This is an index to articles about products including water heaters, tankless water heaters, hot water circulating pumps, warm water circulating pumps, and even some hybrid water heaters.
Hot Water Heater Related Articles
Heat Pump Hybrid Water Heaters use a heat pump much like your air conditioner to heat the water. It’s much less expensive to move heat from the air to the water than to just create the heat with electricity. Rheem advertises that you can cut your energy costs in half with the hybrid water heater. On the other hand they are very slow to heat the water and don’t work when it’s less than about 45 degrees around the heater. They need lots of ventilation.
The A.O. Smith hybrid water heater has a small “buffer tank”, and rumors are that it is about a 15 to 20 gallon tank. Having a buffer tank it can deliver hot water fast, not needing to heat the water first. Before the buffer tank can run out of hot water the heater takes over supplying hot water.
The NEXT is a condensing type water heater with a 90% “thermal efficiency.” and It works with hot water circulating systems. The buffer tank also eliminates that cold water sandwich common with tankless heaters.
The Voltex hybrid water heater uses a heat pump water heater in combination with an electric tank type heater. Heat pump water heaters are very efficient and operate like a refrigerator in reverse. They take heat from the air and transfer it to the water. Any tank standby losses are small compared to the energy savings from latent heat recovery. With a heat pump, as the temperature decreases the efficiency declines until around 45 degrees there isn’t enough heat in the air for the pump to work.
Compares the specs and features of Bosch, Noritz, Rinnai, and Takagi gas tankless water heaters. A table shows what I think are the most important specifications for the heaters. Included in the table are the maximum input BTUs, the energy factor, minimum flow rate to turn on the heater, and the temperature rise. The four brands compared are Noritz, Bosch, Rinnai, and Takagi, and are pretty similar sized units.
The GeoSpring hybrid water heater manufactured by General Electric is a heat pump water heater combined with a electric storage type water heater. Heat pump water heaters are similar to the heat pumps used in refrigerators and window air conditioning units. The heat pump water heater uses heat recovered heat from the surrounding air and puts it into the water.
Like all storage heat pump water heaters, it works well in warm climates and not so well in cold climates. Heat pumps require a lot of air for their operation, and have fans to move the air through the heat exchanger. Heat pump technology has been around forever and is very reliable. If you look around in the forums online you won’t find many unhappy owners of heat pump water heaters like you will with tankless water heaters.
A tankless water heater is a far cry from the traditional storage or tank type water heater that most of us grew up with. Tankless water heaters are considered by most to be a green product. Green because they don’t have the standby heat losses that tank type water heaters have.
The major advantage of a tankless water heater would be the ability to have unlimited hot water. The monetary savings from the higher efficiency of a tankless unit would only be around $5.00 a month and that isn’t enough incentive for me to put up with some of the characteristics of a tankless heater.
Navien has three “A” models, the NR-180A, the NR-210A, and the NR-240A.
Tankless heaters have a minimum flow rate to turn on, requiring .5 to .75 gallons per minute of hot water flow to turn on and to stay on. That makes it hard to obtain a small stream of warm water. Navien tankless water heaters claim to have solved this problem. The “A” models have a unique feature, a built in buffer tank and circulating pump.
The Navien literature states that this feature allows you to use as little as .1 to .2 gallons per minute without the heater turning off. This would also eliminate the “cold water sandwich” that tankless heaters are known for. The Navien tankless hot water heaters circulate the water internally between the heat exchanger and the buffer tank, or you can even connect them to a traditional dedicated return line and the internal pump will circulate the hot water.