Steam from Heat Pump
Just picked this up on the local news
USA company with an air sourced heat pump that produces steam - COP around 3?
John
Comments
-
ConEd is in the process of switching its enormous steam boilers to steam heat pumps.
Retired and loving it.
1 -
Since residential steam is increasingly becoming a niche market I doubt the money is there to develop these systems for people like us… but that would sure be nice!
0 -
I'll believe it when I see it. In my area, the COP at -15 F exterior temperature must be equal or greater than 3.0 to even break even on the electricity, and the BTUh must be at least 400,000 net output at the main.
Oh and it would be nice if the total power draw were ess than 10 KW, so I can run it when the power is off (which happens regularly in the winter around here).
Br. Jamie, osb
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England0 -
Are you guys talking about compressing steam?
0 -
Will it work in one stage?
0 -
They talk in the article about compressing the refrigerant to a higher pressure but don't say a word about how this is done. Either a compressor or another heat source would be needed.
0 -
Air to water heat pumps can produce hot enough water to make steam. If a one or two pipe system is paired with a retrofitted vacuum pump to lower the water temperature necessary to produce steam, it's even easier.
https://www.heat2o.com/
I wonder if Igor Zhadanovsky has already tried prototyping vacuum systems with air to water heat pump.
0 -
Going from a -15 F source to 220 F sink to make the steam is a pretty big ask, if the COP is kept up (as I noted, it must be greater than 3 under those conditions to be viable). There may be such air to water heat pumps out there. Kindly publish the maker and models, as I've never seen one, and to be a bit brutal about it, I have grave doubts.
Suggesting going to an assisted vacuum system (which would be required) to lower the steam temperature is fine, but remember three things: you've just made an exceedingly simple heating system into one which is remarkably complex; second, it is a truly remarkable steam heating system which is vacuum tight; third, you lose radiation power at a near linear rate with reduced temperature, and you may not have adequate radiation.
I will repeat a challenge which I made some years ago, which no one took me up on: it is simply this. I will provide an existing two pipe vapour steam system in very good condition, in an existing structure, with energy use records going back 20 years. You will provide your heat pump system, which is required to have a COP of not less than 3.0 at a source air temperature of -15 Fahrenheit and a net output of not less than 400,000 BTUh at 15.0 psi absolute steam pressure. The system must have a failure rate of less than one failure to operate requiring maintenance per year. If the system requires more than 8 KW of power to operate, the cost shall include a suitable, fully automatic, power source capable of maintaining not less than 7 days of continuous operation without grid (commercial) power. If under any operating condition the system requires more than 24 KW of power, the cost shall include all necessary additions and modifications to the service entrance an electrical equipment. If, after 15 years of running the system, including all energy costs (note: I have a PV system, but energy costs shall be figured at retail public utility rates), initial capital investment depreciation, the cost of loss capital opportunity, and all maintenance, has cost less than replacing the existing oil boiler would have, I'll buy it from you for cost plus a reasonable profit plus market rate interest. .
No subsidies shall be included.
Edit: two more things. First, If the system as installed fails to operate as required above at any time in any respect, you will bear the entire costing of removing the system in its entirely, except for electrical modifications which may have been required, and restoring the existing steam system to its present condition or better. Second, a "failure" is defined as not more than 24 hours out of full operation for any cause requiring maintenance. Each succeeding 24 hours shall be regarded as a further failure, and so on.
That's your competition.
Time to put up or fold, folks.
Br. Jamie, osb
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
2 -
@Jamie Hall can you spec out a steam system for me that can provide AC and must be cheaper to run than a heat pump? :) thanks!
0 -
Re: cheaper to run.
If you take into account the expected lifespan of the equipment and anticipated maintenance and repair costs, then my 75 year old boiler and 20 year old AC might win that one. Efficiency and reducing fuel costs are not everything.
I can build an engine that makes 10 horsepower per cubic inch. It might only last 100 hours. Toyota makes hybrids that are 40 percent thermally efficient. But if the battery is done after 10 years and costs more to replace than the car is worth?
2009 Camry Hybrid, 127,000 miles, $6200. 16 year old battery.
I would buy this, if the price to replace the battery was reasonable. I know you can replace individual cells. That is a half 🐎, duct tape and bailing wire temporary fix.
(click image for larger)
My 2001 Suburban has over 10,000 hours and 200,000 miles. Same range and performance that it had when new.
0 -
But people are not buying boilers, they’re buying furnaces + ACs. If the AC lasts as long as the HP, then how long the furnace (if hybrid) lasts is irrelevant. Otherwise, you’re replacing the HP on around the same schedule as the AC. No big deal.
Ha luckily a Toyota hybrid lasts much longer than 10 years so we don’t have to play that game.
