Are they really better at saving energy than other electric space heaters?
No. All portable electric heaters produce the same amount of heat per kilowatt hour consumed. A claim of energy savings from any portable heater is based on the idea that you’ll turn down your central heat and use the portable heater to keep you warm only in the room you’re occupying. But electricity is one of the most expensive heating fuels in Vermont. So, the cost of the electric heat is likely to outweigh the energy savings from reducing your use of your central heating system unless you turn down the house thermostat substantially. Unfortunately, the colder a house gets, the more you put it at risk of problems like frozen pipes, cracked plaster or drywall, and wetness on the inside of the home and the outside. As notable is the potential problem of condensation forming on cool surfaces. Without enough heat to dry them out, these surfaces can become ideal spots for mold and wood rot. This may happen where you can see it or where you can’t — within the walls, floors or attic. A bet
