Natural refrigerants - heat-pump friendly?

[desA]

If you were told that a natural refrigerant had to be used in your next generation of heat-pumps, which one would you choose, & why?

:)

[install monkey]

my guess would be co2.as like with r410 it operates at higher pressures than previous systems therefore the units will be more compact.and maybe it will have a widget fitted too,

[mad fridgie]

The widget concept was actually born when looking into CO2 heat pumps, (in the transion between trans-critical and sub-critical), when working out the calcs, did it move to more regular refrigerants.
As for the heat pump, do you want to remain sub-critical, and not looking at low evap temps, then go for one of the lower pressure HC, I know it as Care 10, (propane I think R600, but I could be wrong, just check, for a refrigerant with normal boiling of -10C at atmospheric)

[install monkey]

using r600 in heatpumps might sort out the cowboy installers! they wont last long when they leave a leak on the system and womph no face!!!

[mikeref]

Ah Co2? I don't Know much about this gas but wouldn't it use more power to run it than a/c on R600? Besides, Co2 is not drawn from the atmosphere and pumped into systems but made in some factory, adding to so called "global warming" Electricity grids are maxed out now. Correct me if i'm wrong.. Mike. (From Aus not Mike from smoggy Toronto.LoL )

[Magoo]

Hi Des A.
for me NH3/R717. still the most efficient refrigerant, zero ozone, zero global warming. A system only needs grams not kilos. All we need is a can manufacturer to develop a winding with aluminium coils. Don't think this would be good as a split system but great as a hot water heater.
magoo

[MikeHolm]

Ah Co2? I don't Know much about this gas but wouldn't it use more power to run it than a/c on R600? Besides, Co2 is not drawn from the atmosphere and pumped into systems but made in some factory, adding to so called "global warming" Electricity grids are maxed out now. Correct me if i'm wrong.. Mike. (From Aus not Mike from smoggy Toronto.LoL )

Is there no smog in NTH QLD? I wondered why i was coughing so much:D

I have been wondering this as well. Does no one make an appropriate small compressor for NH3? If not NH3, propane sounds good but then, depending on where you live, it will bring in another authority which previously had no say in refrigeration. I don't know about you guys but as soon as a combustable gas is introduced we have the gas authorities to deal with and they are a pain in the butt.

[Josip]

Hi, all :)

For me definitely ammonia .... agree with Magoo ;)



http://www.mayekawa.com/about/history/

1998

http://www.mayekawa.com/shared/img/icon_06.pngDeveloped “VR series” i.e. screw compressor for natural gas.
http://www.mayekawa.com/shared/img/icon_06.pngDeveloped ammonia hermetic motor for a small sized screw compressor.

Why not in use much more? .... answer is: due to global politics ... and will remain the same for a long time ... profit and profit only ...

One day in the future when we change our "imagination" about what's making us rich ... changes would began ... ;)


Best regards, Josip :)

[HAROLDMYCOM]

NH3/R717 or Co2 (transcritical), .. the problem with CO2 is you need a high pressure compressor (150bar), it is possible for small capacity but for bigger capacity there still remain some problems to be fixed.

Also from safety issue I think Nh3 is the better solution.

ammonia21.com is a good site with a lot of info.

[mad fridgie]

If your dreaming then depending upon the heat source then the best natural refrigerant is water. (type of cascade on say an existing large industrial plant)
Multistage axial compressor, (if they can get one to work)
In the short term i would expext to ammonia or the likes to be in smallish type heat pumps, co2 is here.
Large CO2 not a problem technically right now, but the cost would be sky high (industrial gas compressors)

[desA]

Thank IM.

So CO2 : compactness.
Add, high water discharge temps possible.

[desA]

CARE 10 (R600a)

CARE 10 (R600a or isobutane) is a high-purity, single ingredient refrigerant mainly used in domestic fridges and freezers.

Features and benefits
operates at significantly lower pressures than R12 or R134A
lower volumetric refrigerating effect than R12 or R134A
requires a specific R600a compressor
not for use as a retrofit refrigerant
compatible with most common refrigeration materials and lubricants


Physical Property of r600a:
Critical Temperature, °C 134.71
Critical Pressure, MPa 3.64
Specific Heat of Liquid, 25°C, [KJ/(kg•°C)] 2.38
ODP 0
GWP 11

Beginning to like this. Thanks very much MF.

