Need info on Natural gas air conditioning

Ted_9

Customer just called me to see if he could switch to a Nat. gas a/c.

Im looking for companies that sell them and your input.

Unknown

It's been a while....

Arkla/Servel was one company. Bryant was another.

These were gas fired absorbtion water chillers, that worked with water coils in air handlers, and were ground or roof mounted.

Electric was more reliable, this was in the 1980s. I'm not real current on what's out there now.

Ask these guys...

http://hvac-talk.com/vbb/

Noel

mickey_2

Serval

Serval was pushing their unit on Long Island for a while, however they seem to be pulling out of the country now. They have moved most of their operation to Italy. When the system ran it was great.The web site is www.robur.com mayby they can give you so better info.

Troy_3

Robur Servel

Can't give you their web address right now. We installed 3 systems in recent years. They work great. We installed them with Unico high velocity system. Both systems will work as a boiler and provide hot water to your coil or send chilled water to the coil. They are made very solid. Haven't had any trouble. Don't know how many more we will sell till Nat. gas prices stabilize. One of the jobs was on a house with a gas well. Another one wanted the condensing unit 100' away from the house piped underground. Bryant said all warrentees are void if condensate lines are buried. The chiller fit the bill nicely. I can lokk up the website if you can't find it?

jw

Gottel

There is an outfit in Phoenix that makes a gas engine fired chiller/ heat pump. I think the spelling is Goettl. Their units are 10 or 15 ton and modulate based on speed of engine.

John Mills_3

Expensive to buy

and expensive to run in most cases. I crunched the operating costs vs a 10 SEER A/C. This was before natural gas went through the roof. OUCH.

I believe the 3 ton uses about 68,000 BTUs per hour plus about 1kw for fans & pumps.

68K at 1.10 a therm = 75 cents for gas
1kw at our prices of 5 cents = 5 cents

Robur's 3 ton costs 80 cents per hour

10 SEER 3 ton uses 3.6kw per hour
3.6kw x 5 cents = 18 cents

Your gas would have to be very cheap and your electricity outrageous before the Robur would come close to being worth it. Tack on the high price for the unit and I can't imagine any reason to buy it.

Constantin

...unless you had a cheap local supply of gas

... and a very expensive source of electricity. Perhaps folks on ranches in the middle of nowhere with PV for electricity? Under those circumstances though, why wouldn't one simply buy a gas-powered generator and be done with it?

Thanks for the calculations John, this was an excercise I was about to go through... at $1.37 a therm for gas in Boston. I guess I'll stick to a electrically-powered compressor.

Ted_9

Constantin :

This job is in Massachusetts too. In the greater New Bedford area. Its Nstar country.

pperkins

service on gas a/c

Wait untill it needs repair!!!!.There junk compared to electric ac,its the only way to go.

Ted_9

I should also say that im looking for residential split gas a/c units.

Rudy

Operating Costs

Natural gas suppliers in No. Illinois used to give huge summertime rate adjustments to gas AC users. I doubt they still do. My first job in the trade back in the early 80's had me servicing a lot of absorbers and engine drives. Most of those Arkla's and Bryant's were old then and were probably replaced by R-22 systems. Do they still use ammonia as the refrigerant? Potent stuff!

Most engine drive accounts he had eventually switched over to electric. The gas conpany's office complex had no electric service. All power was from generators and the AC was a 35 ton D-B coupled to a Caterpillar six cyl. Even they had an electric service drop installed JUST for their AC becouse unlike the generators there was no backup and when it went down the higher-ups got a little HOT under the collar...literally. I wish I was privy to that phone call when THE GAS CO. had to call for their first electric service drop for a building that was 10-20 yrs. old. We once estimated that those engines ran the equivalent of over 200,000 mi. every season...uphill all the way!!

Ever been in a basement engine room with five 549 cubic inch Harvesters coupled to 100 Ton Trane W-8 compressors. Not a fun place to work when they're running. Great experience working on that stuff but do I miss it....NO!!

Rudy

Troy

I just attended a Unico seminar and see they offer a chiller I think to 10 tons that can pipe to multiple air handlers. I was very intrigued. The Robur Servel has heat pump type reversing valves to provide chilled/hot water? Nice concept! Are you using it for primary or secondary heat source. I was thinking of using a water coil in a Unico install as a secondary to radiant floor but I don't think I would trust it as a primary heat source without some COLD AIR return ducts. Any thoughts?

