Too bad I cannot convert my biomass stove to cool instead of heat.....

[SidecarFlip]

That would be wonderful right now. Been hot and humid here (rains everyday seems like). Temps approaching low 90's every day. Now if I could somehow convert the biomass burner to cool, instead of heat, I could become a very rich person overnight....

 

[peakbagger]

Sure you can, you just need to add an absorption chiller on the hot water output. How Absorption Chillers Work | EnergyLink (goenergylink.com)

YAZAKI - OFF GRID COOLING SOLUTIONS (yazakienergy.com) There is page with biomass solutions.

I have one sitting on a pad down at one my jobsites waiting for the rest of the plant to be set up. Unfortunately they do not sell them in North America in a home size unit. I think there may be small residential units for sale in Europe. We usually generate hot water off a natural gas electrical generators radiator and exhaust and run the hot water to the chiller.

 

[SidecarFlip]

I'd say the principle is the same as the absorption fridge is in my RV. but the fridge in the RV uses Ammonia as a liquid, converted to a gas (by heating it) to extract the heat (and replace it with cold) in the fridge cavity. Continuous cycle, heat the liquid to a gaseous state and then running it through a HX to turn it back into a liquid. Nice thing about that system is there are no moving parts at all. All done by gravity. Would take a huge system (as in expensive) to attain the needed heat exchange however.

 

[ABMax24]

Not to mention that the COP of an absorption fridge is 1.0 in a good system on a good day. A base model central AC is 3.25 or better.

 

[SidecarFlip]

One thing I did to increase the efficiency of mine (it's not very efficient in it's installed condition) was, I added three computer muffin fans wired to the thermal switch so when the finned tube HX heats up (and it does), there is adequate air flow across it to strip off the heat more efficiently.

A some point I may pull the entire unit and replace it with a compact compressor fridge like an Engle or a Dometic. I know it's not really germane to the discussion but in my opinion, the absorption unit is pretty inefficient.

Gotta have cold beverages when camping...lol

 

[ABMax24]

They're definitely inefficient but the simplicity is hard to beat, I have 2 fridges in my trailer, the main is a standard absorption type and we have a compressor type in the outside kitchen, we've never turned the compressor fridge on, although now thinking about it I could run it off the inverter and solar panel I installed in the trailer this spring.

Generally we only use a 30lb tank of propane a year in the RV, which costs less than $20 to fill, pretty hard to complain about that.

 

[peakbagger]

I also used to have a chill vactor system at work. Not many of them around. Put steam in one end, get cold water out the other with no intermediate working fluid, just water and steam. It was about 4 stories tall.

 

[SidecarFlip]

I also used to have a chill vactor system at work. Not many of them around. Put steam in one end, get cold water out the other with no intermediate working fluid, just water and steam. It was about 4 stories tall.

Physically a bit large for residential application...lol

 

[SidecarFlip]

They're definitely inefficient but the simplicity is hard to beat, I have 2 fridges in my trailer, the main is a standard absorption type and we have a compressor type in the outside kitchen, we've never turned the compressor fridge on, although now thinking about it I could run it off the inverter and solar panel I installed in the trailer this spring.

Generally we only use a 30lb tank of propane a year in the RV, which costs less than $20 to fill, pretty hard to complain about that.

About what we use as well but then it powers the stove and oven too. I have minimal solar on mine. I prefer using an Inverter genny to top off the storage batteries and we aren't big into conveniences like a TV or even a microwave. it's wilderness camping for us and I still prefer cooking on an open campfire versus the stove. I have my Lodge Dutch oven which I use a lot. Have a small Champion Inverter and it handles everything nicely. Where we camp (in the woods), no ac needed, always cool under the forest canopy with the bugs....lol Think my HWH uses more fuel than anything else actually. Wife (and I) like hot showers before bed time.

 

[ABMax24]

About what we use as well but then it powers the stove and oven too. I have minimal solar on mine. I prefer using an Inverter genny to top off the storage batteries and we aren't big into conveniences like a TV or even a microwave. it's wilderness camping for us and I still prefer cooking on an open campfire versus the stove. I have my Lodge Dutch oven which I use a lot. Have a small Champion Inverter and it handles everything nicely. Where we camp (in the woods), no ac needed, always cool under the forest canopy with the bugs....lol Think my HWH uses more fuel than anything else actually. Wife (and I) like hot showers before bed time.

