3 ms·

Something ignored in the article is that the old gas furnace was of an early and eceptionaly inefficient type, proven by its rotten flue pipe, newer gas furnace

Something ignored in the article is that the old gas furnace was of an early and eceptionaly inefficient type, proven by its rotten flue pipe, newer gas furnaces are of the condensing type, and exract so much energy from the exhaust, that it condenses water, and the flue pipes are made of plastic, as the exhaust is barely warm.Older furnaces have hot caustic flue gasses, that will rot and corode the pipes. Total efficiency is what counts from an environmental standpoint, and grid electricity can often come with CO² outputs that are high, per delivered heating energy at the load compared to delivered fuels. Heat pumps realy start to look good, when there is grid tied solar PV, and energy bills can drop to 5% or less of anything else.This works as far north as 45°latitude, at least. But the truth is that even @45°n, a house that is built to the best insulation standards, has no heating system whatsoever, as domestic activities and heat air exhangers alone, will produce excess heat, and party gatherings of organic heat machines, will require opening windows to stay comfortable, in the depths of winter.

sagarm 2y ago
Even at a COP of 2, a heat pump powered by a 60% efficient gas power plant will use less gas at the power plant than gas heat.
- metalman 2y ago
  60%? is a very optimistic number, and even if granted, does nit address the horrible reliabilty problems with heat pumps, which change the economics considerably. Heat pumps are noisy, and physicaly intrusive uggly wall lumps inside, and create a clutter outside. Well built passive solar creates a living environment that needs no heat source, is orders of magnitude more reliable in all conditions, while bieng invisible to all but the most observant.An added benifit is that a passive solar house is also acousticaly insulated, and therefor much nicer in a noisy, urban environment, near roads, etc. Financialy, the costs of building a passive house are not excessive, and once established, represent transferable value, while .... :)....insulating you from energy market fluctuations.
  - sagarm 2y ago
    You realize that heat pumps are just ACs that can just run in reverse? Most American households already have central air. They'd just swap to a reversible AC ("heat pump") when they need to replace their AC. Mini-splits are commonly used for retrofits because they're much cheaper than installing or repairing leaky ducting. Incorrectly sized or leaky ducts lead to poor efficiency, comfort, and air quality, regardless of heat source. "Well built passive solar" is all well and good for the tiny percentage of Americans that get newly built passive homes. The rest of us need solutions as well. The idea that building a new home is more economical than $1000 per ton of capacity for heat pumps off Amazon is hardly worth addressing.

sagarm 2y ago

Even at a COP of 2, a heat pump powered by a 60% efficient gas power plant will use less gas at the power plant than gas heat.

metalman 2y ago
60%? is a very optimistic number, and even if granted, does nit address the horrible reliabilty problems with heat pumps, which change the economics considerably. Heat pumps are noisy, and physicaly intrusive uggly wall lumps inside, and create a clutter outside. Well built passive solar creates a living environment that needs no heat source, is orders of magnitude more reliable in all conditions, while bieng invisible to all but the most observant.An added benifit is that a passive solar house is also acousticaly insulated, and therefor much nicer in a noisy, urban environment, near roads, etc. Financialy, the costs of building a passive house are not excessive, and once established, represent transferable value, while .... :)....insulating you from energy market fluctuations.
- sagarm 2y ago
  You realize that heat pumps are just ACs that can just run in reverse? Most American households already have central air. They'd just swap to a reversible AC ("heat pump") when they need to replace their AC. Mini-splits are commonly used for retrofits because they're much cheaper than installing or repairing leaky ducting. Incorrectly sized or leaky ducts lead to poor efficiency, comfort, and air quality, regardless of heat source. "Well built passive solar" is all well and good for the tiny percentage of Americans that get newly built passive homes. The rest of us need solutions as well. The idea that building a new home is more economical than $1000 per ton of capacity for heat pumps off Amazon is hardly worth addressing.