With the price of natural gas thru the roof, these little chillers are extremely expensive to run. Last I saw, Robur's 3 ton took 67,000 BTU plus about 1 kwh for fan & pump.

At our rates,

67,000 X 1.00 = 67 cents
1 kwh X .05 = 5 cents

or 72 cents per hour

3 ton 10 SEER uses 3.6 kwh

3.6 kwh X .05 = 18 cents per hour

making the chiller 4 times the cost to run, much more to buy and few can work on it.

 

I took a bunch of them out in the seventies. They were popular in the 50s and 60s as were natural gas refrigerators.

 

There were quite a few in our community and surrounding areas. In fact, there are still a few Arkla water cooled NG units still in use here! Talk about dinosaurs! If repairs are minor, such as an ignition module or gas valve, they are not so bad to work on. Virtually anything else takes time (lots of it) and usually a good deal of money to fix. There is just simply nothing economical about these units any more. The initial cost is amazingly high compared to electric units and the efficiency and/or operating cost as previously mentioned is high compared to electrical units. Most of our guys fix them by removing and repalcing with electrical units whenever possible. Have not yet had one owner miss the gas fired A-C due to the fact we greatly lowered their operating and maintenance costs. Also, finding a service tech who knows his way around them or is even willing to work on one will be rare. Greg

 

I used to work on some of the old Bryant, Arkla absorption units. Brooklyn Union Gas was pushing them. They were a piece of work, solution pump problems, belts breaking, and if you were really lucky the leaking generator or hairline crack going into the condensor. That famous bryant bi-metal pilot switch that stuck sometimes. The unsuspecting spider that made a nest in the 3rd burner and delayed the combustion long enough to sound like a grenade landed in your backyard followed by an ammonia stench that could knock you on you a--. That really cleared out the neighbors. Alot of them were installed on rooftops as well. I had every size adapter to fit every bathroom sink so I could connect a garden hose out a window to the roof to fill and clean the brine tank. Ah, and don't forget the evaporators stuck on top of some old GE furnace with a cast iron heat exchanger and a giant blower stuffed in it to get enough air through the 4" round aluminum ducts sized for heating only, and the brine hoses connected by a little piece of clamped rubber hose to the copper or steel brine tubing, when they cracked you were left standing in a sea of green/blue stagnent sludge. They really were pretty inefficient also. (Anyone need a steel 3 valve manifold and charging cylinder?)

I even had one residential customer who had McQuay Hydronic Fan Coils in every room. Two 3 Ton Bryant Chillers and a boiler for heat. He used to bypass the chiller in the winter and the boiler in the summer. It worked well and was designed by him. He was an engineer and a tinkerer.

The latest Robur units are more efficient, but with gas rates what they are, cost a fortune to run. The only places I can see installing one of these is where there is insufficient power available for a conventional unit, or you live in a house with a natural gas well.

Rob

 

Robur

Has anyone insight into residential absorption systems? I understand initially they are more costly but the long term payout seems to be worth it. I’m in Houston with plans for future ICF construction and wonder why these systems aren’t widely publicized. Also, how well do they tie in with the heating system.

Thanks,

Jon

They are getting very popular around some of the suburbs of Los Angelus, there was a green study done and they were worth their wieght in efficency.

I work on manyof the old one every now and then, if you never saw one you'd think WTF ...

Very pricey they do like what they sell. Tehy have not change that much other than now, the sail switch for the condenser fan is elctronic and the ignition system is electronic with a electronic control board.

Here is a pdf link to a California Market Brochure http://www.robur.it/corporation/ita/documenti/so_cal.pdf

And anotehr on the benifits found with the high cost of our utilities here.... http://www.jarn.co.jp/News/2001_Q1/003_S_7.htm

http://www.achrnews.com/CDA/ArticleInformation/features/BNP__Features__Item/0,1338,29406,00.html

[Edited by AllTemp on 04-11-2005 at 05:32 PM]

 

Pipe dreams or practicality

I can enthuse with the original poster about how NG air conditioning *might* be desirable, a couple years ago I went through the same thinking. My conclusion is that in the real world, you will be better served by a heat pump. Geothermal if you wish to get radical about efficiency.

Let me offer another direction of thought while it's all imaginary... have you ever thought about lithium bromide (LiBR) absorption system instead of ammonia? It has been used in commercial installations, it operates at far lower temperatures and thus might be usable with solar collectors providing some of the energy. And when required, a shot of NG to make up the BTU shortfall. There was one Texas man who did adapt a LiBr commercial unit to his house, and he discussed using solar energy to provide much or all the heat input, but as far as I know he never actually built it. I would describe him with respect and some affection, as probably an eccentric old coot.

Whatever you do, I would consider it prudent to keep a Trane around for reliability purposes<g>. Any brand actually, so long as it was a designed install by someone who thinks like the leaders on this board.

Best of luck -- P.Student

P.S. Don't forget to engineer a decent ventilation system when you plan your ICF home!

[Edited by perpetual_student on 04-12-2005 at 11:07 AM]

 

Thanks to all who replied. I'm now of the opinion an absorption system isn't the way to go with the rising cost of natural gas, questionable future availability and incurred electrical charges in operating the system. If it wasn’t for the high installation fee, Geothermal would be my choice but it looks like a high SEER heat pump is going to be the route I take.

Thanks again,

Jon

 

Wow..We had one of those monsters on an old house in Las Vegas..Arkla Servel I think? Huge thing attached to the back side of the house and had a small water chiller tower next to it..Damn was that thing expensive to run even back in the 80's!!! Our gas bill was over 250.00 whereas my grandparents house had an original Carrier unit (one of those really old ones with the belt driven condensor fan and the compressor looked like a car engine) and their power bill was less than 100.00 in the dead of summer..We didn't live in that gas house very long..Last time I drove by it, it appeared that old gas AC was still there..Can't imagine what it costs to run today..As far as I know that original Carrier unit is still on my grandparents house too..That house was built in 1955 and mom and I sold it three years ago..Still chugging along..Grampa wouldn't replace it as it was so dependable and also fairly cheap to run..
John