We also have a 3100watt Champion, but now only use it to run the AC when needed. I have a 300watt solar panel that keeps the battery charged, its a big help in the spring and fall when we use the furnace in the trailer when outside temperatures drop as the furnace puts a significant load on the batteries. Our inverter is too small to run the microwave, but it does run the TV. We don't watch TV all that much, but it's nice when we do week or longer trips around western Canada.

 

[SidecarFlip]

I have the smaller Champion. Good little genny. I have a Aims Power 3000 watt PSW inverter with remote. I need it for the CPAP machines. Don't have an ac. No need in the woods and we only camp on our own Northern Michigan property anyway. The forest canopy is always cool. Mine is a truck camper., necessary for us in as much as access to our land is via seasonal road in 4 wheel drive. Solar would be no good as it's always shady. I may switch the frig however.

 

[railfanron]

Years ago (before retirement) I worked on many Absorption chillers in large buildings and factories. They were powered by steam and are still being produced today. They range in size and I have seen them as high as 3,500 tons I believe. To say they are inefficient is incorrect. An RV fridge maybe yes but commercial absorption chillers are very efficient.
Ron

 

[SidecarFlip]

The you must be the 'Chilla from Manila'....

 

[ABMax24]

Years ago (before retirement) I worked on many Absorption chillers in large buildings and factories. They were powered by steam and are still being produced today. They range in size and I have seen them as high as 3,500 tons I believe. To say they are inefficient is incorrect. An RV fridge maybe yes but commercial absorption chillers are very efficient.
Ron

Yes this was in reference to the absorption refrigerators in RVs.

We touched on industrial absorptions chillers back in trade school, but I've never had the chance to work on one. My understanding is it is possible to have a COP of over 5 with these units. That trade school has a small steam turbine to generate electricity for the campus, and of course used to have an absorption chiller heated by low pressure steam off the turbine to cool the campus buildings. Of course somewhere down the line it was replaced with an electrically driven mechanical compression unit.

I miss going to school in buildings like those, as a trades and technology campus the mechanics of the buildings were actually showcased, instead of being hidden from sight.

 

[peakbagger]

Absorption chillers range in COPs from really low, around 0.8 for single effect to 1.4 for double effect to 1.8 for triple effect (new technology. The higher the source temp to drive the unit decides how many effects can be built into the unit. The ones I have installed are waste heat units using radiator water and exhaust heat from big stationary recip engines and only can drive a single effect unit. The double effect units typically need steam to run. They also very large and heavy compared to centrifugal chiller probably 5 to 10 time larger than an equivalent centrifugal chiller. Centrifugal chillers COP range from 2.5 to 6 depending on how they are cooled. So why would anyone want to buy a absorption chiller since they are far less efficient and take up a lot of room?. It comes down to most centrifugal chillers are run by electric power which needs to be generated. If its generated with fossil fuels you have to include the electrical efficiency of the electrical generator into the calculation. The most efficient reciprocating engine generators are 50% electrically efficient so if someone is just generating power with natural gas and turning a centrifugal chiller, that 50% figures into the super efficient COP of the chller. If you generate power with a thermal plant the electrical generating efficiency is even less in the 30 to 40% range.

Where I have made my living the last few years is combined heat and power plants and we look at the overall conversion of fuel into useful work both electrical heating and cooling. I do small plants for factories and institutions that need both electric power and heat (both steam and hot water) or cooling. One of our plants for a papermill was over 80% efficient That means less carbon in the atmosphere and lower energy costs for the owner. In this case, the owners energy cost was about 50% less and his claim was that it was the difference between keeping the plant open or closing it down. The papermill didnt need cooling but some of other plants with mechanical cooling are up over 70%. The big trick is we generate electrical power first and then take the waste heat that normally would go up the stack and generate steam or hot water with that heat. Where low efficiency absorption chillers fit in is they can use the lowest temperature heat that normally would go up the stack. The other selling point is if set up correctly, these plants do not need the grid to run, if the grid goes down they "island". In one case on a stormy night the papermills power plant operator got a call that a very large motor would not run, they called in a supervisor from home to help diagnose the motor. it took then a couple of hours to figure out the electrical transmission line to the plant had tripped and they had been running without the grid for a couple of hours. The reason the big motor would not run is that if was so big that we set it up that if the grid was down the motor would not run as the starting and stopping it might take down the plant when islanding due to the current inrush when turning it back on. For more money up front we could have dealt with it but not worth spending the extra money for a very rare occasion. For several of our projects, the ability to run without the grid is quite important which is why many hospitals have built CHP plants. The assumption in New England is that its very rare for the grid and the natural gas supply to be down at the same time.

