Hacker News Reader

Comment by lsllc | Hacker News Reader

The north east US is the largest heating oil market in the world, we consume 85% of the heating oil in the US. Most of these oil boilers will be 80% efficient at best. It does get quite cold here in the winter!

The answer is building codes that require energy efficient construction techniques, and 0% loans for retrofitting existing houses with better insulation, windows and heating (actually much of this exists via HEAT loans). Tax breaks would help here ...

Previously, the only real choices were some sort of fossil fuels with natural gas being the most efficient and cheapest (although it's only available in urban and most suburban areas).

These days, a heat pump is more than capable of both heating and cooling even in the depths of a New England winter (although you still need a heat source for hot water). However, you need the right sized ducting for this which can make it cost-prohibitive for a retrofit (but there's no reason why any _new_ house should NOT have a heat-pump).

View on HN

The effectiviness of heat pumps is insane. I worked in an architectural firm, and had an epiphany one day that every single one of our highest energy performing projects used some sort of (air/ground/water) source heat pump. We had a 100% glass building that was better performing then buildings designed to PassiveHouse standards because the former incorporated a GSHP.

This is always stunned me how USA manages to spend so much more money on heating than Russia.

Then, I learned that USA has near no cogeneration, and district heating + detached house living with mostly terrible insulation. Most North American apartments are no better, with most highrises looking like radiators.

The US generates $65k per capita vs. Russia's $11k. That we spend more on heating probably has more to do with having more money to spend on heating. I doubt very much that Russia's buildings' insulation is much better.

you would be quite suprised actually. especially in cities.

Also, appartment buildings are far easier to heat, not to mention a lot of soviet era appartments only have communical heating available. Which basically means the heating gets turned on in oktober for entire city/appartment blocks, Some of those don't even have the option to change the temperate/flow.

Some US apartments have shared heating. It’s pretty annoying because you have no control. I’ve had to keep my windows open in the winter because the heating was set too high.

I keep my windows cracked in the winter despite having control (and payment responsibility, mind) of our heating. It's worth being able to think clearly all winter: https://www.yaleclimateconnections.org/2016/07/indoor-co2-du...

Another thing that strikes most Russians when they go abroad is how well ventilated the buildings are, and how high is the indoor air quality.

In Russia, it's most likely an inverse of venue class. Malls, public venues, indoor markets, govt buildings all like to save on ventilation.

Depending on your climate and what you mean by "windows cracked", you would be much better off with a heat recovery ventilation (HRV) system. They have the explicit purpose of pulling in outside air while only losing about 20% of the heat difference between indoor and out.

With slightly open windows, you're losing a bunch of heat for very little ventilation.

Unfortunately I don't own the building but thanks for the info about HRVs

a hundred years ago they thought fresh air was an important part of staying healthy, so building heating systems (those big cast iron radiators) were designed to heat effectively in winter with the windows open.

'Shared heating' needn't mean no control over the heating.

Many buildings in Denmark are supplied with heat (for room heating and hot water) by a municipal system, but each house or apartment can adjust the temperature of the room heating, with radiator valves or electronic thermostats.

We're charged based on how much heat we extract from the system.

Russians take cold seriously. I lived there for two years. Everyone lives in huge apartment buildings which have much less surface area to volume ratio than US single family homes. And heating is done by big centralized plants. It keeps things warm despite the weather. Where I lived it would stay below freezing from September to April.

Also something interesting to note about Russia is hot water is provided by the municipality and not through a hot water tank in your own apartment like in North America. This would certainly reduce heating costs per person by offsetting them to the state.

> This would certainly reduce heating costs per person by offsetting them to the state.

Unless municipal hot water is somehow much more efficient than hot water heaters (and I'm skeptical, given the heat lost in transit), then it doesn't offset the costs per person, because those costs still have to be paid.

The main reason it can be more efficient is that they use waste heat from power plants.

In principle you can do the same thing at a smaller scale. Instead of burning natural gas or diesel/home heating oil in a furnace, burn it in a generator and heat your house with the engine coolant.

