3 ms·

In terms of thermodynamics, a electric resistive heater is 100% efficient, but if the measurement is how many BTU of heating you can put into a room in a day wi

In terms of thermodynamics, a electric resistive heater is 100% efficient, but if the measurement is how many BTU of heating you can put into a room in a day with a certain amount of watt hours, a modern heat pump will always beat it. Also of course 100% electric.

graemep 2y ago
A heat pump is more than 100% efficient on that measure. I am not sure about "always". Does it not depend on the temperature difference? The use cases for steam seem to be where you need more than room heating though: the first paragraph mentions sterilising medical equipment, humidity control, and washing.
- walrus01 2y ago
  My understanding is that it varies by temperature difference, but there's specialized series of heat pumps which work "okay" with very cold outside temperatures, even down to -25C, which are becoming popular to replace oil tank heating systems in Atlantic Canada. Apparently even when operating at -20C outside air they're still more efficient than electric baseboard heating. I don't know of any of the customers of the steam system in downtown Vancouver that use it for sterilization purposes, it connects almost exclusively large office towers. There's no hospital or medical facilities connected to it.
- yencabulator 2y ago
  > I am not sure about "always". Does it not depend on the temperature difference? My understanding: A heat pump is always better than resistive electric heating. Sometimes a outside air using heat pump needs to use extra energy to defrost the outside unit (with resistive electric heating). The defrosting is driven by sensors, but rarely happens more than e.g. once an hour for 5 minutes at a time. Heat pumps really do win over resistive electric heating on everything except initial cost, and that's not even hard -- resistive electric heating is very wasteful.

3 ms·

In terms of thermodynamics, a electric resistive heater is 100% efficient, but if the measurement is how many BTU of heating you can put into a room in a day wi

by walrus01 2y ago

graemep 2y ago
A heat pump is more than 100% efficient on that measure. I am not sure about "always". Does it not depend on the temperature difference? The use cases for steam seem to be where you need more than room heating though: the first paragraph mentions sterilising medical equipment, humidity control, and washing.
- walrus01 2y ago
  My understanding is that it varies by temperature difference, but there's specialized series of heat pumps which work "okay" with very cold outside temperatures, even down to -25C, which are becoming popular to replace oil tank heating systems in Atlantic Canada. Apparently even when operating at -20C outside air they're still more efficient than electric baseboard heating. I don't know of any of the customers of the steam system in downtown Vancouver that use it for sterilization purposes, it connects almost exclusively large office towers. There's no hospital or medical facilities connected to it.
- yencabulator 2y ago
  > I am not sure about "always". Does it not depend on the temperature difference? My understanding: A heat pump is always better than resistive electric heating. Sometimes a outside air using heat pump needs to use extra energy to defrost the outside unit (with resistive electric heating). The defrosting is driven by sensors, but rarely happens more than e.g. once an hour for 5 minutes at a time. Heat pumps really do win over resistive electric heating on everything except initial cost, and that's not even hard -- resistive electric heating is very wasteful.