What are the downsides (except Xplosions)?

[desA]

R600a.

Flammability. What are the acceptable limits, for the 'average Joe' installer, system maintainer, designer?

[desA]

Hi Des A.
for me NH3/R717. still the most efficient refrigerant, zero ozone, zero global warming. A system only needs grams not kilos. All we need is a can manufacturer to develop a winding with aluminium coils. Don't think this would be good as a split system but great as a hot water heater.
magoo

Thanks, Magoo. I've been looking at NH3, I must say. How well would it serve using semi-hermetic compressors?

[desA]

Hi, all :)

For me definitely ammonia .... agree with Magoo ;)


Why not in use much more? .... answer is: due to global politics ... and will remain the same for a long time ... profit and profit only ...

One day in the future when we change our "imagination" about what's making us rich ... changes would began ... ;)


Best regards, Josip :)

Thanks Jossip. Excellent.

[desA]

NH3/R717 or Co2 (transcritical), .. the problem with CO2 is you need a high pressure compressor (150bar), it is possible for small capacity but for bigger capacity there still remain some problems to be fixed.

Also from safety issue I think Nh3 is the better solution.

ammonia21.com is a good site with a lot of info.

Thanks Harold.

[desA]

If your dreaming then depending upon the heat source then the best natural refrigerant is water. (type of cascade on say an existing large industrial plant)
Multistage axial compressor, (if they can get one to work)
In the short term i would expext to ammonia or the likes to be in smallish type heat pumps, co2 is here.
Large CO2 not a problem technically right now, but the cost would be sky high (industrial gas compressors)

Thanks again, MF. It may be interesting to do some comparative performance calculations between : CO2, NH3, water, R600a systems, & explore the limits, constraints & what blue-sky research is going on out there.

[MikeHolm]

Hi Des A.
for me NH3/R717. still the most efficient refrigerant, zero ozone, zero global warming. A system only needs grams not kilos. All we need is a can manufacturer to develop a winding with aluminium coils. Don't think this would be good as a split system but great as a hot water heater.
magoo

I would think there could be a market for a compressor with AL coils, given the price of copper these days but would it work the other way around...AL coils and R410 for example?

[chillerman2006]

Hi DesA

From what I recall from hydrocarbons course under 500 grams indoors is ok as most it will do if ignited is take your hair off, above this starts to get dangerous, explosive mix is 2-10% with air, so easily ignited indoors, I will scan the course book & email it to you this evening

R's chillerman

[chillerman2006]

Hi DesA

sent

having just checked the book it assumes your competant to handle HFC's,

I hope you know a bit about handling mate ;)

R's chillerman

[desA]

Much obliged Chillerman. Lots to read on the safe handling of these flammable gases. :D

[chillerman2006]

Much obliged Chillerman. Lots to read on the safe handling of these flammable gases. :D

Sorry, its not a lot mate, the longest part of the course was that booklet ! ;)

[MikeHolm]

Guys, what is the smallest comp of any type that will run NH3? If one were to even try to start to make it suitable for resi installs then there better be a ready supply of "X" comp. If they are all too big, what would it take to reduce their capacity (from a manufacturing point of view)?

Same holds true for propane. I know nothing about a comp that works on R600.

[chillerman2006]

Guys, what is the smallest comp of any type that will run NH3? If one were to even try to start to make it suitable for resi installs then there better be a ready supply of "X" comp. If they are all too big, what would it take to reduce their capacity (from a manufacturing point of view)?

Same holds true for propane. I know nothing about a comp that works on R600.

Hi Mike

Nh3, still learning so can not comment, but hydrocarbons work with many off the shelf compressors & fridge components, will edit my pics to say which are HC refrigerants, there is a few

R's chillerman

[Magoo]

Hi MikeHolm,
it is the corrossive nature of ammonia. Ammonia eats copper and brass. Aluminium is OK, obviously the motor winding insulatin factor is the problem as well, ali coils in motor windings would be larger and a synthetic sleave type insulation is required as well so windings in motor would be extra large in a can or semi-hermetic. Years ago a manufacturer came out with a removable winding on a commercial compressor, the rotor was in a sleave, similar to a Hermetique ammonia pump, don't know what happened to them.
As for compressors I have used auto air compressors in the past as ammonia vapour transfer pumps as they are all alumimium, open drive though. [ from memory the HGC1000,]
With R600 propane I don't know, I have enough trouble with the BBQ when it doesn'T start.
magoo

