Mechanical and Chiller Rooms
Mechanical and chiller rooms are essential for keeping buildings, plants, and campuses running smoothly. However, due to the various appliances found in these rooms, the risk of a potentially dangerous gas or material leak always exists.
To keep your mechanical or chiller room below workplace exposure limits, you should be meeting ASHRAE Standard 15 (in the U.S.) or CSA Standard B52 (in Canada). Other codes and standards may also apply, such as NFPA and IMC.
CSA-B52 and ASHRAE 15 require occupational hazard monitoring for refrigerant gases with gas detection systems that:
- Are located where a leak might concentrate
- Activate ventilation systems
- Can be heard and seen and are accessible
- Are periodically tested for accuracy
By properly installing and monitoring the appropriate sensors, you can ensure your mechanical and chiller rooms comply with safety codes.
Gases Found in Mechanical Rooms
Mechanical rooms are home to various devices, such as generators, boilers, and hot water tanks. These devices typically require combustible gases to run, and potentially hazardous gases are a common byproduct of burning combustible gases.
To ensure worker safety, you should monitor three main gases in all mechanical rooms:
- Carbon monoxide (CO)
- Nitrogen dioxide (NO2)
- Combustible gases
While most of these gases aren’t dangerous in small amounts, the nature of mechanical rooms is where the risk lies. Mechanical rooms are often subterranean and closer to the center of the building. This means that less airflow is present to naturally allow the gases to dissipate.
The safest way to prevent hazardous conditions is to reduce the risk of gas leaks. Through sensors, you can monitor pumps and pipes to detect leaks.
CO is commonly known, and even homes tend to have CO sensors in the basement. Found when combustion occurs, such as when heating water from boilers, CO’s danger comes from its odorless nature.
NO2 is another byproduct of fossil fuel combustion with generators that operate on diesel. Even low concentrations of NO2 can be smelled, and any sign of NO2 should be a cause for concern.
Combustible gases, such as propane and methane, pose a different risk. Each combustible gas has a concentration limit before the air becomes combustible. This is known as the lower explosive limit (LEL) and is represented as a percentage. LEL sensors have to be calibrated and set to detect specific kinds of combustible gases, as the lowest percentage for LEL varies for each. Knowing what equipment is in the mechanical room so that you can set the sensors to detect the correct gases is critical.
Gases Found in Chiller Rooms
The chiller room plays an important role in keeping buildings comfortable. The process is relatively simple: chemicals (sometimes gases) are used to remove heat, creating cooler water or air. This is done through chillers, condensers, turbo air conditioners, coolers, and other refrigeration devices.
As refrigerant technology has advanced over the past half-century, many chiller rooms have begun using chlorofluorocarbons (CFCs), hydrofluorocarbon (HFC) or hydrochlorofluorocarbon (HCFC) refrigerants.
|Common HFC and HCFC refrigerants include:|
While these gases aren’t always combustible, any leak can pose a serious threat to health. Beyond keeping your workers safe, monitoring gas leaks can:
- Keep chiller rooms running efficiently.
- Mitigate the potential cost of having to purchase new gases.
- Eliminate the need to use extra energy to cool the room.
- Avoid taxes and/or fines associated with leaking hazardous gases.
To detect HFC and HCFC leaks, chiller rooms should use sensors that monitor the specific gases being used in the appliances. Often times, a system may have sensors that detect multiple types of gases in a single room, due to the presence of chillers of varying ages.