The Future of Grid Power?

[Someone]

I can do without that.

In 30 years tankless/bufferless heating will be expensive one way or another. Status quo can not last forever.

Or as we keep banging on about, hot water storage is one of the trivial and economically viable demand management options available.

So far we've heard a lot of "but if I install this system in a stupid way it will produce a bad result". Sizing a water storage system is pretty simple, so nctnico's claim that hot water storage is not possible as it will run out is plainly wrong once again. People who want to have long high flow showers, and the entire building heated to 20 something degrees with inefficient methods can pay the premium for that and stop complaining about cost.... because there are cheaper ways to live (in multiple ways) one of which is switching to heat pumps.

[Someone]

While giving you dry eyes and a sore throat due to a draft of bone dry air. And the constant fan noise on top. No thanks. Nothing beats underfloor heating where it comes to comfort. Especially when it is close to the surface of the floor.

It's matter of taste. I know many people like the warm air flow and have enjoyed it myself too without sore throat. You don't have to use the max fan setting.

I'm not sure how heating air makes it dryer (it could feel dryer as there is higher evaporation rate). But it comes back to the simple point of how is that any different to another source of heating inside the room?

As you say, set the fan speed and airflow direction to whatever is comfortable in the situation. Rather than picking some worst case and dismissing the entire concept/technology just because it could be used poorly.

[coppice]

While giving you dry eyes and a sore throat due to a draft of bone dry air. And the constant fan noise on top. No thanks. Nothing beats underfloor heating where it comes to comfort. Especially when it is close to the surface of the floor.

It's matter of taste. I know many people like the warm air flow and have enjoyed it myself too without sore throat. You don't have to use the max fan setting.

I'm not sure how heating air makes it dryer (it could feel dryer as there is higher evaporation rate). But it comes back to the simple point of how is that any different to another source of heating inside the room?

As you say, set the fan speed and airflow direction to whatever is comfortable in the situation. Rather than picking some worst case and dismissing the entire concept/technology just because it could be used poorly.

With the Daikin models we used to have they just let you set the fan yourself in cooling mode, but in heating mode the fan could be controlled by the unit, with some kind of sensing. So you get lots of air flow when the room is cold, to get the maximum energy into the room, but the fans slow as the room approaches target temperature, to reduce the evaporating cooling that fast air across the skin would cause. It worked very well. They gave us good warm up times and very comfortable rooms.

[TimFox]

With forced-air heating, it is possible to add a humidifier to the ductwork after the fan/blower.

[Siwastaja]

People who want to have long high flow showers... can pay the premium for that

And it even isn't any sort of premium. A 300-liter stainless steel electric boiler costs like 700€ when the smallest ones or in-line tankless systems costs like 300-400€. Totally negligible difference for the lifetime of the boiler (typically 20 years or so).

[tooki]

While giving you dry eyes and a sore throat due to a draft of bone dry air. And the constant fan noise on top. No thanks. Nothing beats underfloor heating where it comes to comfort. Especially when it is close to the surface of the floor.

It's matter of taste. I know many people like the warm air flow and have enjoyed it myself too without sore throat. You don't have to use the max fan setting.

I'm not sure how heating air makes it dryer (it could feel dryer as there is higher evaporation rate). But it comes back to the simple point of how is that any different to another source of heating inside the room?

The ability for air to hold water vapor* is highly temperature dependent: hot air can hold far more moisture than cold air. For example, 0°C air can hold up to 4.84g of water per cubic meter. 20°C air can hold up to 17.2g per cubic meter. If that cubic meter of 20°C air actually contains 17.2g of water vapor, then we say the relative humidity is 100% (17.2/17.2 = 1 = 100%. But if that same cubic meter of 20°C air contains only 4.84g of water vapor, then its relative humidity is just 28% (4.84/17.2 = 28%).

So if you start with fully saturated 0 degree air and heat it to 20 degrees, then its relative humidity will drop from 100% to 28%.

