Science Rant, Not politics: Can CO2 cause "Climate Change?"

[Mister Moose]

We are missing each other here Moose. Sure are.The Freeaire Polar Power System is simply an air side economizer. Same concept that has been used for years to reduce energy usage in building HVAC systems. It is used in every combined cycle plant I have ever worked in to save fuel cost. It is the preferred method for cooling data centers to save energy. It is a well proven concept. If you have outdoor condensers/compressors.

The cold outside air is free. Yes, I get that. No energy gets expended removing the heat. Think the opposite of solar thermal. Fans are used to draw the cold air in (fans use far less energy than compressors). As the air warms in the walk-in cooler fans reject the warmer air outside; air which is still much colder than the air inside the lodge. It still contains heat lost from the lodge, and instead of being returned to the lodge as it would with an indoor condenser, it goes outside and is lost. Total system <electrical> energy consumption is reduced. If you don't believe me run an energy balance calculation. I'm sure there are plenty of well documented ones online.

I agree that heat recovery from compression makes sense but only is you have to run the compressors.

Also, the Freeaire System uses advanced controls, which in itself, compressors running or not, creates efficiencies. Yes, advanced controls are good for any system.

Even better, here is what Killy had to say: Because Killy is such a recognized thermodynamics expert
"Since 2007, Killington Resort has converted 12 walk-in coolers to Freeaire Refrigeration. Freeaire, a Vermont-based company, created and installs systems that use cold, outside air to refrigerate coolers instead of using high energy consuming compressors to cool stored food.

HOW MUCH ENERGY DOES FREEAIRE REFRIGERATION SAVE?
During the 2011-12 ski season the cooler at Rams Head ran for 125 days. During that time, the energy use dropped nearly 1,700 Kilowatt hours This is electricity savings only, and does not account for heat lost in the building that has to be replaced. from when cooling was entirely compressor-based. This single, seasonal cooler’s electrical savings reduced our carbon footprint by 1.1 tons of CO2. Savings can be found in year round coolers as well as seasonal coolers. A year round cooler uses roughly 8,500 Kwh less than it did before the installation of the Freeaire system in a one and a half year period. This one cooler reduces Killington Resort’s carbon emissions by 2.51 tons of CO2 in the same amount of time.

Retrofitting all of the coolers here at Killington Resort with the Freeaire system has greatly reduced energy usage, and has reduced CO2 emissions by 13.2 tons a year."
http://www.killington.com/site/culture/ ... ndex.html/

You have blinders on, or we have different starting assumptions, and you are introducing unnecessary degrees of complexity.

System one: All heat stays in building envelope.

System two: Waste heat from cooler is exhausted outside.

System two is less efficient in the winter by exactly the amount of lost heat extracted when the Freeaire system operates.

It doesn't matter whether the heat needed to keep the building temp at 60 degrees is from condenser heat, compressor heat, or propane fired heat. If you remove a certain amount of condenser/compressor heat, (by eliminating the compressor and using cold outside air and venting waste heat outdoors) it will have to be replaced by an equal amount of propane heat. There is no savings in the winter by eliminating the compressor/condenser heat. There is only substituting electrical savings for propane expenditure.

You can talk about the difference in energy costs between propane and electricity, and carbon footprint between electricity and propane, but the energy lost with Freeaire in the winter is less efficient.

If you can't see that difference, if you don't understand that in the winter a household refrigerator is 100% efficient*, I don't think I can explain it in much more concise terms.

Bubba might be on to this.


*If you vent the household fridge outside for "free" cold air, you are losing heat outside the building envelope, and it is not free.

[Guy in Shorts]

Who hasn't wondered why you can't use the cold winter air to refrigerate. Was glad to see Killington doing it. A little more innovation and it may catch on.

Pretty sure that The Outback had one of the original free air glass cooling systems.

[Bubba]

You neglect to take into account the huge energy offset by not running the compressor in the winter, which drastically reduces net CO2 production. Compression is far more energy intensive than heating.
The compressor does not reject heat the condenser does. Plus locating the condenser inside would make warm months unbearable. The Freeaire system provides significant energy savings from the controls alone.

