#StopBurningStuff by 2030 or sooner

[Just Joe]

We're slowly progressing in the same direction as all of you.

I'm mowing several acres with a 50 year old electric lawn tractor. Love the lack of exhaust and low noise. I do nothing to the yard in a year's time but cut and trim it. Currently trimming and leaf blowing with two-cycle machines but I go through less than a quart of fuel in each all season b/c of the way our yard is structured to be low maintenance. I'll go electric eventually but at this point in my history, any batteries in a weed wacker would age out rather than wear out due to lack of use. When the old lawn tractor batteries wear out, I'm planning to DIY upgrade to used lithium.

I do have an electric pole saw now that doubles as a chain saw (pole comes off to reveal a chainsaw handle). I generally run it from the lawn tractor power via an inverter. I could run for days like that on ~25 cents of electricity. I usually trim up the trees along the yard edges in the spring and fall. I can put the tractor in low-low gear and it will toddle along so slowly that I can cut or pickup sticks walking beside it. Easy to reach over and set the throttle to stop if it gets too far ahead. Best yard machine I've ever owned.

Inverter and tractor battery pack are large enough it could power the family room or the fridge overnight+ in a pinch. However our house came with a propane generator. It rarely runs as the grid in our part of town has improved since we've lived here.

Am switching to gas for $$$ reasons. Local propane company (Suburban) is more expensive than everyone else. Last time we were using up the last of the fuel, they delivered more fuel w/o our permission.

New heat pump for upstairs replaced aged a/c unit with electric strip heat. Already can see the savings. $5 installed. When downstairs unit ages out, going to a multi-fuel heat pump. Our weather is mild enough most years that the gas side would run just a handful of days/nights each year.

We sealed some attic access doors. Want to insulate the backs of these doors before cold weather this year. Who uses interior doors as attic access doors? Well, the previous owners did... House is otherwise pretty tight. Did add an air return in the basement to turn over the air there. Much nicer down there. Drier.

Have an propane instant water heater. Will transition to a heat pump water heater eventually. Electric stove now, electric stove after kitchen remodel. Electric laundry already.

Added us to the TVA Green Switch program. 100% Want to pursue DIY ground solar in the future. We have a good spot for it. Much more homework required to see how the numbers work b/c our electricity is very affordable.

Still riding our ebikes. Still love them. Surprised at how well the batteries have aged. Still not enthusiastic about mixing with cars although I have a slow country road route to use to ride to town. I use the most boost when climbing a couple of blind hills with no shoulder that I would avoid if I could. 

Lightweight/medium speed EVs are a new topic for me. Our town's peed limits are 45 mph or slower. Considering eventually purchasing a lightweight EV for town use. In my state they get registered as UTVs. Can't drive them on highways. They are registered as motorcycles and must carry liability insurance. I might replace our aged second car with this EV. I don't need a long distance deluxe vehicle for 10 mile errands. 

My biggest problem with the typical EV right now is the excessive levels of technology. I don't need (or want) all the touchscreens, the touchscreen HVAC controls, the pseudo-self driving safety equipment. I want heat/air, radio and windshield wipers. And knobs. And a lower price.

In a primary vehicle I would want a big battery so my use seldom deep cycled the battery so it would age slower. And for those occasional trips out of town. I still don't see EVs as a travel vehicle - yet.

I've been doing a deep dive on the XBus pickup/bus prototype from Germany. I think this would suit my needs/wants perfectly. And the forecasted price of around $20K works too. The reality is the price will likely be greatly inflated when it arrives, might be subject to the "Chicken Tax" (still in 2022!), and their battery size/range numbers are very optimistic I think. Until I see one in real life, this will remain vaporware.

Our federal government will probably tell me I can't have one. Because safety. But they will allow me to drive any vintage vehicles on the road. Or motorcycles. Or DIY customized vehicles with sketchy alterations. But not an XBus. Land of the Free dont'cha know... 

It is safer than a motorcycle, safer than a vintage vehicle - and I own both. So I'm not worried about the seating position or any lack of safety systems like ABS or airbags. I'm in a small town, not driving through some metro area on a daily basis. If I was doing the metro lifestyle I'd probably want my family in a Stewart & Stevenson LMTV... ;)

[Syonyk]

Added us to the TVA Green Switch program. 100% Want to pursue DIY ground solar in the future. We have a good spot for it. Much more homework required to see how the numbers work b/c our electricity is very affordable.

Depending on how you do the framing for the panels, I've got a somewhat-worked-out set of A-frame plans that can be done for around $1/W, DIY.  Maybe a bit more if you aren't able to weld up the frames yourself on used pipe, so perhaps $1.25/W.  How big of a system do you want?  They're designed for a post-net-metering sort of world, with the panels pointed east and west to give you a longer solar day for better behind-the-meter consumption, but you could probably point them more south if you wanted - just hang less panels per inverter, no real changes.

It's straightforward to do with string inverters, and a typically 200A house panel will accept one of the ~7kW "modules" with no trouble (25A inverter output, 35A breaker, you can backfeed up to 40A on a 200A busbar via the 120% rule).

I don't know exactly what the permitting and inspection process looks like where you are, but the plans meet NEC 2017 comfortably.  If you want a big system, it can scale up easily as well - a neighbor just did a 21kW system with three of the A-frames in a row and it looks quite epic.

[Just Joe]

The fabrication portion is easy peasy. I have a full shop at my house with a welding machine, etc.

How far from the house can this be done? I may need to position them ~150 from the house.

Generating capacity - not sure yet. I need to see what we are consuming each month and I'd like to build in some expansion capacity b/c regardless of whether the XBus ever comes to my house, our next "local" car will likely be partially or wholly electric.

[Just Joe]

What size system would you recommend for a household consuming ~1400 kwh a month during the summer?