This effect is also why hot air is so much more effective at drying things than room temperature air: 100°C air, for example, can hold 598g of water vapor! That is a typical temperature for a hair dryer on high. So if we suppose your house is at 20°C at 50% humidity (so 0.5*17.2g = 8.6g per cubic meter), then the 100°C air coming out of your hair dryer has a relative humidity of just 8.6/598 = 1.44%!


However, I completely agree with your point that it makes no sense for one type of heating to dry out the air more than another. Every heating type is subject to the same laws of physics.


*Note that this is the “colloquial” terminology that is actually not strictly true. It’s actually solely a function of vapor pressure. But for the purposes of calculating humidity, this doesn’t actually matter. See this page, which is also the source for the numbers used above.)

[coppice]

However, I completely agree with your point that it makes no sense for one type of heating to dry out the air more than another. Every heating type is subject to the same laws of physics.

Different types of heating and cooling do affect things. If the air doesn't move much across your skin (e.g. a room with underfloor heating or radiators), the evaporation is much lower than if you have forced air moving it quickly, without any actual change in the %RH. HVAC which uses a heat exchanger is not tied to the initial air moisture content of the room. If you have any form of open fire in the mix it gives off lots of moisture as the burning occurs - assuming you are not burning high grade coal, which produces little more than CO2. The change from open fires to central heating seems to be where the whole "it makes the air dry" thing started. For cooling, the type really matters, as it can seriously change how much moisture is removed from the room, as condensation on the cooling elements. The better air cons have modes which will dehumidify to a greater or less extent, mostly based on air flow rates. I can't think of a direct equivalent with heating systems. Combinations of humidifier and dehumidifier can fix all of this.

[Siwastaja]

However, I completely agree with your point that it makes no sense for one type of heating to dry out the air more than another. Every heating type is subject to the same laws of physics.

Yeah, and specifically, the reason why air is dry in the winter is the dehumidifying effect of the cool temperature outside. Because the cold air can hold less moisture than warm air; when the temperature is going down, excess water condensates into liquid or deposits into ice (that you then need to scrape off from your car windows; at least it looks decorative on trees). This loss of water is what makes the air itself dry. When you heat it up, this drought realizes in the form of low RH%. And indeed, it doesn't make a difference how it is heated up. Below about -5degC or so the outdoor air is always close to 100% RH and still very dry absolutely speaking, and will always give a dry feeling. To avoid this you need to use a humidifier, or reduce amount of ventilation such that the humidity from breathing (and other stuff being done indoors) keeps the air humid, but that easily leads to poor indoor air quality. In any case, if humidifying is done a lot during winter then the vapor barriers (of walls and ceilings close to the interior surface) of the house should be spotless or risk of condensation and mold inside structures is very real.

[Zucca]

Below about -5degC or so the outdoor air is always close to 100% RH and still very dry absolutely speaking, and will always give a dry feeling

This is why the dew point is a much better indicator about humidity, feel free to correct me I understood it by watching youtube.

PS: I don't wanna know how we drifted from grid power to water in air. 

[Siwastaja]

This is why the dew point is a much better indicator about humidity, feel free to correct me I understood it by watching youtube.

Yeah, dew point is basically absolute humidity expressed in a different unit which is quite intuitive for many uses.

[tooki]

However, I completely agree with your point that it makes no sense for one type of heating to dry out the air more than another. Every heating type is subject to the same laws of physics.

Different types of heating and cooling do affect things. If the air doesn't move much across your skin (e.g. a room with underfloor heating or radiators), the evaporation is much lower than if you have forced air moving it quickly, without any actual change in the %RH. HVAC which uses a heat exchanger is not tied to the initial air moisture content of the room. If you have any form of open fire in the mix it gives off lots of moisture as the burning occurs - assuming you are not burning high grade coal, which produces little more than CO2. The change from open fires to central heating seems to be where the whole "it makes the air dry" thing started. For cooling, the type really matters, as it can seriously change how much moisture is removed from the room, as condensation on the cooling elements. The better air cons have modes which will dehumidify to a greater or less extent, mostly based on air flow rates. I can't think of a direct equivalent with heating systems. Combinations of humidifier and dehumidifier can fix all of this.

