ACHRNEWS

Vegas Has Glitz, But Cooling Stays Basic

May 10, 2001
LAS VEGAS, NV — Most everything going up in Las Vegas is newer, bigger, and more elaborate than anything before.

But when it comes to comfort cooling, many of the long-standing hotel/casinos are not ready to venture off too far into uncharted territories. Systems that have long been running on R-12 are getting newer refrigerants that bear striking resemblance to that familiar CFC.

“Diversity is the reason,” said Rick Branscombe of Universal Systems of America, a manufacturer’s rep in the Vegas area. “The refrigerant does more jobs than others. It can work in walk-in and reach-in coolers and freezers, ice machines, even in automotive applications.” He further noted that the refrigerant “is 8% more efficient than R-12.”

Several of the major established complexes — such as the Flamingo, Circus Circus, Caesar’s Palace, Rio, Tropicana, and others — have made the switch to an R-12 substitute called R-414B.

“The refrigerant has been satisfying to our refrigerant department,” said Karl Spencer, supervisor of Flamingo Hotel Property Operations. “We do highly recommend the product.”

The product first entered the stationary refrigeration market in 1995 when it was introduced by Icor International of Indianapolis, IN, under the brand name “Hot Shot.”

R-414B is a mixture of three HCFCs — R-22, -124, and -142b in a 50/39/9.5 mix — plus 1.5% of the hydrocarbon (HC) isobutane.

Said Icor’s Gordon McKinney, “In the early development of R-12 substitutes, manufacturers concluded that by using R-22 as a base component, an alternative blend could achieve the essential characteristics necessary while remaining environmentally friendly.

“The enhanced performance, oil return, and broad application range of the R-22 blends have proved to be more preferable than the R-134a-based blends.”

R-134a, as an HFC refrigerant, has a longer-term viability than HCFC refrigerants. But advocates of HCFC-based refrigerants contend that 22 will be available another 20 or 30 years, well beyond the lifespan of most equipment now in use in which HCFCs are used.



It’s a Zeotrope

R-414B is considered a zeotropic refrigerant blend, so each component has a different boiling point.

“Therefore,” said McKinney, “while moving through the evaporator and condenser, blends have an unequal phase change. If a leak develops in one of these areas, the result could be a change in the component percentages of the blend. However, in practical terms, it does not occur to the extent that it was anticipated.”

His suggestion: “If you discover a leak in a system that is charged with a blend, first consider the location of the leak and the type of system to help determine if fractionation has occurred.

“Checking your liquid-temperature relationship to the bubble point of the blend will also help you decide if the refrigerant has fractionated.”

The manufacturer also offers information on how to perform a noncondensable test to determine if fractionation has occurred.

A major selling point of using HCFC-based refrigerants is that they can be used with the existing mineral oil of CFC systems (provided the changeout is not the result of a compressor burnout). HFCs require a POE oil and the near-total removal of the mineral oil.

Icor said its refrigerant can be used in a wide range of applications, including direct-expansion reciprocating and screw chillers, industrial process air conditioning and refrigeration, ice skating rinks, cold storage warehouses, supermarket refrigeration, ice machines, and water coolers.

For more information, contact Icor at 10640 E. 59th St., Indianapolis, IN 46236; 800-497-6805; www.icorinternational.com (website).

Sidebar: System Charging With R-414B

There is a specific process recommended by Icor International for charging a system with R-414B.

1. Pull a vacuum with a two-stage vacuum pump. A deep vacuum is necessary to eliminate moisture and noncondensables that may damage the system. Pull the vacuum from both the high and low sides of the system. Use an electronic (micron) gauge to measure the vacuum (an accurate determination of vacuum cannot be determined with a gauge set alone).

2. Make sure the refrigerant leaves the cylinder in a liquid state. Hot Shot is packaged with a dip tube to facilitate liquid removal. Do not turn the cylinder upside down. Vapor charging will result in the improper composition percentage and will affect the system performance.

3. Determine the necessary charge for the unit by using the specified plate rating, manufacturer’s literature, or by weighing the recovered R-12. Using an electronic scale, charge to 80% of the R-12 (10 oz of R-12 equals 8 oz of R-414B.)

If a charging cylinder is used, charge to equal amount (10 oz = 10 oz). Charging cylinders are scaled by volume. R-414B weighs less than R-12 but is the same volume. For expansion valve systems, don’t clear the sight glass.

4. Charging at the liquid service valve is preferred. If system pressures equalize before the full charge is introduced, start the system. Monitor your compressor RLA amp draw and complete the charging on the suction side, being careful not to overload the compressor. Use a quick-charge device that flashes the liquid to vapor prior to entering the suction.

5. Once the system has stabilized, check operational pressures, temperatures, amp draws, superheat, and adjust charge as necessary. Record all final readings. Document the amount of the charge.

Publication date: 05/14/2001