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Heat pumps of the 1800s are becoming the technology of the future

knowablemagazine.org

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Re: Heat pumps of the 1800s are becoming the technology of the future

#111

Post by teruakohatu »

phkahler wrote: post #35
nickpeterson wrote: post #4

Why can’t my whole home participate in this technology? It would seem an ok fit for things like freezers, refrigerators, hot water heaters, etc. When it’s freezing cold outside, it seems crazy that I warm the air of my house and then use electricity to keep the fridge cooler than the air I just heated. Someone needs to make a standard for moving heat/cool through all appliances in a house…

The fridge is heating your home, so that reduces the burden on whatever is heating your home. The coil on the back gets hot.

> The fridge is heating your home

Not really, efficienty aside the heat it puts out the back is coming from inside the fridge... Which is coming from the room housing the fridge. So over the course of a day it should be neutral.

Re: Heat pumps of the 1800s are becoming the technology of the future

#112

Post by fifteenforty »

teruakohatu wrote: post #110
fifteenforty wrote: post #109

In a house I own in Melbourne, Australia, I just replaced an old gas central heating system with 3 new top of the line Daikin mini split heat pumps. The new units can heat the entire house for the same amount of electrical energy that was used to run the FAN in the old gas unit. They are crazy efficient. Ducts are dead. The Daikin Alira X is the gold-plated option and cost $8k AUD for 2x2.5kw and 1x7.1kw units includ…

> Ducts are dead. Ducted heatpumps are a thing here in NZ and make sense to me, not that I have used one. The heatpump sits in the roof and air is pushed into three or so rooms through ducts. If building a new house I think ducts would be the way to go.

You have to think carefully about where you run the ducts. They can be a huge source of energy loss. 40% is the number quoted by the EPA.

Most roofs in Australia still aren’t sealed. The air barrier and insulation barrier is the ceiling. The roof space itself is not insulated, so the ducts are exposed to extreme temperatures, thus destroying the efficiency.

Here is just one article on it: https://newenergythinking.com/2018/10/20/dont-use-ducts/

Re: Heat pumps of the 1800s are becoming the technology of the future

#113

Post by teruakohatu »

Scoundreller wrote: post #98
rpearl wrote: post #17

Earlier quoted context omitted.

There are heat pump water heaters (I have one; AO Smith HPTU-50N). More expensive up front vs tankless but a lot more efficient.

Depends on usage. Tankless efficiency really shines with irregular use. Keeping a big reservoir warm for the sake of keeping it warm only becomes efficient with regular usage.

Tanks can be heated at night (or midday), when electricity is cheaper and, in my case, when non-renewables are contributing less to the grid.

Re: Heat pumps of the 1800s are becoming the technology of the future

#114

Post by teruakohatu »

fifteenforty wrote: post #112
teruakohatu wrote: post #110

Earlier quoted context omitted.

> Ducts are dead. Ducted heatpumps are a thing here in NZ and make sense to me, not that I have used one. The heatpump sits in the roof and air is pushed into three or so rooms through ducts. If building a new house I think ducts would be the way to go.

You have to think carefully about where you run the ducts. They can be a huge source of energy loss. 40% is the number quoted by the EPA. Most roofs in Australia still aren’t sealed. The air barrier and insulation barrier is the ceiling. The roof space itself is not insulated, so the ducts are exposed to extreme temperatures, thus destroying the efficiency. Here is just one article on it: https://newenergythinking.co…

I hadn't considered that.

My argument with split systems, at least how they are installed in NZ, is that they are usually installed in the main living area and if there is a second unit, in a corridor.

So corridors are heated or cooled far hotter or colder than they need to be in order to heat/cool bedrooms.

Re: Heat pumps of the 1800s are becoming the technology of the future

#115

Post by mixmastamyk »

Scoundreller wrote: post #97
retrac wrote: post #10

Earlier quoted context omitted.

> it seems crazy that I warm the air of my house and then use electricity to keep the fridge cooler than the air I just heated The fridge is simply moving a little of the warmth in your room out of its box, and adding a little more warmth to the room in the process. You lose no heat from the room, which is what matters, really. It would be worse to dump the heat outside! At least in winter. The heat has to be removed…

The smart thing to do in winter is put municipal liquid water in your freezer, and dump it outside once frozen to thaw in spring. Rince repeat all winter long. Voila: everyone has heat pump heating! (And dead compressors). The dumb thing is having the compressor itself indoors in summer. Should be outside.

Interesting, how to remove it easily from the container? Or do you use an ice machine? Is this more efficient than using the heater? Guess it uses heat pump tech.

Re: Heat pumps of the 1800s are becoming the technology of the future

#116

Post by radicalbyte »

fifteenforty wrote: post #109

In a house I own in Melbourne, Australia, I just replaced an old gas central heating system with 3 new top of the line Daikin mini split heat pumps. The new units can heat the entire house for the same amount of electrical energy that was used to run the FAN in the old gas unit. They are crazy efficient. Ducts are dead. The Daikin Alira X is the gold-plated option and cost $8k AUD for 2x2.5kw and 1x7.1kw units includ…

How much electricity was the fan using? :)

Re: Heat pumps of the 1800s are becoming the technology of the future

#117

Post by mixmastamyk »

ComputerGuru wrote: post #51
AlanSE wrote: post #22

Earlier quoted context omitted.

The fridge isn't the biggest energy hog in the house, but I'm very sympathetic to the absurdity of heat levels in a house. I often see my HVAC cooling when the set-point temperature is actually _higher_ than the outside temperature. Logically, the house is a heat generator, it makes sense physically. The roof is black, etc. It would offer a good number of benefits if the system could outright open a duct to the outdo…

I've built/retrofitted and a prototype of mechanically operated louvres with push/pull fans for air exchange in an old school building, tied to the thermostat, ac, and a CO2 detector. The idea of doing the same in my home has been taunting me for years now. Ideally you'd have two such louvres, one with a push fan in the upper floor and the other with a pull fan in the lower floor to simultaneously eject unwanted heat…

> But I agree, nothing is more infuriating than seeing the AC on and the outdoor air temperature being lower

Won't cooler temps outside make the AC work more efficiently and get to the desired temp more quickly?

Re: Heat pumps of the 1800s are becoming the technology of the future

#118

Post by throw0101a »

fifteenforty wrote: post #109

In a house I own in Melbourne, Australia, I just replaced an old gas central heating system with 3 new top of the line Daikin mini split heat pumps. The new units can heat the entire house for the same amount of electrical energy that was used to run the FAN in the old gas unit. They are crazy efficient. Ducts are dead. The Daikin Alira X is the gold-plated option and cost $8k AUD for 2x2.5kw and 1x7.1kw units includ…

> Ducts are dead.

Ducts are still needed to circulate air, especially if you want to remove stale air (e.g., bathrooms, kitchen) and bring in (filtered) fresh air (to bedrooms).

Re: Heat pumps of the 1800s are becoming the technology of the future

#119

Post by dboreham »

sschueller wrote: post #106
PinguTS wrote: post #49

Sorry, but I don't see any novelty here. Everything described in the article is commercially available. At least here in Germany. Heat pumps are used to heat a storage container called buffer, a water container of 200l or more of water. This is used to run the heat pump when energy is cheap to warm up the buffer. That is for example in daytime when energy is available from the photovoltaic. If you don't have photovol…

This is like when Apple introduces some new feature that existed on Android for years and claims it as some sort of revolutionary thing. In this case it's just that the mainstream US has discovered heat pumps when they have been mainstream in Europe for many years.

I lived in a townhouse in Santa Clara in the mid 1990s that had heat pump heating (combined with ac).
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