Micro heaters cut 87% off my electric heat bill
richsoil.com
richsoil.com
Then you use insulation. This especially is something that feels nobody in the US has heard of. At least in California.
As a result, your radiators are turned down to 2 out of 10 all day (heating turns off automatically overnight), and you have to sometimes open a window when it's -13C outside so you don't sweat.
Now I don't know how much people spend on heating when they live in a house house, but my apartment's heating bill this winter was about 30 euro a month[2] and I had to keep all my radiators turned off because the one in the bathroom couldn't be regulated. So that alone was enough to heat everything to extremely comfortable levels.
tl;dr don't heat with air, insulate your fucking house, and install modern windows
[1] Could just be where I'm from, but it seems fairly common in Europe and not at all something I've seen in the US
[2] I think my gramps spends about 2k euro in October to pay for natural gas that heats his house until some time in April. So about 300/month for a ~10 bedroom house because he's got a house that's way too big.
Also, if you're in an apartment your place might be so hot because you have a neighbor that has cranked the heat. I used to be able to keep the heat off in a place I lived at because the person that lived below me had their place like a sauna.
I once asked him if there were any wooden houses in Scotland, he replied "Yes, we keep our lawnmowers in them".
Austro-hungarian empire outlawed wooden houses in the early 19th century. Hence we still don't have any, and if you live in a wooden house[1], you are considered to not have been able to afford a proper house and thus looked down upon.
[1] becoming common with drywall construction methods. Particularly because it's cheap and fast.
Much cheaper to build walls from local stone and save the imported wood for the floors and roofs.
in village homes they use pechkas [1]. a giant radiant heater that uses firewood and sits in the middle of the home. most are adapted so that you can use them to cook too.
In defense of Californians, most of us rarely, if ever, turn on a heater and most homes here don't have AC. Our heating and cooling costs are a small fraction of those of you who live in places that have seasons.
There's lots of poorly insulated homes in California, either because they are old or cheaply-made, or because they are in places that have milder weather where it is less necessary. But there are also lots of well-insulated homes in California.
> In defense of Californians, most of us rarely, if ever, turn on a heater and most homes here don't have AC. Our heating and cooling costs are a small fraction of those of you who live in places that have seasons.
As a Central Valley resident, I think you may be falsely generalizing from "the Bay Area" to "California". Even cheap homes in the Valley usually have AC, even if its not central AC.
Given those costs, it's very difficult to get a return on better insulation or insulated windows.
That really depends on where in the state you are. Coastal cities, generally, more so. Inland, even within the SF Bay Area or Los Angeles, you'll find a lot of AC, and in the Central Valley it's a huge determinant of load and peak load.
Then why on earth was I freezing my balls off in Menlo Park this November? The weeks before we realised our house even had heating were miserable. And even afterwards, as soon as the heaters weren't blowing hot air, or you were more than 3ft away, you were instantly cold and miserable.
I bumped into a guy here from Northern Germany who said he's never been so cold as in a kiwi house in the winter.
The NZ government is trying to change minds, but I still see houses going up with empty wall cavities and no air barrier. But then, the natives wear shorts and tees outside in 5 degree weather all winter. So, maybe its just me.
Houses are generally pretty under-insulated though.
It can work for well insulated and airtight houses but I'm not a fan (pun not intended) because you're tying two different functions (heating and ventilation) together.
In Denmark it's getting pretty common to produce it via trash incinerators. They produce a kind of heat that is apparently that not great for electricity generation, but pretty good for district-heat production. So much so that the price of unsorted municipal garbage in both Denmark and Sweden has risen in the past few years, because it has become a valuable energy source.
Most areas which have implemented a trash-to-energy program pretty soon run out of high-grade suitable trash and resort to imports. Entropy always wins.
As others have said, try cooling a house with rads. It's not like North America is oblivious to radiators; they were very much a standard way of heating houses before the popularity of AC made forced air a much more logical choice.
> Then you use insulation. This especially is something that feels nobody in the US has heard of. At least in California.
If you only know about the completely unrepresentative California, why expose your ignorance by projecting to all of the U.S.? And further, why bother calling it "the European model"? Obviously the way houses are built, insulated, and heated in a country like England or Norway is going to differ wildly from how it's done in say, Greece.
Even within California the climate differs so much that there are 4-5 different building codes for insulation. But in general, the minimum code for insulation in California is around half that of states with colder climates (e.g. R30 for ceiling in California, R50 for Wisconsin).
Because I've seen radiators and decent insulation in literally every house I've ever been in anywhere in Europe. Warm places like Greece and Portugal included.
Differences are mostly attributable to the age of a house rather than its location. But arguably old stone houses (200+ years) in hot places have the best insulation in that they are simply built with 1m+ thick walls and super tiny windows.
Insulation. It works. For both hot and cold.
Granted, the moderner your building and the thinner walls and more cement it uses, the likelier you are to need AC in summer. In old buildings you get enough cooling by just airing the house overnight and keeping everything closed during the day ... unless of course you have a big computer in your room. Then you're screwed.
I've always found the popularity of AC in the US bizarre, every single European who've traveled to the US in the summer and had to spend extensive time inside complained about the cold and quickly switched to long sleeves and trousers.
The author seems totally unaware of the efficiency gains that a heat pump can provide. A 300W space heater will be easily outmatched by a heat pump that consumes 300W (unless we're dropping way, way below 0C). The efficiency is likely ~3x [1]. I hope the author isn't making this mistake out of disdain for centralized hvac, since window unit heat pumps are readily available for small spaces.
Without looking into specifics I decided that a couple of small well placed space heaters (in rooms with traffic) might save electricity over the whole house heat pump.
