The hot air is pushed toward the ceiling, walls, or other spots where the sprinkler heads are located. When the air around them reaches a certain temperature – typically 135° F, 155° F, or 250° F (57° C, 68° C, or 121° C) – the liquid inside the bulb expands until the pressure causes the glass to break.
The liquid in the sprinkler head comes in a variety of colors, which indicates the temperature required to activate the head: Orange – 135° F. Red – 155° F. Yellow – 174° F.
At the freezing point of 32 degrees, Fahrenheit water left in your sprinkler system can expand and burst the pipes.
It takes a sustained hard freeze of around 28 degrees to potentially cause sprinkler damage.
Sprinklers must detect a high enough temperature to activate—typically, temperatures of 135° F, 155° F, or 250° F (57° C, 68° C, or 121° C).
Avoid watering grass on a hot afternoon when it's 95 degrees or higher. The best time to water grass is at dawn or in the early evening. Water deeply three times a week instead of a little water daily. Test whether your sprinkler system is watering your lawn evenly.
A common rule that is followed for obstructions within 18 inches of the sprinkler deflector is the “three times rule”. This requires sprinklers to be positioned away from obstructions a minimum or three times the maximum dimension of the obstruction.
Nothing should be in that area between the bottom of the sprinkler heads and the imaginary horizontal plane parallel to the ceiling that is 18 inches below. This is done to allow an even and unobstructed spray pattern from the sprinklers when triggered to extinguish the fire.
When the temperature drops below freezing, water left inside fire sprinkler and irrigations system pipes also start to freeze. As water turns to ice, it expands, putting pressure on the sprinkler pipes and irrigation lines, which can eventually lead to cracks, bursts and other damage.
Don't water everyday.
The more shallow your grass roots are, the less hearty it will be in hot weather. Instead water about two times per week for longer periods of time. The local lawn companies I have spoke with around my area (North Central Texas) recommend about 20-30 minutes per watering cycle twice a week.
While you may be eager to get your lawn back to its pristine green state, it is important to remember that temperatures at and below 32 degrees Fahrenheit put your sprinkler system at risk of freezing.
The colder weather does not evaporate moisture from the lawn as quickly as it does in the warmer weather. Most lawn experts recommend watering your grass until the soil or ground temperature reaches the 40-degree Fahrenheit mark. It is true, less water is required and needed when the temperature drops.
Normally, this is not a problem because the main shut-off, zone valves and heads are below ground and stay relatively insulated. However, if the temperatures do dip down into the 20's, or temperatures remain below 32 degrees for an extended period of time, your irrigation system can be damaged.
A sprinkler system will freeze if the temperature falls below 32° F (0° Celsius). Now, most indoor sprinkler systems are inside of buildings or homes where the temperature won't ever drop into the danger zone.
Should you run your sprinklers before a freeze? If there is enough time for the water to absorb into the ground, then yes, you should. The water will help insulate the roots. However, if the water will freeze on the grass before it absorbs into the ground, it could do significant damage to the grass.
Notably, fire sprinkler systems can fail at any time. The main causes of failure are corrosion, freezing, improper installation, and inadequate parts and materials. Shut-offs and plumbing can be outside or non-insulated, making them more prone to freezing. These failures cause major damage to C&I properties.
Fire sprinkler heads, if tampered with, struck by tools or equipment, or damaged, can also go off without warning. Make sure your employees know never to hang seasonal decorations from sprinkler heads, which is a very common cause of accidental fire sprinkler activation discharge.
The average system uses approximately 15-16 gallons per minute, per station.
The most common reason that sprinklers failed to operate was the system being shut off at some point before the fire. One sprinkler is usually enough to control a fire. In 77 percent of the structure fires where sprinklers operated, only one operated. In 97 percent, five or fewer operated.
In short, yes. Residential sprinkler systems follow simple rules; they go off when the temperature reaches over 56°C. So if you have poor ventilation, or the sun is beaming directly into your windows, there is a small chance this could trick the system and accidentally go off. However, this possibility is minute.
It takes as little as 3 PSI of lateral force for the item hanging on the head to break the glass bulb at the center of the sprinkler head. This immediately causes water to start flowing. Before you are able to shut off your system, 100 to 1000 gallons could be discharged from one sprinkler head.
You can operate 2 or 3 sprinklers at one time with 'Y's and extra hoses, depending on your water pressure. To run more than one sprinkler off the same faucet, attach a 'Y' to your faucet and run a hose to each sprinkler.
During really hot weather, water your vegetables at least two to three times a week. Watering the garden deeply is critical. The water must go down, down, down to encourage deep roots and get away from the hot soil surface.