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Comment by jakedata | Hacker News Reader

In 2017 we installed a very efficient air-source heat pump and solar panels. My electrical utility offers 1:1 buyback of electricity so I am able to build up a credit in the summer and run the heat pump well into the fall and winter on that surplus. The system is sized for cooling the house which means that it is undersized for heating, but during cool fall and spring temperatures it operates satisfactorily as a heat source.

Our fallback is the pre-existing gas boiler which is much simpler, more reliable and able to be powered by a small generator during our all-too-frequent power outages.

If I am still in this home when the current heat pump fails I will seriously consider a ground-source system instead. The ability to operate during an extended power outage is a significant concern and I expect to always retain the gas boiler as a backup.

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Living in the PNW, I'm building a new house and I've chosen a dual fuel hybrid heat pump system as per https://www.bryantbing.com/products/hybrid-heat/

I'll also have solar + battery. Should be able to run the furnace & fan but not the heat pump (too many kW/h) during a power outage and thus heating with gas. It'll run off the heat pump for 90-95% of the year, only using gas on the coldest days, or during an outage. To go full heat pump for 100% of the year you need to seriously upsize the heat pump(s) and you wouldn't have performance during an outage.

Can't heat with gas without electricity, unless you have a genset or power wall kind of thing to provide epower.

I have a sol-ark 12k which allows for grid isolation and a bunch of batteries.

Until a couple years ago we had a gas-fired tankless water heater which used a single D-cell battery for ignition, which had to be changed once every year or two. It wasn't connected to wall power at all.

There are, or used to be, Bosch tankless water heaters which used a small turbine connected to a piezo-electric igniter, no external power source required ever.

But you need a blower or pump in order to circulate heat in a house. Hot water is better than nothing but it won't keep your fish from freezing.

Why not install heated floors? That would be my choice in a new build.

It's expensive and it doesn't cool. Also doesn't circulate the air. I have some fancy filters and humidifiers as part of the system I'm putting in.

It will certainly cost more, especially since you can’t share the venting and blower. But I’d get it quoted to compare. Electric systems have really come down in price per SqFt. Now your climate doesn’t get month after month of freezing temperatures so maybe it won’t be as dramatic but the energy cost savings can be huge. Plus the overall experience of it is the best imo.

You could still circulate air with the blower running in fan mode and you may not need humidifiers as that’s the biggest negative to forced air heat imo.

Curious which humidifier systems you’re looking at?

I got it quoted. Basically would be around $50k CAN for heated floors (it's a big house). Ducted mini split heat pump (2 units to handle the house size) was $60k. Central hybrid gas-heat pump was $30k.

I put in heated electric floors in the bathrooms (about $1k each).

Byrant has a humidifier (https://www.bryant.com/en/us/products/humidifiers/) that integrates with the system. It also has integral HRV. As well as an air purifier: https://www.bryant.com/en/us/products/air-purifiers/dgapa/

It's not a bad compromise for our climate. Currently living in a home I designed that has mini splits everywhere and I really dont like them. Not enough air circulation and it's really hard to balance given a well insulated house on mildly cool days which is very common here.

I intend to always keep the fan going to circulate the air in order to clean (we have allergies) and humidify.

> I put in heated electric floors in the bathrooms (about $1k each).

Smart man.

> Currently living in a home I designed that has mini splits everywhere and I really dont like them.

I have a similar opinion. They're fine in a 1-off room that is isolated but I don't like them much otherwise. They don't look good at all.

Why? heated floor are a little more efficient in heating and for some are a little more comfortable, but from my experience they are also slow to react so it's harder to control the temperature when the weather changes daily for example in the spring or automn.

They’re much more efficient (and comfortable imo) than other systems. You’ll see pretty big costs savings. But yes, you need to be in a climate that sees long, cold winters to get the best of them I guess. Or if your home has lots of tile/stone/concrete flooring.

You’re right though, they take awhile to heat up and if you’re in a place where you may need heat at night and AC in the day, they won’t be ideal.

Pretty big costs savings compared to what? if you compare radiators to floor heating, both connected to the same heat pump system than the savings are not significant

It's because of efficiency. The entire floor becomes a radiant source - this is a massive thermal source. A heat-pump is only part of the equation. You need to deliver the heat still. A radiator is generally a bad way to deliver heat from a heat pump. Radiated floors are much better. About 40% more efficient than radiators from the same heat pump.

Not to mention radiators are sort of lousy ways to heat a room anyways. They take up space and leave one side too hot and the other too cold.

Since your natgas consumption is low, could a wood pellet heater meet your needs instead of natgas?