I had 3 small space heaters that ran most of the day and night and I turned the heat pump down to 50. I was wrong. My electric bill was higher than just running the heat pump, and most of the house was cold most of the time.
But it's hardly the only one, or the best. For northern climates, taking a whole-system approach to home/structure design gets you a tremendously greater payoff in terms of energy savings.
Among the most powerful demonstrations of this I've seen are Thorsten Chlupp / Reina LLC's experiences designing and building zero net energy homes in Fairbanks, Alaska.
His videos are long (~90 minutes) be exceptionally comprehensive. The TL;DR is:
• Total envelope. He pays exceptional attention to any thermal envelope penetrations. All emissions (air, water, sewage) pass through thermal exchanges.
• Thermal mass. The foundation, flooring, central masonry stove, and a 5,000 gallon stratified thermal storage tank all store and scavange thermal energy both passively and actively.
• Moisture control. Heat barriers introduce thermal issues. Chlupp makes use of multiple glazings, window setbacks, and _exterior_ thermal shutters to minimize moisture buildup on windows. Moisture barriers and ventilation of interstitial spaces is designed to clear moisture.
• Heat pumps. Rather than create thermal energy directly (other than the masonry stove), Chlupp moves heat using ground-loop heat pumps.
• Solar and net metering. Solar panels (yes, in Alaska) and net metering help him arrive at net zero energy. His first-year goal wasn't met due to plug-in hybrid vehicles, an oversight in his energy modeling.
Though conceived as a whole-system ground-up greenfield design, the principles are applicable to a lesser degree as retrofit options.
Oh, and for heating your bed: a 1 liter Nalgene bottle, filled with boiling hot water, and slipped into a wool sock, will heat your bed cozily. Two are almost certainly too hot, but you're welcome to try. And they'll last the night.
Alaska's First Net Zero Energy Homes Performance Update http://fixyt.com/watch?v=Xen_VWyDezY
Path to Net Zero Energy Series -- Alaska's first Net Zero Ho... http://fixyt.com/watch?v=AtHkvpRI6fc
In a well-insulated, well-designed house, you won't have any worries about frozen pipes, even with a low thermostat temperature, since all pipes will be inside the insulated enclosure.
There's a whole community of people trying to build better buildings out there. The Passivhaus people, the PERSIST (Saskatchewan) and REMOTE (Alaska) approaches (http://www.greenbuildingadvisor.com/blogs/dept/musings/getti...), Building Science Corporation, the NRC in Canada (http://archive.nrc-cnrc.gc.ca/eng/ibp/irc/cbd/digest-index.h...).
Some of these people are ex-hippies or hippie-ish, and there is a bit of bullshit out there, but there's certainly plenty of better ways to build and renovate homes for energy efficiency.
Key design points:
- Insulation, insulation, insulation. We have 30cm cellulose in the walls and 36cm in the roof plus some 5cm fiberglass in the space between the walls and drywall.
- Airtightness, in combination with a ventilation system (with heat recovery).
- Large windows (triple glazing) on east, south and west sides to get free heat from the sun in the winter but have some screens to keep the sun out in the summer.
- We use a geothermal heat pump to prepare hot water and to be able to heat the house a little bit in the winter when needed, using underfloor heating pipes. Extra bonus that has turned out to be essential: we can use this system to passively cool the house by simply pumping the water through the pipes and into the ground. This can lower the temperature in the house by several degrees in an energy efficient way.
Based on our energy consumption for the two months we've lived here we'll end up at around 3500-4000kWh per year. And that includes everything: heat pump, ventilation, all electrical appliances, ...
Building such a house isn't rocket science. The materials and techniques are well known and readily available (at least here); it's mostly a matter of good planning upfront and paying attention to the details when executing. Not all construction companies are up to speed but they're slowly getting there (or they'll disappear).
As a matter of fact: the EU has mandated that by 2020 every newly built house must be more or less equivalent to a passive house.
And he uses massive amounts of insulation. He creates a large (big enough to walk in) wall cavity, and fills that with blown cellulose. I think it's on the order of twenty tons of cellulose. Not only does it insulate, but it forms a thermal mass.
Similarly for his foundation: a large sand base as I recall, then a slab, which create yet more thermal mass. The masonry stove at the building core is another, and finally a 5,000 gallon vertically-arranged water tank. This has a perforated distributor, and the idea is that he circulates water through his masonry stove and solar thermal panels whenever the output of those is warmer than the water at some point in the tank -- it tends to be ~120F near the surface, and ~40F near the bottom. The water stratifies according to temperature, and he banks his BTUs.
The big stratified water tank is a well known concept but you need to have room for such a big tank. Here in Belgium space is at a premium so houses tend to be on the small side. Solar thermal panels are often connected to a tank of 500 litres or less, simply because of space constraints...
There are several possible construction models; it's a matter of selecting one that fits your local climate and your habits. Not everybody likes a stove for example.
The last couple of years we've seen a shift happening from applying the passive house concepts on new houses (pretty much a solved problem) to renovating existing ones. Here in Belgium there's a massive amount of old houses constructed before the seventies/eighties which is when they finally started putting in insulation. Now that all new houses are energy efficient it's time to tackle the massive waste in those old houses. Most people buy such an old house and start renovating so there's a lot to be gained.
An alternative he points to in Europe is a community / neighborhood storage, where a thermal storage tank serves a number of homes. Another option is seasonal thermal storage using ground-base storage, where you've got suitable geology (no moving water table to whisk your heat away helps a lot), used in at least one instance in Canada. Heat is pumped in during the summer and extracted in the winter, as part of a ground-loop heat pump.
While floor heating is cozy and wonderful, I am somewhat skeptic on the comfort of floor cooling.
Of course my house is all electric, so there are no electric vs. natural gas conversions to make.
