Two years ago, WellSpan York Hospital, located in South-Central Pennsylvania, took the challenge of winter weather seriously enough to make an investment in a long-term solution.
As part of an ongoing $50 million modernization of its emergency department, the hospital replaced its helipad with a much larger landing deck.
“In trauma care, every second counts, and this helipad will enable us to provide care even sooner to our most seriously injured patients,” said Keith Noll, president of WellSpan York Hospital and senior vice president of WellSpan Health.
Three primary aeromedical systems carry on average 200 trauma patients to the hospital each year.
The expanded size of the new helipad allows for larger helicopters with more patient capacity to land directly at the hospital campus. Previously, the bigger aircraft had to land at an alternate helipad with an ambulance transporting patients more than half a mile to the emergency room.
The 580-bed facility is the only Level 1 Regional Resource Trauma Center in a three-county area with a population of more than 1 million people. Each year, the hospital’s trauma team handles more than 2,000 cases.
At 34 feet off the ground, the new 7,200 square feet – 3,000 square feet larger than the old one – is located near the campus entrance.
Many might believe that the reason to snowmelt these areas is to help medics transport the injured from the helicopter to the building. Though important, it’s not the main benefit.
The ice and snow that accumulates on these flat surfaces can pose great risk to everyone onboard the copters.
“There’s an art to maintaining just the right degree of heat within a concrete helicopter pad to ensure that it’s free of ice and snow – which can temporarily blind pilots at a time when they’re most vulnerable,” says Dave Yates, president of installing contractor F. W. Behler, Inc., based in York, Pennsylvania.
Helicopters produce powerful down-drafts whenever they land and take off. This downward thrust of air can lift and carry large portions of snow and ice off the pad. And since many hospital landing pads are located on a roof, the ice and snow gets thrown over the edge and creates hazards to those on the ground below.
To reduce these hazards, hospitals have to put up nets and barriers around the landing pad. But these barriers have the potential to create a “cup” effect, which captures air making landing even more complicated for the pilot.
A snowmelt system removes all these hazards making things safer for the pilot and for individuals walking nearby.
Maintaining York Hospital’s new helipad in the winter months is now simple, thanks to its automatic snowmelt system with three miles of snowmelt tubing installed beneath the surface to keep snow and ice from accumulating.
At the hospital, the project called for hydronic snowmelt not only under the helipad, but also for an access road that was built after the old helipad was demolished as well as the ambulance bay. In all, F.W. Behler installed 11 miles of 3/4-inch RadiantPEX+.
The job proved challenging to Yates and his crew since much of work was completed during the coldest of winter months.
“We’ll never forget some of those high-stress days when no matter what we did,” Yates remembers, “we couldn’t stay warm. Big jugs of coffee, thermal socks, long underwear, down jackets and multilayering were no match for those winter conditions.”
The pad’s design included several areas that would not have any tubing – as they were left open to the space below. This would ensure that in case of a crash landing or ruptured fuel tank, the fuel could drain away, avoiding an explosion.
“The helipad juts out from the side of the hospital,” Yates adds. “Its nearly 40-foot elevation means that it’s exposed to the wind and weather – which meant that snow and ice were sure to collect there if not for the warmth within the pad.
The biggest challenge was wrestling with 3/4-inch tubing in subzero weather.
Yates and his crew found the formula for getting the job done quickly was to wire the tubing to rebar. This required three people: one person to lay the tubing out, one to wire it to the rebar and one to stand on the cold-hardened tubing. They used a motorized wire tie tool to save time, which performed triple wrap twists and cutoffs in less than a second.
“One of the fun parts of installing the snowmelt was the audience we had,” Yates says. “The Watts tubing is bright orange. We were installing it right outside of the hospital with airborne snow swirling all around us. We could glance up at any time and see lots of people from different windows and floors watching what we were doing. Some had binoculars, others took pictures.”
Another design challenge was created by the manifolds for the helipad, which needed to be installed inside of the loop area. Ordinarily manifolds are off to the side in snow melting systems and termination points come straight out, Yates explained.
Because of the bump-out areas for sidewalks around the pad and certain areas not getting snowmelt for emergency fuel drainage, the tubing had to be installed – and terminated – in different angles. At times, Yates only had 5 inches of space to work with.
“Last winter, as we completed the final, remaining few miles of PEX installation, we got real satisfaction when we saw a helicopter coming in for a landing, knowing that the new helipad would provide a safe and swift landing, Yates says. “You can’t ask for much more than that.”
