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Freegrass

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Heat Pumps
« on: January 09, 2024, 03:17:24 AM »
So many threads about electric cars here, but not one dedicated to heat pumps, even though heat pumps will probably be as important in the future as electric cars. So here it is, the heat pump thread, where we can post on new developments and prices.

Let's start off with this. This looks like a good development. Hopefully the prices will drop soon, because this is way too expensive for me and most other people below the middle class.

Will hotter heat pumps win over homeowners?

https://www.bbc.com/news/business-67511954

The first heat pumps Graham Hendra sold, about 15 years ago, weren't very hot.

"To get 50C - that was quite hard," says the former wholesaler, referring to the temperature of the water that these devices sent to radiators, known as the flow temperature.

Today's gas combi boilers are typically designed for flow temperatures of around 50-60C.

The older heat pumps might have struggled to heat some homes adequately unless the homeowner decided to install larger radiators, for example. The increased surface area of such radiators helps transfer heat into the room.

But a new breed of heat pumps is emerging. Engineers have gradually improved the technology, meaning that heat pumps are now able to supply much higher temperatures, sometimes in excess of 70C.

A major change has been the rise of new refrigerants, including R290, or propane. This is the fluid that circulates inside a heat pump. In an air source device, the refrigerant captures warmth from the outside air, even on cold days. By compressing the slightly warmed refrigerant, the heat pump is able to increase the temperature and then transfer that heat into a property.

R290 is more environmentally friendly than older refrigerants so leaks are not as potentially damaging in climate change terms. Plus, it is up to 34% more efficient, which helps heat pumps supply higher temperatures without incurring severe efficiency losses.


Mr Hendra is now technical director at Genous, a firm that gives advice to homeowners on how to make their properties more energy efficient.

"We have a thing in our industry that I call 'temperature anxiety'," he says, likening it to the "range anxiety" that some consumers have about electric cars.

But the advent of hotter heat pumps means that such concerns are increasingly becoming irrelevant, he suggests.

It might take time to convince some, however. Paul Ciniglio, head of whole home retrofit at National Energy Foundation, a charity, is currently working on a project in Bicester covering more than 500 homes.

"We're trying to get as many as a quarter of them to sign up to heat pumps but it's proving really hard going," he says. "There has been so much negative press."

Some residents are sceptical the heat pumps will be hot enough, he explains, adding, "With the advent of this new refrigerant, it could be a game-changer."

Among the firms offering R290-based heat pumps are Octopus Energy, a renewable energy company. It recently announced a heat pump called Cosy 6, which can heat water up to a maximum of 80C. In principle, homeowners could change their heating system over with little fuss, says Alex Schoch, head of flexibility. "Combi boiler out, heat pump in," as he puts it. This could make heat pumps viable in a broader range of UK homes, which are notoriously poorly insulated in comparison with much of Europe.

Vaillant's aroTHERM plus heat pump works in outdoor temperatures as low as -20C and can supply hot water at up to 75C, though to remain efficient it is best not to exceed 55C, according to the manufacturer.

Another company, Vattenfall, makes a heat pump that uses a different refrigerant, R744, or CO2. It can supply even higher temperatures, up to 85C. The company expects to install 300 in Europe this winter, mostly for housing associations.


And a spokesman for Daikin says that its Altherma heat pump, which uses R32 as a refrigerant, can reach 70C. The firm plans to launch a range of R290-based heat pumps in 2024.

Independent non-profit Energy Systems Catapult has, since 2020, been testing 742 heat pumps, of varying models, across different housing types in England and Scotland. Daniel Logue, consultant, says that the R290 heat pumps included in the trial have performed well.

"When averaged over the course of a year, the R290 high-temperature heat pumps were performing significantly better than the R410A heat pumps, which is a refrigerant that's being phased out now," he explains.

These heat pumps were consistently able to achieve a coefficient of performance (COP) of around 3. That refers to the amount of heat energy produced, in kilowatt hours (kWh), for every kWh of electricity consumed. Based on current energy tariffs, for heat pumps to be competitive with gas boilers in terms of running costs, a COP of around 3 or higher is generally desirable.