Yes the condenser does transfer more heat than the compressor. They are often co-located so I didn't bother distinguishing.

Now stop and think about your first and second statement. You are looking at electricity consumed, I'm looking at total energy.

What happens to the energy used by the compressor? Heat from resistive losses, heat from friction, from compression, and heat from the work done in running the refrigerant around the circuit, which comes out the condenser. The final stop of all energy use is heat. (Sure, you can do work and store energy either chemically or gravitationally, but when you use that stored energy the final stop, again, is heat.)

In the winter heat is good. Killington is a winter resort that closes many lodges in the summer, and whose peak walk in cooler demand is in the winter.

If all this heat is directed into the building, the HVAC plant needs to provide less heat, and less fuel is consumed. If you exhaust any of that heat outside, as the Freeaire system does, you lose that heat outdoors. All the warmed air in the walk-in cooler that gets exchanged with cold outside air is wasted. This heat from the warmed air from the walk-in is coming from the heated building. That's the loss in efficiency I'm talking about.

Now envision a system that has the compressor and the condenser located inside the building, with no air exchange for the walk-in. In the winter, all the heat produced is used to warm the building. In the summer, you could easily direct the unwanted extra heat from the condenser outdoors through the same type of duct work.

So in the cool months, the Freeaire system will use less electricity, but lose more net energy. The heat lost with Freeaire is vented outside. Without the Freeaire the heat is retained indoors. The greater use of electricity indoors without the Freeaire is transferred to heat. This heat (from the compressor as you point out) means less fuel is burned by the HVAC plant. It is not wasted.

So to sum up, without Freeaire: More electricity used by the compressor but less composite energy of the HVAC/walk-in total.
With Freeaire less electricity (which requires more HVAC fuel burned to replace the loss in heat produced by using that extra electricity) but greater total energy/fuel consumed as you are venting heat from the building outside. That vented heat must be replaced by burning more propane or fuel oil.

And of course in the summer the Freeaire system has no advantage.

We are missing each other here Moose. The Freeaire Polar Power System is simply an air side economizer. Same concept that has been used for years to reduce energy usage in building HVAC systems. It is used in every combined cycle plant I have ever worked in to save fuel cost. It is the preferred method for cooling data centers to save energy. It is a well proven concept.

The cold outside air is free. No energy gets expended removing the heat. Think the opposite of solar thermal. Fans are used to draw the cold air in (fans use far less energy than compressors). As the air warms in the walk-in cooler fans reject the warmer air outside; air which is still much colder than the air inside the lodge. Total system energy consumption is reduced. If you don't believe me run an energy balance calculation. I'm sure there are plenty of well documented ones online.

I agree that heat recovery from compression makes sense but only is you have to run the compressors.

Also, the Freeaire System uses advanced controls, which in itself, compressors running or not, creates efficiencies.

Even better, here is what Killy had to say:
"Since 2007, Killington Resort has converted 12 walk-in coolers to Freeaire Refrigeration. Freeaire, a Vermont-based company, created and installs systems that use cold, outside air to refrigerate coolers instead of using high energy consuming compressors to cool stored food.

HOW MUCH ENERGY DOES FREEAIRE REFRIGERATION SAVE?
During the 2011-12 ski season the cooler at Rams Head ran for 125 days. During that time, the energy use dropped nearly 1,700 Kilowatt hours from when cooling was entirely compressor-based. This single, seasonal cooler’s electrical savings reduced our carbon footprint by 1.1 tons of CO2. Savings can be found in year round coolers as well as seasonal coolers. A year round cooler uses roughly 8,500 Kwh less than it did before the installation of the Freeaire system in a one and a half year period. This one cooler reduces Killington Resort’s carbon emissions by 2.51 tons of CO2 in the same amount of time.

Retrofitting all of the coolers here at Killington Resort with the Freeaire system has greatly reduced energy usage, and has reduced CO2 emissions by 13.2 tons a year."
http://www.killington.com/site/culture/ ... ndex.html/

On what are you basing the CO2 savings?

