GPM. Pre-1992 heads fall between 4.0-8.0 GPM.
Now figure out your temperature rise by calculating the difference between the temperature of your groundwater (the water entering your house) and what you’d like the end result to be. For instance, if you have a groundwater temperature of 70 degrees and you like your showers to be a pleasant 110 degrees, that’s a rise of 40 degrees. Your ground water temperature is roughly the same as your average yearly air temperature. If your in New England your groundwater temperature is around 40 degress in the during the winter, and you will need a much larger unit to get the cold winter water “instantly hot”.
Once you have your temperature rise, you need to know your flow rates, then you know what size and what kind of water heater will work best for your needs. It’s important to remember in this calculation that you’ll be measuring the amount of hot water you’ll need at one time. Tankless systems never run out of hot water, but if you want to turn on every fixture in your house at the same time, the hot water will be split among them. So estimate the number of fixtures you think you’d need at one time — chances are it won’t be every fixture. Note: If you have a huge family, or large demand for water at one time on a regular basis the better tankless water heater companies offer linking kits, that will link two or more units together. Linked together two or more tankless units work in tandem and can provide all the hot water you could ever use.
Let’s say you live in an older home that has been partially remodeled. You estimate that you’ll need to heat water for your kitchen faucet, one bathroom faucet and two shower heads at one time. One of the shower heads is newer and meets the 1992 standard, while the other is older and has a flow rate of roughly 5.0. The rest of your fixtures also meet the 2.2 standard. Add 2.2 + 2.2 + 2.2 and 5.0 for a total flow rate of 11.6. You live in Miami, so your groundwater temperature is roughly 72 degrees and you like your showers at 100 degrees. This means you should look for a tankless system that can heat 11.6 GPM at a rise of 28 degrees.
Gas- and propane-powered heaters typically provide more hot water than electric models and are generally used for whole-house systems. Electric models are more common in point-of-use scenarios, although sometimes people prefer to use two electric heaters in parallel instead of one larger gas-powered unit. If you want a shower in your pool house or hot water for an outdoor kitchen, you might be a good candidate for a small electric tankless heaters.
We provide top quality plumbing information about services, free estimates, installations and repairs on all Rheem, Ruud, Bradford white, State, and A.O. Smith electric, gas, propane, Bock, Thermaflow/Everhot oil fired hot water heaters, Navien, Rheem, Noritz, and Takagi tankless water heaters, Ruud, Bock, and lochinvar oil fired water heaters, SuperStor storage tanks, Peerless, Laars, and Crown tankless coils, and repairs on all hot water heater throughout the state of Connecticut including Bridgeport, CT- Bristol, CT- Cheshire, CT- Danbury,CT- Derby,CT- East Hartford,CT- East Haven,CT- Enfield,CT- Fairfield,CT- Hamden,CT- Hartford,CT- Meriden,CT- Orange,CT- Middletown,CT- Milford,CT- New Britain,CT- New Haven,CT- New London,CT- Norwalk,CT- East Norwalk,CT- Norwich,CT- Putnam,CT- Shelton,CT- Southington,CT- Stamford,CT- Stratford,CT- Southport,CT- Torrington,CT- Wallingford,CT- Watertown,CT- West Hartford,CT- West Haven,CT- Westport,CT- Wethersfield,CT- Willimantic,CT- all shore areas, and surrounding Connecticut areas.
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