Modern hospitals are designed for both form and function with an added touch of architectural presence. Located beside, above or below the calming façade and designed to help ease patients’ nerves are functional structures – parking facilities or faster-access parking lots when space allows – designed to support a wide range of vehicles, ranging from fire trucks to compact cars.
Whether hi-rise, or on the ground, hospital parking areas must accommodate safe passage year-round. Surfaces typically include a thick concrete slab, stone pavers or asphalt. To be snowmelted, these materials impact how a mechanical snowmelt system is designed, how it performs and what controls are used.
In most cases, the first thing designers think of when designing a snowmelt system is how much snow needs to be managed. Although this is a key factor, it’s not the only consideration.
The chart on this page is a list of attributes and how they impact the overall design.
The better the intended use of an area is understood, the better the system can be designed.
It’s also important for customers and project owners to understand how snowmelt systems function. It may be 0 degrees one day and 30 degrees the next. Snowmelt systems, however, don’t respond instantly when turned on. There’s a period of time required to raise the mass from ambient temperature to melting conditions. The warmer the starting temperature, the quicker the system will reach its melting state.
In addition, once ice melting conditions have been reached, the time required to accomplish removal of snow and ice varies between events. How wet is the snowfall? How fast is it falling? Is it in the middle of the day or the middle of the night?
Selecting the proper control can eliminate the lag time associated with initial startup. Many controls today, such as the tekmar 670, have the ability to interface with an online weather app. This interface allows the system to start in advance of anticipated snowfall improving response time and reducing operational costs.
The other aspect of system performance to be aware of is the variances in snowfalls themselves. A system may be designed to handle the removal of 12 inches of snowfall – but what if a Nor’easter blows in and 48 inches are expected? Smart controls have the ability to adjust fluid temperatures and start times to accommodate those rare challenges.
However, what generally happens is the time to fully clear an area is extended. Instead of taking three hours to clear a heavier snowfall, it may take four or five hours, instead.
Where does it hurt?
When it comes to snowmelt system needs, hospitals require a wide range of application types, uses and response conditions. In addition to helipads, each of the following areas have unique needs and are generally designed as if they’re a standalone system – even though they may be part of the same hospital campus.
Entries: Hospitals never close. They’re open 24-7-365. Of course, with year-round vigilance required, weather can wreak havoc. In the winter months, ice and snow can accumulate quickly, sometimes more quickly than people can respond.
When snow and ice accumulate, accidents happen. Injured people, elderly, and even the very young are entering and leaving emergency rooms, visitor lobbies, and parking garages constantly. For hospitals to meet their responsibility to keep all areas free of hazardous conditions (and to avoid litigation) it’s important that their maintenance crews maintain safe conditions, campus-wide.
Parking garages: Every hospital has at least one parking structure.
Visitors come to hospitals to visit loved ones. Sometimes these visits are casual; other times, visits are urgent and rushed.
In these moments, when visitors are stressed, their mind isn’t as attentive to roadway or walkway conditions. Entrance and exit ramps to parking garages are critical areas. Vehicles change speed rapidly while trying to navigate a generally narrow entry. Any ice can turn a simple event into unwanted damage to a vehicle, or to the structure.
Designing an effective snowmelt system also takes into account more than just figuring out how much tubing is required under areas to be snowmelted. Just as important is the dedicated mechanical solution to deliver heat from the heat source to the snowmelt area. Without reliable mechanical systems, nothing will work properly.
Mechanical solutions take into account the heat source used, such as boilers, steam or waste heat. Each of these sources require different control elements, including temperature input, temperature output and fluid flow. From there, it’s a matter of delivering those Btu to the snowmelt area.
Do fluids from the heat source need to be tempered down? Are there multiple zones? Does the system need built-in redundancy? Do the controls need to interface with a building automation system?
Each of these conditions is critical to how the snowmelt system performs and what’s needed to design a proper solution.
With any snowmelt system it’s important to properly maintain system fluids. Most will require the use of an inhibited propylene glycol and water solution. The concentration of glycol can range from 30 to 70 percent, but most will use 50 percent as a target.
Getting the proper concentration is the easy part. In order to maintain proper operation and to preserve the longevity of the mechanical system as a whole, it’s recommended to test system distribution/heat transfer fluids once a year.
Technicians need to check glycol pH to ensure the glycol hasn’t broken down and is still providing adequate system protection. With a proper maintenance schedule, most snowmelt systems can last 30, 40 and even 50 years or longer.