Correct. Here for example you can see a pipeline running superheated water at ~120 C (250 F) 8 miles from the fourth-largest coal power plant in the world (5 GW) to a medium size city:

https://goo.gl/maps/VmaFQrrX5VvRKFdu6

The plant generates so much waste heat (around 10 GW) while generating electricity that the heat loss in transport is pretty much irrelevant, as the heat is free anyway from the power plant's point of view.

You can use heat from burning garbage as well. My town has an incinerator which burns garbage at high temperatures, the heat is used to warm water which is used to heat buildings (as far as I know not as hot water directly).

My very first apartment in Boston was on the fourth floor of an old building and management controlled (and paid for) the heat. The building was so inefficient that in order to heat the lower floors to a temperature just barely above freezing my unit would regularly be 85 degrees or more with the windows wide open.

I’ll never forget my first big winter storm thinking I was going to die of heat stroke because I had to shut the windows to keep the snow from blowing in. Some people on my floor would leave their window unit air conditioners in year-round to counteract the heat.

It was so wasteful and almost no one in the building had a comfortable temperature in their apartment all because it was cheaper/easier for management to just keep burning a ton of oil instead of investing in a bit of insulation.

A lot of the winter overheating comes from poorly insulated pipes, unmaintained steam valves, and broken radiator controls. I lived in Boston for a few years and had the same issue in my first spot - old apartment complex, big boiler in the basement, and way too hot in the winter.

Afterwards, I moved to a nicer but even older building where the landlord had bothered to retrofit a modern boiler with separate heating zones for the different apartments. Crucially, the radiators had new control valves the lines had modern insulation. It was like night and day. I think the retrofit cost over $10k, so like you said, the path of least resistance is often crappy heat.

This. There was a great video posted on HN a couple years ago, by one of the few guys around who tunes up these old radiator systems. Apparently a lot of them were quite genius in design, but years of neglect make them not work very well. Was a fascinating video to hear him talk about common problems, and the amount of troubleshooting and problem solving involved with making these radiator systems work as designed again.

Dan Holohan, for those interested. https://news.ycombinator.com/item?id=18430512

What a cool video and thread! Thanks for sharing! Sometimes I wish HN had a “random old thread” button like Wikipedia so people could stumble upon the hidden discussion gems like this one.

Should have connected the hot side of your ac to the first floor lol.

>It was so wasteful and almost no one in the building had a comfortable temperature in their apartment all because it was cheaper/easier for management to just keep burning a ton of oil instead of investing in a bit of insulation.

Making old housing stock efficient at scale is fundamentally incompatible with the laws in MA (local as well as state) that make it possible to both make incremental improvements as budget allows and be on the right side of the law.

People suffer through expensive old utility systems because they can't do X without hiring a licenses pro who can't do Y without pulling a permit and the town won't grant a permit for Y unless Z that has to be touched do do Y is brought up to modern code at the same time which would be fundamentally incompatible (usually for cost reasons) with the goal of the work.

Incremental improvement is more or less disallowed by law or at least massively dis-incentivized. You either have the cash to completely renovate a building and put all new everything in or you do nothing.

That’s true, and I’ve suffered from the same problem when I later bought a home in Southie built in the 1870s. Just replacing the water heater was thousands of dollars.

In the case of my first apartment though I know for a fact my landlord had more than enough cash to update the building if she wanted to - her husband owns the Red Sox.

I lived in the Southern California mountains. For those who are unaware, yes, that means snow. Winter temps down to the low 20s(f). In summer, it seldom got over 90s. It was the house I grew up in, and I purchased it from my dad. Because it was an FHA loan, we had to have a heating/cooling unit installed, so we had a heat pump added.

Aside from being absolutely hideous, the unit was utter shit. The "heat" was mostly cold air in winter. The pump would turn on, and ducts' air was cold (being outside and all), cooling off the house MORE when it was already freezing. Eventually some lukewarm air would come in until the unit got too hot and would turn off, again pushing colder air back into the house. And in summer, the cool air was nowhere sufficient to cool the house. Your only bet would be to keep it on all day with all drapes closed, lights off, do not cook, and don't move around too much.