[Syonyk]

The fabrication portion is easy peasy. I have a full shop at my house with a welding machine, etc.

Perfect, you'd have no trouble building the frames, then.

How far from the house can this be done? I may need to position them ~150 from the house.

About as far as you want, really.  You need to run 4x 12AWG and either a 10AWG or 12AWG ground per 7kW module, so you're in for wire cost, conduit cost, and hassle of pulling.  But with only 7-8A per 12AWG pair typically, you don't need to worry about voltage drop much on them.  They're designed for a 600V max winter open circuit voltage, and normally operate around 400V, so it's fairly efficient even for a long run.  150' is no problem at all - it's far more important to get them in good sun, because the ground mount frames don't have per-panel optimization.  If you can have multiple modules in a row instead of next to each other, that's better - mine self shade more than I'd prefer in the morning and evening.

What size system would you recommend for a household consuming ~1400 kwh a month during the summer?

Play around with PVWatts for your location... I've no clue where you live.  It also depends on what your local incentives and net metering arrangements are.  Some places don't let you exceed your consumption by much, some don't care, etc.  The most cost effective option would be to put one array in and trim your highest cost power, and you won't have to upgrade your panel or mess around with derating main breakers for that.  Adding more modules starts to get more complex, depending on how your home is wired, what your panel busbar ampacities are, etc.

[Just Joe]

We have a really good place for it. Plenty of sun and space for panels. The lot is oriented pretty well for PV too. Thank you for the details.

Maybe this winter I'll sit down and try to detail out what it would take after studying your website and asking more questions. I've wanted to do this for years and bought this house with DIY PV in mind.

[Syonyk]

I should get back to the book I'm writing on this particular style of solar install too.

It's trivial to swap stuff around to be south facing, I just don't actually like south facing solar that much.  It doesn't produce when the grid demand is high (morning/evening), and it overproduces midday.  The east-west A-frames still end up with a peak midday, but they're a lot better out on the ends.

This is what my east/west frame generation curves look like, with the south frame overlayed (and scaled to match nameplate kW on the east/west frames).  Sometime around peak summer...



Anyway, if you're interested in building something similar to what I built, I'm happy to help out!  I'd love to get more feedback on this sort of system/install/etc.

[Just Joe]

Hey that is a neat website!

A 12KW would likely cover all our needs including the electric dryer and heat pumps. That's without optimizing anything in the house beyond what we are doing by buying better appliances as the old ones wear out. 

That doesn't take into account a shading tree line situation during the winter.

 

[Syonyk]

Do the math with half the panels pointing west at a 45 degree slope and half pointing east at 45 degrees - that's what the A-frames are.  You'll probably need a bit more nameplate than south facing, but it's grid friendlier and will hopefully work better if you drop away from kWh for kWh net metering.

On a 200A panel with nothing special, you'd have to derate the main breaker or upgrade the main panel to a 225A busbar for that.  Unless you went with a pair of Sunny Boy 3.8s, which you could backfeed into a 40A slot with appropriate continuous derating (they're 16.0A AC output, so 32A continuous, which is permitted on a 40A breaker), but you'd be clipping hard and running the inverters at 100% for long periods of the day.  It won't cause anything to fail, but I generally try to avoid running power electronics at 100% for long periods of time.  However, depending on your panel, that might be a cheaper option than replacing the panel and doing a bunch of other work.  I'd buy a spare inverter or two if you plan to run them like that.

[Just Joe]

All good information. Thank you.

[rockeTree]

500 miles on the ebike, a Blix Vika+. A rough guess of when the avoided car driving makes up for the carbon emissions of making a bike and shipping it from China is around 1200 miles, so I am looking forward to that milestone. Assuming most but not all of my avoided drives also avoid train station parking, the bike pays for itself in avoided cash money spending around 1600-1700 miles, woo hoo. Seeing a lot of bikes on the train, btw, biggest hurdle for folks is the weight. If your train has the hanging hook racks and you have to heft a 60 pound Rad up there all the folks on $200 beater mountain bikes are def laughing at you (one reason I got a folder, though still a bear to get down the stairs to exit the train car to the platform below gracefully).

Loving the HPWH for anyone on the fence; the noise some folks complain about is not at all noticeable in the finished area of the basement (separated from the "utilities" area of the basement only by a wall made out of old pine siding boards with vents cut in it). I like to think that it and the chest freezer are helping each other out down there, passing around the heat and cold.

The induction stove wiring is in place and the stove is ordered; when it gets here is anyone's guess.

[Just Joe]

I haven't ridden my ebike nearly as much this summer as I wanted to. Its been so hot and we've been so busy...

Well summer departed and I got the itch to ride. Went for a six mile country road ride one evening this week. It renewed that urge to bicycle.

So the bike went to work with us on the back of our car b/c DW had to work late (we carpool). At lunch I made a grocery store run and brought the goodies back to my office. And then rode home after work.

Holy cow the traffic was heavier than I've ever seen it before. Made me glad I rode the route I did. An alternative route takes me up a couple of very steep blind curve rural hills with no shoulder. If that road was as busy it would have been super risky. Still, the ride felt good. Some muscles complained.

Brought it work today again and rode to the hardware store for some rattle can paint for a project I've been working on in the evenings. Undecided whether I'll ride home today or drive with DW as usual.

I wish our town had more than a singular 4-5 mile bike path. Wish there were proper bike paths radiating outward from the center of town. I can legally use sidewalks where they exist but they too are incomplete. Our town is mostly people who drive b/c the town isn't set up for bikes or walking anywhere useful much.

[rockeTree]

Congrats on getting some rides in though and getting home safely!  I admire your carpool, too.

