Insulation is _dirt cheap_ compared to lifetime heating costs AND it also keeps the house cool during the summer. Such a no-brainer.
It's only one data point, but I'm in New England and from my home office I've watched builders replace 3 1960's-era homes with large colonials. Each is insulated with fiberglass, no visible foam, and nothing outside the sheathing (exterior plywood) except vapor paper / tyvek.
Sure, it meets code requirements for inches of insulation, but it's far from air tight or efficient.
This is how your thermos knows wether to keep your drink hot or cold.
So except for the sun shining through windows, insulation keeps heat out of your house.
Of course, once the heat is in, you need a way to get it out (at night, through windows).
Unlike a greenhouse, insulation is not directional.
The biggest problem though is the dryness during the winter, cold air comes in and expands, lowering the relative humidity, warm moisturous air is pushed out by mechanical fans. You get extreme dryness, lower then in the desert, which is not good for mucus membranes. I believe that if we could revolutionise air conditioning systems we could prevent the next pandemic (and maybe help the global climate).
Most people these days want more than natural cooling. As soon as you decide to have an AC system installed more insulation is better for the reasons you state.
I'd think barns would have very low mass in comparison to their size, but would stay close to surrounding temp by way of having very little insulation and being very "drafty"
It doesn't completely shift the issue to later in the season. Yes, it will shift some of it, but you still have the night/day average effect. This can still be beneficial, especially if in a shady location.
Barns can be drafty if you are talking about wooden barns. Stone barns, or stone foundation barns built into a hillside, can actually be cooler inside than outside during the heat of the day. That's part of why horse owner sometimes leave their animals in the barn during the day and turn them out at night (typical summer schedule).
That has similar issues with peak load to AC in the summer but most people do not live in places which are consistently so cold that you don't have a significant amount of time where the heat pump efficiency savings are substantial. As a matter of public policy, encouraging systems which work for 90% of the population is an easy call — especially because that can pair with code changes and subsidies which work anywhere (insulation, install of ground cooling loops, efficiency improvements, etc.).
Heat pumps work in Alaska:
* https://www.nrel.gov/news/features/2021/even-in-frigid-tempe...
https://www.nordicghp.com/2017/01/heat-pump-effective-temper...
What if homes had some kind of centralized modular heat exchanging infrastructure? That way we could move heat from hot things that need to be cold to cold things that need to be hot. Move heat from my computers to a water heater or something. Gotta use all that excess heat for something, right?
I don't get why this is an advantage. That's just plain old air conditioning, which is genreally considered to be a wasteful, energy guzzling luxury in colder climates.
The heat pump hype is a bit puzzling to me. Here's a TreeHugger article which puts it better than I can: https://www.treehugger.com/why-are-there-so-many-fist-pumps-...
Heat exchange in the house happens through floor heating. So during a hit summer, the reverse capability just pumps the cold water through our floors (controlled for the dew point) and the warm floor water into the ground. That, combined with controlled ventilation over a physical heat exchanger, keeps the warmth out. Or, during cool seasons, the warmth in.
Our heat pump uses about 1 Kwh electricity (from ecological resources like water or wind only) to generatev3 to 4 Kwh of heating. Without producing carbon dioxide. Airflow based heat pumps are less efficient, and more noisy outside, of course.
Good point. The source and destination of heat can be air, water, or "ground source". But it's still all just the same concept as A/C units. Pump heat to one place, using less energy than what it would take to heat it using resistance heating. There is nothing special about ground source heat pumps, except that they're a pain to install in densely populated areas.
All types of heat pumps, unfortunately, often leak. Depending on the type of refrigerant they use, this can be a serious climate concern as well.
A/C or heat pump efficiency is directly related to the temperature difference over which you're trying to pump. If the temperature difference is twice as large, you need to spend twice as much energy to pump the same amount of heat.
Furthermore, the days where you need a heat pump (or A/C) the most are the peak cold/heat days where the temperature difference between your house and the air is much larger than usual. Because of this, a ground source heat pump can do the same thing by spending much less power than an air source heat pump, so it is "greener" - though the installation is more cumbersome and expensive.
As for the "pump heat from here to there" ... while we are cooling we are warming the ground below. And as at our place, the ground's consistency keeps the warmth rather local, we reuse it later when we warm our water during the night.
We do live in a densely populated area and about every fifth hoiuse built here during the last 10 years uses a ground-based heat pump. As for electricity use: each house has two hours of "blockage" where the pump is not allowed to run, so that the power lines aren't stressed. That's no problem at all, because all houses are highly insulated and thus buffer rather good.
Also, you have your units wrong. Electrical demand is measured in just kilowatts (kw). Actual usage is in kilowatts-hours (kwh) which is just an unusual way of saying joules.
It's fine to talk about it in terms of energy as it would be to talk about it in terms of power.
And I'd argue that kWh is exactly the usual way of saying 3600000 joules.
Also name "geothermal heat" for ground heat pumps might be a local US marketing term. In international English geothermal means rather what Iceland is mostly doing. Pumping water into very hot rocks deep below to extract heat. And it doesn't work in reverse because it would be additional work to pump heat into very hot rocks instead of dumping it into the air or into the cool ground 2 meters below the surface.
https://www.energy.gov/energysaver/heat-and-cool/heat-pump-s...
Geothermal works with either vertical holes in the ground or a big loop spread out horizontally. Neither one is very deep nor does it involve hot rocks.
Geothermal heat on the other hand is a wider term https://en.m.wikipedia.org/wiki/Geothermal_heating of which geothermal heat pumps (ground source heat pumps) https://en.m.wikipedia.org/wiki/Ground_source_heat_pump are just a subset.
Anyway, for one unit input we got about 3.6 units of output, which has been produced with an almost zero carbon footprint, as we buy only ecologically produced electricity.
And yes, English is a second language.
This is only true when the ambient temperature dips below the geothermal temperature which depending on your location should make you prefer one over the other.
And last but not least: ground / water carries much more energy per volume unit than air does. So air based heat pumps would make more sense in Europe's south and less sense farther north.
The tubes are about 100 mm in U-form, drilling mostly is offered in combination with the heat pump. And costs where payed of after about 7 years.
Costs and problems depend on the ground's structure. When I talked with the guys of the drilling team, they told me that problems occur if they work in hill regions with cavernous spots in the ground. That's because the tubes need firm contact to the ground to transfer heat.
Edit: here's an image of the drilling machine in operation: http://www.cynix.net/2008/img_1757.jpg and the tubes are those black ones on the rolls in the front.
In cold climates you eventually hit an efficiency wall with the air-exchange units and need to use a ground-source heat pump, with glycol pipes being run deep in the ground to exchange heat. And/or also have a supplemental source of heat that only comes on during the very coldest periods (oil-fired furnace, natural gas, cast-iron stove, or even resistance heat).
In hot climates you can increase the efficiency of a heat pump by adding water mist, making it a hybrid swamp cooler. Evaporating water will take out a bunch of heat energy.
As was mentioned, insulation is key otherwise you're just spending money on heating or cooling the outdoors. Walls, door, and windows that don't have thermal bridges, controlled air exchange with the outdoors (ERV energy recovery ventilator units), and so on.
One big advantage is that they can also be run in reverse so you could cool the house in summer (although you might need a special heat pump to do this, especially to separate from the hot water). In areas where it gets very cool, one can also use connect the heat pump to the ground as heat sink which improves efficiency even more.