I quoted Killington. So its not my calculation. But those numbers are a significant under estimate based on eGRID, U.S. annual non-baseload CO2 output emission rate, year 2012 data.

Considering that Vermont utilities, i.e. GMP, as individual entities use little to no fossil fuel, the CO2 savings might be greatly overstated.

[brownman]

".. Retrofitting all of the coolers here at Killington Resort with the Freeaire system has greatly reduced energy usage, and has reduced CO2 emissions by 13.2 tons a year."

Perhaps someone can do the math on the net energy savings .. butt one would think the resort could afford to run at least a groomer with a trailing rope up pipedream.

Nevermind ..

[Woodsrider]

We are missing each other here Moose. Sure are.The Freeaire Polar Power System is simply an air side economizer. Same concept that has been used for years to reduce energy usage in building HVAC systems. It is used in every combined cycle plant I have ever worked in to save fuel cost. It is the preferred method for cooling data centers to save energy. It is a well proven concept. If you have outdoor condensers/compressors.

The cold outside air is free. Yes, I get that. No energy gets expended removing the heat. Think the opposite of solar thermal. Fans are used to draw the cold air in (fans use far less energy than compressors). As the air warms in the walk-in cooler fans reject the warmer air outside; air which is still much colder than the air inside the lodge. It still contains heat lost from the lodge, and instead of being returned to the lodge as it would with an indoor condenser, it goes outside and is lost. Total system <electrical> energy consumption is reduced. If you don't believe me run an energy balance calculation. I'm sure there are plenty of well documented ones online.

I agree that heat recovery from compression makes sense but only is you have to run the compressors.

Also, the Freeaire System uses advanced controls, which in itself, compressors running or not, creates efficiencies. Yes, advanced controls are good for any system.

Even better, here is what Killy had to say: Because Killy is such a recognized thermodynamics expert
"Since 2007, Killington Resort has converted 12 walk-in coolers to Freeaire Refrigeration. Freeaire, a Vermont-based company, created and installs systems that use cold, outside air to refrigerate coolers instead of using high energy consuming compressors to cool stored food.

HOW MUCH ENERGY DOES FREEAIRE REFRIGERATION SAVE?
During the 2011-12 ski season the cooler at Rams Head ran for 125 days. During that time, the energy use dropped nearly 1,700 Kilowatt hours This is electricity savings only, and does not account for heat lost in the building that has to be replaced. from when cooling was entirely compressor-based. This single, seasonal cooler’s electrical savings reduced our carbon footprint by 1.1 tons of CO2. Savings can be found in year round coolers as well as seasonal coolers. A year round cooler uses roughly 8,500 Kwh less than it did before the installation of the Freeaire system in a one and a half year period. This one cooler reduces Killington Resort’s carbon emissions by 2.51 tons of CO2 in the same amount of time.

Retrofitting all of the coolers here at Killington Resort with the Freeaire system has greatly reduced energy usage, and has reduced CO2 emissions by 13.2 tons a year."
http://www.killington.com/site/culture/ ... ndex.html/

You have blinders on, or we have different starting assumptions, and you are introducing unnecessary degrees of complexity.

System one: All heat stays in building envelope.

System two: Waste heat from cooler is exhausted outside.

System two is less efficient in the winter by exactly the amount of lost heat extracted when the Freeaire system operates.

It doesn't matter whether the heat needed to keep the building temp at 60 degrees is from condenser heat, compressor heat, or propane fired heat. If you remove a certain amount of condenser/compressor heat, (by eliminating the compressor and using cold outside air and venting waste heat outdoors) it will have to be replaced by an equal amount of propane heat. There is no savings in the winter by eliminating the compressor/condenser heat. There is only substituting electrical savings for propane expenditure.

You can talk about the difference in energy costs between propane and electricity, and carbon footprint between electricity and propane, but the energy lost with Freeaire in the winter is less efficient.

If you can't see that difference, if you don't understand that in the winter a household refrigerator is 100% efficient*, I don't think I can explain it in much more concise terms.