Despite R290 allowing for improved efficiencies when supplying higher temperatures, you still get the best COPs when you run your central heating as low as possible, stresses Leah Robson, co-director of Your Energy Your Way, which installs heat pumps and solar panels among other technologies.

She adds that there are some limitations with R290-based heat pumps, such as the fact that they cannot be located near to air bricks or windows at ground level, to eliminate the risk of the refrigerant, which is flammable, leaking into such areas.

Sue Beesley, a homeowner in Cheshire, had an R290 heat pump installed a few months ago. While not strictly necessary, she took the decision to change her radiators and keep flow temperatures to no more than 45C.

That means higher efficiency for her system overall. "What I've got now is a house with a very even temperature all the way through," she says. The COP, in terms of her central heating, is staying near to 4, she adds.

Heat pump performance is not really a significant barrier to adoption in the UK, suggests Mari Martiskainen, director of the Energy Demand Research Centre at University of Sussex Business School: "We have supply chain issues, we have skills issues."

Around 72,000 heat pumps were installed in the UK last year - a far cry from the 600,000 per year target set by the government.


Mr Hendra, though, argues that a wider range of heat pumps and improved technology could entice more homeowners away from fossil fuel-based boilers. In his opinion, this is long overdue.

"We are appalling at heat pumps in the UK," he says, pointing out that the UK was recently ranked 20th out of 21 European nations. "Which is truly embarrassing."
90% of the world is religious, but somehow "love thy neighbour" became "fuck thy neighbours", if they don't agree with your point of view.

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jai mitchell

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Re: Heat Pumps
« Reply #1 on: January 13, 2024, 08:20:54 PM »
Good video showcasing the tech for heat pump water heaters.  I have had one in my garage since 2009, it paid for itself in 3 years (differential cost from a non-heat pump electric resistance heater).

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El Cid

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Re: Heat Pumps
« Reply #2 on: January 13, 2024, 10:32:10 PM »


Will hotter heat pumps win over homeowners?

https://www.bbc.com/news/business-67511954

The first heat pumps Graham Hendra sold, about 15 years ago, weren't very hot.

"To get 50C - that was quite hard," says the former wholesaler, referring to the temperature of the water that these devices sent to radiators, known as the flow temperature.

Today's gas combi boilers are typically designed for flow temperatures of around 50-60C.

But a new breed of heat pumps is emerging. Engineers have gradually improved the technology, meaning that heat pumps are now able to supply much higher temperatures, sometimes in excess of 70C......

You do not need 70C water. You do not even need 50 C. I have a geothermal heat pump, in a well insulated house with floor heating. The water is heated to 45 C and that is perfectly enough. We keep the thermostat at 24-25 C (wife does not like the cold). Heating cost is cca 60 kWh/m2/year. Cooling during summer is almost free, something like 5 kWh/m2/year. And it can get quite hot here...

If you have good insulation and modern heating systems you do not need very hot water at all.

(just as an example since the average electricity cost in Europe is cca 0,3 euro/kWh, that means that for a 100 m2 house heating costs should be 6000kWh*0,3 euro/kWh= 1800 euro /year or less in the temperate zone)

https://ec.europa.eu/eurostat/statistics-explained/index.php?title=Electricity_price_statistics#Electricity_prices_for_household_consumers

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Re: Heat Pumps
« Reply #3 on: January 13, 2024, 10:40:49 PM »
Be aware that the Legionella bacteria can survive up to 55 C.
Have a ice day!

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Re: Heat Pumps
« Reply #4 on: January 13, 2024, 10:49:13 PM »
Lower temperatures require higher volumes of water so it depends on system design. New systems should be designed with lower temperatures as they are more efficient but retrofits must account for the current design or upgrade accordingly.

Freegrass

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Re: Heat Pumps
« Reply #5 on: January 14, 2024, 11:47:54 AM »
If you have good insulation and modern heating systems you do not need very hot water at all.
The problem that needs solving is that most people don't have the money to renovate their home AND buy a heat pump. The purpose of higher temperatures is to make sure people don't have a cold house after they invest in a heat pump, but not in floor heating and insulation (yet).

