Not all penguins live in the Artic. Some prefer a bit of radiant heat, too.

Radiantly heated nests help an endangered penguin species breed at a Seattle zoo. Photo: Ric Brewer


Penguins? Radiant heat? Don’t they like things ice-cold?

Not the 10 pairs of male and female penguins you’ll see at the new 17,000-square-foot exhibit that just opened last month at the Woodland Park Zoo in Seattle.

These are Humboldt penguins to be precise, native to the relatively warm and certainly snow-free coastline of Peru. The penguin’s new home features shoreline cliffs, nesting burrows, a beach and two pools, one inside with 6,000 gallons of water and the main one outside with 50,000 gallons.

For heating and cooling the water as well as the birds’ nests - a vital part since the zoo wants the endangered species to multiply - the zoo turned to Gerard Maloney, owner of Earthheat, Duvall, Wash.

Maloney originally started his business as Cherry Valley Heating & Cooling, but started specializing in tapping into geothermal energy for much of his radiant heating work 10 years ago.

“After being introduced to geothermal technology and realizing that we could combine the comforts of radiant heating with the ultra-efficiency of a geothermal heat pump, I was sold,” he explains.

Humboldt penguins like their water between 50-60 degrees F. Considering Seattle’s climate, that means the water needs to be cooler in the summer and warmer in the winter. But geothermal makes that easier.

“The ground water alone is 52 degrees,” Maloney explains. The geothermal design for the pools operates on two stages with two compressors, one at a time, with a large tankless gas water heater as a third stage. Thanks to the temperate ground water, however, Maloney doesn’t think the system will ever need the third stage.

The water-to-water heat pump also will cool the pool water on a reverse cycle in the event the water temperature rises above  the desired temperature. This also operates in two stages.

The radiant zone snakes throughout the nests and the indoor pool room, remaining at an indoor air temperature of 65 degrees F. Photo: Gerard Maloney/Earthheat Inc.

Humboldts come ashore to nest and Gerard installed radiant tubing throughout the exhibits “cliffs” to keep things cozy. No doubt smelly, too, since the penguins prefer to bed down in guano, or poop by any other name. The monogamous duos can breed at any time of the year. Females typically lay one or two eggs, and it takes about 40 days for an egg to hatch.

The radiant zone snakes throughout the nests and the indoor pool room, remaining at an indoor air temperature of 65 degrees F.

Maloney’s ground loop source has eight 300-foot vertical bores using 1-inch u-bend coils spaced 15 feet apart with a propylene glycol solution.

Zoo officials believe the geothermal heating and cooling systems will save about 75 million Btus of energy annually.

“Ongoing operation and maintenance costs are amplified for nonprofit societies like the zoo,” says project engineer Rick Grove, P.E., CDi Engineers, Lynnwood, Wash. “Animal welfare comes first and the new geothermal system not only keeps the animals happy, it provides the lowest cost for heating and cooling the water versus all the systems available for the project.” (While we chose not to write about it, an innovative water filtration system for the exhibit will also save the zoo millions of gallons of water each year, too.)

Maloney’s radiant system also cools down the nest and ground areas for the penguins in the summer. “Radiant cooling is not done often since floors can condense and the moisture can be a slipping hazard,” Grove adds. “For this project, the condensation on the radiantly cooled floors is not an issue.” However, the floors are coated with a nonslip surface and receive regular wash downs for cleanliness.

Grove also mentioned another aspect of radiant heating and cooling we hadn’t thought much about. “Animals and visitors don’t like mechanical noise,” he says. “Other systems such as cooling towers and furnaces distract from the experience of the visitors and social interactions of the penguins.”

While an interesting project, Maloney is certainly doing a lot of business these days for those other kinds of “zoos” we call homes and offices. He installed 75 systems last year during the run-up in energy costs. When he first started specializing in geothermal, he was lucky to install 10 his first year out.

Maloney estimates the cost of running a geothermal system in a 3,000-square-foot home would be about $700 annually, compared with a natural gas system costing as much as $3,000 a year.

Obviously, there’s always a catch in saving energy. Maloney says his cost for residential or commercial geothermal systems are usually 50 percent higher than traditional systems running off fossil fuel. While energy prices aren’t as high as they were last year, he still thinks geothermal can pay for itself in less than six years for most homeowners.

Maloney says one big obstacle to building his business is that most people simply don’t even know what a geothermal system is. But he says the recent publicity in solar energy has helped him explain the benefits of geothermal to the public.

“The earth is the biggest solar collector we know,” he adds. “It’s a learning curve. More than anything, geothermal is about thinking out of the box.”