You really do get a very different sense of a place on a bike than in a car. I have developed a very indirect route because the obvious one involves a) two miles on a very busy road full of speeders and b) cutting across to the next main road on the way (which is pretty good for bikes) via a narrow road with a narrow bike lane that is always full of trash and has tree limbs hanging in the way, so practically you are just in the narrow lane making the drivers mad.

[rockeTree]

Radbikes on sale from $500 (!) for the e-bike curious https://www.radpowerbikes.com/pages/sales-deals

[rockeTree]

How are folks doing? Back ordered induction range finally showed up and is fan-tastic! Car use continues
to decline with the bike, the hp water heater dehumidifies the basement enough that clothes hung up to dry down there are done noticeably faster reducing dryer use a bit (electric dryer but still nice), all is well here!

The furnace remains for now but I haven't had to turn it on yet this winter; three cheers for insulation.

[NorCal]

How are folks doing? Back ordered induction range finally showed up and is fan-tastic! Car use continues
to decline with the bike, the hp water heater dehumidifies the basement enough that clothes hung up to dry down there are done noticeably faster reducing dryer use a bit (electric dryer but still nice), all is well here!

The furnace remains for now but I haven't had to turn it on yet this winter; three cheers for insulation.

My heat-pump got its first real test this morning, as it got down into the mid 20's with some overnight snow.

As the installer told me, they work really well at maintaining a temperature, but they do take longer to bring the temperature up.  I'm overall happy with the performance, but I'm having to adjust my thinking about how cold I let the house get down to at night.  I'll probably only let the temperature drift down 2-3 degrees overnight instead of the 6-8 degrees I used to let it slide.

I'll also experiment with turning the temperature up a few degrees in the afternoons, as it has a higher efficiency when it's warmer out.  I'm not sure what the net effect will be, but I might be able to wrangle a little more efficiency out of it. 

It's also sinking in how much more energy we use in Denver for heating over cooling.  While it's something I knew previously, it doesn't really sink in until I was able to watch the home energy monitor tick up.  It was a much more invisible expense when it was the harder-to-monitor natural gas. 

[Sanitary Stache]

I am moving in both directions.  Burning less home heating oil and gasolene, but burning wood.

We have had a fire in the wood stove 4 days so far, but the furnace isn't turned on yet.

The ebikes are certainly replacing car rides and our gas expense was down by 30 dollars last month. 

Our electric use is way up though since we kept a warming light on 30 chicks for the past month.

[Glenstache]

SO and I have been considering moving to a different neighborhood and have been looking at a few houses as a result. It has been a shocking reminder of how terribly energy inefficient a big chunk of the US housing stock is. I have seen a lot of effort put into cabinets and flooring, but leaving walls with literally no insulation. There is a lot of low hanging fruit out there. I understand that a lot of people are not in a month to month financial situation to make investments that pay back over 5 years, but a lot of them are so bad the payback would likely be a lot faster. Hopefully the IRA will a) not be repealed by the next congress and b) will speed up a lot of those energy improvements.

[NorCal]

I am moving in both directions.  Burning less home heating oil and gasolene, but burning wood.

We have had a fire in the wood stove 4 days so far, but the furnace isn't turned on yet.

The ebikes are certainly replacing car rides and our gas expense was down by 30 dollars last month. 

Our electric use is way up though since we kept a warming light on 30 chicks for the past month.

Wood is generally considered a climate-friendly fuel source, but the details matter greatly.

A tree absorbs CO2 out of the air as it grows, and it is released as you burn it.  This makes it carbon-neutral, as long as the wood is gathered in a way where new trees will replace it.  So gathering a few logs out of the woods is fine.  But clear-cutting a forest for a farm or parking lot is not.

[Syonyk]

How are folks doing?

I picked up a kerosene lantern and heater habit?  And some incandescent bulbs.  Playing around with the concept, reasonably well supported, that the blue light in LEDs is pretty well human toxic, actually, from a range of reasons, so I'm going back to more low color temperature incandescent lighting at night.  An incandescent on a dimmer doesn't use much power, and the amount of light required is rather low too, but the lanterns are so, so nice in terms of light quality, plus useful heat output.  My office heats on propane or kerosene, no huge difference between them.  Kerosene has less of a metallic tang, though.

As the installer told me, they work really well at maintaining a temperature, but they do take longer to bring the temperature up.  I'm overall happy with the performance, but I'm having to adjust my thinking about how cold I let the house get down to at night.  I'll probably only let the temperature drift down 2-3 degrees overnight instead of the 6-8 degrees I used to let it slide.

I'll also experiment with turning the temperature up a few degrees in the afternoons, as it has a higher efficiency when it's warmer out.  I'm not sure what the net effect will be, but I might be able to wrangle a little more efficiency out of it.

Sounds about right from my experience.  I've been wondering about that temperature difference as well - I'd assumed it was due to "dumb" thermostats running the backup coils, but the heat pump grinding away at the coldest time of the morning for hours doesn't seem particularly efficient either.

It's also sinking in how much more energy we use in Denver for heating over cooling.  While it's something I knew previously, it doesn't really sink in until I was able to watch the home energy monitor tick up.  It was a much more invisible expense when it was the harder-to-monitor natural gas.

Oh, absolutely.  Winter on electric is nasty.  We use 2MWh/mo in really cold winters to stay... "not cold."  I'd say "warm," but 65-68F doesn't qualify to most people in the house.

[NorCal]

How are folks doing?

I picked up a kerosene lantern and heater habit?  And some incandescent bulbs.  Playing around with the concept, reasonably well supported, that the blue light in LEDs is pretty well human toxic, actually, from a range of reasons, so I'm going back to more low color temperature incandescent lighting at night.  An incandescent on a dimmer doesn't use much power, and the amount of light required is rather low too, but the lanterns are so, so nice in terms of light quality, plus useful heat output.  My office heats on propane or kerosene, no huge difference between them.  Kerosene has less of a metallic tang, though.