Air flows between rooms / through doorways can also be surprisingly stubborn, but it does happen.
The specifics will depend on the size of the interior space, position of the kitchen, access to exterior walls, etc.
Don't worry about energy consumption; it's negligible for the hot water bottle, and for the electric blanket as well, especially compared to keeping your house heat up high at night. Not really worth debating, though do note: the hot water bottle has a fail-proof, gradual, automatic shutoff, it fits any size bed, requires no electric outlet, requires minimal storage space during warmer months (so you can have an extra for guests), and has an initial investment of, like, $4. :)
The soft-walled ones may discolour slightly.
I put boiling water into a fairly thin-walled rubber one, and it sprang a leak a few minutes later, so I'm more careful now.
Source on that? I had a quick search, and it seems to be one of those rumours... The only reference I could find was old (pre 2001) and faulty models.
What I've found is that a liter bottle packs a goodly amount of heat, the sock regulates the release just about perfectly (and keeps you from scalding yourself against it), and the result is quite toasty. There's also nothing quite like having warm toes in bed.
The bottles are still warm in the morning under a good duvet.
A highly effective low-tech solution.
Yes, the efficiency of heating the water in the first place may vary, though that's energy that's almost certainly delivered to your residence space, so in that regard it's pretty much a wash.
Most homes are heated using fuel oil. We moved into an awesome old house last summer, and we were worried about heating costs. The landlord had a heat pump installed last fall. I'm sure we would have had some $300-$500 heating bills (per month) last winter if we were using oil, but the heat pump never cost more than $150 per month.
That was a relief, because we spent one winter in a drafty house with a malfunctioning boiler system. That was not fun at all, and we moved out just because of heating costs.
I'm hoping to buy a house sometime in the next few years, and the first thing I'll do is complete a thorough heating overhaul of the house.
(I ask because we just bought a house in montana and are thinking about a heatpump before winter...we have propane radiant heat now. We'd want one that would work with cold temps though it rarely gets bellow -10 F here.)
Most of our winter weather hovers in the mid 30's, day and night. We get occasional cold spells in the 20's, but it's rarely in the teens and I've seen single digits once in twelve years here. I don't think it's ever been below zero here.
It was interesting to get used to the heat pump just being on low all the time. Our monitor stove would come on in bursts, and you'd notice a steady heating/ cooling cycle throughout the day. The heat pump just puts out a steady, slightly warm airflow all day long.
I'm not sure how heat pumps behave in colder climates. Our landlord did not remove the monitor stove when he had the heat pump installed, and it was nice to know we could fall back on the monitor if the heat pump was not putting out enough heat. You might consider leaving the propane system in place this winter if you do try a heat pump. It might just give you a little peace of mind about not having an issue in the middle of a cold spell.
Feel free to send an email if you're curious to ask more.
It's one of his design goals. Minimizing your furnace requirements (but not eliminating them) gives you progress, but it remains a major expense (for installation and operation). Eliminating it entirely addresses a huge cost element for northern construction.
I don't live in Alaska myself, and can't speak to the full validity and credibility of his work, though it seems pretty solid. But I'm absolutely impressed with his attention to detail and the specifics of his methods and approaches.
What I've found is that almost all of our home's electrical usage comes from heating (heaters, clothes dryers, and hot water).
Everything else is almost a rounding error. For example: I saw almost no change when we switched from incandescents to LED lighting (even in the summer when we're not heating the house) but I saw a large change with efficient shower heads and washing clothes on cold.
However, if you're cooling your house incandescents are a triple whammy as AC isn't nearly as efficient as heating.
But electronics is not nearly as benign as you suggest, it depends on your lifestyle. E.g. I have 4 TiVo boxes running 24x7. Each draws about 40W. In my area 1W works out to about $1/yr. So my TiVo boxes cost me $160/yr just in electricity.
I also believe that LED lighting saves money. In our family room I used to have a 75W light bulb on for at least 12 hrs/day. That's $37/yr for just a single bulb. I replaced it with an 11W Philips LED. It's now costing me $5.50/yr. That's an over $30/yr savings on a single bulb. The same savings applies anywhere light bulbs are on for a long time.
And it's not just standby-mode "phantom consumption", as the EPA used to think. Today there are more devices with larger, sharper screens and hungrier batteries to charge, all left on for longer than ever before [2]. And it all adds up.
[1] http://www.eia.gov/consumption/residential/reports/2009/elec...
[2] http://www.energystar.gov/ia/partners/prod_development/downl...
http://tungwaiyip.info/blog/2011/12/24/home_power_usage
There are probably a separate category of problematic electronics that really sucks power. I was offended to find my set-top box suck 18W. I am doubly offended by your array of Tivo boxes. For 40W, my laptop will be doing computation intensive task with the fan running loudly. My mac mini consume only 11W when idle. A big huge TV would use power. I only have a 32" TV and I use it only a few hours a day at most anyway.
"I think that this does produce some savings, but not as much as you might think. If you set your thermostat to a constant 70, the heater works a little at a time throughout the day. If you drop it to 50 at night or in the middle of the day, the heater stops working, but then when the time comes to warm the house again, the heater has to work at full power for a long time to get the temp back up - thus losing a lot of your savings."
WRONG WRONG WRONG WRONG WRONG WRONG WRONG WRONG WRONG
Heat losses are driven by two factors:
1. The temperature differential between the hot and cold sides.
2. The thermal conductivity (or exchange) between the hot and cold sides.
That's straight out of Newton's Law of Cooling / Fourier's Law:
http://en.wikipedia.org/wiki/Convective_heat_transfer#Newton...
If you're running heat constantly, you're maintaining a constant flow of heat from your interior to the exterior. That is, you're maintaining a high heat exchange rate to the exterior, and you're constantly wasting a large portion of heat.
