High-tech liquid pool 'covers' coming to Ann Arbor school pools

By Danielle Arndt K-12 education reporter

Posted on Fri, Aug 17, 2012 : 5:55 a.m.

Ann Arbor Skyline's swim team watches the diving competition during a meet last season at Ann Arbor Huron High School. Huron will have liquid pool cover technology installed before the summer is over. Skyline's pool could not house the equipment.

AnnArbor.com file photo

Ann Arbor’s middle and high school pools no longer will require a plastic cover to protect against heat loss and water evaporation.

A new system that pumps a vegetable oil-like substance into the pools will conserve water, maintain temperatures and reduce energy costs by creating a thin coating over the water, according to district officials.

Randy Trent, executive director of physical properties for Ann Arbor Public Schools, said it costs substantial money to constantly heat and fill the pools.

The district will spend a portion of $7.81 million planned for energy-saving projects to install the liquid pool cover technology at Huron High School and all five middle schools, excluding Ann Arbor Open, prior to the end of summer.

Mack Indoor Pool, which is attached to Ann Arbor Open School, is operated and maintained by the city of Ann Arbor. Pioneer and Skyline high schools did not have enough room for the pumping equipment that's necessary to make the automated liquid pool cover system work, Trent said.

The $7.81 million was earmarked in April to complete the fifth phase of an energy savings capital improvement program that Ann Arbor has been involved in for a number of years. Phase 5 will include upgrading mechanical and air conditioning units, boilers, hot water pumps, and replacing a variety of lights throughout the district. Every building within AAPS will see some improvements from the plan, Trent said.

Johnson Controls Inc. was awarded the contract for the work. Johnson Controls guaranteed the district an annual energy savings of $699,359. Phase 5 also is expected to generate a one-time savings of up to $400,000.

From Ann Arbor Public Schools

The liquid pool cover is an isopropyl alcohol product that is filtered in and out of the pool. Trent said the product has properties similar to vegetable oil in that it will not mix with water and clings to the surface of the pool.

The product is biodegradable and its release into the pool is controlled using a programmable, peristaltic pump that connects to the main return line of the swimming pool, according to its website.

Trent said the technology Ann Arbor will install can be set to filter most of the product dose out into the pool when the pool is not in use.

However, according to information provided by the district, the pool cover product does not need to be removed from the pool for swimming. The product is said to “break apart” whenever the water is “sufficiently disturbed,” but re-forms when the water is calm again. But Trent said AAPS will run the covers from midnight to 5 a.m.

According to the product’s website, evaporation accounts for between 70 percent and 90 percent of pool water heat loss. Liquid pool covers can save up to 40 percent of normal heating costs, the website says.

Watch the video below to learn more about liquid pool covers.