Fan Coil System Restoration Overview and System Factors

The single, most difficult issue in a fan coil restoration project is the logistics. Doing the actual work has to be precise and calculated.  Accessibility, funding, start dates, site co-ordination, storage etc.  are conditions that need to be predetermined and therefore require good planning.

In general, the by-laws of most high-rise condominiums determine that the fan coil is not a common element, but the responsibility of the owners.  For apartment buildings the building owners are responsible. The tricky part of this equation is trying not to inconvenience  too much during the construction period.

The following is an overview about the history of fan coils and eight system factors.

Fan Coil Systems

The original fan coil unit controls were very basic. A unit mounted thermostat (line voltage) with a three speed fan switch. It would cycle the fan on and off, and blow air through a water coil (like a radiator in a car), until the desired temperature was reached. There were no other internal controls. Hence, the name of the unit, fan and coil, shortened to “fan coil”.

The vertical fan coil system began their popularity in the 1970s. Manufacturers (mostly American) developed the unit as an economical approach to supply cooling and filtration, in addition to heating, against the popular baseboard radiation systems of that era.

Most of those original fan coil units did not address the issues current manufacturers and service companies, are addressing at this time, regarding indoor air quality, mould, and energy efficiency. Nor had any thought been given to the lifespan of the system, and any replacement procedures.

A number of problems have been identified with the original fan coil systems, predating the year 2000.

Original fan coil systems actually used steel riser systems. The conversion to copper risers didn’t begin until the late 1970s to about 1980. This presents a significant issue in the performance of buildings that predate 1980. Depending on the water treatment in those systems:

• The steel risers may be pitted and/or corroded.
• The system water may be rusty, or discolored (should be clear as drinking water). The system may be clogged with sludge and debris from deterioration.
• The original insulation on the risers, at that time, was fiberglass, and later replaced with a closed cell foam.
• The original fire stopping was a fiberglass batt stuffed into the floor sleeves (the point where a set of risers passes through the floor slab), and then sealed with a mortar topping.

Fan Coil Restoration System Factors

The following are eight systems factors which include the age, maintenance, fan coil deterioration, risers, riser insulation, water coils,  drain pans and cabinet.

Age   

Buildings that are over 35 years of age should be considering a system overhaul by the age of 40 years.

Maintenance        

Depending on the caliber of regular (twice a year) maintenance that was done during the initial 35 years of the systems life, the performance of the fan coil may have deteriorated.

Fan Coil Deterioration  

The internal inspection of the fan coil will show signs of deterioration, like rusty drain pans, plugged drain hoses, moldy insulation, dirty water coils, and seized control valves.

Risers

Although it is impossible to see the internal riser condition with cutting a sample, we can speculate that after 35 to 40 years of water velocity scouring the steel or copper, that there has been a reduction in the tubing wall thickness, at a minimum.

It is possible, though, to see riser issues, within the fan coil unit, by the location of the supply and return tees. If they are too far in one direction or the other, there is definitely some type of issue happening with the riser.

The risers, the insulation, and the fire stopping, should all be addressed in a proper system renovation.

Riser Insulation

Some of the original insulation used on the riser piping was a closed foam insulation called Armaflex, or Therma-cel. This product, over time, becomes brittle, loses its’ flexibility, and ultimately, loses its’ efficiency.

Water Coils

If the water coils in the fan coils have not been cleaned on a regular basis, then the fins will plug up with dust and dirt. This will not allow air to travel through the coil, causing the unit to run longer or work harder to maintain the required temperature.

Drain Pans

If the waterproof mastic coating that protects the drain pan has not been applied on a regular basis, the sheet metal that the drain pan is constructed of will deteriorate (rust), eventually perforate, and ultimately lose all integrity.

Cabinet

The insides of the cabinet are covered with a ½” thick fiberglass insulation that has a special black coating on it. That coating makes it resistant to mould and fungi growth. If that barrier has been damaged or removed, then the unit will be susceptible to mould growth.

The best way to determine your building’s current condition, is to have one of our experienced technicians do a site visit, and give you a complete analysis of your fan coil system, and the options available.

The single, most difficult issue in a fan coil restoration project is the logistics. Doing the actual work has to be precise and calculated.  Accessibility, funding, start dates, site coordination, storage etc.  are conditions that need to be predetermined and therefore require good planning.

Rely on the experienced team at Climanetics Inc. to work your management team and board of directors for a smooth transition. The first step is to contact us for a price quotation.