0 -
I have no need for air conditioning.
I am asking for an essentially drop in replacement for Cedric. Somewhat tongue in cheek, because I know you can't do it, any more than a Tesla can self drive itself from the nearby village to Cedric's home (2.5 miles).
I love unicorns and rainbows as much as the next guy or gal, but I live in the real world — and so does the vast majority of the population.
Br. Jamie, osb
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England0 -
@Jamie Hall i do not want to replace your boiler and never have. You’re denying reality here - heat pumps outsold furnaces last year. It might make you uncomfortable or whatever, but this is what’s happening. It is not helpful to claim otherwise if you truly want to help the average American. You don’t need to belittle us.
0 -
The average American lives in a city or a suburb somewhere where the design temperature is above 0. The average Brit lives similarly. I'm fine with them having heat pumps. No problem. In fact, I would recommend them for new construction. Just stop pushing heat pumps as a solution to staying warm in climates and situations where they just don't work. For reference, the Brits and Germans tried that — and it brought down the governments.
Br. Jamie, osb
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England0 -
Ha luckily a Toyota hybrid lasts much longer than 10 years so we don’t have to play that game.
My money, my equipment, I decide the game.
https://en.wikipedia.org/wiki/Toyota_Camry_(XV40)
Its a 1.6 kWh NiMH battery pack. How Much? Doesn't have to be OEM, just new. Parts and Labor.
Toyota hybrids are one of the lowest fuel cost cars made. Great for what they are. If you drive 50,000 miles per year they are a no brainer. If you drive 3000 miles a year, not a good choice.
This Fall, consumers in North America will no longer get a choice. All 2025 Camrys will be Hybrids.
1 -
Heat pumps are of course very competitive in rural areas too, often more so because you’re competing against higher cost fuels.
@WMno57 I truly do not care how much a replacement battery for a 16 year old Camry costs. If you don’t want a Camry hybrid, don’t buy one.
0 -
Heat pumps are of course very competitive in rural areas too
Unless the home is off the grid. (click once for bigger, twice for Huge)
1 -
That’s yours?! Beautiful!
0 -
As regard heating/cooling, looking at this table: https://www.captiveaire.com/CatalogContent/Fans/Sup_MPU/doc/Winter_Summer_Design_Temps_US.pdf?v=17112015 , there is no such a thing as an average American climate.
There are a lot of places in USA where I wouldn't need cooling.
Looking at the same table, it is cooler and hotter in Germany (continental climate) than it is in the UK
0 -
I believe that stat is 90% of US homes have AC (including non-ducted). Need isn’t the same thing as want - Americans want AC, and they want it enough to pay for it.
0 -
It's been tried here too- remember the Acadia?
All Steamed Up, Inc.
Towson, MD, USA
Steam, Vapor & Hot-Water Heating Specialists
Oil & Gas Burner Service
Consulting0 -
Not mine. Upper Peninsula of Michigan. Owned by a guy and his father who does some interesting DIY off-grid electrical projects.
https://offgridcabin.wordpress.com/
I looked at a property near there in 2018. Large acreage with 1920ish Sears kit home and half a dozen outbuildings, all in very poor shape. It was on the grid, but very rural.
I really liked it, but it was more work than I could handle (a man's gotta know his limitations). It had been for sale for years. A month after I looked at it, it sold for less than $1000 per acre. It had been logged 15 years previously, so not much timber value yet.
Instead, I bought a 1916 home in Indiana. Home in better shape with outbuildings that still need too much work and 1/30 of the acreage. Rural, but it has Natural Gas service. Has some Hickories and Oaks that need at least another 20 years to be marketable.
My Crib. Yes it is a genuine corn crib. Came with a house to. House is good, Crib is going to revert to nature if I don't do something soon.
Mother nature gave me this house warming gift for the Pole Barn a week after I closed.
I'm fortunate to have what I do. The value of many Rural properties has gone through the roof. Covid changed everything. I heard a statistic that the number of people who work remotely has quadrupled. Also, Solar has driven up the cost of rural land.
If I only had a crystal ball.
0 -
Back to Heating and Electrification. 100 year old houses that were originally hydronic (no ductwork) are much more difficult and expensive to electrify. My 1916 home had a packaged type AC (rooftop unit) placed alongside the house and spacepak type mini ducts run through the basement. No AC on second floor. It works OK. Unless its really hot, I just open the windows. When it dies, I might be able to replace it with a HP. We get a lot more power outages out here too.
Rural reality is much different than Urban reality. What works in cities and suburbs, might not work here.
Same situation with Steam buildings in NYC. The USA can make greater progress towards carbon reduction if we focus on the doable instead of focusing on an unrealistic fantasy of eliminating traditional fuels (some pejoratively call them fossil fuels).