Bubba might be on to this.


*If you vent the household fridge outside for "free" cold air, you are losing heat outside the building envelope, and it is not free.

You are assuming large ambient heat loss to the fridge and high heat recovery from the condensers. Are you even sure the affected systems have heat recovery condensers? Regardless only a fraction of compression input energy is converted to heat. Compression is a terribly inefficient method of generating heat.
I am assuming the majority of the cooler heat loss is from cooling objects placed inside, cooler controls are used to minimize the building air losses when the door is opened and the cooler is well insulated. All reasonable assumptions.

What I believe your are missing is the air side economizer system requires a balance between compression cooling and outside air cooling. There is a thermal break even point on building heat losses and compression losses that is dependent on outside air temperature/humidity and is controlled by the system. An energy balance identifies this thermal break even point and is programmed into the system.

It should also be mentioned that to be the best snowmakers in the world, I think Killington knows a little about thermodynamics.

[Mister Moose]

if you don't understand that in the winter a household refrigerator is 100% efficient ...If you vent the household fridge outside for "free" cold air, you are losing heat outside the building envelope, and it is not free.

You are assuming large ambient heat loss to the fridge and high heat recovery from the condensers. Neither one matters, but this illustrates why you don't follow me yet. . Are you even sure the affected systems have heat recovery condensers? If the condenser is INSIDE THE BUILDING all heat is recovered. Where else can it go other than being absorbed by the building? Regardless only a fraction of compression input energy is converted to heat. Compression is a terribly inefficient method of generating heat. Where does the heat of compression from any air compressor go? In fact, where does all the energy from an air compressor go in an automotive shop in the winter when they keep the doors closed?
I am assuming the majority of the cooler heat loss is from cooling objects placed inside, doesn't matter cooler controls are used to minimize the building air losses when the door is opened and the cooler is well insulated. Beneficial, but still doesn't matter. Fancy controls don't change the net loss. All reasonable assumptions.

What I believe your are missing is the air side economizer system requires a balance between compression cooling and outside air cooling. There is a thermal break even point on building heat losses and compression losses that is dependent on outside air temperature/humidity and is controlled by the system. An energy balance identifies this thermal break even point and is programmed into the system. You are still stuck on optimizing electrical consumption, not the total electrical/heating plant combination.

It should also be mentioned that to be the best snowmakers in the world, I think Killington knows a little about thermodynamics. They also know about marketing, which is why they even bother to tell us about how green they are.

You aren't answering any of my questions. If you ignore my questions, and continue talking engineeringspeak on how fancy the controls are, you won't see the bigger picture.

So let's break it down, and this time please answer each question.

Do you agree that in the winter, a household refrigerator is 100 % efficient? By that I mean it performs its function of being a heat pump, cools the interior, and that all the energy used to do so is transferred as additional heat in the house which is useful, not wasted.

Do you agree that (essentially, over a very long period of time) 100% of the energy, ie electricity, used by the refrigerator is turned into heat which warms the house? That there is no other work done, it all turns to heat in the house?

Do you agree that heat released outdoors in the winter (in any quantity, at any temperature differential) is still heat lost, and must be replaced by the heating plant of the building?

[Woodsrider]

On what are you basing the CO2 savings?

I quoted Killington. So its not my calculation. But those numbers are a significant under estimate based on eGRID, U.S. annual non-baseload CO2 output emission rate, year 2012 data.

Considering that Vermont utilities, i.e. GMP, as individual entities use little to no fossil fuel, the CO2 savings might be greatly overstated.

That is a very good point Bubba.

[Woodsrider]

if you don't understand that in the winter a household refrigerator is 100% efficient ...If you vent the household fridge outside for "free" cold air, you are losing heat outside the building envelope, and it is not free.