I wasn’t addressing cooling in any way.

I also wasn’t addressing the human perception of different types of heating. I literally only addressed humidity.

Ok, fair enough, I didn’t think about open fires, since those aren’t a significant source of heat in developed countries, except for mood. Yes, a fireplace would affect things as fresh air is drawn in to replace what’s lost up the chimney. I don’t think the moisture produced during combustion matters much, because if you had enough combustion products in the air to keep it humid, you’d also be having serious problems with the combustion products besides water…

So the baseline heating systems are either forced air, radiators, and underfloor, and little electric heaters for portable heat. It makes no difference to humidity which one of those you use.

[coppice]

I also wasn’t addressing the human perception of different types of heating. I literally only addressed humidity.

Its not just perception. The drying and chilling effects of evaporation are strongly affected by air speed, so it really makes a difference.

[Connecteur]

The monopoly that Edison fought so hard to attain, has become a reality today, in the form of "virtual monopolies," where a few big players share the market, keeping out any lower cost alternatives by exerting heavy competition against them in price.

[TimFox]

John Stuart Mill pointed out the “natural monopoly” correction to Adam Smith’s theories back in 1848.

[Gyro]

The monopoly that Edison fought so hard to attain, has become a reality today, in the form of "virtual monopolies," where a few big players share the market, keeping out any lower cost alternatives by exerting heavy competition against them in price.

So after 9 pages in this thread and 2 pages in the other (not to mention the one before that), you haven't taken anything on board. You are just trolling to try to keep the thread going.

When I was a kid, I knew an old guy who told me that at one time, every small entity had their own power plant. Towns and cities, farms and apartment buildings ran their own generating plants.  Most of that ended when the power grid appeared, undercutting the costs of running your own generating plant in most cases.

But did we expect that the grid would become a monopoly? Are the big power plants the only game in town?  Not so much, I think anymore.  Granted, it's still very expensive to set up your own power generation, and the grid is still cost-competitive, but for how much longer?  Should the power companies be allowed to continue exploiting their monopolies? 

I think technology is making it easier and easier to manage electrical power, and perhaps a cooperative sharing grid is the way of the future, minus the monopolies.

( https://www.eevblog.com/forum/chat/do-we-really-need-a-grid/ )

[Siwastaja]

So after 9 pages in this thread and 2 pages in the other (not to mention the one before that), you haven't taken anything on board. You are just trolling to try to keep the thread going.

This guy is a pro troll. But I like him. He creates threads that somehow turn into good and interesting discussions nevertheless.

[tggzzz]

So after 9 pages in this thread and 2 pages in the other (not to mention the one before that), you haven't taken anything on board. You are just trolling to try to keep the thread going.

This guy is a pro troll. But I like him. He creates threads that somehow turn into good and interesting discussions nevertheless.

Yes, but in spite of his contributions, not because of his contributions.

[Connecteur]

The often misused term, "troll" has a simple meaning; someone who comes to a forum, trolling for a fight.  And fighting is the point.  That's why it's tossed at someone being provoked (hopefully) into a fight.  Ironically, the person misusing the term, "troll" is likely the one spoiling for an online fight.

[Zucca]

So after 9 pages in this thread and 2 pages in the other (not to mention the one before that), you haven't taken anything on board. You are just trolling to try to keep the thread going.

This guy is a pro troll. But I like him.

Definitely. I imagine he is using white cotton gloves while typing and he is enjoying every split second of his crafted art posts.
Same here, I hated him but now I am enjoying his contributions.
Can't wait to see his next move.

[Connecteur]

"Hate" is a trolling word that belies your purpose here.

[tggzzz]

Don't feed the troll.

Everybody has the "right" to be wrong, and we can't correct everybody.

[Connecteur]

I don't expect any forum to be micromanaged to the point of suppressing all trolls, but it would be nice to be able to discuss one's ideas without triggering online combat.