CHURCH MUTUAL AND HARTFORD STEAM BOILER SENSOR TECHNOLOGY PROGRAM: IDENTIFYING FROZEN PIPE EXPOSURES Where to Install Pipe Temperature Sensors for Freeze Protection 1
WHICH PIPES SHOULD I MONITOR FOR FREEZE PROTECTION IN MY CHURCH? Any pipe containing water that could be exposed to temperatures below 32 F can freeze, rupture and cause extensive water damage to property. It is important to assess the existing church piping systems to determine the best pipes to monitor. Typical water containing pipes in churches include cold water pipes, hot water pipes, hydronic heating system pipes, wet fire sprinkler system pipes, dry fire sprinkler pipes (containing undrained condensate drip legs), and steam boiler and condensate pipes. When deciding which pipes to monitor with sensors, you should consider: Is the pipe vulnerable to freezing due to its location in the building? Has the pipe had any history of freezing? If the pipe was to burst and it released water, what would be damaged in the area? What is the size of the water pipe? What is the pressure in the water pipe? Is the pipe located on an upper floor with the potential to do multi-floor damage? What items would be irreplaceable if damaged? How would the burst pipe and water damage affect normal business operations? How long would it take to recover from the burst pipe event and return to normal? What would the water damage cost? Look for pipes that are most likely to be exposed to freezing temperatures and could do extensive property damage during a pipe rupture and water release. Review the following pages to help you consider where your most likely pipe-freeze condition could occur in your church. Use the pipe temperature sensors on the pipes that need the most protection from damage and you ll prevent catastrophic property losses for your church. 2
WATER PIPES IN MECHANICAL ROOMS This cold water supply line is a good candidate for freeze protection monitoring. What would happen if someone left the basement window open during a freezing-cold night? Pipe freezing occurs very quickly when the cold air is wind-driven across the pipes. 3
HYDRONIC HEATING SYSTEM PIPES LOCATED ON OUTSIDE WALLS Hydronic heat unit ventilators are located along the cold outside walls of the buildings. If the heating system fails, the supply and return pipes in this unit can easily freeze. Many of these unit ventilators have outside air dampers for ventilating the room. If the outside air dampers jam in the open position, cold air can blow into the unit and freeze the heating pipes. 4
PIPES LOCATED IN BOILER ROOMS Pipes located in boiler rooms can freeze if the boiler shuts down unexpectedly. Boiler rooms have outside air requirements for the boiler burner combustion air. You can see the outside air duct and open window in the upper right of the photo. When the boiler operates, the air that goes up the chimney is replaced by fresh air drawn in through the combustion air ducts. Any pipes in the path of this airflow could freeze. Window and duct below 5
WET OR DRY FIRE SPRINKLER RISER PIPES Fire sprinkler riser pipes are usually near outside walls and may have holes drilled through the walls for pipe penetrations. The system drainpipe may pass through a hole that is oversized and not air-sealed properly. Due to the size of the pipe and the water pressure, a burst fire riser pipe can completely flood a building in very little time. The dry-sprinkler system shown in the photo has water pressure in the pipe from the floor-line up to the large red bolted casting above. Water filled from floor to here 6
PIPES NEAR OUTSIDE WALL VENTS The copper pipe on the left connects to a hose faucet on the outside wall of the building. This pipe is very close to the outside combustion air intake for the gas furnaces in the mechanical room. When the furnaces run, a vacuum is created in the room that pulls in the outside air through the louver in the wall. If this pipe bursts, water will be released at 60 lbs/in². Potential frozen pipes Outside air vent 7
HYDRONIC HEATING SYSTEM PIPES AND COILS IN AIR HANDLERS Non-flowing water in hydronic heating system pipes within horizontal air handlers can freeze when cold outside ventilation air blows across the heating coil. The copper heating coils use much thinner copper walls on the pipes compared to the supply and return piping. A frozen and burst coil can cause extensive water damage to the air handler and building contents. 8
FIRE SPRINKLER PIPES IN UNHEATED ATTIC SPACES Ceiling fire sprinkler pipes that are routed through unheated attic space are vulnerable to periodic freezing temperature conditions. Even though the pipes may be insulated, a long period of extreme cold can allow the water in the pipes to freeze and cause extensive damage to property. Insulation alone does not add any heat to the pipes. It only slows down the transfer of existing heat. In some cases, electric heat-trace cables are needed to prevent pipe freezing. 9
HOT AND COLD WATER PIPES ENCLOSED IN CABINETS ON OUTSIDE WALLS The hot and cold water pipes that supply sinks in enclosed cabinets that are against outside walls are at risk of freezing. The closed cabinet doors prevent the room heat from easily reaching the pipe locations. The cold outside wall locations and restriction of the room heat into the cabinet can cause pipe-freeze conditions. These locations could be monitored for low temperature. 10
HOT AND COLD WATER PIPES ROUTED THROUGH UNHEATED CEILING CAVITIES Unheated areas above dropped ceilings can become very cold depending on the amount of roof and pipe insulation that was originally installed. Insulation is sometimes removed and not replaced after repairs. This can leave the pipes more exposed to a freeze condition. Monitoring the ambient temperature of the ceiling cavity will give warning to possible pipe-freeze temperatures. 11
WATER HEATERS AND PIPING IN ATTICS WITH NO ROOF INSULATION Piping and water tanks in attics with no roof insulation can freeze and burst. If the electric heater element for this tank fails during an extended cold period, the pipes and tank will be subject to rapid freezing. With the room thermostats turned down for energy conservation, very little heat will exist in this space. A pipe burst due to freezing conditions will cause extensive damage to the ceilings, walls, flooring and building contents. 12
PIPES ROUTED DIRECTLY IN FRONT OF OUTSIDE AIR LOUVERS Pipes that are directly in front of through-the-wall, outside air louvers can quickly freeze due to continuous airflow through the louvers into the room. High winds or a negative building pressure created by other exhaust fans or fuel-fired appliances in the building can cause a steady inflow of outside air across the pipes. Pipes in front of outside air louver 13
WATER PIPES IN ROOMS HEATED WITH A DEDICATED HEAT SOURCE Pipes are sometimes located in rooms with outside walls and a dedicated heat source such as this electric room heater. If this unit heater fails to operate, the pipes in this room may freeze and burst even though the main building heating system is working properly. The ambient air temperature or a critical water pipe temperature should be monitored in these rooms. 14
PIPES THAT EXIT THE BUILDING OR ARE ATTACHED TO EXTERIOR WALLS Hose faucets and lawn irrigation system piping need to exit the building at some location. These pipes need to be winterized each year to prevent equipment damage due to freezing. Some hose faucets are frost-proof and close the water supply within the building by utilizing a very long valve stem and setback faucet washer and seat. Others need to be valved in the closed position and drained each winter. Failure to winterize these systems can result in a frozen pipe and an unexpected water release. 15
HYDRONIC PIPES AND CONVECTORS USED FOR PERIMETER HEATING Hydronic pipes and convectors are typically run under rows of windows. Leaky or opened windows and the cold outside walls can expose the heating pipes and convectors to freezing conditions. Indiscriminate use of set-back thermostats or turning off (or too low) individual room temperature controls can contribute to excessively cold rooms and pipe-freeze conditions. If you have any questions about identifying frozen pipe exposures, please contact us at 877-610-4128. 16