One approach introduced in recent years has been to inject a formulation of organosilanes directly into the system regardless of where the leak might be located. The solution flows throughout the system as a liquid with the refrigerant and oil. When it reaches a small leak it exits the system at that point. Atmospheric moisture then causes it to crystallize and form a bond.
It is a process that is gaining greater attention.
Here, for example, are three case histories showing how servicing is done with the product, how it can be incorporated into an overall company policy regarding its use, and how distributors can better inform their contractor customers about this option in leak repair.
THE METHODDavid Keivel, of Comfort Solutions Heating & Air-Conditioning in Dayton, Ohio, adapted this sealant approach as a way to offset the claim by some other contractors that the only way to deal with small leaks in residential units is with an annual "shot" of refrigerant rather than attempting to make a repair.
"I explain to the customers how the sealant (in this case made by Cliplight Mfg. of Toronto under the brand name SuperSeal HVACR) works, and they're quite appreciative of the procedure especially when they see the money they're saving over the long run," he said.
He said he was skeptical at first but noted that the first few systems he started up this spring "have been running flawlessly." To date, he has repaired more than 20 leaking air conditioners with the product.
"I make sure the customer realizes I've saved them money by repairing a slow leak because refrigerant prices will always go higher," he said. "They also appreciate the environmental aspect that their system is no longer releasing refrigerants into the atmosphere."
When a unit is a pound or more low on refrigerant over the course of a year, he uses an electronic leak detector. He noted leaks are usually in an inaccessible area such as interior portions of coils.
After ensuring the system is free of moisture and contaminants, Keivel injects a 3-ounce can of the product, which he keeps in stock on his truck and is designed for systems from 1 Â½ to 5-tons. (For larger systems, Cliplight has Seal 3-Phase, which Keivel also has for possible use with commercial customers having a leaking chiller, condenser or other large components).
Keivel hooks up the vacuum-packed can with the charging hoses that come with the product to the low-pressure side of the system. After purging the air out the hose, the can is pierced to allow refrigerant to enter the can and mix with the sealant. Turning on the unit draws the sealant into the system where it moves freely with refrigerant and without damage to components, according to Keivel.
On only one occasion so far has the hole been too large and therefore unable to be sealed with this method, he said. (Cliplight's specifications designate that only holes of 300 microns and smaller can be effectively sealed with the SuperSeal product 99 percent of the time. The company also recommends attempting to find the leak and fixing it conventionally before using the sealant as a last resort for inaccessible leaks or hard-to-find leaks.)
So far, Keivel has only used electronic sniffers to find leaks, but said he is planning to use the sealant in conjunction with fluorescent dye and UV leak detection systems, especially with today's newer systems using R-410A.
THE MARKETINGLosing impatient customers was the concern of Jim Gates, president of State Automatic Heating & Cooling in Batavia, Ill. So he established a company-wide policy for central air conditioning leak detection and repair.
Typically, a leaking condenser or evaporator coil results in two or more trips to the site involving hours of leak detection, component repair or replacement, and refrigerant recharging. State still offers that service, but it also offers the option of sealing the system with SuperSeal, usually at about 50 percent of the cost of the other more conventional approach, said Gates.
"Sealing the system saves customers money, but more importantly the service crew is tied up only an hour or two instead of a day or more, which is critical during the start up season."
The new leak detection/repair policy requires all service techs to first search for field installation-related leaks with bubble soap and electronic leak detectors around brazes and joints at visible, accessible connections with hopes that a leak can be located and repaired quickly. If the leak isn't found, the service technician can then offer the homeowner two options:
Gates said that in most cases the customers choose the sealant route, although he tells them there are no guarantees with that approach. He does maintain records showing that of the 34 applications of the sealant since 2004, all but one has remained sealed. (He said the unsuccessful one was because of holes too large for sealing caused by damage in an underground line-set put in by another contractor.)
"The sealant option sells itself by product brochures (carried on all techs' trucks) combined with explanations of the great record we've had with 33 previous applications. Plus, if their systems develop another leak, the sealant will probably seal it as it occurs because it stays in the system and continues working."
DISTRIBUTOR PERSPECTIVELike most distributors, cfm Distributors of Kansas City, Mo., find some contractors reluctant to try new things. So many new products are first tried and tested in one or more of the company's five buildings before they are promoted to the contractor customer.
For example, at the Wichita, Kan., branch, a unit from a ductless mini-split air conditioning line the company carries operates for showroom cooling, service techs' malfunctioning electronics are tested at the counter with a multimeter the distributor sells, and rooftop air conditioners that were once leaking R-22 have been repaired using the SuperSeal product stocked by the supply house.
Such an approach pays off, according to Rick Swenson, manager of the Wichita branch.
For example, he said, "In the case of refrigerant sealants, many service techs are skeptical of putting in anything but oil and refrigerant. But when you show them solid evidence that a sealant stopped a refrigerant leak on your equipment without damaging components, they are more apt to try it."
Publication date: 10/02/2006