What needs to happen now is for the price to come down a lot, so everyone can afford one to replace their old system without the need to renovate their entire house.
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Bruce Steele

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Re: Heat Pumps
« Reply #6 on: January 19, 2024, 06:24:51 PM »
Freegrass, There are some large rebates for homeowners of moderate incomes in the US starting sometime this year. Because my existing HVAC is twenty three years old , electric A/C and gas heating, it seems prudent to think about a replacement before this system quits.
 I had contractor come give me some quotes. A three room mini split Mitsubishi installed was $26,133.
I think maybe the system he quoted was larger than I need because for another smaller Mitsubishi two room mini split he quoted $10,000.
 My current 3 ton A/C doesn’t really keep things cold when outdoor temperatures get above 40C and it uses lots of kW in the late summers but my solar/ battery system generates enough power to keep it running with very little grid use. My total utility bill for all A/C , refrigeration , lighting, water pumping is about $500 per year so spending $10,000 to switch to a heat pump isn’t a easy decision. There are substantial rebates but even so I will have a big expense .
 I will get a new heat pump and keep the old A/C as a backup . The heat pump will replace the current gas heater and at some point I need to replace the gas water heater but once I get there I will have a 100% electric farm and home. My electric tractor is maintaining three acres of garden so electrics are paying part of my food bill and utilities are very inexpensive. So I will have food, water, heating , refrigeration and lighting running on a 5.8k solar system and two powerwalls.
 My costs ballpark $12,000 for solar panels installed, $12,000 for batteries, $12,000 for a small electric tractor, and another $5,000 ? for a heat pump . Those costs would double without rebates .
My out of pocket expenses are less than many people pay for a EV.
 NRCS has agreed to pay half the cost of an energy audit if I can find a qualified engineer to do one.
 I think the heat pump will reduce my summer daily kW use and the energy I save can be used to pump water for an acre or two of trees I am planting( soil / carbon improvement+Food )Once the infrastructure is all working and paid for the job of documenting calories of food produced begins.
 Maybe it is overly simple question but can one man run a farm on 100% solar /electric , and how much food can he produce ? What is the cost of the infrastructure and how many food calories can be produced over the ~ 20 year lifespan of the hardware ? Can electrics substantially reduce the current ten calories of fossil fuel to product one calorie of food.
« Last Edit: January 19, 2024, 06:46:32 PM by Bruce Steele »

jai mitchell

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Re: Heat Pumps
« Reply #7 on: January 19, 2024, 07:30:04 PM »
Freegrass, There are some large rebates for homeowners of moderate incomes in the US starting sometime this year. Because my existing HVAC is twenty three years old , electric A/C and gas heating, it seems prudent to think about a replacement before this system quits.
 I had contractor come give me some quotes. A three room mini split Mitsubishi installed was $26,133.
I think maybe the system he quoted was larger than I need because for another smaller Mitsubishi two room mini split he quoted $10,000.
 My current 3 ton A/C doesn’t really keep things cold when outdoor temperatures get above 40C and it uses lots of kW in the late summers but my solar/ battery system generates enough power to keep it running with very little grid use. My total utility bill for all A/C , refrigeration , lighting, water pumping is about $500 per year so spending $10,000 to switch to a heat pump isn’t a easy decision. There are substantial rebates but even so I will have a big expense .
 I will get a new heat pump and keep the old A/C as a backup . The heat pump will replace the current gas heater and at some point I need to replace the gas water heater but once I get there I will have a 100% electric farm and home. My electric tractor is maintaining three acres of garden so electrics are paying part of my food bill and utilities are very inexpensive. So I will have food, water, heating , refrigeration and lighting running on a 5.8k solar system and two powerwalls.
 My costs ballpark $12,000 for solar panels installed, $12,000 for batteries, $12,000 for a small electric tractor, and another $5,000 ? for a heat pump . Those costs would double without rebates .
My out of pocket expenses are less than many people pay for a EV.
 NRCS has agreed to pay half the cost of an energy audit if I can find a qualified engineer to do one.
 I think the heat pump will reduce my summer daily kW use and the energy I save can be used to pump water for an acre or two of trees I am planting( soil / carbon improvement+Food )Once the infrastructure is all working and paid for the job of documenting calories of food produced begins.
 Maybe it is overly simple question but can one man run a farm on 100% solar /electric , and how much food can he produce ? What is the cost of the infrastructure and how many food calories can be produced over the ~ 20 year lifespan of the hardware ? Can electrics substantially reduce the current ten calories of fossil fuel to product one calorie of food.