If you're heating only while you need a warm interior, then as the interior temperature falls, the energy flux to the exterior decreases. You're no longer pumping heat into the external environment.
Yes, you'll run your furnace/heating system continuously for a while in raising the interior temperature, but that is largely adding heat to the interior space, not to the exterior.
The net is expending less energy.
Your most efficient strategy is to turn interior heat down to the minimum essential level (ultimately: enough to keep pipes from freezing), or the minimum level the thermostat allows (often ~50F in the US). My own practice is generally to turn any heating system off entirely at night.
From a moisture management perspective, you also win as cold air has a lower absolute humidity, that is, the quantity of water it can hold is lower. Heating cold humid air reduces the relative humidity, allowing walls and surfaces to dry out.
The overnight heat loss is also a very clear sign that Paul Wheaton is dealing with an exceptionally poorly insulated structure. And a very poor grasp of thermodynamics.
The same principle holds for AC as well, though here you want to increase the temperature setting at which the AC comes on, or disable AC entirely while you're out of the home.
A better way of thinking of this is to minimize the energy input (heating or cooling) when it's not needed.
See:
http://www.uswitch.com/energy-saving/guides/heating-on-all-t...
http://www.straightdope.com/columns/read/2970/does-turning-d...
Central European buildings used to have walls so thick as to achieve a cave effect, which gave them nearly constant temperature through most of the year. With some minimal-ish heating during winter as a side-effect of cooking with wood to combat the effect of bad windows.
I don't know what Paul's house is built of, but mine was solid brick, which probably matched the structure and function of the dense brick/cob building of Europe. The thermal mass was a blessing, as my only form of central heating was wood/coal-burning cylinder stone in the center of the home. In the dead of winter (lows often in the -5 to -15F range at night), a short, intense burn first thing in the morning would charge the house, with minimal burning during daylight hours to maintain a comfortable temp around the core living areas (55-to-65F). Just before bed, load and tweak the stove for a long slow burn. By morning, even on the coldest of nights, the temp never dropped below 45F.
As for his heat-the-person-not-the-room method, that's an obvious, old technique which I applaud Paul for using. For me, a thick down comforter on the bed pre-charged with heat via old-fashioned hot water bottle an hour before (they have nice, newfangled silicone models these days) was all it took. The water was, of course, heated on the wood stove.
During the day, wise clothing (layers, wool, hats) and space heating made the place livable. As did the occasional bout of labor to build up head (an old saying is that chopping wood heats you twice). Yes, there is also some acclimation that takes place. Several years after abandoning the lifestyle, I still cannot tolerate indoor temps much warmer than 70.
Frankly, given that Paul has a rocket mass heater (much, much more efficient than my stove ever was), I am surprised he needs much in the way of spot-heating. Unless his home is of stick/frame construction.
However, some systems do lead to this because of flaws in the the implementation. My ground heat pump, for instance, has a backup electric heat system that it will automatically, and unavoidably, utilize if it hasn't reached the target temperature within a set, relatively short period of time. So in my very well insulated home I do indeed see significant cost increases if I do temperature setbacks, as the recovery period sees more expensive/less efficient electric heat kick in, versus just incrementally using the heat pump through the day. Some fuel-based systems go to a less efficient high-heat stage in the same sort of situation.
If you're heating with electric for example you can sometimes buy electricity far cheaper at night (demand is low and traditional production can be easily spun-down). Thus buying electricity all night and keeping the house warm, whilst using more electricity, could be cheaper than paying for peak rate electric.
Physics alone could explain it in very rare circumstances - board construction that expands in warm air closing gaps, cool air opens gaps and causes more cooling. Heat exchange rate from in- to outside is then possibly greater at lower temperatures. Houses aren't simple to model.
The rest is possible, but I'd file using expensive electricity instead of cheap electricity under the thermostat not doing a very good job, or more precisely the person setting it up not doing a good job of setting it up to run more cheaply.
I'm sure there are exceptions to this somewhere, but it doesn't seem common. Thermostats don't typically have a way to command anything besides on and off.
Also, the "straightdope" link doesn't exactly dispute that setting the thermostat down is ultimately a much more modest ~6% energy savings on average. Nothing to scoff at, but ultimately you come out better by taking a holistic approach. If you can afford it, of course.
The answer would depend on your heating/cooling cycle and usage. Most usage peaks are bimodal: early morning and early afternoon. Those would tend to correspond to morning and evening heating peaks, assuming your residence is largely uninhabited during the day. Overnight demand is usually low.
This could lead to, say, greater use of steam/water heating using thermal storage. Heating a well-insulated water storage tank with off-peak energy, then transferring that to the structure when it's most needed, would be a form of demand averaging / peak shifting. Depending on the storage methods used, boiler explosions might become an increased risk.
If you're using direct-delivery methods, e.g., radiant electric heat as described here, peak pricing would make some of the options used less beneficial on a cost basis.
wikipedia: "In order to be effective as an insecticide, diatomaceous earth must be uncalcinated (i.e., it must not be heat-treated prior to application)[13] and have a mean particle size below about 12 µm (i.e., food-grade – see below)"
Its used occasionally for deworming people and considered a low risk insecticide. Just because you can eat it and it has some benefits in use cases doesn't mean you should consume as much as you can. Its the classic vitamin snake-oils sales pitch, "X is good for you thus more of X must be better for you"
It is helpful to realize that in a pre-industrial society, parasites were very common among humans (and still are in less developed nations), including many introduced via food. Whether or not DE could combat that is arguable, but a regular intake might be argued if you're subject to parasites in your food supply. I'm more in favor of alternatives such as cooking.
There was an article about this in the American Journal of Physics [1, 2] a couple years back, and the authors calculated that heating a room from 273K to 300K (32F to 80F) causes it to expel about 10 percent of the air inside it.
