The hunt for the most efficient heat pump in the world | Hacker News Reader

The hunt for the most efficient heat pump in the world

wired.com

33 pointsludsan13 comments

http://web.archive.org/web/20240704113444/https://www.wired....

Love my Bosch heat pump. I noticed when I got rid of solo heater coils for this new air handler and pump was that it managed to keep the air temperature more consistent.

What has helped the most however was adding in a humidifier. Dry desert air is unforgiving and adding in water to the air made a huge difference in comfort. 68* F with 40% humidity is much more comfortable than the same with 5%.

Why not get a swamp cooler?

To save someone else the time spent looking:

The data recording setup they are typically using only works for air-to-water heat pumps, like you might use to heat water for radiators. They rely on a 'heat meter' that measures the water flow rate and temperature.

Typical setup: https://shop.openenergymonitor.com/level-3-heat-pump-monitor...

If your system is a typical US air-to-air 'split' system, you probably have a long loop of refrigerant in a pressurized tube to carry the heat. To measure efficiency, I think you either need to measure air flow accurately inside or outside, or measure refrigerant flow rate. Either one harder than the commercial meter for hot water.

So, no easy drop-in COP measurement for me.

> It only takes a little electricity to power this process, which can raise the refrigerant’s temperature by many degrees Celsius.

And the same electricity can raise the temperature by even more degrees Fahrenheit!

Using a temperature system built around water to measure air temperature. I mean I can use it but the range of fahrenheit is more useful.

What we really need is a combination of the two. Something that measures air temperature and water content because 68F at 5% humidity is a lot different than the same temp at 40%>

> Several accounts of how he originally defined his scale exist, but the original paper suggests the lower defining point, 0 °F, was established as the freezing temperature of a solution of brine made from a mixture of water, ice, and ammonium chloride (a salt). The other limit established was his best estimate of the average human body temperature, originally set at 90 °F, then 96 °F (about 2.6 °F less than the modern value due to a later redefinition of the scale).

Nothing beats scientific accuracy and thoroughness, right? So it then actually ended up being tied to water as well:

> For much of the 20th century, the Fahrenheit scale was defined by two fixed points with a 180 °F separation: the temperature at which pure water freezes was defined as 32 °F and the boiling point of water was defined to be 212 °F

(from https://en.wikipedia.org/wiki/Fahrenheit)

So that's why one unit Celcius is roughly 2 units Fahrenheit!

For some reason I never noticed there are exactly 180 degrees between freezing and boiling points on the Fahrenheit scale. 100°C is a nice "round" number, and 180°F divides evenly into a lot of smaller numbers.

Wet bulb temperatures account for evaporation, but I don't know if weather stations report wet bulb or dry bulb.

> What we really need is a combination of the two. Something that measures air temperature and water content because 68F at 5% humidity is a lot different than the same temp at 40%

The "feels like" apparent temperature accounts for things like humidity and windchill[1].

Many weather apps provide the "feels like" temp, including my app: https://uw.leftium.com

I was going to drop the "feels like" reading in my new weather app (I just didn't notice a major difference), but maybe I'll keep it...

[1]: https://www.wikiwand.com/en/Apparent_temperature

Heat in F chill in C, et voilà! free energy.

Unit arbitrage. I love it.

I'd buy that for a dollar!

Reply on news.ycombinator.com