[MikeHolm]

Hi MikeHolm,
it is the corrossive nature of ammonia. Ammonia eats copper and brass. Aluminium is OK, obviously the motor winding insulatin factor is the problem as well, ali coils in motor windings would be larger and a synthetic sleave type insulation is required as well so windings in motor would be extra large in a can or semi-hermetic. Years ago a manufacturer came out with a removable winding on a commercial compressor, the rotor was in a sleave, similar to a Hermetique ammonia pump, don't know what happened to them.
As for compressors I have used auto air compressors in the past as ammonia vapour transfer pumps as they are all alumimium, open drive though. [ from memory the HGC1000,]
With R600 propane I don't know, I have enough trouble with the BBQ when it doesn'T start.
magoo


Never use a spark igniter on the BBQ as they always break so always a butane lighter. Also check for spiders in the tubes, happens all the time.......but I digress.....If you come across any of the old compressor info let us know. I think it is time someone rocked the boat (or at least looked at the possibilities)

I guess king valves etc, would have to be stainless and are there reversing valves in steel or SS? RESI sized???

[install monkey]

only pots ive seen on r290,600 are standard domestic,danfoss sc15's and lunite aj type.
as long as it has a ptc relay and a lil flammable sticker hey presto! compressor changes are fun,just tape up ur eyebrows-wooomph! haha

[nike123]

For R600a LEL (lower explosive limit) is 38g/m^3 or 1,8% koncentraction (safety factor 4).

[desA]

Are spark-proof tools required?

[install monkey]

they do do reclaim rigs and vac pumps that are spark proof-but ive done pot changes on freezers with a bog standard vac pump. just keep the area well ventilated and use plenty of nitrogen

[MikeHolm]

they do do reclaim rigs and vac pumps that are spark proof-but ive done pot changes on freezers with a bog standard vac pump. just keep the area well ventilated and use plenty of nitrogen

Install, you mentioned freezers, but what other kinds of systems are using R290 or R600? From an operational point of view what are the advantages?

[install monkey]

Install, you mentioned freezers, but what other kinds of systems are using R290 or R600? From an operational point of view what are the advantages?
cascade freezers for medical stuff -80 's,domestic fridges use either r134a or r600

[paul_h]

R600a? Electrolux and some sharp domestic refrigerators are using that now, gets them a higher efficiency rating over R134a.
R290? People are putting that into their car a/cs or R22 split systems themselves over here. Hychill is a local crowd selling HC rerigerants, I don't know if it's straight R290 or some HC blend though.
edit: http://www.hychill.com.au/products/

[MikeHolm]

Excuse my ignorance but can you just use BBQ propane? Why buy it from a refrigerant supplier?

[install monkey]

Material Safety Data Sheet

R290 PROPANE




CHEMICAL PRODUCT AND COMPANY IDENTIFICATION

PRODUCT NAME:


PROPANE

DISTRIBUTOR:


National Refrigerants, Inc.

661 Kenyon Avenue

Bridgeton, New Jersey 08302

FOR MORE INFORMATION CALL: IN CASE OF EMERGENCY CALL:

(Monday-Friday, 8:00am-5:00pm) CHEMTREC: 1-800-424-9300

1-800-262-0012




COMPOSITION / INFORMATION ON INGREDIENTS

INGREDIENT NAME CAS NUMBER WEIGHT %

Propane 74-98-6 100




HAZARDS IDENTIFICATION

EMERGENCY OVERVIEW: WARNING! Flammable gas. Contents under pressure. Causes damage to the following organs: Nervous System. Vapor may cause flash fire. Keep away from heat, sparks and flame. Do not puncture or incinerate container. Keep container closed. Use only with adequate ventilation. Contact with rapidly expanding gases can cause frostbite.

POTENTIAL ACUTE HEALTH EFFECTS:

SKIN:


No known significant effects or critical hazards.

EYES:


No known significant effects or critical hazards.
INHALATION:


Acts as simple asphyxiant.

INGESTION:


Ingestion is not a normal route of exposure for gases.