Somewhat surprisingly, the authors don't comment on how relevant this is to the question of when to turn your heater off. The fact that allowing a room to cool draws in cold air from the outside means that the practice is worse than you would naively think, but I don't know when if ever that actually suggests leaving the heater on a constant setting. I'd be very curious to see someone extend the calculation to give an answer.
[1] http://scitation.aip.org/content/aapt/journal/ajp/79/1/10.11...
[2] http://www.stat.physik.uni-potsdam.de/~pikovsky/teaching/stu... [PDF]
A 10 percent increase over atmospheric pressure might not seem like that much, but it's enough to notice, and would probably be uncomfortable. It's like being under 1 meter of water. It's also enough to break large windows.
This is, by the way, why hard drives have filtered air holes rather than being completely sealed.
With regard to letting a house cool down at night, that's impossible. If you heat a quantity of air from 273 K to 300 K at constant volume, the pressure increases from 1 atm to 1.1 atm. That may not sound like much, but it's better expressed as a pressure differential of 10 kilonewtons per square meter, and the surface area of your house is such that it could severely damage the walls and blow the door open -- popping it like a balloon.
(The fundamental mathematical error made by those who minimize this effect is ignoring the surface area of the building)
No, the ideal structure should minimize heat loss from air exchange.
I'm not fully up on my air exchange rates, but it's fairly typical for ranges to be in the 4-20 range, that is, the interior air is exchanged with the exterior 4-20x per hour.
In my Thorsten Chlupp references elsewhere you'll find he makes extensive references to heat exchangers which minimize thermal losses. He does this by a twofold process for his Fairbanks, AK, homes: entering air is routed first through the ground where it's heated from very cold ambient temperatures of as low as -40C / -40F to a temperature closer to freezing (~0F). It's then passed through a heat exchange where the exiting warm air transfers much of its heat to the entering cold air.
The purpose of tightly sealed windows and other possibly entry/exit points isn't to eliminate air exchange so much as to control it: you want air entering and exiting through your designated ventilation systems and transferring heat properly, not traversing the envelope arbitrarily.
See:
Chlupp discussing this issue: http://www.greenbuildingadvisor.com/community/forum/general-...
http://www.engineeringtoolbox.com/air-change-rate-room-d_867...
Another way of putting it: A well-designed structure should minimize random, unintentional air exchange, but provide sufficient deliberately-engineered ventilation to keep the air and people happy. For efficiency, that ventilation should go through a heat recovery ventilator (HRV) or energy recovery ventilator (ERV) as appropriate to the climate and budget. (An energy recovery ventilator also exchanges moisture).
Beyond Chlupp, Lstiburek is a great engineer and writer on these topics.
I've got mote sensors in every room in my house, including the hall. When my kids leave the front door open in winter for a few minutes, as kids tend to do, I can see the temperature in the hall dive on the graphs. But close the door again, and the temperature is right back up very close to where it started in just a few minutes - even when the heating is off.
In winter in particular, the rate of through-roof air leaks is also greater when temperatures are warmer due to the stack effect. The author is completely wrong on this front - it's far better to let your house cool down and then re-heat.
The only time this isn't true is if you have a two-mechanism heating system such as a heat pump with resistance heat backup, where a large temperature swing invokes the more expensive resistance heater. The author doesn't.
Thermal density (specific heat) of air is going to be ~1000x less than that of solid objects.
The specific heat of gypsum (the primary constituent of drywall) is 1.09 kJ/kg.K
For dry air it's 1.0 kJ/kg.K
Air's density is 1.225 kg/m3.
A 6m x 9m x 2.3m (20' x 30' x 7.5') room has a volume of about 130m^3, so a 10% exchange would be 13m^3, or 16kg.
That's about 15 kJ of heat energy per degree C, or roughly 0.0004 liter (0.0001 gallon) of heating oil equivalent.
The drywall would be (in feet) 20x7.5x2 + 30x7.5x2 + 20x30 ft^2 (I'll assume the floor is some perfect insulator for now, and that the room has no doorways), and 1/2 inch thick, or 1.6 m^3. That's about 3600 kg of gypsum, which has a heat capacity of about 4000 kJ per degree C, or about 0.1 liter (0.027 gallons) of heating oil equivalent.
If I'm doing my maths right.
Sources:
Specific heat of gypsum: http://www.engineeringtoolbox.com/specific-heat-solids-d_154...
Specific heat of dry air: http://www.engineeringtoolbox.com/air-specific-heat-capacity...
Density of gypsum: https://en.wikipedia.org/wiki/Gypsum
We adopted the fan always on with scheduled temperature adjustment here at our office, it is more comfortable for sure and less dusty. I do not know if it affected energy costs. When I tried this at home it was more comfortable but my electric bill went up by ~$20
In my limited experience the run/start capacitors fail more often than the motor itself.
Starting a motor is not something you do lightly for bigger motors (but big like a subway or a car) but I doubt they're that heavy for it to be a big concern.
My bet is that it'll spend the starting power in around 5s of running, tops.
Your #3 point strikes be as fairly valid: large electric motors do impose a very high load, and the current draw could be harmful to the motor (and switching / control circuits), while the imposed load might also be hard on other equipment. I doubt the energy usage argument (for cycling the motors off) really carries much weight, and it should be possible to idle such systems at low power. For most commercial buildings, you've got systems for heating, chilling, and air handling which are pretty much all operating simultaneously: you have a need for hot and cold air in different places, there are mixers which will deliver what's needed where it's needed (at least in theory), and the fans blow all the time.
Though I've only a pretty glancing familiarity with HVAC in general, not particularly my area of expertise.
