Propane (R-290) for heat pumps?

[ICanHas]

I have credible reference here that propane actually performs WORSE than R-22. You can not credit refrigerant as being inherently more efficient when other highly influential factors changed.

R-290 propane has different characteristics than R-22 and has a lower volumetric capacity. Common test method is based on dump gas and go method that free loads on efficiency gain attributable to reducing load on coils and compressor by reducing capacity.

In real life, you want the motor as close to fully loaded as possible for lowest production cost, but 75-80% load results in increased motor efficiency. So, using the same hp, higher displacement compressor effectively reduces the magnitude of impact.

To say R-290 is more efficient is like saying you get better mileage in 4th gear than 5th gear at the same RPM, because 4th gear in the gearbox is superior efficiency. This neglects the impact of the fact that road speed dropped here. The first paper makes a compensation comparable to changing the final drive so that 4th gear at same RPM provides the same road speed as 5th gear with original drive ratio.

According to Hwang, Gado and Radermacher as published in January 2003 ASHRAE journal, R-290 performs WORSE than R-290. A reduction of 3-6% in capacity, 5% reduction in steady state efficiency and a lower SEER value. They concluded that the poor performance applied to heating cycle as well until the outdoor temperature was below 17F. In this experiment, adjustments were made at the compressor and expansion device so that the system closely matches the original capacity of R-22 while using R-290.

Don't listen to turd polished BBQ gas sales people. Do your own research if you disagree with the above findings.

On two stage units, you'll find that EER on first stage at 67% the rated capacity is generally better than on 2nd stage at 100% capacity. Equipment manufacturers have raised the SEER on units by increasing the evaporator and capacitor size to BTU capacity ratio.

Any gains made due to changing coils to BTU size under same usage conditions can not be attributed as refrigerant being superior.

Also, any attribution of efficiency gain to using R290, its commercial equivalents such as Coolant Express 22a, Envirosafe ES22a or the like products that exploits the fact that existing system is oversized and giving the product the credit for gains made through increasing the run-time using a reduced system size is cheating.

In a paper by CHINNARAJ, GOVINDARAJAN and VIJAYAN published by THERMAL SCIENCE, Year 2011, Vol. 15, Suppl. 2, pp. S383-S390 suggests the above is true. They tweaked some hack chopped jury rigged window shaker and optimized charge levels for each of the three refrigerants they used, R22, R290 and R407C but used the same heat exchangers originally equipped with the unit.

I normalized their findings so that R-22 is referenced to 1.
The paper's data shows
R-290 shows a 11% reduction in capacity and a 4% rise in COP.

The reduction in capacity means the condenser and evaporator are both unloaded compared to R-22 which gave R-290 an unfair leverage. The test discussed in first paper took this away and found reduction in COP compared to R-22.

I've attached both papers for your reference.

[ICanHas]

It doesn't get much more credible than ASHRAE Journal.

If you guys have credible references demonstrating propane, HC blends to perform superior to R22, R410A, or F-gas blends after adjustments are made to provide the same capacity under the same usage conditions, please share the sources for discussion.

[jeff5may]

Originally Posted by oil pan 4

BBQ gas isn't R-290.
I read some where that propane fuel had up to 10% butane and a few percent of other hydrocarbons in it.

from the PROPANE 101 website:

"Propane is considered propane regardless of the grade but the reality is that three grades of propane are processed or refined in the United States. Each of the three grades, HD5, HD10 and commercial propane differ in propane consistency and are used for different purposes. All grades of propane come from the same raw materials (crude oil or natural gas). The differing grades are created during the refining or processing of the gas at the refinery. In other words, the refinery specifies which grade is to be processed. Each grade of propane is stored separately following processing to ensure that the propane grade loaded at the refinery is what was specified by the buyer.

HD-5 Propane
HD5 grade propane is "consumer grade" propane and is the most widely sold and distributed grade of propane in the U.S. market. HD5 is the highest grade propane available to consumers in the United States and is what propane companies ordinarily sell to their customers. What does HD5 propane mean in terms of specification to an ordinary consumer? It means that the propane is suitable and recommended for engine fuel use, which was the original purpose of the HD5 grade propane specification. HD5 spec propane consists of:

Minimum of 90% propane
Maximum of 5% propylene - propylene is used in the manufacture of plastics
Other gases constitute the remainder (iso-butane, butane, methane, etc.)
The HD5 specification is based on "allowable" contents. For instance, 99% propane and 1% propylene is HD5 grade propane the same as 95% propane and 5% propylene is HD5 propane. Although the product consistency and purity is different, both mixtures are considered HD5 propane because they fall within the allowable limits for the product to be named and labeled as such. Consider this: 10,000 gallons of pure propane (100% propane) is classified as HD-5 grade propane.

