Click Forever Hot Water for a demonstration of the Rinnai tankless water heater.
Efficiency, That's what the tankless water heater offers. Tankless water doesn't heat until there's a demand for it, which takes roughly five seconds from the time the tap is turned on until the water comes out of the faucet.
1. What is a tankless water heater?
Tankless water heating systems are revolutionizing the way modern homes meet their water heating needs. These compact units can produce and supply endless streams of hot water to multiple outlets at once without any fluctuation in temperature.
2. What type of fuel do tankless water heaters use?
The tankless units we user are either LP or natural gas fired. This is because clean burning gas systems can be designed to provide hot water to a large household at the highest efficiencies available.
3. Does Whitney Homes install electric tankless units?
No. There are electric tankless units available, but they have two distinct problems:
First, the cost of electricity is, on average, significantly higher than LP or natural gas. The operating cost of electric tankless units tend to be much higher.
Second, 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 well over half the amperage capacity of a typical home and 5 times the amperage of a typical central air conditioning system.
4. How does a tankless system work?
Conventional water tanks heat and store hot water around the clock. Because of this you are heating and re-heating water, and constantly losing energy up your vent and through the walls of the tank. A tankless water heater only comes on when you start to use hot water, and immediately shuts off when you are done, so you are not wasting energy when you do not need hot water.
Tankless water heaters have much more effective heat exchanger and burner systems than conventional tanks. This allows you to utilize a much higher percentage of your energy dollar rather than wasting it up the vent stack of a conventional tank water heater.
5. What is the Energy Factor of tankless heaters?
Water heaters are performance rated by the US Department of Energy. The performance measure that they have developed is the Energy Factor (EF). The higher the Energy Factor the more efficient the water heating system is. Most gas fired water tanks have an Energy Factor of only about .62. If you have an existing older tank it is likely to be .55 or less. The tankless units we install all have Energy Factors of .80 or greater so they are much more efficient than tanks.
6. Does a higher Energy Factor mean that I will always have lower operating costs?Given a specific fuel and a specific number of gallons of hot water used, the higher the EF, the lower the operating cost.
Some people do not experience as much savings with tankless because with tankless there is no longer an artificial barrier to hot water use. With conventional tanks you will run out of hot water after a period of use, but with Rinnai tankless, this will not happen. In some homes this increases the gallons of hot water used, but its great to have all the hot water you need, when you need it.
Given different fuels EF may not accurately predict energy cost. For instance a tankless unit with an EF of .85 will always have far lower operating cost than an electric tank with an EF of .90 (given current national average fuel costs.)
7. Do Tankless water heaters qualify for an energy tax credit?
Yes, most tankless units qualify for the 2006-2007 $300 tax credit.
8. How much do tankless heaters cost?
In general modern tankless units cost 2 to 2-1/2 times as much as conventional tank type water heaters. However, the energy saved typically results in paybacks of a few years or less for a family of four.
9. Why are tankless units so expensive?
Tankless units cost more than tanks, but are a better value. They save money every day, provide a high level of performance and safety, and last twice as long as a normal tank type heater. They save floor space and have a unique flexibility to be placed in locations closer to points of use to further cut energy cost and reduce water consumption. They are one of the best investments you will ever make.
10. Whitney Homes installs exterior units. Do they freeze in the winter?
Exterior units will not freeze even well below zero as long as they have electrical power and gas. However, the water connections to an exterior unit must be properly protected from cold conditions by the installer to prevent these water lines from freezing.
11. How much power does a tankless unit use?
This varies based on the size, but this is typically less that 100 watts per hour during operation, and adds up to only a few dollars of electrical energy per year. The unit operates on normal household 120 volt AC current.
12. Why do I need exterior combustion air?
Many units utilize combustion air from inside your home. While this might sound like a good idea, we have found that it is not. Tankless water heaters have a large gas capacity and can need a lot of combustion air. Most homes do not have the free space necessary to install a tankless water heater to code with out making significant modifications to your home. For us, it just makes sense to do it right the first time and not take the risk associated with improper interior make-up air design.
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.
13. What is the minimum water flow rate required to operate a Rinnai?
The Rinnai tankless water heater must be able to sense water flow in order to initiate operation. Most Rinnai models will operate with flow rates as low as 0.5 gallons per minute. This is the lowest minimum flow rate in the industry and is an important benefit.
14. What is firing rate?
Unlike old style tank water heaters which fire at only one rate, most modern tankless water heaters will use only the amount of gas necessary to heat the hot water being used at any given time. To do this they measure the incoming water temperature and the flow rate, compare that to the desired output temperature, and fire at the rate necessary to meet this need. If you change any of these variables, the tankless unit re-calculates and adjusts its firing rate accordingly. The tankless unit will therefore fire anywhere between its minimum and maximum firing rate.
As with minimum flow rates, the lower the minimum firing rate the more flexibility you will have when you only want a small amount of hot water.
