When selecting the right refrigerant recovery unit, first consider the type of service work you'll be doing with it. Robinair, Montpelier, Ohio, offers the following advice.

If you mainly concentrate on appliance and vending machine service, your needs will be different from a contractor who does everything from rooftop units to chillers. What type of training do your technicians receive. and what's more important to them - automatic features or budget considerations? And remember, you might need more than one type of recovery unit to efficiently handle all the service situations you might encounter.

Match the recovery unit to the system:

Appliances, ice makers, window ac, vending machines

  • Move small amounts of refrigerant

  • Little heat exchange

  • Lightweight, quiet running

    Residential ac, heat pumps

  • Move up to 10 pounds of refrigerant,

    under varying temperatures

  • Reasonable heat exchange

  • Lightweight, easy to carry

    Light commercial ac

  • Move larger amounts of refrigerant

  • Ample heat exchange

  • Vapor and liquid control

    Large commercial ac/r, such as rooftop

    chillers and walk-in freezers

  • Move large amounts of refrigerant

  • Large heat exchange

  • Liquid recovery

Track 'em down

Identifying refrigerant leaks can take time. Even with the trail left by dirt and oil, you need to locate the exact point of the leak to repair it. And once one leak has been located, a technician will want to make sure there aren't other leaks in the system that could do even more damage.

Why ultraviolet leak detection? An ultraviolet leak detector, like Robinair's Tracker® System, is an efficient way to detect leaks. The fluorescent dye combines with the refrigerant lubricant to move throughout the system. If there's a leak, the oil (and dye) will migrate out at the leak point and be visible in the light of the Tracker lamp, even in bright sunlight. How does this change the technician's service routine?

It doesn't. The technician doesn't have to recover, evacuate and recharge the system to add the dye. It can be added to a fully-pressurized system. The dye works with mineral, polyol ester and alkylbenzene oils, so it won't affect system performance. Because it is universal, there's no guessing as to what dye to use, and the correct type of dye is always available.

How much dye is enough?

The technician can decide how much dye to use based on the system size or the amount of oil in the system. In general, use 1/4 ounce of dye for every 16 ounces of oil in the system.

The technician adds the dye once. It will be there the next time the system is checked for leaks and will stay fluorescent for two years or more. This works well for preventive maintenance programs since new dye does not need to be added every time.

Here are two ways to locate leaks in those hard-to-get-to spaces:

Can't shine the beam directly on a suspected leak point? Use a mechanic's mirror to reflect it into the area.

Still can't see it? Rub the area with a clean cloth or swab, then shine the UV lamp on it. If there's dye on the cloth/swab, you've got a leak.