Even for those who can, it would take several years for the investment in a heat pump plus the waste of the old heating system to become carbon neutral, let alone cashflow positive.

Don't feel bad. This entire thread is filled with people who think they know better. Must be why UX is in such high demand these days.

I get the enthusiasm though, head pumps are really neat.

You sure it's drawing 700W? Are you running multiple GPUs or what? Is that a server? Have you measured?

Someday if I ever get to build a custom house, I plan to install a full 42U rack that is tied into the houses central air to optionally heat the house with the waste heat.

But not only is the efficiency rating important but the specific model’s efficiency curves at cold loads and hot loads, 20%, 50%, and 100% loads. Paying attention to your components and what level of power usage they will be at for most of their usage will dictate what the most efficient specific model of power supply (at a reasonable price point for you). This of course makes reviewing and purchasing power supplies quite complicated.

Many people, especially in mid-tier or lower builds where every dollar for price vs performance has been calculated to the decimal point will opt for the cheapest power supply that meets the wattage and connector requirements their particular build requires, efficiency and longevity be damned.

My opinion is that getting a guaranteed 80% power conversion efficiency rating (as compared to, say, a 75% conversion efficiency rating) on a 500 watt PC will save you 25 watts of power over the years that you use it, plus a manufacturer that actually goes through the process of getting the approval will probably have also put a little extra care into their manufacturing process and so probably has a better reliability rating than one that did not.

Unless you are scraping to get any PC together it may well be worth an extra $10 in price variance, all other things being equal, for that piece of mind and minor electricity savings to boot.

I went out of my way to research my current power supply to make sure that given my usage and components, it would operate in peak efficiency (I believe mine is at nearly 95% efficiency at average load, would need to measure it more thoroughly, it has been a few years).

I feel a power supply is like tires. They are the only thing that actually touches the road(electricity). They are worth paying for something halfway decent, not bottom of the barrel.

I do agree, but I would be shocked to see a non-80+ psu at a reputable store like Micro Center.

https://www.newegg.com/p/1HU-0027-00010?Item=9SIAXE5EGG6813&...

650 watt, no-name non-80+ power supply for $40. That's the sort of thing I'm talking about. There are 80+ rated power supplies in the same price range or 80+ from reputable companies for $10 more but it's still a thing worth looking for when you're a newish builder or if you have any concern for the overall efficiency of your computer.

After all, base 80+ rating still means that for every watt your PC actually gets to use you're converting .2 watts directly into heat. That's not a big deal for a workstation that may only draw 100 watts under load but if you have a beefy PC with 3090s and an overclocked 12 series i9 processor with a lot of fans, you could be burning 100 watts or more just to power the thing, so it would definitely be worth it to go for gold or platinum 80+ rating just to save the money in waste heat and in cooling that waste heat after the fact.

But for a huge number of people (probably the majority) who live in more temperate climates (most of Europe and the US), they are a net win both in their energy bills and environmentally marginal extremely cold climates. That's the people whom LEDs target, not the people in marginal extreme cold climates running high power-draw servers in their homes.

How would that be the case?

I still like the heat pump because in the summer my power bill for cooling a 2600 sq ft home is about $50/month, and in the winter I do have a wood burning stove that I can run to heat the house when the temps are below 36. That and recirc mode on the fan unit can keep my power bills to a minimum.

Year round? So you mean the polar regions? Because they can work even at -10F. Efficiency is reduced, but they can work. Crappy ones will cutoff earlier though. If you are not in one of the planet's poles, we have seasons so it's better to use LEDs for at least 3/4 of the time (maybe more as even northern latitudes only have a few really severe winter days).

Modern LED lamps are tiny and use very little material. Incandescent bulbs are no longer considered 'exotic' because of how old the tech is, but tungsten was a very exotic material at some point.

That's the point where I'd strongly consider cryptocurrency mining.

Switch to LED and your heating system will need to supply that extra 0.5kW.

In a climate where you are almost always running heating, this makes the benefit of switching to LED much smaller, and considering that they are much less environmentally friendly to produce, it may even tip the scale the other way.

Depending on where the bulbs are located, they may be emitting into a ceiling cavity that exits the building's envelope more quickly than the location of the heating coil. Some bulbs are actually outside the building.

And of course, the heating system can supply 0.5kW for less than 0.5kW of power with heat pumps or (net including generation and transmission) natural gas.

Beyond that, heat pumps are still much more efficient than direct electric heating.

Also, if you have air conditioning at any point in the year, those incandescent lights are just going to make your air conditioner work that much harder.