A new motor will cost hundreds of dollars, more so if the blower and fan cage are a single assembly. You'll need to amortize that cost into your comfort level.
It will also quit at the least convenient time, following a combination of Tuttle's and Murphy's Laws. Again, ask me how I know this.
Well, it is mainly a matter of installing a proper ventilation system.
So improving energy efficiency of heating for existing houses with lesser insulation is very useful.
it is, but it can never reach the levels of energy savings coming form decent insulation (where decent means: German standards for instance)
But the walls are indeed very thick!
What happens with the remaining energy if you heat with less than 100% efficiency? Does it start to rotate things?
Some devices will use more energy to get a room to X Celsius.
Those devices are less energy efficient than the other devices.
[0] https://en.wikipedia.org/wiki/Electric_heating#Environmental... [1] experience
I think the most electric heating systems I have seen are using the rather bruteforce and inefficient (only near 100%) method. The basic principle that they heat a resistor and something quickly transfers the heat away so the resistor doesn't burn out and/or your house doesn't catch on fire.
An other fun method to increase the "efficiency" of electric heating would be heating with bitcoin miners. It wouldn't make the heating more efficient in the sense it would cost the same energy but at least you could get some of your money back spent on heating.
Here's an example of one manufacturer and products: http://www.nibe.eu/Domestic-heatingcooling/Airwater-heat-pum...
And to add another use of 'efficient' to the mix, just to keep things interesting ;) , when people say 'heating a house with a CV (water) based system powered by natural gas is more efficient than using electricity', what they mean is that A) electricity is generated from other sources and there are losses in the conversion/transport/etc, whereas for gas that's not so; and B) that it's just much cheaper. So yeah, sorry for the confusion, but in energy use land, 'efficient' is a highly overloaded word.
It's better to look at this as comfort. I just recently bought one of those 20 watt heat mats, for one specific reason: while using a computer it is impossible to keep my feet warm. Socks, boots, anything? Doesn't work. It was a huge problem while I was studying.
Since I got one, for 20 W, my feet are warm. In fact, my perception of room temperature as a whole has been massively improved. This is a lot less power usage then any type of whole room solution.
I'm going to be buying pair of these for the upcoming winter; they're dirt-cheap, machine washable, and will last several seasons:
http://www.amazon.co.uk/gp/product/B00FG1XINO/ref=oh_aui_det...
I have been thinking about thermal socks as well ( http://www.amazon.co.uk/Pairs-Mens-Thermal-Socks-Size/dp/B00... ), and furry boots for the great outdoors.
I cannot stop laughing.
You can get heated toilet seats - they're quite common in Japan. One example: http://www.heatedtoiletseat.com
Shit Norwegians Say: “There’s no such thing as bad weather, only bad clothes”
>FAQ: It might work in Montana, but in Seattle, our windows would get moldy
>There are a variety of ways to mitigate the mold problems that occur in cold, humid climates. I did some experimenting when I lived in the Seattle area and have compared notes with people that are still living there. This is a really large issues even if you don't try this. While there are many things to be done, I think the first two would be: 1) learn how to properly clean mold problems (borax, not bleach) and 2) a dehumidifier nearly eliminates all mold problems and gives off heat.
A 50-50 vinegar-water solution can simply be sprayed onto walls, floors, carpets, and other surfaces.
Another is fully airing out a bathroom. I'll set a fan to move air until the walls and other surfaces are dry. Especially useful if you've got an interior bathroom. Otherwise, an openable window is highly useful.
Aren't you just ensuring the whole house is damp then, unless your humidity is low enough in the first place I suppose.
They key is to understand that a shower is essentially a big humidity generator. So you want to shower with internal doors closed, but external windows open, if they're available. Otherwise you're simply pumping moisture into the residence. Once you've completed your shower, you're no longer introducing more moisture into the environment, so removing / diluting what you've got is the key.
An exhaust fan is also useful, though most are relatively low-flow -- this is one element where if I am designing my own structure I'd have a high-capacity, high-flow, and if at all possible, quiet, fixture. A typical 100 CFM fan will require over 5 minutes to achieve a 100% exchange of air within even a modest-sized bathroom, say 6' x 12' x 7.5'. They'll rarely keep up with the generation of humidity during a shower. The real key is that a high-mounted fan removes the moist air that pools above your door jamb.
The situation also depends on whether you're in a warm or cold, heating, cooling, or ambient, and humid or dry environment.
In cold-weather winter climates, your usual problem is that interiors are too dry, so your bathroom humidity is useful for interior comfort.
In a temperate/warm and humid environment, your main concern is venting the bathroom (first) followed by reducing standing moisture. And if it's humid enough that interior humidity is an issue I've likely got a dehumidifier for high-humidity periods.
My usual strategy (yes, I've got a bathroom venting strategy) is:
For an exterior bath or one with an openable skylight: shower with interior doors closed and the window open. Humidity is generated by tends to escape, keeping total build-up limited. I may or may not shower with the exhaust fan on, but always turn it on afterward, if only to evacuate high-rising moisture. Following shower, spray down shower doors/curtain and walls with vinegar or other (preferably organic) anti-microbial. If the area has higher humidity, a 14" floor fan is good to help evaporate standing water on floors or walls. Mildew tends to form most aggressively in areas in which water pools, and by removing that water and treating it to be inhospitable, you'll virtually eliminate any build-up.
For an interior bath, shower with the interior door closed. Exhaust fan is either on or turned on following the shower (much more out of concern for noise than energy -- most fans I've encountered are annoyingly loud as well as relatively ineffective). I'll crack the interior door to allow fresh air in for a minute or so, then swing it wide open.
Swirling a towel can help achieve a good vertical air mix (moist, warm air tends to rise), which levels out total humidity and eliminates high-humidity spots.
