ENGINEERING specialist *Paul Appler explains how service technicians, plant supervisors and building managers can often save both money and help the environment when servicing their refrigeration and heating, ventilation and air-conditioning (HVAC) systems.
Don’t blow the budget fixing faulty HVAC/R units this summer — there is another way It’s mind-boggling how many pieces of HVAC/R equipment there are in commercial buildings, factories and industrial processing plants.
Most people relate to rooftop air conditioning equipment, but there could be dozens and maybe hundreds of pieces of equipment in a building or on a site, ranging from walk-in coolers, refrigerators, ice makers, chillers, food service equipment and process cooling technology.
Unfortunately, all of that equipment has a great potential to leak refrigerants someday — and what more irritating and disruptive time than when the equipment is under heavy load during a long, hot Australian summer?
Fixing or replacing a suddenly leaking $30,000 rooftop HVAC/R unit on a factory, process plant, retail store, hospital, office building or some other public or private building can shock even the most bountiful maintenance budget of a facility.
Maintenance managers who understand the options available to restore failing equipment can not only save money, but also help save the environment from leaking refrigerants and therefore contribute to running “greener” facilities. This is because refrigerants escaping into the atmosphere from leaking (HVAC/R) equipment are major contributors to ozone depletion and related environmental concerns.
Most HVAC/R units eventually leak because of mechanical wear of components, vibrations, and various forms of corrosion.
All units have the potential to leak to some extent over their lifespan, because it is impossible to manufacture a 100% leak proof system.
The time taken for the system to completely lose its refrigerant charge can vary from one to 30 years.
Then comes the decision a facility manager must make with the service contractor—repair, component replacement, or total unit replacement. On a $30,000 rooftop unit:
1) a repair might range from $300 to $1,000;
2) a component replacement such as a coil might cost $750 to $2,000; and
3) of course a total unit replacement can be $30,000 or more, not to mention added labor and installation costs.
There is, however, a fourth option that might be one of the best-kept secrets in maintenance today—HVAC/R system sealants that stop leaks permanently and seal future leaks for several years.
These are typically employed after a service technician tries to repair a refrigerant leak conventionally—finding the leak and brazing it.
Unfortunately, not all leaks can be located or accessible to repair even if they are found.
Continually putting in refrigerant into a leaky system, even though they know it will leak out over the course of the next six to 12 months and their services will be needed again, should not be an option. This method is called, “topping up” a leaking system.
It’s not only detrimental to the environment and equipment, but illegal in some countries. (Contractors and their unknowing commercial building management clients in Australia can receive hefty fines from the Environmental Protection Agency (EPA) and the Australian Refrigeration Council (ARC) if discovered).
In such situations, sealants should be considered. HVAC/R sealants have only appeared on the market since early 2000, but they are already one reason why fewer refrigerants are being accidentally released into the environment. Sealants are a blend of organosilanes that react to moisture.
When injected into an HVAC/R system, they move freely through the system with the refrigerant and oil. In a leaking system, the refrigerant and sealant leaks out of an exit hole.
The sealant reacts to moisture in the atmosphere and crystallizes around the hole, forming a bond, and prevents any more refrigerant escaping into the environment. This is very similar to the human body and how blood clots to stop the bleeding of a wound.
Super Seal™ is a patented formula of such organosilanes that remain in a liquid state within the refrigerant once injected into the refrigeration system.
When the refrigerant leaks out of a hole of 300 microns or smaller, however, the reaction with atmospheric moisture causes Super Seal™ to crystallise into a hardened bond around the exit point, thus stopping the leak.
One of the great strengths of the system is that users don’t have to dig through concrete and steel to get to pipes that may be buried within structures, costing money to access.
An extra advantage of this technology is the preventative maintenance aspect. The residual sealant remains active in the system and immediately stops future leaks as they occur.
The facility manager nor the contractor will really know how many times other leaks occurred and were repaired. Bonded leaks are permanent and residual sealant can last up to five to 10 years, sealing future leaks, thus giving a new lease on life to an aging system.
In addition to delaying replacement of our (say) $30,000 rooftop equipment by 10 years, the environmental benefits include fewer refrigerants being leaked into the atmosphere and less equipment being retired to landfills.
Additionally, an HVAC/R system runs more efficiently under a full refrigerant charge thus using less energy.
The technology involved has now been proven in countless applications globally, including Australia.
One of the first uses of sealants helped prevent a Ford plant in Windsor, Canada, from shutting its engine production line in 2001.
Maintenance engineers had the choice of replacing a leaking chiller component vital to the production process, which could have taken up to a week of idle time, or sealing the system. They sealed the system in just a few hours with two inexpensive cans of sealant.
The chiller is still running flawlessly today and hasn’t leaked since.
*Paul Appler is Technical Director of Research & Development at Cliplight Mfg Co, www.cliplight.com, whose products are distributed throughout Australia and New Zealand by GO Distribution.