As the installer told me, they work really well at maintaining a temperature, but they do take longer to bring the temperature up.  I'm overall happy with the performance, but I'm having to adjust my thinking about how cold I let the house get down to at night.  I'll probably only let the temperature drift down 2-3 degrees overnight instead of the 6-8 degrees I used to let it slide.

I'll also experiment with turning the temperature up a few degrees in the afternoons, as it has a higher efficiency when it's warmer out.  I'm not sure what the net effect will be, but I might be able to wrangle a little more efficiency out of it.

Sounds about right from my experience.  I've been wondering about that temperature difference as well - I'd assumed it was due to "dumb" thermostats running the backup coils, but the heat pump grinding away at the coldest time of the morning for hours doesn't seem particularly efficient either.

It's also sinking in how much more energy we use in Denver for heating over cooling.  While it's something I knew previously, it doesn't really sink in until I was able to watch the home energy monitor tick up.  It was a much more invisible expense when it was the harder-to-monitor natural gas.

Oh, absolutely.  Winter on electric is nasty.  We use 2MWh/mo in really cold winters to stay... "not cold."  I'd say "warm," but 65-68F doesn't qualify to most people in the house.

Interestingly, our installer said we don't need the backup heating elements based on the insulation in our house.  I'm cautiously optimistic this is true.  But I'm not getting rid of our gas fireplace until we've had a few sub-zero days. 

The thermostats are another thing to get used to.  We have a Mitsubishi unit that is variable-speed everything, but is only compatible with their proprietary thermostats.  I can watch it on the home energy monitor drawing anywhere between 1kW and 7kW depending on what it's trying to do.  While the thermostats are simplistic from a UI standpoint, the overall system is clearly heavily computer controlled with fairly sophisticated algorithms dictated what is going on at any given point of time.  It's very different from the electric signature of a standard AC unit. 

2MWh/mo is crazy.  Our installer estimated about 3MWh for the entire year in our 3,400sqft house.  I think this will be fairly close based on my initial observations.  We use about 1.5MWh for cooling in the summer. 

[NorCal]

I also made the completely facepunch worthy decision to get a reservation on a Tesla.  I'm sort of ashamed by this in these parts, but I think it was the right call for the family. 

I wanted to make a smaller Leaf or Bolt work.  But we're at the point in life where we're doing road trips to national parks and sports tournaments an hour away with the kids.  We've also gotten pretty good at limiting short-range trips around town.  I work from home and my wife bikes to a train station.  In all likelihood, we would have put maybe 30% of our family miles on a Bolt or Leaf, while I think we can put 95%+ of our family's miles on a Tesla.

[Syonyk]

2MWh/mo is crazy.  Our installer estimated about 3MWh for the entire year in our 3,400sqft house.  I think this will be fairly close based on my initial observations.  We use about 1.5MWh for cooling in the summer.

That was the first winter out here, brutally cold for the area, with lows well below 0F (locally known as "Snowmagaddon"), and I also learned, several years later, that our heat pump was in the "30 minute defrost cycle" mode, so that burned an awful lot of the 15kW of backup coils we have (by default, it kicks those on when it goes into defrost - I can't turn them all off, but I did turn off the 10kW main bank, leaving only the 5kW bank shared with the furnace blower enabled - I can turn the rest on if really needed).  It hasn't been nearly that bad since then, but that's my peak consumption month in the winter.

We use... quite a bit more than 3MWh/yr, though.  Closer to 15.  However, that includes transportation energy (the Volt), and includes water coming from a fairly deep well, and is literally the only source of energy feeding into the house.  I'm working on getting it down... facepunch away.  It's a 2015 era 2k sq ft manufactured, and some blower door tests and such have indicated it's quite tight, but I don't have a home energy monitor on the place to really fine tune where power is going.  All of those units are vile "You pay in the data" grade IoT, App Based monstrosities, and the one I'm building isn't fully online yet.

[Indio]

After a year of planning, net zero goals are finally being realized. Replaced damaged "tankless", natural gas, hot water system with a smart heat pump hot water tank that can control water temperature and timing so water isn't constantly being heated, especially while everyone is sleeping. We now have a process in place where any electric intensive appliances are only run after 8pm when electricity is cheaper. Sold nat gas unit on craigslist for spare parts.
Installed 5 mini-split heat pumps in the bedrooms and 2 common areas. Electrician will connect everything next week. Family members all prefer different bedroom temps at night. Having a dedicated room unit will reduce the amount of morning whining I have to listen to when kiddos won't get out of bed and get ready for school because it's too cold.
Bought 23 solar panels with IQ8+ microinverters that will be delivered next week. Installation is scheduled for first week of December, but the date keeps changing. Hopefully, they will be installed before it begins snowing.
Hung solar string lights in south facing windows to act as passive lighting. It definitely adds ambience to the living and dining rooms.

[rockeTree]

It's cool to see everyone's progress, and issues - I would not face punch the tesla given a reasoned analysis myself, though it is not for me. I do find that the regular car maintenance on a car I use less and less is annoying. Just had to replace a battery and was unreasonably irked.

When I had one of the old 80s heat pumps in a previous house you really couldn't let it go very low overnight or it would never catch up before the next night without the emergency resistance strips; I wonder if that's more or less true in cold climates with the better ones nowadays? Perhaps the fancy thermostat is working on learning the climate and habits of folks over time.

If the chicks are for eggs and reducing food waste presumably some of that increased use is replacing energy used in intensive battery farm operations that would otherwise provide food. Home production presumably is less efficient in some ways but my recollection is a lot of those farms heat with natural gas so your electricity may be cleaner overall.

Still no need for central heat here is the coolest fall of the rest of my life :-/

[NorCal]

Here's an update on the new heat-pump with zero backup elements.

