I wrote:
> Running hot water through the dishwasher and down the drain in the kitchen > does not heat the kitchen much. It triggers the water heater to supply 12 > kW for a while, so that much heat is going through the system. > Actually, it is probably more than 12 kW. A U.S.-style tank water heater with 12 kW heater gets measurably colder if you run the water full blast through the kitchen for about ~4 minutes. Mine does, anyway. This means you are taking more than 12 kW of heat out. The heater cannot keep up. The whole point of making it a tank instead of a heat-on-demand heater is to have a reservoir of heat so the instantaneous heat from the gas fire can be less than your peak demand. Here is a heater that has to keep up with demand, with no reservoir: "Bosch Water Heating AE-115 Electric Tankless Whole House Water Heater" It is 18 kW. Flow Rate at 45 Degree F Rise: 2.6 GPM That's not enough of a flow for my whole house! I digress. To answer Mary Yugo's question, they are wearing overcoats because most of the heat from the reactor is warming up the sewer pipes below the building. Note that people in Europe and Japan keep buildings cold by American standards. They often wear overcoats indoors. Ah ha . . . I see now that I tested this very thing on Dec. 7, when I ran tests with water running through the bathroom sink for an hour and a half, where I tied together the hot and cold pipes. I monitored ambient temperature. It is a small bathroom. The tests triggered the water heater, and the hot water cooled down. So 12 kW was not keeping up. Ambient temperature did not change much. In other words, letting hot water gush through the sink and down the drain did not heat the room much. Ambient rose from 19 to 22 deg C . . . Good thing I did not toss out these notes. The bathroom is off of the hall which has the central heating thermostat, so that would prevent the temperature from rising if the warm air from the bathroom warmed up the hallway. But the door was closed much of the time because it was noisy. There is a ceiling vent with a fan. Running water through the sink does not heat up the air, but running it though the shower will, because the water mixes with a lot of air. It puts a lot of moisture into the air. In my house, when you open the bathroom door after a shower, the water in the air may trigger the smoke alarm in the hallway. You have to remember to turn on the ceiling fan while showering to prevent this. - Jed