Spray walls and floors with vinegar mix, finish my grooming, then turn on a floor fan to remove additional standing moisture on walls / floor. Airing out bath mats also helps markedly.
Note that a bathroom is rarely more than 10% of your total interior area as well (and often less). So even dumping a 100% humid bath's air into your residence will tend to provide less than a ~10% boost in interior humidity. My experience is that air tends not to feel overly humid until it gets above 60-70% humidity, and that humidity tends to normalize fairly quickly over a larger area. The real threat is _standing_ water.
End result is that I very, very rarely have bathroom mildew issues, rarely use a chlorine-based mildew treatment (though I've got a spray bottle of bleach too that may get used 1-4x monthly), and spend only a few seconds a day dealing with the matter.
That was one of the parts that made me go %O most - when you live in a house where the internal climate is such that it will let mold grow, it's downright unhealthy to live there. It's like saying 'yeah driving while drunk is dangerous, you'd better have a box of band aid laying around in your car for when you get into an accident'. Uh no, don't drive while drunk, eh?
Why do you believe this?
> In addition, in 2004 the IOM found sufficient evidence to link exposure to damp indoor environments in general to upper respiratory tract symptoms, cough, and wheeze in otherwise healthy people and with asthma symptoms in people with asthma. The IOM also found limited or suggestive evidence linking exposure to damp indoor environments in general to shortness of breath, to respiratory illness in otherwise healthy children and to potential development of asthma in susceptible individuals. In 2009, the World Health Organization issued additional guidance, the WHO Guidelines for Indoor Air Quality: Dampness and Mould. Other recent studies have suggested a potential link of early mold exposure to development of asthma in some children, particularly among children who may be genetically susceptible to asthma development, and that selected interventions that improve housing conditions can reduce morbidity from asthma and respiratory allergies, but more research is needed in this regard.
Whether that counts as "downright unhealthy" is up to you.
http://www.euro.who.int/__data/assets/pdf_file/0003/78636/Da...
What's the transition point below which efficiency is markedly reduced?
Assuming you are not producing any EM radiation at frequencies that go through the skin of your house (radio, X-ray, visible light through the window, etc), any resistive heater will produce the same amount of heat.
Because guess what happens when EM radiation is adsorbed? It turns into heat. Any EM radiation.
This entire discussion is bizarro world for me. It costs nearly $400 a month to keep my house at 74deg in the summer.
Installing solar screens helped a ton. Our power bills are down around 30% this summer since installing them.
But I no longer live in NYC. I don't miss the rats or cockroaches or traffic or air pollution. C'est la vie.
That system can also be designed to provide hot water (both as a water supply and as heating) for a nearby city, and many cities do so, it's cheap and efficient.
See https://en.wikipedia.org/wiki/Cogeneration for some description if you're interested.
You need to convince yourself that you'd be comfortable at higher temp and humidity. E.g. in Hawaii the "natives" sneer at the new arrivals who don't like the high humidity.
Fortunately this area has reasonably low humidity. But if I were in Florida, I could probably be comfortable at 78F as long as the AC got rid of about half the relative humidity.
1. Keep it at 80 for a couple of weeks, you'll get habituated quickly enough and will suffer less outside as a byproduct.
2. Use the AC only in the room you are actually in and close the door.
3. Unless it's very very very warm outside, and once you got used to higher temperatures a couple open windows or a simple fan will do wonders.
Source: I live in Rome, I have AC but I only turn it on when it's over 95 outside, because I have thick walls and good circulation.
Of course, it made summers unbearable. But for the most part, I was used to heat.
Seriously, it is that simple.
/lives in a country where triple windows are standard for all new buildings intended for people.
You don't need to live in a cold climate to want good insulation, it can save a bundle in hot climates too if your a fan of extreme AC; think 72F that some I know live by. I do the ceiling fan method, 78F and a nice big ceiling fan in every room.
http://www.familyhandyman.com/smart-homeowner/energy-saving-...
Most people want "summer inside the house" which is absurdly wasteful
Of course, it sucks when changing clothes or taking a shower, but there are ways of heating locally.
Of course, I realize that many people don't care for that. More power (and smaller bills) to them.
In a world where people paid for the true cost of their energy use, this argument might fly. But in most of the world today, this isn't the case, not by a long shot.
If you heated to "summer inside the house" and bought high-quality carbon offsets corresponding to your increased energy use, I think most people wouldn't call that "wasteful". "Warm" might be the adjective I'd use. :)
I want summer in my house during the winter. This should be an explicit goal, because you can't get there by just cranking up the heat since it doesn't deal with draughts and the like. If this were a recognized goal, then everyone would be better off in every way.
According to [1], the cost for offsets are $5.50 to $29 per ton of CO2. According to [2], 1 kWh produces 2.08-2.18 lbs kg of CO2 when burning coal (0.94-0.99 kg). Thus, the cost for the offset is about 0.52-2.9 US cents/kWh, or when using different power sources[3], 0.32-1.7 US cents/kWh, hence your number is about right.
Now I guess the next thing to check is how solid those offset efforts really are. Also, probably they are cheap because they are the low-hanging fruits, I suspect that if everyone would offset their usage, the offset costs per kWh would become much higher. Thus, your assertion that the world would look almost identical if everyone would pay the true cost may well still be wrong.
[1] http://gogreen.whatitcosts.com/carbon-offsets.htm [2] http://www.eia.gov/tools/faqs/faq.cfm?id=74&t=11 [3] http://carbonfund.org/how-we-calculate "On average, electricity sources emit 1.222lbs CO2 per kWh (0.0005925 metric tons CO2 per kWh)"
It may be wasteful, but that's what I want. I don't ever want to step out of the shower in the morning and shiver again, I find this deeply unpleasant. I also don't want to have to wear thick woollen clothes around the house. In pursuit of this I actually moved to Australia for a while, but it turns out I missed the temperate climate and UK culture (also my family, I guess...)
