| Have you ever had to stand shivering in the cold | | | | Grundfos Comfort System are two such |
| morning air waiting for hot water with your arm | | | | systems, and the Hot Water Lobster is another. |
| outstretched, fingers extended into the cold | | | | The Hot Water Lobster doesn’t have a |
| stream of water. It seems to take forever for | | | | pump, but relies on the fact that hot water rises, |
| the water to get hot. Speed up your hot water | | | | and the Lobster valve has to be substantially |
| with a hot water circulating system. | | | | higher than the water heater for the system to |
| Traditionally, if you had a hot water circulating | | | | work. |
| system, it meant that you had a hot water pipe | | | | Unfortunately these “tepid water” |
| that ran in a big loop from the outlet of the | | | | systems consume a lot of energy since you are |
| water heater to each fixture one after the other, | | | | heating that big loop of piping and return line and |
| and then back to the inlet of the water heater | | | | its surroundings. The cost of the energy will far |
| through a small pump. By continuously pumping | | | | outweigh any monetary savings from water |
| water through the loop you have instant hot | | | | conservation. |
| water at every fixture. | | | | Another class of systems that use the cold |
| This is very convenient. Hotels and motels have | | | | water line as the return line is the “Hot Water |
| hot water circulating systems; otherwise it could | | | | Demand Systems”. These systems only |
| take hours to get hot water with such long pipes | | | | pump the water to the fixture when hot water is |
| as they have. | | | | “demanded” by the user. The pumping |
| However, instant hot water is also very | | | | costs are small; typically demand systems use |
| expensive. Not only do you have to pay for the | | | | less than $2.00 per year in electricity costs. This is |
| energy to run the pump continuously for long | | | | because they run for such a brief time, typically |
| periods of time or even full time, but you also | | | | less than 1 minute per use. |
| have to pay for the heat energy being radiated | | | | When the user turns on the pump it runs until hot |
| into the environment from that big loop of hot | | | | water reaches the fixture and then the pump |
| water piping. The cost of heating the water is | | | | automatically shuts off. The cold water line does |
| considerably more than the cost to run the pump. | | | | not end up full of warm water. |
| There are a number of manufacturers producing | | | | With the demand system the energy consumed |
| hot water circulating systems that utilize the cold | | | | is no more than if the user just ran the tap as |
| water line as the hot water return line. | | | | normal. Hot water is not being circulated. And |
| Some of these pumping systems use small | | | | since the hot water is not being circulated it does |
| pumps that pump water very slowly, and are | | | | not affect the life of your tankless water heater |
| temperature controlled. The pump turns on when | | | | or the warranty. |
| the water temperature drops below a set point, | | | | The water is pumped more quickly than if you |
| and then shuts off when the water temperature | | | | ran the faucet full throttle. You save time, water, |
| in the pipe reaches another set point. This keeps | | | | energy, and money! |
| the water your entire piping system full of | | | | There are at least three manufacturers of |
| luke-warm water. The water is warmer near the | | | | demand systems, Metlund, RedyTemp, and |
| water heater and colder the further you get from | | | | Chilipepper. The Chilipepper will run any tankless |
| the water heater, but it is tepid through out the | | | | water heater. Some models of the Metlund |
| piping system. | | | | system will run tankless water heaters, and some |
| Most folks don’t really want the cold water | | | | won’t, so be sure to inquire before you make |
| pipe full of warm or tepid water. You don’t | | | | a purchase. The RedyTemp will not work with a |
| get “Instant Hot Water” as the | | | | tankless water heater. |
| manufacturers claim. I think they should be honest | | | | Choose the type of system that best suits your |
| and call them “Instant Tepid Water | | | | needs and enjoy the added convenience of quick |
| Systems”. The Lang Auto-Circ and The | | | | hot water while being kind to the planet. |