Sep 10
10
Energy Saving Instant Hot Water
Do you leave your lights on at home all day and night? Of course not. Do you leave your cars engine running while parked at work or in the garage at home just to keep it warm? Ridiculous! Then, why is the water heater left on all day and night just to keep the water warm when no one is using it?
Water heaters with tanks constantly heat and reheat water all day and all night. Sure, adding an insulation blanket helps keep water in the tank warmer a little longer, but heated water in the pipes cools off continuously, not to mention all the natural gas and propane that is just wasted warming the flue all day and night.
How do you save money and stop wasting energy?
Replace your home water heater with one or more tankless waterheaters. Tankless water heaters heat water when you need it and not when you don’t.
Tankless Water Heater Brands
Several Tankless Water Heater brands are available. The most popular (in alphabetical order) are Bosch, Paloma, Rheem, Rinnai, Ruud, and Takagi.
Sizing a tankless water heater
Plumbers recommend water heater sizes based on how much water is used and how long it takes to reheat a full tank of water after it is used. I bet you don’t have time to wait 30 minutes or more after each family member showers? Bigger needs demand water heaters with bigger tanks. As an example, a typical 40 gallon tank natural gas water heater operating at 40,000 BTUs might take as long as 40 minutes to reheat a full tank of water. A typical electric water heater might take a full hour to reheat a full 40 gallon tank.
Not so with tankless water heaters. Tankless waterheaters deliver instant hot water. A mid-sized system with a 6 gallon / min (6 GPM) flow rate delivers 360 gallons per hour continuously. Tankless hot water heaters are sized differently. Use the table below for approximate tankless water heater sizing. Obviously a small unit delivering 2.2 gpm would be appropriate for a single bathroom or kitchen, but isn’t big enough to serve full house needs. Medium sized tankless water heaters deliver 6 – 6.6 gpm while large residential tankless water heaters deliver up to 8 gpm. Up to 4 residential tankless water heaters can be strung together in a centralized system to serve large homes, or can be distributed around the house to provide “instant on” hot water supply.
| Gallons/minute (gpm) | Low flow | Regular | Pre-1992 |
| Restroom Faucet | 0.5 – 1.5 | 2.2 | 3.0 – 5.0 |
| Kitchen Faucet | 1.5 – 2.0 | 2.2 | 3.0 – 7.0 |
| Utility Faucet | 1.5 – 2.0 | 2.2 | 3.0 – 7.0 |
| Bathtub Spout | N/A | 5.0 | 5.0 – 14.0 |
| Shower Head | 1.0 – 2.0 | 2.2 | 4.0 – 8.0 |
| Dishwasher | N/A | 1.3 | N/A |
| Clothes Washer | N/A | 3.3 | N/A |
NOTE: Please consult your local building, plumbing and electrical codes and hire a licensed plumber to install your tankless waterheater, and a licensed electrician for an electric appliance.
Sep 10
17