We got through our first cold snap of the year, and it performed just fine down into the single digits.  We had a high of 22 and a low of 7 on the coldest day, and it ran for roughly an hour every other hour.  We'll still get some colder days in January and February, but I feel good about its capabilities and sizing.  It also keeps the temperature in our bedrooms much more consistent than the prior furnace.  I'm also appreciating the humidifier and the improved air quality with the fancier filter.  So it's a functional win in many ways.

On the negative side, it seems to be sucking down more electricity than I originally expected.  It's too early to come up with a full-year estimate, but I don't think the couple-hundred of annual savings I expected will materialize.  It might even cost more than gas, but it will probably be a small difference.  It used roughly 50kWh of electricity on that cold day I mentioned above, and uses roughly 25-30kWh on a more mild say like yesterday (a low of 20 and a high in the low 50's).

[rockeTree]

Sad to see Syonyk depart us but passing along news of a device allowing folks with 100 amp service/panels to add car charging by pausing the battery charging whenever the house approaches the maximum load/switching between specific loads depending on setup.

https://simpleswitch.io/pages/press

[RWD]

Sad to see Syonyk depart us but passing along news of a device allowing folks with 100 amp service/panels to add car charging by pausing the battery charging whenever the house approaches the maximum load/switching between specific loads depending on setup.

https://simpleswitch.io/pages/press

That looks really slick!

[nereo]

That does look nice

Not exactly the same, but we opted for a charger that has two whips and runs off a single circuit (which could be set at 20, 30, 40 or 50amp). When both vehicles are charging it splits the current in half. As soon as one finishes (or is unplugged) it sends all the juice to the remaining vehicle

As we were upgrading the service to 200amp we wired it for 50amp, because the run was <10 feet and the cost difference was negligible. But a 240v/20amp is plenty to recharge even two cars overnight for anything except extreme commutes.

[TheAnonOne]

Living in MN, and having a large(r) house, I don't think its feasible to dump the gas furnace for electric, as far as heating goes. I have heard good things about heat pumps but, I don't think that's 100% gas free either.

The gas range, gas water heater, and gas clothes dryer are all candidates though, but most are very new and it's probably worse for the environment to sunset appliances early.

The upside we have is a fairly large solar array, so maybe that balances it out a bit!?

[scantee]

Living in MN, and having a large(r) house, I don't think its feasible to dump the gas furnace for electric, as far as heating goes. I have heard good things about heat pumps but, I don't think that's 100% gas free either.

The gas range, gas water heater, and gas clothes dryer are all candidates though, but most are very new and it's probably worse for the environment to sunset appliances early.

The upside we have is a fairly large solar array, so maybe that balances it out a bit!?

I’m in MN and purchased a heat pump in spring to replace my extremely aged AC. The heat pump has worked great so far. It is set to automatically switch to the furnace when the temp dips below 5 degrees. Right now, I have it fully switched over to the furnace because of the cold snap we’re going through. I plan to do that any time the daytime high isn’t forecast to get above 10 degrees for more than a day as I don’t want it to be regularly switching back and forth between the heat pump and furnace.

My understanding is that in MN you need a back-up heat source unless your house has a tight building envelope like those on passive houses. Few homes do have that, even brand new ‘high-quality’ ones. I am fantasizing about my next house having a passive house (or more likely Pretty Good House) envelope and getting off of gas entirely.

[NorCal]

Living in MN, and having a large(r) house, I don't think its feasible to dump the gas furnace for electric, as far as heating goes. I have heard good things about heat pumps but, I don't think that's 100% gas free either.

The gas range, gas water heater, and gas clothes dryer are all candidates though, but most are very new and it's probably worse for the environment to sunset appliances early.

The upside we have is a fairly large solar array, so maybe that balances it out a bit!?

This is one of those things that's evolving rapidly, and seems to be changing faster than most HVAC contractors are willing to change their habits & practices.  Their fear of a dissatisfied customer and a call-back is greater than their desire to try something new.  Which I get, but it is a challenge in moving the market forward.

You're looking for that balance of what a heat-pump can deliver and what type of backup is needed.  As heat pumps become effective at lower and lower temperatures, the balance of what your backup looks like may shift.  If you get a heat pump effective down to -20, it may be that an electric backup isn't a horrible idea, as it would be used pretty infrequently.  Or maybe gas backup would be needed, but only on a few days a year.  Or maybe my knowledge is irrelevant in MN.  You'd want to talk to some expert installers to figure out what works in your climate.  You probably have multiple realistic options, with various HVAC installers pushing their own preferred solutions

I recommend at least talking to a local installer that specializes in heat pumps and home electrification when you're ready.  Some have popped up in the Denver area, and I think most metro areas will start seeing them in the next few years as the IRA incentives start being better marketed.  I think your options and prices for heat pumps will improve over the next few years at manufacturers ramp up production and installers become more familiar with them. 

My no-backup heat pump is about to get tested with a -16 low and a 3 degree high on Thursday.  This is my personal moment of truth. 

I've run the numbers for myself on the emissions savings of electrification in Colorado.  I've found that there is overall savings in switching from gas, but the savings is on the smaller side due to how much coal we have in our power mix.  However, our grid is cleaning up pretty fast, so the emissions savings will really start to accrue in the back half of this decade.  I'll say that this is something that is super important in the long term, but it isn't something you should feel needs to be urgent.  Most of the emissions savings exist in the future when coal is a smaller part of the electricity mix.  Your numbers in Minnesota would be a bit better than Colorado's, as you have a lot of nuclear power in your mix.  But I expect the overall story would still hold.

I still recommend prioritizing the heat-pump water heater.  Based on my math, that will pay for itself in about 5 years if you can get it installed for a reasonable price.  That's both an emissions savings and a financial no-brainer.  The HVAC, dryer, and stove would have a much lower financial ROI. 