0 -
If I had to use air source electric heat pumps to replace steam heating boiler I'd consider compounding. For example regular heat pump to heat condensate to 120° and compress that to steam.
1 -
The staged concept is a very good one. I suggested that to SpacePak a few years back … and got a corporate stock "thank you for your interest" reply.
One really interesting possibility, though — at least to my feeble mind — lies in remembering that water itself actually has some very interesting properties as a refrigerant. So… Stage one would provide the lifting from a lowest operating temperature of perhaps -20 F or so, with an appropriate refrigerant. Stage two, then would be heated by the high side of stage one at perhaps 100 F or so — and evaporate water at that temperature directly. Then compress the water vapour and send it out to a perfectly normal steam system (no change required if it's two pipe) at a pressure of about 15 psi absolute where it would condense in the radiators, just as it does now, and return. Rinse and repeat…
Like any refrigeration cycle, the real trick is to keep non-condensible gas (air) out of the thing. Most steam systems aren't really vacuum tight — they don't need to be — but if that could be done… preferably without mechanical vacuum pumps to evacuate stray air… haven't solved that problem yet!
Br. Jamie, osb
Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England0 -
Interesting technology, but I think burning B100 biodiesel or hydrogen will get the market share for Steam.
0 -
Unfortunately, the greater the 'delta-T' the poorer the COP, and going from well below freezing up to boiling is a huge 'delta-T'
The maximum possible COP to pump heat from -15 F to 212F (247K to 373K) is 373 / (373-247) = 2.96. I doubt that any current practical heat pump gets half of the theoretical maximum. Current heat pumps with COP of 3 (or above) work with smaller delta-T values, eg. pumping 45F heat into a 70F room.
Also getting 117kW of heat with 10kW in is going to be a non-starter, unless the delta-T is quite small.
I don't think your metrics will ever be met :)
I'd love to have some sort of vacuum steam heat pump backed up by a fuel boiler for the coldest days. Say something working with 65C steam so that my big old radiators were not oversized for my air sealed house. I would run the heat pump to make steam on the mild days, burn fuel to make hotter steam on cold days, and be happy as a clam.
I currently have minisplit heat pumps, and use them for heating when the outdoor temperature is above freezing. I use oil steam for colder days. The heat radiating off the radiators is subjectively nicer; the minisplit is blowing warm air, so I find on the minisplits that I need to have a higher room temperature to be comfortable. But using this hybrid system my oil use went from 350 gallons per season to 150 gallons, and my annual electricity use went up 1000 kWh. IMHO a nice win.
-Jonathan
0 -
Since this thread was from April, I wonder if it started on April 1?
0 -
Lmao, heat pumps. We have had them for years. Owners curse them as they used electric auxiliary heat. To get the temperature necessary to heat the space, the customer would have $1000+ electic bills every month. Government decided to incentivize purchases of heat pumps last year or two. Covered half the installation. My rezzi side installed hundreds, a couple guys jumped on it. Govenment ended incentives last year. Asked the rezzi guys about how many sold since incentives have ended and how the hp are working. Not one sold and nothing but complaints. Oh, and we sold gas furnaces for back up. Wasted millions of tax dollars pulling working equipment out and scrapping it. For what? And now we get to deal with the service calls about poor heat, gas bills and electrical usage. Mitsi and dakian say theirs work down to 5f or so. The btu is negligable at that temp.
Ive done bigger refrigeration with supermarkets. Heat reclaim coils are a thing, similar to heat pumps. They cant keep up in the winter even with a place to pull those btus from. Still need gas heat as back up. Our lowest temperature in last 20 years is -10f. Gas heat takes over at well before that.
My gut says using air based heat pumps for steam boilers is a pipe dream for now. Maybe a preheat, especially for hw, but not a total solution. And at what cost? We sit on ng levels i cant even imagine. More reliable and sustainable long term.
As my motor guy says, you cant get something from nothing. Theres no free ride. If you want to stay warm, something has to die, otherwise you die.
0
Categories
- All Categories
- 86.5K THE MAIN WALL
- 3.1K A-C, Heat Pumps & Refrigeration
- 53 Biomass
- 423 Carbon Monoxide Awareness
- 96 Chimneys & Flues
- 2K Domestic Hot Water
- 5.5K Gas Heating
- 101 Geothermal
- 157 Indoor-Air Quality
- 3.5K Oil Heating
- 64 Pipe Deterioration
- 928 Plumbing
- 6.1K Radiant Heating
- 384 Solar
- 15.1K Strictly Steam
- 3.3K Thermostats and Controls
- 54 Water Quality
- 42 Industry Classes
- 48 Job Opportunities
- 17 Recall Announcements