I guess it depends if your natgas bill has a big fixed cost (and I guess you’ve already covered the sunk cost of connection…)

A wood pellet heater can be a fairly complex item, for a backup (depending on what usage frequency backup entails) a wood fired furnace might be more suitable if the owner is happy with having to add fuel every once in a while.

Myself, I would like a ground source system that lets me store in heat from an oil fired AGA, a wood burning furnace and water heater panels on the roof.

Still waiting for one of these people who rave about their heat pump system to actually rely on it full time without a backup. Most folks could barely afford to replace an existing furnace in a place that has all the fixtures installed, much less pay to install a second one based on different setup, and then pay for maintaining two systems on top of everything else. It is absurd to think that this is a plausible way forward for anyone other than the wealthy tech enthusiast. Same thing for induction stoves. You all should start a club or something.

The tech is not ready if you need a backup. I've lived in extreme cold climate areas and no gas furnace I've had has ever needed a backup.

I live in the snowy Great Lakes and I rely on a ground source heat pump and hot water heater full time. No issues at all. Cost similar to a high end gas furnace system when the tax credits were applied. Probably cheaper with air source systems today.

I live in the city and don't lose power, but I'm hoping to eventually use a EV as a battery backup when the equipment is available and standards are finalized.

A battery in a compact like the Chevy Bolt could power my heating system for several days.

It's not like modern gas furnaces don't require power to operate. In a recent Buffalo blizzard power went out and many people with gas heating still froze and had their pipes burst.

If gas remains expensive in Europe, it won't be absurd, so much as an economic no brainer to have a air to air heat pump, alongside a back up gas boiler. This should happen pretty quickly as renewables take off, and gas is no longer needed for electricity generation when the wind is blowing.

At some point a bit further on, the backup can be simple direct electric heating.

I know a couple of people who rely on a ground source heat pump without a backup in Europe. They also both have induction hobs as it happens!

The induction comment was weird. I went from electric to induction a few years ago, and it's not life changing or anything, but it works reliability. I suppose it's faster, but for me the main benefit is it makes it much harder for me to accidentally leave a burner on and burn my house down.

> Still waiting for one of these people who rave about their heat pump system to actually rely on it full time without a backup.

Eh? Most new houses in Ireland have them these days (it's more or less the only way to meet the efficiency requirements). There's never a backup.

> Same thing for induction stoves.

Eh? Again, these are pretty standard these days, and why would you need a backup?

Different geographies have different requirements. You're not likely to need to face a week or more of no power after an ice storm in -10'C in Ireland.

We don't have power outages after ice storms. Temperatures of -10°C are regularly in Scandinavia as well as in Austria, Swiss and Germany.

We are living in a developed world with working infrastructure.

Power outages happens only by accident like when an US helicopter tries weird landings: https://www-abendzeitung--muenchen-de.translate.goog/bayern/...

There are occassional outages. But the pylons are designed with icing in the mind and that does the difference. More outages are due to poorly trimmed trees falling on wires than ice itself. That usually affects only small area and can be fixed quickly.

Issue with the ice accretion is that when things get bad… they get very bad:

https://www.rcinet.ca/en/2017/01/05/canada-history-jan-5-199...

Or a crane barge not making it under the power lines overhead:

https://www.cbc.ca/news/canada/toronto/hydro-one-downtown-po...

> We are living in a developed world with working infrastructure.

You're welcome, we bombed all your infrastructure into oblivion about 80 years ago, now it's all new! And also, your country is quite a lot denser than North America, so you can bury every single power cable (though you don't, obviously) and if you think -10C is cold, just wait until you see what much of North America experiences during the winter.

Sure, as I said, different geographies have different requirements.

Define backup? I have a heat pump as my only source of cooling/heat, but it does have a single heat strip in it for the couple days a year it gets too cold for the heat pump alone. There no "second fixture" to maintain.

This is common for my area.

Same for where I live. And in fact it's arguably a simpler setup since where I live you also need air conditioning in the summer, so many homes already have 90% of what they need for a heat pump setup (which is after all just an AC running in reverse). Installing some other heat source alongside the AC you already have instead of just installing a heat pump for year round needs is arguably the more complicated option.

My heat pump was a retrofit to an existing home with a fully functional gas boiler. Being a ductless split system, it did not interfere with the existing baseboard heat in any way. By retaining the boiler I was able to afford the installation of solar panels and the heat pump in the same year and probably reap 85% of the efficiency benefit for a substantially reduced up-front cost.

I’ve a 6kW nominal, ground-source heat pump as the only heat source. This is a well insulated building standing atop the soil of a European country with a temperate climate*. It does a great job at +35°C (passively cooling) and just as great at -35°C.