POTENTIAL CHRONIC HEALTH EFFECTS:

CARCINOGENIC EFFECTS:


Not available.

MUTAGENIC EFFECTS:


Not available.

TERATOGENIC EFFECTS:


Not available.

____________________________________________________________________________________________________ ________


MSDS: PROPANE Page 1 of 6 Current Issue Date: December, 2008

PROPANE

MEDICAL CONDITIONS AGGRAVATED BY OVEREXPOSURE:


Acute or chronic respiratory conditions may be aggravated by overexposure to this gas.

See Toxicological Information (section 11)


FIRST AID MEASURES

No action shall be taken involving any personal risk or without suitable training. If fumes are still suspected to be present, the rescuer should wear an appropriate mask or a self-contained breathing apparatus. It may be dangerous to the person providing aid to give mouth-to-mouth resuscitation.
SKIN:


In case of contact, immediately flush skin with plenty of water. Remove contaminated clothing and shoes. Wash clothing before reuse. Thoroughly clean shoes before reuse. Get medical attention.

EYES:


Immediately flush eyes with plenty of warm water for at least 15 minutes. Get medical attention.

INHALATION:


Immediately remove to fresh air. If breathing has stopped, give artificial respiration. If breathing is difficult, qualified personnel may give oxygen. Get medical attention immediately.

INGESTION:


Do NOT induce vomiting unless directed to do so by medical personnel. Never give anything by mouth to an unconscious person. Get medical attention if symptoms appear.

FROSTBITE:


Try to warm up the frozen tissues and seek medical attention.




FIRE FIGHTING MEASURES

FLAMMABLE PROPERTIES

Flammability of product:


FLAMMABLE

Autoignition temperature:


841.7°F (449.85°C)

Upper flame limit (volume % in air):


9.5%

Lower flame limit (volume % in air):


2.1%

Products of combustion:


These products are carbon oxides (CO,CO2).

Fire hazards in presence of various substances:


Extremely flammable in presence of open flames, sparks and static discharge of oxidizing materials.

Fire fighting media and instructions:


CO2, dry chemicals, water spray, or fog.

If involved in fire, shut off flow immediately if it can be done without risk. Apply water from a safe distance to cool container and protect surrounding area.

Extremely flammable. Gas may accumulate in confined areas, travel considerable distance to source of ignition and flash back causing fire or explosion.

Special protective equipment for fire-fighters:


Fire fighters should wear appropriate protective equipment and self- contained breathing apparatus (SCBA) with a full facepiece operated in positive pressure mode.

____________________________________________________________________________________________________ ________


MSDS: PROPANE Page 2 of 6 Current Issue Date: December, 2008

PROPANE




ACCIDENTAL RELEASE MEASURES

PERSONAL PRECAUTIONS:


Immediately contact emergency personnel. Keep unnecessary personnel away. Use suitable protective equipment (Section 8). Shut off gas supply if this can be done safely. Isolate area until gas has dispersed.

ENVIRONMENTAL PRECAUTIONS:


Avoid dispersal of spilled material and runoff and contact with soil, waterways, drains and sewers.




HANDLING AND STORAGE

NORMAL HANDLING:

Keep container closed. Use only with adequate ventilation. Keep away from heat, sparks and flame. To avoid fire, minimize ignition sources. Use explosion-proof electrical (ventilating, lighting and material handling) equipment. Do not puncture or incinerate container. High pressure gas. Use equipment rated for cylinder pressure. Close valve after each use and when empty. Protect cylinders from physical damage; do not drag, roll, slide, or drop. Use a suitable hand truck for cylinder movement.

STORAGE RECOMMENDATIONS:

Keep container tightly closed. Keep container in a cool, well-ventilated area. Cylinders should be stored upright, with valve protection cap in place, and firmly secured to prevent falling or being knocked over. Cylinder temperatures should not exceed 52°C (125°F).




EXPOSURE CONTROLS / PERSONAL PROTECTION

ENGINEERING CONTROLS:

Use only with adequate ventilation. Use process enclosures, local exhaust ventilation, or other engineering controls to keep airborne levels below recommended exposure limits. The engineering controls also need to keep gas, vapor or dust concentrations below any explosive limits. Use explosion-proof ventilation equipment

PERSONAL PROTECTION:

SKIN:


Personal protective equipment for the body should be selected based on the task being performed and the risks involved and should be approved by a specialist before handling this product.