To contrast this, we generally used a wood stove to heat the house. A few logs would keep the house nearly uncomfortably warm for hours. In the summer, we ran an evaporative/swamp cooler. As long as there were no thunderstorms, the house was very pleasant. I cannot be convinced that heat pumps are the way to go.

It sounds like you had some kind of compliance system that was low-quality or not big enough for your needs. Heat pumps and air conditioners are the same technology, you just make the hot side the inside instead of the outside. They're how your freezer works, but in reverse.

Their main limitation is that they aren't effective in extreme cold. To pump heat there needs to be some to begin with. But most populated areas don't get that cold too often and they can be backed up by resistive heaters for the couple of nights a year when it is.

> Their main limitation is that they aren't effective in extreme cold.

I've researched this a lot since I want to install one and live in a cold climate. The new ones can put out a lot of heat at low temperatures.

As an example, see the linked "AHRI Certificate" for the product below. It states:

- 11,800 BTU/h at 47 degrees fahrenheit

- 7,800 BTU/h at 17 degrees fahrenheit

I feel like I've even seen some that say they put out 100% of the rated heat at like 5 degrees fahrenheit.

You have to make sure you get a cold weather one, with a base pan heater. They're usually more expensive.

Here's one I've looked at for reference. It costs $300 more than the less extreme temperatures one. I don't think it comes with a base pan heater, but I'm not sure: https://senville.com/12000-btu-mini-split-air-conditioner-se...

I have a friend who just installed a modern air source heat pump in a new build in Mass at the end of last year and he's pretty happy with it so far. The tech has improved significantly in recent years -- up until recently, they were not recommended north of DELMARVA.

>These days, a heat pump is more than capable of both heating and cooling even in the depths of a New England winter

Are you talking about air source or ground source? And by "the depths of a New England winter" do you mean temperatures below 50 F?

I lived in an apartment for a while that had some sort of heat pump, but there was a switch for "emergency" (i.e. resistive) heat that was necessary for any warmth in the winter.

It would be ground source, and a day of 50°F would feel like shorts and sandals weather that time of the year.

You don't have to tell me. I was looking for sources of misunderstanding. In a multifamily structure, at 50 F, in my experience, heat through shared walls probably keeps you reasonably warm without any heat of your own.

Modern air source heat pumps can be effective down to -25C (-13F) in heat pump mode, and will automatically switch to resistance heating if needed.

I'm building a house where it can get to -35C at times (but usually above -20C in winter) and we will have an air source heat pump for hot water, heating and cooling [0]. Combined with good insulation and 10kW of solar on the roof, we should generate more electricity than we use over the year, and no need to burn any fossil fuels.

My wife has insisted we have a wood burning stove for atmosphere, so that will function as a backup heat source if needed, but most likely it will generate too much heat to be used regularly.

[0] https://www.daikin.eu/en_us/product-group/air-to-water-heat-...

I tend to take a dim view of the phrase "can be" because it's so weak. It's logically equivalent to "may not be" and is entirely consistent with "essentially never is".

But sure, the heat pump in your future home may well be much better than whatever they were doing decades ago. I don't know if my apartment used ground heat, but I doubt it.

I meant "can be" in that if you buy one rated for those temperatures it will reach that, but not all heat pumps are rated for that.

Your heat pump had something wrong with it. Quite possibly it wasn't going into defrost mode or wasn't able to actually finish defrosting by the end of a cycle. The way that's intended to work is that after running for a bit when the ice starts blocking air flow and insulating the coils on the outdoor unit it'll switch to cooling mode and turn on resistive heating. That quickly thaws out the coils and then it switches back to heating and turns off the resistive heating inside. I find it odd that you even had to manually turn on emergency heat to get any heating out of it. Normally if the thermostat is too far below the setpoint it'll automatically start using resistive heating as well (most thermostats will indicate "aux heat" when that happens). Maybe your thermostat didn't? Or it did and the reversing valve was stuck so it was just stuck in cool mode 100% of the time.