[NorCal]

Does anyone have experience with window inserts?  There's no way I could financially justify replacing windows in my house, but I know windows are one of my major source of energy losses.

I'm specifically looking at https://www.windowinserts.com/.  They're still pricey, but it's a DIY project that may have a reasonably ROI.

I'm thinking about trying them in a few rooms in our upstairs that end up with a bit of a temperature differential from the rest of the house.

Has anyone else tried them?

[nereo]

Does anyone have experience with window inserts?  There's no way I could financially justify replacing windows in my house, but I know windows are one of my major source of energy losses.

I'm specifically looking at https://www.windowinserts.com/.  They're still pricey, but it's a DIY project that may have a reasonably ROI.

I'm thinking about trying them in a few rooms in our upstairs that end up with a bit of a temperature differential from the rest of the house.

Has anyone else tried them?

I've got some experience.  I actually volunteer with a community group that makes window inserts for families in need in New England, and I've made my own now for three different houses.

see here:
https://windowdressers.org

If you are the least bit handy it's dirt simple to do and runs about $10-12 per standard window if you have to buy all the materials at full price. There are ways of doing it much more cheaply.  In brief, you need a wood frame (normally 1-by wood, but you can get creative and use whatever's on hand or rip a 2x4), some screws, a pack of window film (buy a large roll if you are doing > 3 windows!) and some foam weather stripping.

Step 1: make a wooden frame that is ~1/2" smaller than your existing window
Step 2: apply window film on BOTH sides (this will create TWO insulating air pockets on your window
Step 3: apply 3/8" foam weather stripping all around the window frame.  Friction fit.

If you feel comfortable with tight measurements you can cut the clearance to 3/8" and use 1/4" weather stripping, saving you a few bucks per window on foam. I use a kreg-jig and do pocket holes the same way you'd build a face-frame for a cabinet, but you can also just screw directly in from the sides... you won't see the screws anyway (they will be behind the weather stripping).
It's also a good idea to add an eye-hook to two corners to facilitate removing the insert in the spring (they act like handles)

PM if you have further questions. 

[rockeTree]

Interesting, tempted to try that in our ugly and leaky big window that we never open and rarely even open the curtains in front of. We mean to fix it but keep delaying for one reason or another. (Money, supply chains, decision paralysis about what to get/who to hire)

Good luck on the heat pump acid test Thursday!

[NorCal]

Does anyone have experience with window inserts?  There's no way I could financially justify replacing windows in my house, but I know windows are one of my major source of energy losses.

I'm specifically looking at https://www.windowinserts.com/.  They're still pricey, but it's a DIY project that may have a reasonably ROI.

I'm thinking about trying them in a few rooms in our upstairs that end up with a bit of a temperature differential from the rest of the house.

Has anyone else tried them?

I've got some experience.  I actually volunteer with a community group that makes window inserts for families in need in New England, and I've made my own now for three different houses.

see here:
https://windowdressers.org

If you are the least bit handy it's dirt simple to do and runs about $10-12 per standard window if you have to buy all the materials at full price. There are ways of doing it much more cheaply.  In brief, you need a wood frame (normally 1-by wood, but you can get creative and use whatever's on hand or rip a 2x4), some screws, a pack of window film (buy a large roll if you are doing > 3 windows!) and some foam weather stripping.

Step 1: make a wooden frame that is ~1/2" smaller than your existing window
Step 2: apply window film on BOTH sides (this will create TWO insulating air pockets on your window
Step 3: apply 3/8" foam weather stripping all around the window frame.  Friction fit.

If you feel comfortable with tight measurements you can cut the clearance to 3/8" and use 1/4" weather stripping, saving you a few bucks per window on foam. I use a kreg-jig and do pocket holes the same way you'd build a face-frame for a cabinet, but you can also just screw directly in from the sides... you won't see the screws anyway (they will be behind the weather stripping).
It's also a good idea to add an eye-hook to two corners to facilitate removing the insert in the spring (they act like handles)

PM if you have further questions.

Thanks for sharing!  What a great organization.

I will look into that.  It's within my DIY capabilities.  I just need to figure out if my wife has a strong opinion about the appearance of film vs. the more expensive panes.

[nereo]

If you don’t like the look of film, you can use clear 1/8” acrylic.  On the plus side it makes the inserts look better and much more durable (can be used year-after-year without redoing the film). The obvious downside is a two layers of acrylic for each window can drive the cost up close to $100 per insert for a medium-sized window…

 

[NorCal]

Here's an update on the no-backup heat-pump's performance in Denver.  For context, this is the coldest Denver has been in several decades, although it doesn't constitute a record.

It was 40 degrees out when I came home at 4pm yesterday.  It was 0 degrees by 6pm, and -8 when I went to bed last night.  It's been hovering between -10 and -14 this morning.  We expect a high of 0 or 1 this afternoon.

Typically, we'll get a few days per year where it dips below zero in the morning with highs in the mid-single digits.  So this more extreme than I've seen in my 4 years here. 

I pre-warmed my house all  the way up to 77 degrees yesterday due to the uncertainty and left the thermostat set there overnight.  I normally set it at 68.  It stayed at that temperature until at least 10pm last night.  When I woke up this morning, the house had dropped to 73 degrees.  So it was still on the warmer side, but it was beyond the heat-pumps capabilities to keep it all the way at 77.  The heat-pump was still generating heat throughout, just not enough to keep it all the way to the set temperature. 

I ran our gas-insert fireplace a bit this morning.  The temperature stabilized at 73, and even increased to 74 as I was typing this.  I'll go the rest of the day without the fireplace and see how the temperature turns out.

