Air conditioning and heating maintenance is largely a matter of economics.

If you manage commercial buildings you know that there are two approaches to HVAC maintenance.  One option is what we refer to as “break and fix”.  The other approach is  “scheduled preventive maintenance” with repairs as needed.

While the scheduled approach is intuitively the way to go, there are other factors, not so readily apparent, that reinforce the validity and economy of this approach.

Deferred maintenance (break and fix) is costly in the following ways.

¨    Increased energy consumption

¨    Repairs are usually more costly because of a “cascading” effect in the system, where a small problem tends to cascade to other system components

¨    Occupant comfort and related productivity

¨    Poor reliability resulting in down time

¨    Premature equipment aging and the accelerated need to replace equipment

We can further elaborate on these factors as follows:

¨    Airborne dust and debris particles accumulate on heat transfer surfaces and air filters.  This reduces air flow and heat transfer capacity, meaning you get less of the desired cooling, heating or ventilation capacity per unit of energy.  This causes the machine to run longer at a lower efficiency rate.

¨    A loose or worn drive belt on the blower can cause the cooling coil to ice over and damage the compressor or over-heat the heat exchanger in winter.  This is an example of the “ounce of prevention” adage and the cascading failure principle.

¨    The effects of poor reliability are quite obvious if you are a building manager.

A maintenance program is relatively low in cost and usually involves four visits per year to perform inspections and maintenance.  A maintenance check list is developed and followed for each specific building and system.

There are examples of 30-year-old equipment which was properly maintained throughout its life and is still operating reliably.