EYE:


Safety eyewear complying with an approved standard should be used when a risk assessment indicates this is necessary to avoid exposure to liquid splashes, mists or dusts.

RESPIRATORY:


Use a properly fitted, air-purifying or air-fed respirator complying with an approved standard if a risk assessment indicates this is necessary. Respirator selection must be based on known or anticipated exposure levels, the hazards of the product and the safe working limits of the selected respirator.

The applicable standards are (US) 29 CFR 1910.134 and (Canada) Z94.4-93

HANDS:


Chemical-resistant, impervious gloves or gauntlets complying with an approved standard should be worn at all times when handling chemical products if a risk assessment indicates this is necessary.

____________________________________________________________________________________________________ ________


MSDS: PROPANE Page 3 of 6 Current Issue Date: December, 2008

PROPANE

Personal protection in case of a large spill:


A self-contained breathing apparatus should be used to avoid inhalation of the product.

Consult local authorities for acceptable exposure limits.


PHYSICAL AND CHEMICAL PROPERTIES

MOLECULAR WEIGHT:


44.11 g/mole

MOLECULAR FORMULA:


C3H8

BOILING/CONDENSATION POINT :


-43.2°F (-41.79°C)

MELTING/FREEZING POINT:


-302.6°F (-185.89°C)

CRITICAL TEMPERATURE:


205.9°F (96.6°C)

VAPOR PRESSURE


: 109 psig

VAPOR DENSITY:


1.6 (Air=1)

SPECIFIC VOLUME (ft

3/lb):
8.62069

GAS DENSITY(lb/ft

3):
0.116

PHYSICAL CHEMICAL COMMENTS:


Not available




STABILITY AND REACTIVITY

STABILITY and REACTIVITY:


The product is stable.

INCOMPATIBILITIES with various substances:


Extremely reactive or incompatible with oxidizing agents.




TOXICOLOGICAL INFORMATION

TOXICITY DATA:

IDLH:


2100 ppm

Chronic effects on humans:


Causes damage to the following organs: the nervous system.

Other toxic effects on humans:


No specific information is available in our database regarding the other toxic effects of this material for humans.

SPECIFIC EFFECTS:

Carcinogenic effects:


No known significant effects or critical hazards.

Mutagenic effects:


No known significant effects or critical hazards.

Reproductive toxicity:


No known significant effects or critical hazards.

____________________________________________________________________________________________________ ________


MSDS: PROPANE Page 4 of 6 Current Issue Date: December, 2008

PROPANE




ECOLOGICAL INFORMATION

Products of degradation:


These products are carbon oxides (CO,CO2) and water.

Toxicity of the products of biodegradation:


The product itself and its products of degradation are not toxic.

Environmental fate:


Not available

Environmental hazards:


No known significant effects or critical hazards.

Toxicity to the environment:


Not available.




DISPOSAL CONSIDERATIONS

Product removed from the cylinder must be disposed of in accordance with appropriate Federal, State, and local regulations. Return cylinders with residual product to Airgas, Inc. Do not dispose of locally.




TRANSPORT INFORMATION

DOT PROPER SHIPPING NAME:


Propane, see also Petroleum Gases, Liquefied

SHIPPING LABEL(s):


FLAMMABLE GAS

PACKING GROUP:


Not applicable (gas)

HAZARD CLASS:


2.1

UN NUMBER:


UN 1978




REGULATORY INFORMATION

U.S. FEDERAL REGULATIONS:

TSCA 8(b) inventory: Propane

SARA 302/304/311/312 extremely hazardous substances: No products were found.

SARA 302/304 emergency planning and notification: No products were found.

SARA 302/304/311/312 hazardous chemicals: Propane

SARA 311/312 MSDS distribution – chemical inventory – hazard identification: Propane: Fire hazard, Sudden Release of Pressure

Clean Water Act (CWA) 307: No products were found.

Clean Water Act (CWA) 311: No products were found.

Clean Air Act (CAA) 112 accidental release prevention: Propane

Clean Air Act (CAA) 112 regulated flammable substances: Propane

Clean Air Act (CAA) 112 regulated toxic substances: No products were found.