You are assuming large ambient heat loss to the fridge and high heat recovery from the condensers. Neither one matters, but this illustrates why you don't follow me yet. . Are you even sure the affected systems have heat recovery condensers? If the condenser is INSIDE THE BUILDING all heat is recovered. Where else can it go other than being absorbed by the building? Regardless only a fraction of compression input energy is converted to heat. Compression is a terribly inefficient method of generating heat. Where does the heat of compression from any air compressor go? In fact, where does all the energy from an air compressor go in an automotive shop in the winter when they keep the doors closed?
I am assuming the majority of the cooler heat loss is from cooling objects placed inside, doesn't matter cooler controls are used to minimize the building air losses when the door is opened and the cooler is well insulated. Beneficial, but still doesn't matter. Fancy controls don't change the net loss. All reasonable assumptions.

What I believe your are missing is the air side economizer system requires a balance between compression cooling and outside air cooling. There is a thermal break even point on building heat losses and compression losses that is dependent on outside air temperature/humidity and is controlled by the system. An energy balance identifies this thermal break even point and is programmed into the system. You are still stuck on optimizing electrical consumption, not the total electrical/heating plant combination.

It should also be mentioned that to be the best snowmakers in the world, I think Killington knows a little about thermodynamics. They also know about marketing, which is why they even bother to tell us about how green they are.

You aren't answering any of my questions. If you ignore my questions, and continue talking engineeringspeak on how fancy the controls are, you won't see the bigger picture.

So let's break it down, and this time please answer each question.

Do you agree that in the winter, a household refrigerator is 100 % efficient? No. there are frictional losses resulting in wear that is not converted to heat. If your assumption was correct, refrigerators would never wear out.By that I mean it performs its function of being a heat pump, cools the interior, and that all the energy used to do so is transferred as additional heat in the house which is useful, not wasted.

Do you agree that (essentially, over a very long period of time) 100% of the energy, ie electricity, used by the refrigerator is turned into heat which warms the house? That there is no other work done, it all turns to heat in the house? See above. When you design a frictionless system I'll built you a perpetual motion machine.

Do you agree that heat released outdoors in the winter (in any quantity, at any temperature differential) is still heat lost, and must be replaced by the heating plant of the building?Yes. But again, heat lost is less that total energy saved.

Your premise is good, just misguided. Condenser heat recovery is an excellent method of increasing system efficiency. So is cold side economizing. Both have pros and cons. In a perfect world a combination of both would be used. But there is a point of diminishing returns based on numerous factors. Retrofitting an existing cooler to use waste heat recovery is expensive and usually means relocating the condenser. Which is even more challenging when the compressor is co-located with the condenser. Freeaire retrofits are typically less complicated and less costly.

[Mister Moose]

Do you agree that in the winter, a household refrigerator is 100 % efficient? No. there are frictional losses resulting in wear that is not converted to heat. If your assumption was correct, refrigerators would never wear out.
Friction does nothing but generate heat. Accumulated wear is not stored energy. Do you now agree that the fridge is 100% efficient? This is not the same as asking if the fridge is perfect and lasts forever. It is asking from an energy use point of view, is the fridge 100% efficient in the winter?

Do you agree that (essentially, over a very long period of time) 100% of the energy, ie electricity, used by the refrigerator is turned into heat which warms the house? That there is no other work done, it all turns to heat in the house? See above. When you design a frictionless system I'll built you a perpetual motion machine. Not an answer. If 100% of the energy is not transferred as heat to the house, please explain where it resides.

Do you agree that heat released outdoors in the winter (in any quantity, at any temperature differential) is still heat lost, and must be replaced by the heating plant of the building?Yes. But again, heat lost is less that total energy saved. Are you talking about electrical energy saved?

[Woodsrider]

Do you agree that in the winter, a household refrigerator is 100 % efficient? No. there are frictional losses resulting in wear that is not converted to heat. If your assumption was correct, refrigerators would never wear out.
Friction does nothing but generate heat. Accumulated wear is not stored energy. Do you now agree that the fridge is 100% efficient? This is not the same as asking if the fridge is perfect and lasts forever. It is asking from an energy use point of view, is the fridge 100% efficient in the winter?