HD5 Propane Quality - Fact vs. Fiction
Retail propane companies that advertise "highest quality propane" are actually selling propane that conform to the specifications as required to be labeled and sold as HD5 propane. An important fact to note is that there is no higher grade than HD5 propane available for resale through retail propane companies in the United States...HD5 is the highest grade propane available to U.S. consumers. A company stating that their propane is of a higher grade than HD5 is inaccurate in their claim. As presented above, a tank holding pure propane contains what is classified as HD5 propane.

HD-10 Propane and Commercial Propane
HD10 propane is a grade below HD5 and is commonly found in California. HD10 grade propane allows up to 10% propylene in the propane/propylene mixture and is still labeled as "propane". Because propylene is used in creating plastics, HD10 can possibly create problems in some engines and vehicle applications. Propylene can cause engine components to "gum" or stick during operation. However, HD 10 spec propane works just fine in domestic and commercial propane powered appliances. The only problem that may be encountered in using HD-10 propane involves its use as an engine fuel (vehicles, forklifts, etc.).

Commercial grade propane and HD10 grade propane are sometimes used interchangeably due to the fact that both grades are sub-HD5 spec product and do not meet the standards of engine grade propane. Refineries use commercial propane in their processes and fractionation of chemicals for end use in numerous industries. Although commercial grade propane can be used in a manner similar to that of HD10 propane, it is not used in vehicle applications."

Now the r-290 (or hc-290, or freon 290, or care 40, or...) standard is much more complicated. It also varies by manufacturer. For example, Tecumseh says it must be 99.5% propane by weight and have less than 25 ppm moisture content to run under warranty in their compressors. Linde gas specs their bulk r290 at >97.5% pure propane and <10 ppm moisture content. ADVGAS specs their r290 as grade 2.5, which includes more caps on contaminants than the 2 previous examples. As with most lab chemicals, there are a large number of grades you can choose from, and 99.98% pure r290 costs out the ying yang compared to "regular" Lindegas grade.

I chose Lindegas as the generic example because it is the largest supplier in the world. Since 911, they have devoured or absorbed most of their competitors in competition. They are the Borg.

[jeff5may]

Originally Posted by ICanHas

It doesn't get much more credible than ASHRAE Journal.

If you guys have credible references demonstrating propane, HC blends to perform superior to R22, R410A, or F-gas blends after adjustments are made to provide the same capacity under the same usage conditions, please share the sources for discussion.

Any competent engineer can make numbers on spreadsheets lie in their favor, or set up any test to produce the outcome their customer wants. If at first the testing yields unfavorable results, they just change parameters. At the level of discipline you are describing, these engineers have a whole bag of tricks at their disposal, and can conjure results like wizards.

ASHRAE parameters are what they are: if you have a certain type of system, they have a set of conditions rigged for that type of system. If you have another type, they have another set of conditions. Not surprisingly, the overwhelming majority of shelf parts available are built to conform to one of these standards and drop right in with predictable results. The standards make it easier for the refrigeration techs and engineers to do their jobs.

Most of us in the forums engaged in "hacking" together systems of our own are building custom configurations that do not fall within the standards and guidelines that the ASHRAE have dictated. Especially when natural refrigerants are used, heat exchangers, metering devices, and compressors don't act the same. When you feed them "strange" gases or conditions, the entire system tends to stray from the path well travelled.

Our intentions here are more practical than anything. Trying to prove or argue a theoretical point to some endpoint is way beyond what happens in the garage, workshop, or back yard. I for one don't have the resources, time, or desire to change the world. I am not trying to build things that conform to industry standards in any general way, nor perform standardized, specialized tests to prove that my rig does better than some corporate behemoth. I just want to make my dirt cheap rig perform better than that beige box hooked up to my furnace.

[ICanHas]

Originally Posted by jeff5may

Most of us in the forums engaged in "hacking" together systems of our own are building custom configurations that do not fall within the standards and guidelines that the ASHRAE have dictated. Especially when natural refrigerants are used, heat exchangers, metering devices, and compressors don't act the same. When you feed them "strange" gases or conditions, the entire system tends to stray from the path well travelled.

Our intentions here are more practical than anything. Trying to prove or argue a theoretical point to some endpoint is way beyond what happens in the garage, workshop, or back yard. I for one don't have the resources, time, or desire to change the world.

One of the problems that popped up in this thread is the difficulty in verifying the supposed efficiency gain commonly associated with the use of R-290. Did you even read the paper? They used off the shelf R22 units, but increased the compressor displacement in order to get the same capacity as R-22. They also adjusted the metering device to make it an even playing ground.