STATE REGULATIONS:

Pennsylvania RTK: Propane: (generic environmental hazard)

Massachusetts RTK: Propane

New Jersey: Propane

CANADA

WHMIS (Canada):


Class A: Compressed gas

Class B-1: Flammable gas

CEPA DSL: Propane

____________________________________________________________________________________________________ ________


MSDS: PROPANE Page 5 of 6 Current Issue Date: December, 2008

PROPANE




OTHER INFORMATION

UNITED STATES

LABEL REQUIREMENTS:


Flammable Gas

Contents under pressure

Causes damage to the following organs: Nervous System.

Vapor may cause flash fire

CANADA

LABEL REQUIREMENTS:


Class A: Compressed Gas

Class B-1: Flammable gas

HAZARD RATING SYSTEMS:

NFPA RATINGS: HMIS RATINGS:

HEALTH =1 HEALTH =1

FLAMMABILITY =4 FIRE HAZARD =4

INSTABILITY =0 REACTIVITY =0

SPECIAL =None PERSONAL PROTECTION =C

National Refrigerants, Inc. believes that the information and recommendations contained herein (including data and statements are accurate as of the date hereof). NO WARRANTY OF FITNESS OR ANY PARTICULAR PURPOSE, WARRANTY OF MERCHANT ABILITY, OR ANY OTHER WARRANTY, EXPRESSED OR IMPLIED, IS MADE CONCERNING THE INFORMATION PROVIDED HEREIN. The information provided herein relates only to the specific product designated and may not be valid where such product is used in combination with any other methods of use of the product and of the information referred to herein are beyond the control of National Refrigerants. National Refrigerants expressly disclaims any and all liability as to any results obtained or arising from any use of the product or reliance on such information.

____________________________________________________________________________________________________ ________


MSDS: PROPANE Page 6 of 6 Current Issue Date: December, 2008

[paul_h]

Excuse my ignorance but can you just use BBQ propane? Why buy it from a refrigerant supplier? Moisture and incondensables. Need to purify propane remove crap and moisture.
That said, I'm not sure who makes a business selling just R290 like I said, I'm sure they sell many other HC refrigerants and have other things in there.

[chillerman2006]

Hey Install...have you got the full up to date version in larger print...having trouble reading that one

[install monkey]

thought u might of gone blind from watching dogwanks haha-i only copied and pasted it-the data sheet haha

[MikeHolm]

Looking at the MSDS sheet, it would seem that there are no additives. I can see the moisture issue as it could be as high as 12% from my 20 year old fuels courses (it is for natural gas although this is a product of combustion and that includes the humidity in the combustion air).

I would look at it more closely. This might be a question for Refrigeration 101 but why is Ammonia more efficient than r410 for example (other than the pressure issue) and is r290 also more efficient? If one were to create an industry change to either of these, there must be more benefit than just lower pressures.

Again, I let my ignorance show.

[alvinsmith]

Thanks install, I've got some ideas in your post. I'm just a learner so excuse me guys. thanks.

[mikeref]

Excuse my ignorance but can you just use BBQ propane? Why buy it from a refrigerant supplier?
Mike, From what i have read, hydrocarbons for refrigeration are specific quantities of isobutane/ propane/ n-butane, minus the water factor in BBQ gas, that has everything in it including the kitchen sink. (So to speak.. might just be an Aus saying :rolleyes: .) BBQ gas is in liquid form at 188 PSI, give or take, depending on where you live, so my gas supplier tells me. So many imported domestic and light commercial equipment with R600a and R290 here now, yet i've not had the opportunity to work on them yet..Mike.

[chillerman2006]

why is Ammonia more efficient than r410 for example (other than the pressure issue) and is r290 also more efficient? If one were to create an industry change to either of these, there must be more benefit than just lower pressures.