Do you agree that (essentially, over a very long period of time) 100% of the energy, ie electricity, used by the refrigerator is turned into heat which warms the house? That there is no other work done, it all turns to heat in the house? See above. When you design a frictionless system I'll built you a perpetual motion machine. Not an answer. If 100% of the energy is not transferred as heat to the house, please explain where it resides.

Do you agree that heat released outdoors in the winter (in any quantity, at any temperature differential) is still heat lost, and must be replaced by the heating plant of the building?Yes. But again, heat lost is less that total energy saved. Are you talking about electrical energy saved?

Come on Moose. Friction does more than generate heat. This is what Tribology is all about. Deformation of material due to frictional forces represents irreversible energy loss. I haven't tried it, but I am sure wear and and formation of dissapative structures during friction can be modeled by entropy production if you need to put it into thermodynamic terms.

[Mister Moose]

Do you agree that in the winter, a household refrigerator is 100 % efficient? No. there are frictional losses resulting in wear that is not converted to heat. If your assumption was correct, refrigerators would never wear out.
Friction does nothing but generate heat. Accumulated wear is not stored energy. Do you now agree that the fridge is 100% efficient? This is not the same as asking if the fridge is perfect and lasts forever. It is asking from an energy use point of view, is the fridge 100% efficient in the winter?

Do you agree that (essentially, over a very long period of time) 100% of the energy, ie electricity, used by the refrigerator is turned into heat which warms the house? That there is no other work done, it all turns to heat in the house? See above. When you design a frictionless system I'll built you a perpetual motion machine. Not an answer. If 100% of the energy is not transferred as heat to the house, please explain where it resides.

Do you agree that heat released outdoors in the winter (in any quantity, at any temperature differential) is still heat lost, and must be replaced by the heating plant of the building?Yes. But again, heat lost is less that total energy saved. Are you talking about electrical energy saved?

Come on Moose. Friction does more than generate heat. This is what Tribology is all about. Deformation of material due to frictional forces represents irreversible energy loss. I haven't tried it, but I am sure wear and and formation of dissapative structures during friction can be modeled by entropy production if you need to put it into thermodynamic terms.

From an energy point of view, friction does nothing else but generate heat. The fact that friction causes wear to mechanical components does not change where the energy goes.

Deformation, entropy, call it what you want, it does not affect the energy path. A worn bearing will take energy to repair, but does not store any energy. (An example of stored mechanical energy would be a compressed spring. Frictional losses are losses, not stored.) All the heat from the wear inducing friction you focus on dissipates... where? Into the metal, into the house. All conductive surfaces flow toward equilibrium. Heat from the fridge motor bearing friction flows to the room the fridge is in.

Entropy is a measure of randomness, not heat.

Back to the questions above.

[Woodsrider]

Do you agree that in the winter, a household refrigerator is 100 % efficient? No. there are frictional losses resulting in wear that is not converted to heat. If your assumption was correct, refrigerators would never wear out.
Friction does nothing but generate heat. Accumulated wear is not stored energy. Do you now agree that the fridge is 100% efficient? This is not the same as asking if the fridge is perfect and lasts forever. It is asking from an energy use point of view, is the fridge 100% efficient in the winter? Not necessarily. The COP is purely dependent on the difference in reservoir temperatures. The highest "efficiency" will be when the refrigerator and room are almost the same temperature. Season has no effect.

Do you agree that (essentially, over a very long period of time) 100% of the energy, ie electricity, used by the refrigerator is turned into heat which warms the house? That there is no other work done, it all turns to heat in the house? See above. When you design a frictionless system I'll built you a perpetual motion machine. Not an answer. If 100% of the energy is not transferred as heat to the house, please explain where it resides.Based on my theoretical calculations I have to agree with this. I was wrong. Removing the ideal conditions will only cause an increase in entropy, which based on the 2nd Law of Thermodynamics, causes the temperature differential to increase, which also reduces the efficiency of the system.

Do you agree that heat released outdoors in the winter (in any quantity, at any temperature differential) is still heat lost, and must be replaced by the heating plant of the building?Yes. But again, heat lost is less that total energy saved. Are you talking about electrical energy saved?]]I am talking about total energy inputted into the system regardless of source as long as it remains within the boundary in question.

