It is common knowledge that air conditioning systems control indoor temperatures, but a less-known fact is that they also remove indoor humidity. In the case of ducted configurations with ventilation included, the system is also responsible for providing a constant supply of fresh outdoor air, preventing the accumulation of air pollutants indoors.
Air conditioning systems have a large number of moving parts, and thus they are susceptible to mechanical wear. To keep cooling systems in optimal operating conditions, regular maintenance is necessary. This article will describe some common issues that affect poorly-serviced air conditioning systems, and you should get an inspection if they are present in your building.
Improve the performance of your air conditioning system.
1) Excessive Noise and Vibration
A certain level of noise and vibration is normal when dealing with mechanical equipment, but excessive levels are a clear warning sign that equipment must be inspected and serviced. Higher levels of noise and vibration can have many possible causes, ranging from misaligned shafts in mechanical equipment to damaged mounting pads. In applications that use electrical motors, unusually high vibration levels can also be a consequence of voltage imbalance or damaged motor windings.
Vibration can accelerate mechanical wear in moving equipment, and it can also propagate through structural elements and other building components. Keep in mind that sensitive devices like HID lamps are vulnerable to propagated vibration, which shortens their service life. Suspended ceiling grids can become especially noisy when exposed to vibration, given the large number of contact points around the ceiling tiles and lighting fixtures.
2) Air Ducts Releasing Particles or Unpleasant Odors
The interior of air ducts can accumulate dust and other solid pollutants over time, and air diffusers may start releasing particles indoors. An inspection is recommended if you notice this, but do not assume the entire air duct is polluted right away - maybe you only have a few clogged diffusers.
The US Environmental Protection Agency only recommends cleaning air ducts when considered necessary, not as part of routine maintenance. Air duct cleaning can be a disruptive activity for indoor areas, and the ducts themselves may become loose if they are manipulated and adjusted frequently. Special care must be taken when cleaning the surfaces of fan coils and evaporators, since the thin metallic fins can be bent with little force.
Immediate action is required if the smell of mold can be perceived: its spores can cause allergic reactions and they are highly irritating, especially for asthma patients. Mold is notoriously difficult to eliminate, since its spores are physically resilient and they spread everywhere. However, mold thrives on moisture, and the presence of mold means you have humidity problems. The following are important considerations when cleaning mold:
- Severe mold infestations can only be removed by a qualified remediation company.
- Smooth surfaces can be cleaned, but porous surfaces may be damaged beyond repair. For example, it may be possible to remove mold from metallic surfaces in ventilation, but moldy insulation must be replaced.
Mold spores cause allergic reactions and irritation even when dead. This means mold patches must be cleaned even if you have already addressed the moisture problem. If many occupants in your building have experienced respiratory health issues lately, perhaps there is a mold patch hidden somewhere in your air ducts.
3) Unexpected Increases in Electricity Bills
If your electricity consumption has increased, and you have not expanded your property or added new equipment, it is very likely that your HVAC efficiency has been decreasing. However, keep the following recommendations in mind when comparing power bills:
- An increase in power bills is normal between winter and summer. Consider that gas-fired heating equipment stops being used, and electrically-power cooling equipment becomes the main load in the building. Ideally, you should compare power bills from the same month in two consecutive years.
- If you notice that the power bill increased, make sure that the increase is not caused by higher electricity tariffs - do not compare the dollar amount, but rather the kilowatt-hour amount. If kilowatt-hour consumption has increased between two summers and there is no clear cause, your cooling systems probably need maintenance.
HVAC inspections are an excellent opportunity for a complete energy audit, where you can identify promising energy efficiency measures for other building systems as well. Note than energy audits and retro-commissioning are mandatory at 10-year intervals for all NYC buildings covered by Local Law 87 of 2009.