Beyond the other better insulation comments, pairing electric with heat pumps that are SEER 10+ goes a long way to improve heating efficiency. Old resistive heaters are 1:1 on energy to heat, while newer heat pumps operate to much lower temperatures, and give you 1:10 or 1:15 electric:heat energy ratios.
My heat pump is SEER 19, and it can't heat my house below 25F. I think this is mostly due to it not being large enough - it was sized to cool my house on the hot summer days, and more energy needs to move on the cold winter days.
SEER, while a useful first-order approximation of efficiency, is for cooling and not heating. HSPF-V is for cold climates. Likely you just don't have a cold-climate heat pump which maintains full capacity down to -10°C (and some a little lower still), even before you get into appropriate maximum capacity.
That's not even close to correct. At the design lowest temperature (if <15°C), the very best get 2 COP, but most are 1.5 or lower. The problem is you have to accommodate the worst case.
The average of installed units is closer to 2.0 COP average, unfortunately. Multi-head units really drive down efficiency. A single-head Gree Sapphire can do 4-5 COP on average and that's the best you can get, so still nowhere near your guess.
Under what circumstances? I've seen higher-end units that do maybe 1:5 in ideal conditions (heating to 68F when the ambient temp is 55F), but never seen units that do 1:10 or 1:15. This was about 2-3 years ago I did this research. Have things improved that drastically in the last few years?
Too many folks here do not understand or care to appreciate the constraints of the real world. Heat pumps are excellent and relatively cheap but have limitations. One of the biggest limitations is that a heat pump's efficiency drops as ambient temperature drops. This is the worst possible situation for heating as the conditions when the risks of losing heat are the highest, are precisely the conditions when these devices are least efficient.
As long as they remain more efficient than resistive heaters down to the lowest temperatures you experience, it's a win. Heat pump efficiency is still improving. You can get heat pumps that can handle down to -35°C now with even better ones in the works.
I'm not questioning the merit of heat pumps. I should know because i have two in Ontario, Canada, one rated to -35 C and the other rated to - 25 C.
What i remain opposed to is this persistent idea that heat pumps work in all situations, for all people and for all time. They do not, and heat pumps create a unique set of problems that we might not be fully prepared for.
One could go farther and complain that it's a waste of a microcontroller at all to control a fan when an analog circuit for fan speed vs temperature would work fine.
True, a very simple analog circuit would be enough.
However the bane of analog circuits was that they age, so a control circuit that works perfectly today will drift and no longer work as intended after some years.
The second problem is that analog circuits need adjustments to set them at the exact desired parameters.
Adjustments can be done either by using an adjustable element in the circuit, e.g. an adjustable resistor or capacitor or inductor, or by measuring many resistors and/or capacitors and/or inductors and selecting the ones with the right values to be used by your device.
Redoing periodically the adjustments also solves the aging problem. However, both the initial adjustment and any periodic readjustments need a lot of work, so they are no longer acceptable in the industry.
When doing something for yourself, you may make an analog controller and the initial adjustment would not be a problem, but even in this case it would be annoying to keep track and remember something like having to readjust a fan controller every 6 months, to be sure that it still works as intended.
You're over thinking it. If the application is very simple and needs to do one thing, an analog system works fine. Once you start needing sequencing, multiple adjustments, and maybe a little smarts then a CPU can get involved.
I worked at a shop that had an old closed loop water-air chiller for a laser. The water temperature controller was a small PCB with an op-amp chip with some passives and the temperature was set by a potentiometer. That thing ran fine until the compressor died and it sent to scrap.
My analog fan control comment was a bit tongue-in-cheek, but turning a knob on a potentiometer to adjust fan speed has some personal appeal - no digging around for a sw utility, no poking interfaces to see if the motherboard mfr bios exposed the control, of if it exposed it but doesn't actually hook the right plug, no adjusting to see if the right temp input is reading correctly. Fewer layers of things to go wrong can be so nice.
I bet you can. But you can't turn a simple single linear amplifier into a PID controller with zero physical changes, can you?
My point was that, if you want additional behavior, you need to bake that in from the start. With an MCU you can trivially switch it in-the-field to literally anything you can imagine.
Yup. You could use a quad opamp to build a PWM controller with closed loop control but then you need all the passives to setup the oscillator and so on.
I went through this years ago making a fan driver for my vehicles HVAC blower. The analog setup was fun to make but you use more board space, higher BOM count, and really, higher BOM cost vs a micro-controller.
It's crazy how far technology has advanced. A μc with RAM and a bunch of input and output ports and some code is cheaper today than a pile of analog components.
Practical freedoms are often more constrained by economics making political freedoms moot and less valued by the masses. Eroding practical freedoms has other negative lasting effects on maintaining all forms of freedom
If humans didn't manage risks to livestock on an industry scale they would be at risk. It requires a constant investment from both commercial industry and government. Activities like the dept of agriculture and university ag depts have been really so good at what they do. Its like the rest of civilization has forgotten what it takes and the costs involved if we neglect the investment. Agriculture and livestock is just one foundational civilization technology where we have forgotten the significance of
What is considered livestock varies over time - chickens range from "free range and can survive in the wild" to "so fat they can't live". One guess as to which is the most common by numbers - one reason that if you do decide to have a backyard flock, go with something "more natural".
More dangerous in all these is the monoculture - a hundred years ago we would have a wide range of crops and livestock; now 90% of meat chickens are probably the same genetically; similar with cows and bananas and corn and rice and pigs, etc. That sets us up for a "wipe out 90% of chickens" risk.
Monoculture is definitely a risk, one exacerbated by megacorps and overly corporatized industry - but if you look at the history of ag departments they have introduced multiple variants and variations across crops and animals time and time again. They also work with smaller growers in communities in many ways - natural pest controls consultations for example
It's been known to people working in the space for a long time. Heck, I was working on similar stuff for the Maxwell and later Pascal over a decade ago.
You do have a lot of "MLEs" and "Data Scientists" who only know basic PyTorch and SKLearn, but that kind of fat is being trimmed industry wide now.
Domain experience remains gold, especially in a market like today's.
The richest people I know talk to a range of people like personal assistants, but really the PA is valued for getting things done reliably and in the real world with any needed resources. Even calling in experts as needed - of course they may indeed talk to an AI too
The health insurance industry drives highly increased administrative costs - costs which the insurance companies are happy to foist off onto non insurance channels?
It "may be other than health care" but most (all?) other modern nations on multiple continents in multiple cultures spend less percent GDP on healthcare with longer life expectancy than the US
reply