Hi Mike

Ammonia's specific hit transfer is far better than R410a & all hydrocarbons are far lighter than fluoro based refrigerants roughly half the weight & as they are measured in kj per kg they have twice the mass to carry out the work, hope that helps mate

R's chillerman

[chillerman2006]

Mike

Here is some more info

Note R600 half cooling capacity of R134a

Also shows charging/decanting/brazing procedures

R's chillerman

[MikeHolm]

This will take some time to digest.....keep it coming

[chillerman2006]

Hi MIke

am on limits of my understanding here so please wait for confirmation from another before taking all as 100% correct ( DesA / Peter_1 HELP !!! before I drown )

Right well if we go back to Ammonia v's R410a first

Ammonia has a high 'specific heat capacity'

R410a has a lower 'specific heat capacity'

specific heat capacity (cp) is measured as 'joule per gram' and the higher the number the more work that fluid can do or the more heat that fluid is able to absorb

Water for instance has a high 'cp' (4.186) but the more glycol that is mixed with water the lower the 'cp' becomes & the less heat that fluid can now absorb

The less work a fuid can do (less heat it can absorb) the more the system has to run to acheive the same results

R's chillerman

added .... its ok Mike ... confirmed by Peter_1

[Peter_1]

... Years ago a manufacturer came out with a removable winding on a commercial compressor, the rotor was in a sleave, similar to a Hermetique ammonia pump, don't know what happened to them.

Frigopol of Austria is it MAgoo, a mix between a hermetic and an open compressor. I have some in my shop, vertical compressors.
But Bock did the +/- same on their AM range but they still needed a shaft seal.
They are still fabricated these days. www.frigopol.com

You can use a small open compressor like a Dorin for NH3. But you then loose a part of the absorbed power. But NH3 gives a very high discharge temperature, especially when you superheat it the suction in a controlled way a little bit further then normal.

@Chillerman, I think you explained the term specific heat very well in your las post...the heat absorbing ability of a refrigerant I should call it.

[Peter_1]

I thought 150 gr was the max for R290.
They're researching a lot on R290 for the moment. A paper was presented very recent by DTI (the same university of Coolpack)

Had last a domestic freezer to repair for a friend and he told me that he had a leak around the door heater (discharge pipe around the door) He asked me to bypass the door heater so that I could recharge it with R134a.
Never looked to the nameplate - very stupid of me - and took my brazing torch to solder a schradervalve in the suction port of the hermetic. Process tube came loose from the compressor and you can guess..the R290 (no r134a) was still on it.
We didn't needed to repair it afterwards, it burned as a constant flame of 15 cm to 20 cm high, full power for at least 1 minute. The back of the freezer was complete melted. Lucky, I was in my open shop.
So 150 gr is dangerous, I saw and felt it like and smelled like a roasted chicken.

[chillerman2006]

Hi Peter

some limits shown on attached

R's chillerman

[paul_h]

I thought 150 gr was the max for R290.
They're researching a lot on R290 for the moment. A paper was presented very recent by DTI (the same university of Coolpack)

Had last a domestic freezer to repair for a friend and he told me that he had a leak around the door heater (discharge pipe around the door) He asked me to bypass the door heater so that I could recharge it with R134a.
Never looked to the nameplate - very stupid of me - and took my brazing torch to solder a schradervalve in the suction port of the hermetic. Process tube came loose from the compressor and you can guess..the R290 (no r134a) was still on it.
We didn't needed to repair it afterwards, it burned as a constant flame of 15 cm to 20 cm high, full power for at least 1 minute. The back of the freezer was complete melted. Lucky, I was in my open shop.
So 150 gr is dangerous, I saw and felt it like and smelled like a roasted chicken.
Wow, lucky no injuries.
But using a peircing valve and recovering all refrigerant, and purging with nitrogen first should be the normal technique anyway, regardless of the refrigerant?

[Peter_1]

Paul_H, you're of course right but why recover if the unit is already 'empty' and you hardly have time to do such a s..t job like repairing a domestic fridge? But it was for a friend and between 2 jobs in a hurry.
Mmm, I think it's not allowed to recover R290 with a standard recovery unit
The fridge is still here, should make some pictures of the back of it.
We work regular on ethylene and propylene systems, so I know how to do it safely.
But only to say that 150 gr is not so little as they say where you will only see a small spark. It burns heavy and long. You can learn from my faults.
BTW Paul, we drive our van's the opposite way (your avatar) I knew it was a mirror view as we drive here but I didn't knew I had to turn my mirror the other direction, upside down.

[Peter_1]

Hi Peter

some limits shown on attached

R's chillerman
Is this something you have to know for the UK the F-gas exams? Do they question you about this? This is something we may not ask for the Belgium F-gs exams but I talk about it in the lessons for max 5 minutes.

