3 ms·

And in most areas, way more than a mile, especially with 97+% efficient appliances.

• amluto 8y ago
  In an average house, there are no opportunities for an obviously winning 97% efficient gas burning appliance. A gas stove is nowhere near that efficient. A gas heater may be, but the competition is a heat pump that is far above 100% efficient (in the sense of heat delivered / energy consumed). Same goes for a water heater. (Water heaters are odd. Where I live, there are no highly efficient gas-fired tank water heaters because no one makes one that meets the NOx rules. You can get highly efficient tankless heaters as well as indirect fired heaters. And you can get heat pump water heaters.)
  • gwbas1c 8y ago
    You also need to take into account the efficiencies of delivery. I know grid electricity is usually about 1/3rd efficient. (Rough numbers.)
    • amluto 8y ago
      Measured how? If you mean delivered energy / higher heating value of fuel, I’d believe it. But a good heat pump may have a COP greater than 3. And an increasing fraction of grid power comes from renewables. (I’ve seen swimming pool heaters with heat pumps that quote a COP of 6 in mild weather. In appropriate climates, you can get a heat pump that pumps heat from your house to your pool, which can be extremely efficient.)