Refrigerant

[Samarjit Sen]

Do you feel that CO2 and Ammonia are the refrigerants of the future. Both of these are easily available and is from nature. The cost is low at the same time it is low priced.

From Air Conditioning application to Sub Zero refrigeration application both these refrigerants can be used individually or in Cascade as the need be.

The general opinion of the members shall be very much appreciated.

[The MG Pony]

there is no poll?

I say CO2, NH3, and all the hydrocarbon ones will be the refrigerants of the futur, the current route we are going isn't helping the plannet, not refer techs fualt but general humanities incompitance of thinking. (IE: Air dusters: R-134a; R-152a) Any thing that is harm full to the plannets atmospher needs to be banned as the first idiot to get ahold of it sprays it in the air for fun or other such stupid ventures.

Depressing thing when one thinks about it *Sighs*

[winfred.dela]

Do you feel that CO2 and Ammonia are the refrigerants of the future. Both of these are easily available and is from nature. The cost is low at the same time it is low priced.


Hi Samarjit,

Natural Refrigerants could be the future if the equipment designers and manufacturers can find ways to lower their cost. Cost is one of the driving force in the system designers and customers decision.

I for one wanted to have an ammonia aircon plant so long that the price could be lower than the halocarbon system.

Again, we need to be on a look out on cost component of the new equipment for natural refrigerants. With lower prices, natural refrigerants can really be the future.

Regards
Fredy

. . . :)

[US Iceman]

I for one wanted to have an ammonia aircon plant so long that the price could be lower than the halocarbon system.


Myself and another gentleman worked on this problem about 10 years ago for NH3 water chillers. It's possible to do, but you have to think like an HVAC manufacturer, not an industrial refrigeration manufacturer. These are two different mindsets.

Ammonia has some limitations due to the strong smell it has (that and the safety and occupancy codes). We did build an ammonia water chiller for an industrial office building. However, since the site was classified as an indutrial occupancy we were able to do this.

Commerical office buildings will require a change in codes to be accepted I think.

[winfred.dela]

Ammonia has some limitations due to the strong smell it has (that and the safety and occupancy codes). We did build an ammonia water chiller for an industrial office building. However, since the site was classified as an indutrial occupancy we were able to do this.


In our country, the code is not as strict as yours. The smallest NH3 chiller i have built used a 15.0 TR Semi Welded PHE and small Bitzer compressor (open recip) that are suitable for NH3. This can only be used in industrial application due to its price.

Compared with Aircon Chillers, the price of an NH3 system is way above the BPHE Chillers that are applicable to R-22 or other refrigerant.

There is already small NH3 suitable BPHE (all SS) from Alfa Laval but the price is so prohibitive that it cannot compete with the BPHE for R-22.

. . .:)

[US Iceman]

Hi Winfred,

That's the same problem we ran into. The heat exhangers...

We looked at enhanced carbon steel tubes for the shell & tubes. Since we manufactured those, that's what we had to use.

Our problem was the cost of the tubes. They are probably cheaper now, but 10 years ago (maybe more) they were quite expensive.

A flooded evaporator has too much refrigerant, so a better alternative would probably be a spray-type chiller.

Our prototype looked very similar to a normal HVAC chiller with the compressor mounted on top of the condenser or chiller.

The baseline we used was $ per Ton. On large systems it was close. On small systems, you can't win. The equipment is just too expensive as you mentioned already.

[winfred.dela]

A flooded evaporator has too much refrigerant, so a better alternative would probably be a spray-type chiller.


In a spray type chiller, NH3 with steel tubes will be expensive as the R-22 refrigerant will just use copper tubes.

I believe when the prices of (1) SS BPHE and (2) air cooled condenser with SS tubes will be a little bit lower, price of NH3 system with ice builder (running at 24 hours a day) will outprice and outlast a R-22 HVAC chiller.
In addition, the energy cost will be a lot cheaper if we can make the NH3 chiller smaller (operating 24 hours) than the conventional HVAC chillers that are not built to run 24/7 operations.


On large systems it was close. On small systems, you can't win. The equipment is just too expensive as you mentioned already.


Maybe as of now in a 150TR capacity (airside) aircon system, the price can be competitive. At around 30TR, HVAC chiller is very cheap compared to NH3 chillers.

. . . :)

[Samarjit Sen]

We have some restrictions on the use of NH3 in our country. It is only in the industrial areas that plants with NH3 are permitted.

However considering the efficiency and the performance of CO2 and Ammonia, is it not feasible and better to use it in refrigeration plants. I personally do not have much experience with NH3 and have been using R 22 and R 404A till now. But after going through the various posts in the RE on Ammonia and CO2, I feel that these could be the refrigerant which would be more in use in the near future.

Unfortunately the Ammonia system being used in our country which is generally for Potato Cold Storages are based on old technology. These have incurred high electricity bills and have not been able to maintain the required conditions. This has resulted in closure of most of the Cold Storage plants. I am sure if new technology is applied and better equipments are installed, then the story would be different. The Cold Storages would run efficiently with low electricity charges and the same could be used for storage of varied crops round the year.

[winfred.dela]

Unfortunately the Ammonia system being used in our country which is generally for Potato Cold Storages are based on old technology. These have incurred high electricity bills and have not been able to maintain the required conditions.


NH3 equipment are durable and can run 24 hours without much problem, so equipment can run on its optimum capacity.

Incorporating the latest controls technology, i see no reason that the efficiency could be as good with any halocarbon equipment.

. . . :)

[SIGNSTU]

We hve cut our electric bills from $12000 with r22 to $4500 with nh3 and of coarse a good micro that controls everything. I have seen flooded plate and frames for Nh3, little space needed and great efficiency.

[Samarjit Sen]

One should see the system being adopted here in India for NH3 plants. The basic problem is that the customer instead of approaching a refrigeration firm, prefers to go to an untrained technician who might have worked as an operator in some plant and has now started claiming that he is an expert. His total budgetary cost is so low ( which will gradually increase as the work progresses ), that the customer is attracted to him. The so called expert has never heard of compressors of Vilter, or J&D Hall. He either picks up the compressors from a scrap yard or a locally manufactured one. There is no load assessment nor any controls. The refrigeration firms stand no chance against such competition and as such avoid such contracts.

After the unit starts with all sorts of problem, then the customer realises his error, but then it is too late. There are hundreds of such plants lying all over the country in abandoned state.