[chillerman2006]

Is this something you have to know for the UK the F-gas exams? Do they question you about this? This is something we may not ask for the Belgium F-gs exams but I talk about it in the lessons for max 5 minutes.

No Not F-Gas mate

this was for 'Hydrocarbon handling course'

R's chillerman

[paul_h]

Paul_H, you're of course right but why recover if the unit is already 'empty' and you hardly have time to do such a s..t job like repairing a domestic fridge?
I understand, but the only 'evidence' people who are against HC refrigerants as far as safety reasons, are the stories about how normal safe procedures weren't carried out, and the resulting fire/explosion.
I'm not pro HC by any means, but talking about the flammability, when the job wasn't done the correct way...
OK it was more hazardous and did damage to the fridge with the flame. But none of us like burning HFC refrigerants or oil either.

[chillerman2006]

I understand, but the only 'evidence' people who are against HC refrigerants as far as safety reasons, are the stories about how normal safe procedures weren't carried out, and the resulting fire/explosion.
I'm not pro HC by any means, but talking about the flammability, when the job wasn't done the correct way...
OK it was more hazardous and did damage to the fridge with the flame. But none of us like burning HFC refrigerants or oil either.

Yes I would say so...the video's we watched included systems not fully recovered and leaking tubework ..... they just put a flame to them and all that happened was a torch like flame, similar to a plumbers propane torch, no big bang .... nothing

The time you have a problem is if the exact mixture is present to explode (2-10%) a small leak will disperse easily and are large leak will quickly saturate the air above its explosive mix ... so fairly safe really

there is one big hoax going round where a domestic blew up the kitchen and took the rear wall down .... that was proven by insurance investigators to be a delibrate explosion using the house hold gas appliance .... the refrigerator did not have the charge/mass to cause that damage ... worst way with domestics is if it explodes it will take some of your hair off and you may need clean pants ... well probaly will need the pants !

R's chillerman

[chillerman2006]

Had last a domestic freezer to repair for a friend and he told me that he had a leak around the door heater (discharge pipe around the door) He asked me to bypass the door heater so that I could recharge it with R134a.
Never looked to the nameplate - very stupid of me - and took my brazing torch to solder a schradervalve in the suction port of the hermetic. Process tube came loose from the compressor and you can guess..the R290 (no r134a) was still on it.
We didn't needed to repair it afterwards, it burned as a constant flame of 15 cm to 20 cm high, full power for at least 1 minute. The back of the freezer was complete melted. Lucky, I was in my open shop.
So 150 gr is dangerous, I saw and felt it like and smelled like a roasted chicken.

Hi Peter

A flame and some damage but no explosion

Should help some to realize, be careful but not afraid

R's chillerman

[install monkey]

bp experimentented with hydrocarbons at their services on the m6 at leicester forest. they fitted a coldroom , walk in freezer and aircon was installed, the fridge condensers were foreign and they had to install an extract system for the aircon.dont know how it went after the numpty that installed it crossed his pipework for the condensers so i had to pump down and swap condensers over-it prob got ripped out because on a different site the same guy degassed a 5kw fujitsu with 2kg r22 and charged 350grm on isceon 59, i spent ages pressure testing it to find no leaks!

[al]

Desa

Some others are looking at "miniturising" ammonia compressors:

http://www.ammonia21.com/content/articles/2009-02-19-ammonia-in-small-systems--challenges--compressors.php

it's funny that NH3 was used in the early days of cooling and i presume a lot of work was done at the time to make domestic versions before the "invented" refrigerants came out, and here we are redoing all this work!!

For me NH3 wins every time, relatively safe, requires a proper training to handle and cheap to buy!

alec

[Magoo]

Thanks al,
A GOOD READ, seems Mycom are onto it with a hermetic scroll for NH3

[MikeHolm]

I could only find the first part of the article and i went to the MYCOM website but there is no mention of anything in the 5-20 kw range except some CO2 machines. Maybe i missed something.

[Bigfreeze]

Theres an Austrian heat pump manufacturer (neura) that uses propane extensively in their range of DX heat pumps up to 30kw. All equipment is outdoors though and the heating water is circulated to the exchanger outside which is its biggest downfall. Achieving COP's of 5+ at the unit, but the losses in having to tranfer the water out of the house is not accounted for in that COP.