Ted_9

again im looking for residential gas fired a/c split system.

Ted_9

Need info on Natural gas air conditioning

anyone?

Greg Swob

What, specifically are you looking for? Products, availability, dependability, parts (sooner or later you will need them if you install), testimonials, advice??? We had a bunch of them in this community, now we change them out to electrical units whenever possible. Have to maintain anti freeze in the transfer fluid, if this leaks, danger to pets, and a clean up hassle.

Products- not sure what all sizes are available on the market today, used to be 3,4,5 Ton and of course, large commercial units. We have trouble getting parts, let alone worry about trying to order units. Cost is several times a comparable electric unit. Thousands, rather than hundreds for just a condensor. Ordered spare condensor fan motors early last spring, got them last fall. Stole motors of non operating units all summer long to limp the others along for the summer.

Try www.robur.com for the latest in products. Robur is the current owner of the formerly Arkla-Servel firm.

Operation - at one time, very economical, now outrageous. Electrical consumption is not that far off from standard electrical A-C units, plus a gas bill for the burner.

Dependable- yes, there are many still operating that are fairly old, compared to average life span of electrical units. However, once repairs are needed, this becomes a very costly venture. Cost of parts outrageous compared to electrical units.

Advantage- use hydro-air type air handlers so boiler heat can be used in a building, without need for cumbersome ductwork. If piped correctly, no major deal to convert from heat to A-C, if not, those weeks in early spring/ late fall where the possible need for both in a 24 hour period is needed will make for interesting days.

Disposal of existing units - chromate is used to keep the ammonia referigerant from corroding internal metallic components, you have a hazardous waste disposal fee of approx $250 per condensor unit upon disposal.

Service? Easy sometimes, but as with anything can be a nightmare! A pump, very similar to an automobile power steering pump needs maintenance of seals, spring, check valves, etc. Very messy job & then if oil (power steering type fluid) leaks or is spilled during service, you have a local environmental issue to contend with. Most general problem is with the ignitors or sail switches. If a power failure or other event occurs and the unit was operating, it could be in what is referred to as 'stored out' condition needing the referigeration to be rebalanced. Pain in your seat to deal with. Referigerant: Ammonia- give me R-22, R-410a, R-anything any day. One slip and you can get an ihnhale that is irritating beyond description - other serious hazards, of course as with any refrigerant also possible.

No doubt, there may be a place for these units, but the landfill or metal recycling yard (minus chromate) is the best place I can think of. Only a couple of the 'old timers' in our office can effectively work on them and even they get seriously flustered once in a while.

All that said, I am referring to units that have been in use for any where from a few to many years. Perhaps the newest products offer better long term dependability and some of the service nightmares have been reduced to bad dreams. Our office has not installed one for over 5 years. Once upon a time, many were in the area, now thankfully, we can count them on just a few hands.

Did any of this help? Would you like more specific info? Ask specific questions and I will try to assist without as much bias as my previous statements displayed.

Greg

Troy_3

Goebig

I used them as secondary heat in all but 1 job. Radiant heat is the primary heat. A/c is the primary function. The job where it is the primary heat the owner is in a wheel chair. Temp and humidity control is critical due to health reasons. It has worked flawlessly for the last 2 seasons. The gas well makes it the least expensive option for him. Ironically he wouldn't listen to any radiant heat. We have 2-Munchkin M199s providing 4000 sq. feet of snowmelt in asphalt. Surprisingly It keeps up wonderfully.

Ted_9

Greg Swob : You gave me plenty if info. Its a direction that I do not want to go.

Rudy

Troy

Thanks for the input. I'm doing a large addition with A LOT of glass and am worried about radiant and hardwood on design days. I was considering CIBB as second stage as there's standing iron in the rest of the house but since I'm installing a Unico anyway.......thanks again, Tom

Ken D.

Gas AC

Servel is still around. Continent Supply in Philadelphia is a big dealer in them. Also York International makes a natural gas fired piston engine driven unit. Servels are time consuming to service and are expensive to buy.

Ted_9

I went to http://www.robur.com/index2.html and got some info for my customer.

sunshineed

arkla servel air conditioners

i want to remove the one in my backyard, but was told a professional heating and cooling guy would have to do it because it contains ammonia. is this true? am i unable to remove it myself?