Bruce,

Really fascinating!  I love your journo on this, I can probably provide some inputs.

First off: you said,
Quote
I think the heat pump will reduce my summer daily kW use and the energy I save can be used to pump water for an acre or two of trees I am planting

The answer is, yes and kind of.

A new Mitsubishi heat pump will have around a 30 SEER if it is high efficiency, your older AC unit will probably operate around 10-12 depending on its material condition, so you should see about half the demand (slightly less than half) for the same cooling, it sounds like on really hot days you will use it more so guess half)  But. Pumping water is VERY energy intensive, no way around it. so you will probably (certainly) only see a partial benefit and increased overall demand.

If your AC system is on a ducting system and you are opting to install minisplits, that is probably a bad idea, cutting new holes and mounting new equipment instead of retrofitting the ducting and doing a one for one replacement is not only the most cost effective but also the most energy saving option.  The only reason to not do this and install mini splits is if the minisplits are zonal supplemental cooling or heating, meaning you have 10 years or more left in your current AC.  you don't.

Often ducting is a real probalem on older units, even small leaks at joints can produce significant energy losses, same wtih air infiltration.  An energy audit ususally can be done for under $300, even with a blower door test, I strongly recommend it as they produce valid savings right away.

For heating and cooling, nothing beats an additional 6 inches of blown-in cellulose in the attic space, if conditions permit.  That is the first look for efficienct homes.

What kind of electric tractor do you have?  I may be in the market soon!

Amazing that you have a smaller system and still only have $500 per year energy costs.  My non-energy portion of my electric bill is more than that (transmission, distribution, fees etc.)  It would be higher if I had solar :(  (california).

we discussed this project years ago I am glad to hear you are doing it.  I grow and can about 500 lbs o tomatoes every year and make my own saurkraut, but still mostly peppers, tomatoes, cabbages, garlics, pac choi (for kimchee) and brassicas/lettuces.  Not a whole lot of calories but necessary foods.

Have you looked at amaranth?

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Bruce Steele

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Re: Heat Pumps
« Reply #8 on: January 19, 2024, 11:21:06 PM »
Jai, When I put solar up eight years ago electric rates were pretty low and payback time was suppose to be fairly long, but rates increased and payback period was shortened. Same with the powerwalls .
Powerwalls have a great app. that allows real time monitoring of use and production. The pressure pump on my water system eats energy . If you watch the app. and pay attention to what is running you soon learn where the energy goes. But you learn and know where to improve things.
 Thanks for the advice on the mini split system. Ducting is likely leaking and crawl space is tight , there are other obvious issues with windows etc.  I thought the mini split installation was easier than trying to fix the existing system. So if the Mini split could get us by most of the time I could still have the old A/C as a backup. I think the mini split will work fine as a heater but as a cooling system in the dog days of summer I don’t know. The $26,133 quote isn’t an option so whatever I do will be something short of gold label .
 I got the Solectrac tractor a couple years ago. It is suppose to be 25 horse but it only has 15 horse at the PTO. It has a bucket so I can turn the compost and move materials around. I have a five foot wide tiller that it can run but we move very slowly. But I can still keep a few acres in garden , cover crops ,or mowed pasture. If all you ever gardened with was a walk behind rototiller the electric tractor is a huge step up but it just doesn’t have near the power of a diesel. For my purposes it is great. I have started and maintained some pretty large gardens with nothing more than a shovel and a hoe. An electric tractor I can charge off the solar is way, way easier than how I gardened in my youth. Turning any kind of large compost pile is very difficult by hand but the tractor makes it easy and kinda fun. It going to rain for a few days so I spent the last two days tilling in some compost and planting spring spelt and another area with black barley. I have planted amaranth of various types but red root amaranth is very weedy and volunteers every year. I have about a half gallon of windowed red root amaranth seed in the drying shed. I use a little electric coffee grinder to turn it into flour, purple flour that cooked in a rue makes a good gravy for potatoes.
 