Come on Moose. Friction does more than generate heat. This is what Tribology is all about. Deformation of material due to frictional forces represents irreversible energy loss. I haven't tried it, but I am sure wear and and formation of dissapative structures during friction can be modeled by entropy production if you need to put it into thermodynamic terms.

From an energy point of view, friction does nothing else but generate heat. The fact that friction causes wear to mechanical components does not change where the energy goes.

Deformation, entropy, call it what you want, it does not affect the energy path. A worn bearing will take energy to repair, but does not store any energy. (An example of stored mechanical energy would be a compressed spring. Frictional losses are losses, not stored.) All the heat from the wear inducing friction you focus on dissipates... where? Into the metal, into the house. All conductive surfaces flow toward equilibrium. Heat from the fridge motor bearing friction flows to the room the fridge is in.

Entropy is a measure of randomness, not heat.

Back to the questions above.

A refrigerator cannot be 100% efficient. But this sounds like a fun thermodynamic riddle. I'll attempt a proof later.

Later: Thank you that was a fun exercise. I had forgotten about the ideal Carnot Refrigerator. Essentially, you cannot calculate the efficiency of a refrigerator so they call it the coefficient of performance. Theoretically, it is limitless. The closer the temperature of the hot and cold reservoir the higher the COP. Unity is when Tc=0.5Th. Since this is misleading, I put the energy source within the same boundaries as the refrigerator to calculate actual efficiency (ideal heat engine + ideal heat pump) and to get 100% efficiency the cold reservoir needs to be at absolute zero. The fun part is how this demonstrates how entropy works. Now that was purely theoretical using ideal parameters (adiabatic, isothermal, zero friction, etc). The calculations are based on the very limits of the physical world. Nothing can be better and reality is drastically worse.

I think I answered all your questions.

Regardless, none of your questions changes the original questions as to whether a Freeaire system is more or less efficient that a standard system. Based on my theoretical calculations, if the outside air of a Freeaire system is closer to the temperature of the walk-in cooler than the temperature of the lodge, than the Freeaire system is more efficient, e.g. less work is required. Again, efficiency of a reverse heat pump is misleading.
Since I answered your questions, please answer mine. Are you certain that the walk-in coolers in question had an existing condenser heat recovery system?

[killyfan]

Deformation, entropy, call it what you want, it does not affect the energy path. A worn bearing will take energy to repair, but does not store any energy. (An example of stored mechanical energy would be a compressed spring. Frictional losses are losses, not stored.) All the heat from the wear inducing friction you focus on dissipates... where? Into the metal, into the house. All conductive surfaces flow toward equilibrium. Heat from the fridge motor bearing friction flows to the room the fridge is in.

Entropy is a measure of randomness, not heat.

So.... as an aside here since this thread is getting waaay too nerdy/techie for me - I actually know a guy named Entropy. His parents are 60's hippies - Entro's dad still wears tunics and wood beads. Entropy was born in the early 70's and is no hippy - he's a maple farmer up near Smuggs. Can anyone tell me WTF his parents were thinking in their drug-induced state when they bestowed that name upon him??!!?? He has considered changing his name many a time, but to date has not and just goes by "Entro." One of my best friends is his partner, and they have three kids with normal names.

All that being said they live off grid, in a large solar powered home on the side of a mountain deep in the woods - and have no problem with lack of electricity due to cloudy/snowy days or shade Mr Moose.

They transport their 150 acres of maple sap with gravity to their sugar house. Mentally Entro struggles with the amount of wood he has to burn to condense his sap into VT Gold, so I'm wondering how he could convert from very labor intensive wood burning for his condensers to something else with a smaller carbon footprint to make the lovely syrup. Has this been studied yet? Can we talk about something else for a bit please? He's a smart guy, and I'm sure he's looked at whatever options exist, but I'm curious too and since we only get together about once a year, haven't had any time to chat with him about it.