>but there's no reason why any _new_ house should NOT have a heat-pump

Are heatpumps always more economical than gas/oil? I know that natural gas almost always beats electrical resistive heaters in terms of cost, even though resistive heaters are more efficient than natural gas. Heatpumps are supposed to be more efficient than resistive heaters, but in areas with expensive electricity it still might be more expensive.

>"even though resistive heaters are more efficient than natural gas."

You have to be careful about what you measure. Resistive heaters are 100% efficient by definition, but you have to look at the whole chain. The energy has to be converted from X (coal, natural gas, isotopes decay) to electricity and transmitted to your home. Only the last step is 100% efficient. You lose a lot of energy in generation and transmission of electricity.

I was curious about this a while ago and did some napkin math.

Natural gas is roughly $15 for 1 million BTU. There are 3412 BTU in a kwhr, so if you heated resistively, you'd need 293 kwhr to get 1 million BTU.

In my area, which I feel has pretty high electricity cost, we pay $.24 per kwhr, so that'd be $70.

Therefore, you need a 70/15 (4.666) COP for your heat pump to match natural gas by price. My understanding is that that would be an unusually high number for cold weather conditions.

The State of NH Office of Strategic Initiatives has a nice Fuel Price comparison page that they keep up to date (and are adjusted according to cost per MMBTU):

https://www.nh.gov/osi/energy/energy-nh/fuel-prices/index.ht...

You can see that as of June 2, measured at $ per MMBTU (million BTU):

  Natural Gas           $8.31
  Oil                  $17.62
  Propane              $32.93
  Wood pellets         $21.92
  Resistive electric   $48.84
  Air src heat pump    $18.74

The fossil fuels are all measured assuming 80% heating efficiency, whereas for propane or natural gas you might well have a high efficiency unit up to 97% which gains you a bit more savings.

These prices may vary depending on location and also I think natural gas isn't that common in NH as it's a mostly rural state.

Holy moly. That price per million btu is a lot less than the number I stumbled across. Makes it even more obvious.

Remember, oil prices cratered over the past few months. I'd take the current numbers with a grain of salt.

We also don't know what the long-term fallout is going to be. Natural gas has been unusually cheap recently because it's a byproduct of fracking for oil. But low demand for oil means less demand for fracking which mean less natural gas production.

It's really hard to predict where prices are going to be in a year, because you really have to predict how well the oil industry can predict future demand in this environment. If they shut down too much production and then demand comes back there could be a price spike. If they expect a quick recovery and are wrong, prices could remain on the floor for a good while.

This is also the "off" season for heating oil, so it's usually cheaper.

According to the NH page, that price was June 2. For the Commonwealth of MA, as of late May it was $2.07 on average and it's down 33% on last year:

https://www.mass.gov/service-details/massachusetts-retail-he...

You can see it has dropped from $3.04 on Jan 7 2020.

I'm really glad I recently replaced my old 80% efficient oil boiler with a 97% efficient natural gas boiler. My winter bills are less than half what they were and it barely uses any gas during the summer for hot water.

With 80% efficiency, you have to burn 1/0.8=1.25 units of fuel to get one fuel unit worth of useful heat. With 97% efficiency it's 1/.97≈1.03 units.

So if fuel prices and the amount of useful heat usage stayed the same, then your bill should be 1.03/1.25≈82% of what it was before. If your bill is "less than half" then something else must have changed.

He switched from burning oil to burning natural gas. According to the table, gas is way cheaper.

Yes, I switched from an oil burner (#2 heating oil) to a high efficiency natural gas boiler. The other key ingredient is that the oil boiler was 20 years old and did not have "cold start" (so it always keeps itself at temp even in the summer).