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Re: Heat Pumps
« Reply #9 on: January 20, 2024, 12:51:09 AM »
I got a 3/4 ton mini split installed a few years ago for $850. That is about as small as they come, only a single head and inflation has been high. $26,000 sounds overpriced to me have you tried getting another quote?

jai mitchell

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Re: Heat Pumps
« Reply #10 on: January 20, 2024, 02:07:18 AM »
Thanks!

I expect that the contractor will engineer the system for your house, it is required by code in many states. Like I said, a 1 for 1 replacement with a new heatpump is typically the most cost-effective and highest efficiency option.  Thanks for the update on your garden Happy for you.  I no-till mine.
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Bruce Steele

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Re: Heat Pumps
« Reply #11 on: January 20, 2024, 02:19:37 AM »
Interstitial, I think that quote was for more than I need. He also quoted me $10,000 for a 1.8 ton with two heads. I have been looking around for what others are paying . Yes need another quote .
 Do you think a 1.8 ton mini split with a high SEER can replace a three ton standard older A/C.,
Hoping Jai is correct about that because I am headed that way.

Jai, experimenting with clover and fescue to see if I can get perennial cover in some areas. Then plant in trees. Requires more water to keep green year round. I keep a log on my irrigation pump and I can compare my energy use and water use to the past several years.

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Re: Heat Pumps
« Reply #12 on: January 20, 2024, 02:21:59 AM »
Thanks!

I expect that the contractor will engineer the system for your house, it is required by code in many states. Like I said, a 1 for 1 replacement with a new heatpump is typically the most cost-effective and highest efficiency option.  Thanks for the update on your garden Happy for you.  I no-till mine.
Quotes for the same work can vary by 50% or more assuming a similar price from other contractors is foolish.

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Re: Heat Pumps
« Reply #13 on: January 20, 2024, 02:36:19 AM »
Interstitial, I think that quote was for more than I need. He also quoted me $10,000 for a 1.8 ton with two heads. I have been looking around for what others are paying . Yes need another quote .
 Do you think a 1.8 ton mini split with a high SEER can replace a three ton standard older A/C.,
Hoping Jai is correct about that because I am headed that way.

Jai, experimenting with clover and fescue to see if I can get perennial cover in some areas. Then plant in trees. Requires more water to keep green year round. I keep a log on my irrigation pump and I can compare my energy use and water use to the past several years.
A very quick internet search found a 3 ton 20 seer multizone heat pump for $4,000. (higher seers available at higher prices but do not try to get the absolute highest seer as they are like computer chips the absolute latest is only a little better but much more expensive. You might be able to get 24 or 26 sear for a reasonable price but maybe not.) than That is not everything needed (maybe another $1,000 for other parts) and does not include installation. I do not know the specifics but I would expect to be able to get a 3 ton system installed for under $10,000. Prices for labor vary greatly by region.
« Last Edit: January 20, 2024, 02:44:02 AM by interstitial »

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Re: Heat Pumps
« Reply #14 on: January 20, 2024, 03:19:17 AM »
A 1.8 ton or more likely 1 3/4 ton heat pump is an odd size a 2 ton would probably be cheaper. The price difference between 2 ton and 3 ton units I am seeing is not that great ($400).




This recent article suggests a 2 ton heat pump installation should cost between $2500-5000.
https://www.forbes.com[color=var(--theme-col-txt-url-path)] › home-improvement › hvac › heat-pump-installation-cost


I found a 3 zone 3 ton 21.5 seer at home depot for 4300. It includes almost everything except about $200 or less for electrical parts.




I think the $25,000 quote is about $15,000-18,000 to high.  Sometimes a busy contractor offers an extremely high price knowing that some people will just pay it rather than shopping around. [/color]

jai mitchell

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Re: Heat Pumps
« Reply #15 on: January 20, 2024, 06:40:03 PM »
not sure about whether that mini split would work for you.  Like I said, the system needs to be engineered with a software model to be sure.  Taking into account insulation value, building design/layout, orientation and other factors.  having more than 2 receivers on that system will be too many for heavy cooling load and so some parts of the home may not be cooled adequately.

My recommendation is a 1 for 1 replacement with duct repair on a rooftop system - just as an uninformed observer without real information and details. . .   8)
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