Use of R-290 has essentially the same effect as say putting a 2-ton compressor in a 3-ton system. THERE'S LOSS OF CAPACITY associated with using propane. If you get an old 4-ton 10 SEER unit and replace the compressor with the one taken from another 10 SEER 2-ton, you'll get improvement in efficiency, but a reduction in capacity as well.

Liars are the companies that do nothing more than turd polish propane and spew off marketing gibberish proclaiming hydrocarbon is more efficient but don't mention the loss of capacity, flammability, etc.

Testing at ASHRAE parameters ensures before and after results are at least somewhat consistent, so you don't have R-22 test done at 90F and R-290 test done at 80F to make the results look better in favor of chemically manufactured semi-synthetic petroleum hydrocarbon refrigerant.

A system designed for 60Hz will operate at 5/6 capacity on 50Hz. In the past, R-500 was used instead of R-12 when 60Hz machines had to operate on 50Hz. The higher capacity of R-500 cancelled out the reduction in compressor displacement.

If it operated on original R-12 charge, there would be efficiency gain, but capacity loss on 50Hz. Capacity loss is not something easily measured by DIY backyard window AC tamperer.

[AC_Hacker]

Originally Posted by ICanHas

One of the problems that popped up in this thread is the difficulty in verifying the supposed efficiency gain commonly associated with the use of R-290. Did you even read the paper?

So how are you going to build your own heat pump?

-AC

[jeff5may]

I argue this:
r-12 and r-22 are dinosaurs. I could still buy them if i had an EPA license. A 30 pound cylinder of either would run me in excess of $200. Or, I could go to my favorite local gas station and buy 20 pounds of HD-5 propane for less than $20 without a license. I could put it straight into my r-22 air conditioner, and it would work at least 90% as well.

Dollar per dollar, propane is a better gas.

[ICanHas]

Originally Posted by jeff5may

I argue this:
r-12 and r-22 are dinosaurs. I could still buy them if i had an EPA license. A 30 pound cylinder of either would run me in excess of $200. Or, I could go to my favorite local gas station and buy 20 pounds of HD-5 propane for less than $20 without a license. I could put it straight into my r-22 air conditioner, and it would work at least 90% as well.

Dollar per dollar, propane is a better gas.

SO2/R768, anhydrous ammonia/R-717, methyl chloride and methyl formate predates fluorocarbons and petroleum distillate products like propane, butanes predates everything.
If CFC and HCFCs are dinosaurs, R-290 is dinosaur's great grand mommy.

Purchasing R-22 for your own use and using it without EPA 608 is illegal, as is purchasing durgs off the street.

Using explosive gas like R-290 as a refrigerant is also illegal.

What makes legal compliance a concern to you when it comes to acquisition of R-22, but not when it comes to unlawful use of prohibited refrigerant?


The point of my post was debunking the myth that highly processed, semi-synthetic hydrocarbon HC-290 produced from crude oil petroleum feedstock that sales literature claim to be "natural refrigerant" do not live up to purported superior efficiency compared to HCFC 22 made from natural gas, sea water and fluorospar rocks.

Originally Posted by AC_Hacker

So how are you going to build your own heat pump?

-AC

What do you mean? The process is the same regardless of refrigerant used and R-290 do not have magical properties that makes its use unavoidable. HFC-410A, HFC-134a, HFC-507, etc are all available, as well as HCFC-22.

I was under the impression that you guys are looking at beyond the "$$$ of upfront direct cost".

[AC_Hacker]

Originally Posted by ICanHas

One of the problems that popped up in this thread is the difficulty in verifying the supposed efficiency gain commonly associated with the use of R-290.

Use of R-290 has essentially the same effect as say putting a 2-ton compressor in a 3-ton system. THERE'S LOSS OF CAPACITY associated with using propane. If you get an old 4-ton 10 SEER unit and replace the compressor with the one taken from another 10 SEER 2-ton, you'll get improvement in efficiency, but a reduction in capacity as well.

I do believe that you have found the proper answer to your own dilemma.

Unfortunately, your habit of confusing capacity with efficiency has hidden your discovery of the answer.

Perhaps it would be clarifying for everyone if you would state in clear language what your definition of efficiency is?

-AC

[ICanHas]

Originally Posted by AC_Hacker

I do believe that you have found the proper answer to your own dilemma.

Unfortunately, your habit of confusing capacity with efficiency has hidden your discovery of the answer.

Perhaps it would be clarifying for everyone if you would state in clear language what your definition of efficiency is?

-AC

Efficiency is work out vs work in, but it's only realistic if compromises aren't made. Attribution of gain to propane wrong, just as attribution of mpg gain to superior "gear" for mpg gain resulting from shifting down to 4th gear from 5th gear while maintaining the same RPM is wrong.

Proper efficiency gain mean increase in mpg, but without losing speed. In the above case, the miles traveled per gallon improvement is mostly from reduction in load from your speed actually dropping.