The trade off is these are complex systems and not cheap to build compared to less efficient systems. I dont see a home sized system being sold although Honda did sell a generator/hot water system in England for a few years. In theory if the grid goes renewable, then no worry on carbon and the centrifugal chillers make the most sense. The last number I saw for the state I work in is the overall grid generation efficiency is 44% so if we can build systems in the 70 to 80% range, the overall carbon impact is a big savings.

 

[SidecarFlip]

Regardless, in a few scant months, we will all be back on our heat cycle again and roasting the accumulated cobwebs out of the venting... I cannot wait and I do need to get sticker shock on pellet fuel yet. Why do I think pellets will be up substantially from last year?

 

[tlc1976]

Here it’s been 60s and the wind off the lake makes it feel colder. Had frost in places on the first day of summer.

On the rare occasion it does get to 90s and high humidity, I just hang out in the basement. Dehumidifier makes it feel like a dry icebox.

 

[EbS-P]

I think the steam chillers while not efficient can help reduce electric demand on peak summer days. Umaine used to request faculty students and staff work from home if possible and then fire up the backup generators on those days to avoid surcharges on their power bill. The clean room and building was cooled by a steam chiller.

Here it’s been 60s and the wind off the lake makes it feel colder. Had frost in places on the first day of summer.

On the rare occasion it does get to 90s and high humidity, I just hang out in the basement. Dehumidifier makes it feel like a dry icebox.

I just spent 3 days over 97F on the beach in Maine. Read that sentence again….

Being from NC(via Kansas), it was stupid hot. Water was 53F. So somewhere on the walk from the water to the umbrella I was comfortable for about 30 seconds. High in the 60s for the next few days.
I do think the absorption chillers, while inefficient, can shift some demand from the electric grid and should not be discounted as a cooling source. Solar chillers?????….
Just put up PV panels……

 

[ABMax24]

This is intriguing:

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[SidecarFlip]

Subscribed to his channel along with 'Smarter Everyday'. I enjoy people like that. A stagnant mind is a bad thing. My issue is always converting metric to SAE.

 

[tlc1976]

I think the steam chillers while not efficient can help reduce electric demand on peak summer days. Umaine used to request faculty students and staff work from home if possible and then fire up the backup generators on those days to avoid surcharges on their power bill. The clean room and building was cooled by a steam chiller.

I just spent 3 days over 97F on the beach in Maine. Read that sentence again….

Being from NC(via Kansas), it was stupid hot. Water was 53F. So somewhere on the walk from the water to the umbrella I was comfortable for about 30 seconds. High in the 60s for the next few days.
I do think the absorption chillers, while inefficient, can shift some demand from the electric grid and should not be discounted as a cooling source. Solar chillers?????….
Just put up PV panels……

Yes I kinda feel for the rest of the country and parts of Canada that are baking, while I’m running around in a coat. Must be being surrounded by the Great Lakes.

Ever since I got a camper almost 20 years , I wondered if they could make large scale absorption refrigeration to use as AC. Basically as long as the sun beats down, it focuses the sunlight to simulate the gas flame. More heat means more cooling.

If you lived off grid in the sticks, you could set up a system large enough to cool a small house. Inefficiency wouldn’t matter because operating cost would be free. I haven’t googled but I’m sure someone has rigged up something.

Of course then again you just build underground to accomplish the brunt of the cooling.

 

[ABMax24]

Subscribed to his channel along with 'Smarter Everyday'. I enjoy people like that. A stagnant mind is a bad thing. My issue is always converting metric to SAE.

As am I, "Veritasium" is another good channel.

 

[SidecarFlip]

One of my very good hunting buddies built a new home not far from here and has a 'water furnace' with an in ground thermal loop and his utility bill winter and summer is 70 bucks a month, never changes. Has ac in the summer and heat in the winter. I'd consider that but I'm too old to realize any benefit, besides with free corn, I can do even better in the winter anyway...lol

 

[gthomas785]

What I really need is a stove that cools my house while cranking out perfectly seasoned splits of hardwood

 

[SidecarFlip]

Perfecting that will make you more wealthy than Elon Musk.