Also, SEB - I was definitely joking when I said you should get a tattoo! And I agree that the kid's quote is too large - but he definitely doesn't display it. He keeps it covered. His 'rents don't know about it yet, but his very supportive grandmother does. Apparently the 'rents are very religious southerners, and would have a BIG issue with it...

[madhatter]

Deformation, entropy, call it what you want, it does not affect the energy path. A worn bearing will take energy to repair, but does not store any energy. (An example of stored mechanical energy would be a compressed spring. Frictional losses are losses, not stored.) All the heat from the wear inducing friction you focus on dissipates... where? Into the metal, into the house. All conductive surfaces flow toward equilibrium. Heat from the fridge motor bearing friction flows to the room the fridge is in.

Entropy is a measure of randomness, not heat.

So.... as an aside here since this thread is getting waaay too nerdy/techie for me - I actually know a guy named Entropy. His parents are 60's hippies - Entro's dad still wears tunics and wood beads. Entropy was born in the early 70's and is no hippy - he's a maple farmer up near Smuggs. Can anyone tell me WTF his parents were thinking in their drug-induced state when they bestowed that name upon him??!!?? He has considered changing his name many a time, but to date has not and just goes by "Entro." One of my best friends is his partner, and they have three kids with normal names.

All that being said they live off grid, in a large solar powered home on the side of a mountain deep in the woods - and have no problem with lack of electricity due to cloudy/snowy days or shade Mr Moose.

They transport their 150 acres of maple sap with gravity to their sugar house. Mentally Entro struggles with the amount of wood he has to burn to condense his sap into VT Gold, so I'm wondering how he could convert from very labor intensive wood burning for his condensers to something else with a smaller carbon footprint to make the lovely syrup. Has this been studied yet? Can we talk about something else for a bit please? He's a smart guy, and I'm sure he's looked at whatever options exist, but I'm curious too and since we only get together about once a year, haven't had any time to chat with him about it.

Also, SEB - I was definitely joking when I said you should get a tattoo! And I agree that the kid's quote is too large - but he definitely doesn't display it. He keeps it covered. His 'rents don't know about it yet, but his very supportive grandmother does. Apparently the 'rents are very religious southerners, and would have a BIG issue with it...

A semi-permeable membrane is used to separate water from sugar, minerals, and other impurities. In the maple industry we use the reverse osmosis systems, but instead of keeping the purified water we keep the concentrated sugar, minerals, and other impurities as concentrated maple sap to finish boiling into maple syrup.

[Mister Moose]

All that being said they live off grid, in a large solar powered home on the side of a mountain deep in the woods - and have no problem with lack of electricity due to cloudy/snowy days or shade Mr Moose.

They transport their 150 acres of maple sap with gravity to their sugar house. Mentally Entro struggles with the amount of wood he has to burn to condense his sap into VT Gold, so I'm wondering how he could convert from very labor intensive wood burning for his condensers to something else with a smaller carbon footprint to make the lovely syrup. Has this been studied yet? Can we talk about something else for a bit please? He's a smart guy, and I'm sure he's looked at whatever options exist, but I'm curious too and since we only get together about once a year, haven't had any time to chat with him about it.

A semi-permeable membrane is used to separate water from sugar, minerals, and other impurities. In the maple industry we use the reverse osmosis systems, but instead of keeping the purified water we keep the concentrated sugar, minerals, and other impurities as concentrated maple sap to finish boiling into maple syrup.

The big advances in maple syrup over the years have been:
Gravity fed lines to a central collection tank
RO to raise the sugar percentage prior to boiling
Suction pumps on gravity lines to increase sap production

Not sure what the fanciest fuel/energy source is out there to boil with, but most of what you see is wood.

Of course solar works anywhere in VT, Killyfan. It will work in my basement with one window. The output you get vs the cost of the panel is what changes. If you can adapt your energy needs to that which your array produces, you can be self sufficient. That ignores the cost of solar vs any other method, and the benefit of putting that same array in a better location. If you are going to the expense of a half-Meg array, wouldn't it make sense to place it in the highest production area available?

Killington doesn't keep their cow-power cows in Bay1. The array doesn't have to be in Pico's parking lot.