[mech9879876]

If you were comparing gasoline in a car to an EV I would maybe see what you are talking about- engines are like 30% efficient so the conversion to useful energy requires a large multiple of potential energy.

But in the case of an oil- or gas- fired furnace, their thermal efficiency is at least 80%, and often more, so their potential energy usage is close enough to directly comparable to their heating value.

[ryao]

Mine was 86% efficient, although for accounting purposes, I considered the waste energy to be part of energy consumption, which seems to be the most sensible way of doing it.

[_aavaa_]

I don’t know that I disagreed with you. Yes it might be close to their heating value but it’s fundamentally measuring something different.

[ryao]

Energy usage as does not care about whether any of the energy is wasted. If it did, a 100W incandescent light bulbs would only use 1W of power.