I got an email from the heat-pump installer, and I'm pasting it here verbatim:

It looks like it might be exceedingly cold later this week. We wanted to remind you that although the cold climate heat pumps we installed at your home work all the way down to -24 degrees, they do lose some heat output below 0 degrees (our "design" temperature), and we want to make sure you are prepared for a potentially colder home.
 
Here are a couple of things to consider for the cold snap:
 

    Pre-heat your home. Turn your thermostats up more than usual and do not turn them down at night.

    Consider a back-up heat source. An inexpensive electric space heater, while not particularly efficient, can help. A 1500 watt heater can provide over 5000 btus/hour for about $5/day. If you have a fireplace, this is also a good backup heat source. And in a pinch some folks will even use an oven (bake lots of holiday treats!), but only if you have an electric oven as gas can produce carbon monoxide.

    If you have had trouble with freezing pipes in the past we recommend running a drip of water per fixture to keep them clear.

 
Lastly, just so you know, we purposefully design our heat pump systems to meet the expected range of Denver weather. If we design your heating system to meet these extreme temperatures (<1% of the year), the overall system efficiency suffers. It's like installing a giant engine in your Prius; it can go up the hills super fast, but the overall gas mileage will suffer.

Please let us know if you have any questions or concerns. Have a very happy holiday season!

I'm sorta torn about how this is going.  On one hand, I'm happy with the system, and I can clearly use it to keep my house warm on even the coldest day.  But I don't think I'm comfortable completely cutting the gas line, and I don't know how acceptable this pre-heat solution will be to the average consumer.  Or whomever I eventually sell my house to.  Most consumers just want a thermostat they set and never think about. 

Hopefully this information is helpful to those of you considering a heat pump. 

[RWD]

Interesting information, @NorCal. The house only dropping 4F degrees overnight sounds like a major win to me. I'd be curious how well it can hold a lower temperature, say ~67F degrees, in extreme cold. Because 73F degrees sounds way too warm for me in the winter. If I had my thermostat set at 68F and woke up to the house at 64F that would be perfectly acceptable in my opinion (but I suspect that the system would keep up better if the temp was set lower).

In a climate where it was expected to get even colder on a regular basis I think a ground source heat pump would probably be worth considering.

[nereo]

Thanks for the update NorCal

FWIW, here’s what we had in Quebec: an 18,000btu Fujitsu halcyon for a 1,050 living space, with three baseboard electrical heaters (one in each of the two bedroom, plus one in the main living space). Temperatures were considerably colder than what you are experiencing in Denver- weeks of temperatures where it never rose above 0°F and the coldest nights would drop down to around -30°F (our coldest night over an eight year period was -35.5°F according to our external weather station).

The heat pump handled everything down to about 0°, when the baseboard heaters were needed to keep the home at a more reasonable 66-68°. This came pretty close to maximizing efficiency as well iirc. We never had an issue keeping the home at a reasonable temp, even during extended cold snaps. It was also an automatic setup - the baseboard heaters just kicked on as thermodynamics caused the home temp to drop a few degrees. That said, I know I’m my new model there are ways of tying the heat pump to another heat source seamlessly.

I’m not a fan of a gas backup heat source as the hookup charges can add up - certainly far more than the extra electricity cost of resistive electrical heat, plus all the negatives of a gas distribution network.

[NorCal]

Interesting information, @NorCal. The house only dropping 4F degrees overnight sounds like a major win to me. I'd be curious how well it can hold a lower temperature, say ~67F degrees, in extreme cold. Because 73F degrees sounds way too warm for me in the winter. If I had my thermostat set at 68F and woke up to the house at 64F that would be perfectly acceptable in my opinion (but I suspect that the system would keep up better if the temp was set lower).

In a climate where it was expected to get even colder on a regular basis I think a ground source heat pump would probably be worth considering.

Yes, it was way too warm for me last night.  I was starting from a point of being conservative on it, and probably won't set it that high again. 

The biggest change for me is my mental model about how to run the heat.  Traditionally, the most efficient way to use a furnace is to let the house get cold at night and turn on the furnace in the morning.

However, a heat-pump takes a longer period of time to increase the temperature than a traditional furnace, even though it is extremely efficient at holding a temperature.  So I don't let the house get quite as cold at night, and I have it kick on a little earlier in the morning.  After fiddling with it, I've found that a nighttime setting of 65 is best, but I have it go back up to 68 at 4:45am so that the house is warm enough when I'm up between 5 and 5:30.  A setting of 64 just takes too long to warm in the morning.

In addition, the system is noticeably more efficient when the ambient temperature is higher outside.  There's a noticeable inflection point above freezing.  This is visible in my home energy monitor, but not in any other noticeable way.  So my most efficient option is to usually crank up the temperature a few degrees in the mid afternoon when it's warmer out.  This still feels a little backwards to me, but the numbers seem to support it.

[grantmeaname]

Man, I'm bummed I didn't find this thread sooner, but glad I got to spend a big chunk of today reading through the history.

I've bought a house rather than renting apartments for the first time in my life and moved in a month ago. I've got 2200 sq.ft. in the Midwest, so cold winters and hot humid summers. The prior owner was here 53 years and yet the house is hilariously unoptimized - $2k of insulation in 1969 would probably have saved him six figures in 2022 dollars.

So far I've done ceiling fans, induction stove, an energy audit, and refililng failed double-pane windows. In two weeks I get insulation in the walls and attic. Then in the spring we're looking at geothermal and heat pump water heater, and a standing seam metal roof and PV solar, and then hopefully no more spending money for a good long while.

That will leave just transportation as the last big carbon user. The first couple pages of this thread triggered a few hours of good hard thinking about replacing my '12 Fit with a new Chevy Bolt, but we can't get the credit and without it even the hilariously cheap Bolt's ROI is just not good enough to add to the list.

[Glenstache]

Man, I'm bummed I didn't find this thread sooner, but glad I got to spend a big chunk of today reading through the history.