So when I own my own home in a few weeks it will be getting insulated to hell and back. Eliminating drafts, insulating attic space, replacing some of the old windows with double or triple glazed ones, checking the state of the wall insulation... etc etc.
But when it comes down to it, I'll pay the heating costs and swan around in my t-shirt all year. I like being warm.
But yeah, improving isolation, having a bathroom heater, using heat pumps instead of electrical heaters are better than just cranking up the heat and paying the bill.
Solar photovoltaics get all the attention, but solar warm air/water is less expensive and simple to manufacture.
Systems for heating water/air using solar can be quite inexpensive as well; converting light to heat is rather easier than converting it to electricity.
E.g., I've seen cheap pool-heating systems that just pump the water through wide flattened black pipes exposed to the sun and send it back into the pool. Voila, solar heating!
For heating a house with solar (not PV) -- it would depend on insulation level, I'd imagine. I do know people who use it for "most of the time" water heating, with good results.
Living that far north and depending on one heat source is crazy! Think about the power going out when its -30 out... or if you used gas, running out or having your furnace break down.
(Not to mention electric is usually the most expensive way to heat). Most houses where I live have 2 or 3 heat sources. I have wood, LP and electric...
If your power goes out long enough for all the heat to leach out of your apartment or house you probably have some serious problems with either the electric company or your insulation.
Granted, I might not have had to go to the hospital if we had gone to a warming shelter earlier than the sixth day. (My father is rather stubborn, and it damn near killed me. When I got out of the hospital, I left the house and paid for a hotel room in a part of town where power had been restored.)
If you do lose heat, the solution is generally to use blankets outdoor gear until it is fixed. But this has never happened in my 20 or so years of living there.
Did you live in town, or in the country?
They cooled the office so much in the summer that some of the people in the office (I'd say 5 out of 20) used electric heaters under their desk to warm their feet.
"DELIVERING EFFICIENT LOCAL THERMAL AMENITIES (DELTA)"
We (http://www.flair.zone) were looking into grant funding and saw it. All I could think of was heated/air conditioned underwear lol.
Unfortunately even a cheap table in the U.S. is more expensive than it should be. There's an opportunity for someone to create kotatsu tables and things like them for the American market.
Which is strange, because carpet is more comfortable than tatami.
Local Warming: http://senseable.mit.edu/local-warming/
Comes from old, leaky wooden houses, but idea is the same. Lot of bad habits here still, but heating the upstairs guest bedroom all winter long isn't one of them
What I'd really like to know is: why not switch to gas?
- for half the year, you don't heat but you still light, so you automatically gain savings for that whole period. (also if you have air conditioning, in summer you heat the house with lights then have to cool the air again) - Lights are on the ceiling. Hot air rises. Therefore heat coming from lights does almost nothing to improve your thermal comfort. - If you are heating using gas rather than electricity, it is far more efficient to heat air with energy from the gas boiler than from the electric lighting
Of course it saves energy if you don't heat the house, that's obvious. What's less obvious to many is that it saves much less than you think if you live in a house in Northern Sweden, heated with electric heat (which I happened to grow up in).
Not to say that it makes sense, but still.
Also, changing out multiple incandescents means more manufacturing, more truck deliveries to the store, more manufacturing, etc. vs. using a single LED bulb for two decades.
If you live in coal country, then you definitely want to reduce your electrical load and instead rely on a less-bad option of natural gas for warmth.
That said, it's true that some of the heat ends up not being useful (just like a lot of the light from the bulb doesn't either) -- unless there's a heated story above, of course.
And I never implied that I think it's a bad idea to get rid of incandescents, for all the other reasons you mention.
Your point about fixtures and heat losses through ceilings are actually well-taken. Recessed "can" lighting is actually a huge pathway for heat loss two ways:
1. The radiant heat from bulbs which is transferred into the ceiling and attic spaces, rather than the living space.
2. Other heat flow losses, including often very significant airflow, through the lighting fixtures. Thorsten Chlupp (mentioned elsewhere) includes lighting fixtures among his anti-penetration measures. He also keeps his wiring and plumbing runways along the inner insulates spaces, rather than outside the thermal barrier (with concomitant envelope penetrations).
There is a current internet legend that the heat from incandescent bulbs does not contribute significantly to building heating. This is entirely wrong for the obvious thermodynamic reason. It's even been tested experimentally with the result that almost all the heat from the bulbs ends up as general heating:
I just wear a sweater as my personal heater. Heater only comes on for visitors.
Iraq was _not_, repeat, NOT, N O T, about oil. Iraq was about stability, about a nut case leader who terrorized and killed his own people, who let his sons terrorize people. It was about all the terrorists caught who had evaded worldwide, WORLDWIDE authorities for decades in many cases, found hiding out in ... Iraq.
Hussein disregarded Bush elder, Clinton and Bush junior, covering 3 US Presidencies, both major US political parties. He shot missiles at the very ally planes charged with making him keep his army at bay.
He plotted to kill the very US President (Bush elder) who forced him to back out of Kuwait:
http://www.washingtonpost.com/wp-srv/inatl/longterm/iraq/tim...
Yes, it's a bit disagreeable to run across even minor, aside comments that disagree with something you believe strongly, but please just deal with that on your own time.
Because of course your comment will be unpleasant for people to read who feel just as passionately that you're wrong, and some of them may be compelled to post wall-o-text comments here to rebut your claims.
Here, in this discussion about micro-heaters.
I mostly want to improve future discussions, not scold/shame people; my own posts aren't always on-topic and informative, though I like the goal.