Turf Heating Systems Popular in Stadiums, not Private Residences
Turf heating systems are becoming a popular component in the construction of NFL and Major League Baseball stadiums, but the cost of these systems may be too high for many private consumers.
Stadiums such as Safeco Field in Seattle; FedEx Field, home of the NFL’s Washington Redskins; the Philadelphia Eagles’ new home, Lincoln Financial Field; and Gillette Stadium, home of the New England Patriots, all are using turf heating systems to ensure year-round ideal playing surfaces.
Many professional football and baseball teams are moving away from the use of AstroTurf, opting for natural grass or synthetic-grass surfaces that are safer for the players.
Despite predominately being used in Northern climates, turf heating systems are not used to melt snow. Instead, they are in place to facilitate grass growth throughout the year.
Workers install heating coils at Safeco Field in Seattle, where the turf heating system is used to “trick” the turf root structure into thinking it’s spring. This allows the grass to grow earlier, resulting in an extended growing season.
The Philadelphia Eagles are playing their home games on a field composed of Kentucky Bluegrass, which is a far cry from the cement-like turf that carpeted their old home, Veteran’s Stadium. In order to keep the bluegrass growing throughout the winter months, Lincoln Financial Field features a complex system of drainage and irrigation pipes and nearly 28 miles of plastic “heat-pipe.” A mixture of water and antifreeze is pumped via computer through the heat-pipe to keep the grass from going dormant.
Gillette Stadium in Foxboro, Mass. has a similar system in place to keep its turf healthy. The Patriots’ radiant heating/turf warming system, manufactured by Watts Radiant, uses 153,000 lineal feet of PEX tubing that feeds warmth to the soil. Mark Fries, sales and engineering manager at Watts Radiant, said the ideal conditions for turf growth at Gillette Stadium are temperatures of 60-65 degrees two inches below the root zone.
“There are sensors located throughout the field, and the system kicks in when temperatures dip below that range,” he said.
With the Watts Radiant system at Gillette Stadium, warm water mixed with glycol (an antifreeze-like substance) is pumped through hoses or tubing embedded several inches below the surface at the root zone. This warm environment helps to create an incredibly healthy root zone that leads to a much stronger turf.
Typically, the heating systems are activated Monday through Friday, and turned off a few days before game day. If it did snow, and the system was on, there is a chance that slush would form, which poses a danger to the field and potentially unsafe conditions for the players. The heating system being turned off a few days before a game also allows the turf to stabilize.
Watts Radiant specializes in radiant heat solutions for hydronic heating, electric radiant heat and snow melt technologies. Mechanical contracting firm E.M. Duggan Co. was responsible for the installation of Gillette Stadium’s heating system. Dick Lucy, E.M. Duggan special projects manager, said Gillette Stadium officials wanted to have the ability to change zone temperatures between the field’s hash marks, where the bulk of NFL action occurs.
“The grass gets beat up quite a bit during the game,” he said. “If you have it slightly warmer in this area and throw seed down, the grass tends to grow quicker.”
The price of the Gillette’s system also grew as a result. Lucy said their system cost about $1million, which is slightly above the $700,000-$800,000 average cost of a radiant heating system.
“They have more sensors in place than a standard installation,” Lucy said. “Basically, they wanted all of the bells and whistles available for their installation.”
At Seattle’s Safeco Field, the turf heating system is used in a slightly different manner. There, turf warming “tricks” the root structure into thinking that it’s spring. This gets the grass growing early for an extended growing season and it helps make up for the typically cloudy winters in the Northwest.
Lucy said radiant heating is popular in Europe, with most stadiums there using some form of heating at their stadiums. Fries added that some colleges and higher end golf courses — courses on the level of Augusta National — use forms of turf heating on their putting greens. In those cases, only a few putting greens on the course may have the heating system.
“The cost is so high for the systems that you get to the point that the costs outweigh the benefits,” Fries said. “This is why you don’t see too many individuals using these types of systems.”
Fries added that if someone who has a lot of money to spend, and is already paying to have their sidewalks heated, it is possible to have a turf heating system installed for their lawn.
“Possible, but not very likely, due to cost,” he laughed.
Gillette Stadium’s $1 million turf heating system uses 153,000 lineal feet, or 29 miles, of cross-linked polyethylene (PEX) pipes that feed warmth to the soil. This system has more sensors embedded into the field than most installations, including sensors located between the football field’s hash marks, where the bulk of the turf is damaged on game day.