I've bought a house rather than renting apartments for the first time in my life and moved in a month ago. I've got 2200 sq.ft. in the Midwest, so cold winters and hot humid summers. The prior owner was here 53 years and yet the house is hilariously unoptimized - $2k of insulation in 1969 would probably have saved him six figures in 2022 dollars.

So far I've done ceiling fans, induction stove, an energy audit, and refililng failed double-pane windows. In two weeks I get insulation in the walls and attic. Then in the spring we're looking at geothermal and heat pump water heater, and a standing seam metal roof and PV solar, and then hopefully no more spending money for a good long while.

That will leave just transportation as the last big carbon user. The first couple pages of this thread triggered a few hours of good hard thinking about replacing my '12 Fit with a new Chevy Bolt, but we can't get the credit and without it even the hilariously cheap Bolt's ROI is just not good enough to add to the list.

If you are going to a metal roof, is it worth also going to spray foam insulation in the attic? Kudos on all the efficiency upgrades. Not only will those save you money, but will also make the house wayyy more comfortable. Don't forget to seal all of the air entry points (lights, fans, etc) in the attic before you add insulation if you are going the blown-in insulation route.

[tygertygertyger]

I've bought a house rather than renting apartments for the first time in my life and moved in a month ago. I've got 2200 sq.ft. in the Midwest, so cold winters and hot humid summers. The prior owner was here 53 years and yet the house is hilariously unoptimized - $2k of insulation in 1969 would probably have saved him six figures in 2022 dollars.

So far I've done ceiling fans, induction stove, an energy audit, and refililng failed double-pane windows. In two weeks I get insulation in the walls and attic. Then in the spring we're looking at geothermal and heat pump water heater, and a standing seam metal roof and PV solar, and then hopefully no more spending money for a good long while.

We're in a similar boat! Bought a house in the midwest about a year ago, the previous owners lived here for 50 years, and yet there were cold breezes coming in around multiple windows because they had never caulked around them. One set of windows had a couple inch gap between the bottom of the window frame and the drywall. We fixed the gap, but recently found using thermal imaging that the drywall has no insulation in it... despite it being in the "new" part of the house.

We have done air-sealing in the attic and are getting ready to add more insulation to the meager 3-4 inches up there. Hopefully that'll be done in the next couple weeks. I'm impressed by your efficiency on getting so many projects done!

[grantmeaname]

If you are going to a metal roof, is it worth also going to spray foam insulation in the attic?

I don't think so, but I am a novice in this area. I read the marginal gains from going past R-49 (or even past R-38 honestly) were very tiny, like tens of dollars per year, so I thought R-49 blown cellulose and air sealing was plenty. Do you have a different view?

Kudos on all the efficiency upgrades. Not only will those save you money, but will also make the house wayyy more comfortable. Don't forget to seal all of the air entry points (lights, fans, etc) in the attic before you add insulation if you are going the blown-in insulation route.

I've got enough other house stuff going on that I'm just writing a check for all the work rather than writing a check for the walls (dense pack cellulose foam) and doing the rest myself. They're doing duct sealing, attic air sealing, and replacing lights as part of that. Better to get it done than let the project languish and fall down the to do list - especially since it's holding up the geothermal system.

[grantmeaname]

We're in a similar boat! Bought a house in the midwest about a year ago, the previous owners lived here for 50 years, and yet there were cold breezes coming in around multiple windows because they had never caulked around them. One set of windows had a couple inch gap between the bottom of the window frame and the drywall. We fixed the gap, but recently found using thermal imaging that the drywall has no insulation in it... despite it being in the "new" part of the house.

Truly amazing. My jaw dropped when I found out.

I'm impressed by your efficiency on getting so many projects done!

To be honest I'm only really efficient at writing checks and calling contractors. As far as things we've done ourselves so far, it's mostly calculating electrical demand/system sizing, running ethernet to the whole house (way easier when there's no insulation to fish through), and putting in the induction stove. But I think we will be going the DIY route on the solar build - $7k for a weekend of work is too much money to pass up.

[bacchi]

If you are going to a metal roof, is it worth also going to spray foam insulation in the attic?

I don't think so, but I am a novice in this area. I read the marginal gains from going past R-49 (or even past R-38 honestly) were very tiny, like tens of dollars per year, so I thought R-49 blown cellulose and air sealing was plenty. Do you have a different view?

It's probably worth it to install some rigid foam on top of the deck. R38 in the attic is less overall because of thermal bridging.

Table 1 has the ratio for top:under deck insulation. https://www.buildingscience.com/documents/building-science-insights-newsletters/bsi-100-hybrid-assemblies

[grantmeaname]

I've got to blow new insulation because I'm at like R-11 in the attic (*shudder*). It seems like this is suggesting I could blow a few less inches of cellulose and then install rigid boards and a second layer of sheathing, but won't that be more money and more work for an equivalent total R-value (thermal bridging aside)? If I'm definitely going up to R-49 for the blown cellulose, is it still worth it to also do rigid foam and sheathing?

Who does this work - roofers? Motivated DIY?

Thinking about ROI and it's looking really hard to get there. Is there a good way to estimate the heat loss savings?

[bacchi]

For our metal roof, roofers installed the rigid foam boards and purlins (1x4s) instead of a 2nd layer of sheathing. However, it does mean extending or replacing the fascia, which can be a PITA.

In your case, I'd rent a blower at Big Box and blow in a lot of cellulose. It's a huge ROI if you DIY.

[grantmeaname]

I think the ROI is still huge paying to have it done.

It's a small fraction of the cost of the total project I'm having done - $2k of $7k - and just buying the cellulose at the hardware store is north of half of that. (The dense pack cellulose in the wall cavities is $4.7k, and the air sealing and fire dams for lights and the like are a tiny minority.)