Any modern boiler (gas or oil) will almost certainly be cold start, so it only fires when there's a call for heat. This alone probably saves a gallon of oil a day at least.

There's a reason the Energy Saving Trust over here in the UK discourages people from replacing their gas boilers with heat pumps thinking it'll save them money, even though our climate is more suited to it than the colder parts of North America. Unfortunately, that doesn't stop our press pushing the idea we should go for heat pumps because Germany has. (They don't have such widespread natural gas connections to homes as the UK and so are reliant on oil-fired home heating, which as you can see has very different economics.)

A heat pump is only moving heat from one place to another, it's not heating "resistively". So your energy cost is to run the heat pump, not to "heat" the house.

Having said that a typically, your system is designed for a 99% "heating" or "cooling" dry-bulb outside temp from the ASHRAE climatic design conditions based on your location.

For example. Boston (Logan Airport) the 99% heating temp is 12.3F, so you'd size and design your system for this to get your heated space to 70F. There's a secondary heat source that fires if the temps drop below this (which happens, the 99.6% heating temp for Boston is 7.4F and it often goes below 0F). This is often resistive, but could be a hydronic coil if you had an on-demand gas combi-boiler for hot water. This is also used in an air-source heat pump for de-icing the condenser. A ground source heat pump (aka geothermal) doesn't have this problem, but requires a well to be drilled (100ft per ton of heating/cooling) to provide ground water as a heat source.

In the UK they want to move as many people as possible onto heatpumps, away from natural gas combi-boilers.

I don't know how it works for blocks of flats.

If you don't want fossil fuels (even natural gas), then it'll likely be a ground source heat pump. You just drill a number of deep wells -- each 100' of well gives you about 1 ton of heating/cooling (1 ton is 12,000 BTU/hrs or ~3.5KWh). For a decent sized building you'd be looking at probably a dozen or two 1-2K ft deep wells.

The nice thing is, you don't need much room on site, you can even drill them into the basement after the foundation is done before the steel goes up.

With a split system, the heat-exchangers can be in the basement and the refrigerant (R410A) run to the air handlers located elsewhere.

Of course, the more you insulate the building, the less heating and cooling you need.

Austin, TX area:

We used to live in 1800sqft house built in 1992 in the affordable neighborhood (so fiberglass bats in 4x2 walls). Gas heater, electric cooling. Gas water heater. Gas stove (we don't cook much, so this one probably doesn't have significant effect). We regularly got a bill over $250 in the summer for electricity + gas. Sometimes over $300. In the winter combined bill would be around $150. In summer second floor was never comfortable (part of it was poor circulation I am sure, but part of it was HVAC not cooling well enough)

We also just finished new 3100sqft house. The new place doesn't have natural gas, so we decided to go all-electric - water heater, HVAC, cooktop/ovens, and new addition - pool-heater. Our electric bill now fluctuates between $200 - $280 year around. All appliances, including water heater, are heat pumps. Extra bonus - garage, where the water heater is located, is cool during summer. Both water heater and HVAC has resistive heating elements for very cold days (we get enough of these to matter).

I am sure I can get average bill lower a bit if I tweak pool water and heat pumps schedule.

The house has open cell foam installed around the envelope (so the attic is alright to be in even during the hottest days) and we have forced ventilation (since the house is sealed essentially).

The water heater (80 gal) I bought myself and it was $900 on ebay. Similar product bought at Home Depot would cost probably $1,200 - $1,400. A bit more than natural gas heater, but not prohibitively so. HVAC installation (2.0 and 2.5 tons units) was under $20k for the whole house. Not sure how much traditional gas+electric non-heat-pump install would be, but I don't think it would be significantly cheaper.

So yeah, at least for southern places, heat-pumps appears to make a big difference.

Heat Pump Domestic Water Heaters are becoming very popular, plus you can combine them with a Drain Waste Heat Recovery system that would provide you with a very efficient system, that you could take long showers. This system would be a good for the environment but a hard sell compared to 90+ efficient natural gas boiler systems.

Reply on news.ycombinator.com