During installation we've even made a mistake and it heated the building up to something like +27°C inside during early winter all without breaking a sweat (or my wallet.)

The tech is ready. Many attempts to apply it is what’s getting botched.

* EDIT: having checked, most of europe falls within temperate – the country is up north.

Its always funny reading such comments while others are running for years their heat pumps without any problems needing a backup.

Not only they are used in Scandinavia for years. Also in Germany they are used for years. The company Waterkotte operates since the 1980s in Germany and is a pioneer in this showing it is working.

But there are always people ignoring the facts.

Loads of countries have effective power grids which go down incredibly rarely. I can't even remember the last power cut I had - maybe a few years ago? It's certainly rare enough that I don't need my main source of cooking and heat to take it into account.

My parents live in rural Scotland and use a ground source heat pump for heat and an induction stove for cooking. Power outages happen more often - but still pretty rarely. If they do, they burn wood for heat and eat cold food for a few hours.

And when the grid goes down, then what will you do? How will the utility compensate you for your death when they find you frozen?

This is not an academic question, especially in North America. The weather here can be very harsh.

We lost power earlier this year as the temparature dropped to 0F (-18C). Our contingency (oil heat, oil generator) kicked in and we were fine, but many people were not.

After power was restored, people with air source heat pumps were still stuck, as the heat pumps don't function well at all at those temps, and heating up a house after it has cooled to a low temp is not what a air source heat pump is good at. These are not problems at all for an oil furnace.

If I didn’t have a fireplace I’d probably invest in some kerosene space heaters or similar.

I haven’t had a power outage lasting over an hour for as long as I can remember (years), but that doesn’t mean I’m not considering that scenario. There could be wars or sabotage or whatever. One should always be able to manage for a week or so without power and that will require some form of backup such as a combustion heater of some sort. But having a backup solution that keeps you alive for a week isn’t so expensive. You don’t need two completely separate and redundant heating methods simply because one of them relies on the power grid.

The article is light on technical details, pointing to a heat pump vendor site for "proof" that they're great.

I live in a heavily populated area with high standard of living, and yet we have had power outages lasting up to a week in the years we've lived here. Almost all in the winter, but also some due to hurricanes. We have have solar, which is great in the summer heat, but not as wonderful in the winter. We have air source heat pump, but also oil furnace backup.

We normally run the heat pump when its above 35F, as the efficiency of the heat pumps drops like a rock below 40F and its just not worth running below 35F. The heat pump is not an ancient POS. It works great 99% of the time, but 1% of 365 is 3.65 days per year. Banking on "most of the time" to be alright all of the time is foolish.

We have diesel generator in case of power outage, which allows us to run the oil furnace using the same fuel as the furnace. This strategy has allowed us to ride through many 1% case scenarios without drama.

Your normal experience is far outside what most people in Europe would prepare for, so our comments on this thread should probably be ignored by North Americans.

Looking at [1], I can see only two power cuts lasting more than 24 hours (Barcelona, 2007 and Cyprus, 2011).

Instead, "major power cut" refers to things like "The power cut occurred at 4:20 pm and power was slowly restored between 5:20 and 6:30 pm." (Glasgow, 2009.)

I can't remember being without power for more than 6 hours, and it's probably more like 3 or 4. I've been responsible for some colocated servers for about 8 years, and there's been one occasion where grid power was lost. That was about 20 minutes. A Raspberry Pi I have in a village in England has lost power once in the last three years.

[1] https://en.wikipedia.org/wiki/List_of_major_power_outages

> I live in a heavily populated area with high standard of living, and yet we have had power outages lasting up to a week in the years we've lived here.

Maybe you are in the USA? The infrastructure situation seems to be different there. We don't have any above-ground power lines in this country (except for high-voltage long-distance transmission trunks) and in the past ten years the power has gone out exactly twice, according to my uptime logs - once for 40 minutes and once for about three hours.

At the risk of asking a dumb question, doesn't working great 99% of the time represent a pretty good solution to most problems by any standard? The tone of the post you're replying to seems to suggest having a backup heat source for rare situations is somehow an indictment of heat pumps, as if addressing your climate control needs 360 days a year without relying on fossil fuels is somehow a failure. Sure, those few days where an alternative is necessary means you might need a backup plan. But that's light years ahead of having to rely on the backup plan every day.

I'd also suggest that the necessity of a backup plan can be reduced as well. Having an unreliable power grid is probably not an immutable law of nature so much as a policy choice and modern heat pump technology performs well at considerably lower temperatures than you describe.

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