Winnetka looking at geothermal heating, cooling for Village Hall

A geothermal heating and cooling system that could serve Winnetka’s Village Hall for more than 75 years once installed, at a cost lower than replacing the current HVAC system with a similar one, got a friendly thumbs-up Tuesday from Village Council members. 

Thanks to a federal investment tax credit provided through the Inflation Reduction Act, the cost of the system would be within the $2.7 million tentatively included for the project in the village’s five-year capital improvement plan, Public Works Director Tom Powers told trustees, “with the caveat that this is very early” planning. 

The system helps Winnetka meet sustainability goals, Powers said, and has a lifespan of more than 75 years. Its equipment will all be below grade, compared with large portions of equipment that would have to be built above ground if the existing HVAC is simply replaced with a similar system. 

Powers also said village staff, who are recommending the geothermal system, also believe shutting the entire hall down for several months while installing the system would also allow construction of a new ADA-compliant ramp, installation of a new fire alarm system and other needed improvements all at the same time, for an overall shorter period of work.  

When Trustee Kim Handler asked how hall staff could work through a building shutdown, he said much work could be done remotely, as it was during the COVID-19 pandemic. Other services for the public, such as processing permits or bill payments, could be done off-site in temporary trailers, or elsewhere. 

“We reached out to Metra to use some of their space,” Powers said, adding “We intend to reach out to the library … and there is some bank space that’s not currently utilized.” 

Geothermal heat pump systems make use of pipes buried deep underground to heat or cool buildings.

Cost estimates for the geothermal system would ordinarily run just under $2.2 million, compared to replacing the current so-called variable refrigerant flow, or VRF, system for just under $1.75 million; however, using the tax credit as well as a community energy bonus would drop the final geothermal system price to an estimated $1.57 million for Winnetka.

The ramp and fire alarm system replacements, along with other maintenance and preventative work should be just under $390,000, according to Powers’ report.

Powers said simply replacing the current system with a similar one had several drawbacks: the existing refrigerant is no longer legal to use unless it’s recycled material; the VRF equipment used is no longer supported by its new manufacturer, Panasonic; increasingly few technicians are familiar with the system; and an automated building system is obsolete.  

In his review of Village Hall’s HVAC history, Powers noted that several HVAC studies were done between 2001 and 2007. Between 2007 and 2009, major system upgrades were recommended and designed, but the council at the time rejected the proposal in 2010 because of its cost estimates. The project cost was cut down and rebid in 2011. 

Powers said that if Village Council ultimately approves the geothermal system, staff hope to put construction bids out in October, with construction set to start in January of 2027. Working in the winter could lower costs, because construction of the 12 500-foot deep bores that need to be dug for the system’s pipe can be more easily dug in cold weather. They would be constructed under the hall’s existing parking lot. 

Trustee Scott Myers asked how the noise of boring would affect nearby homes, since staff and consultants estimate the sound of that drilling to range between the sound of automobile traffic and a loud hairdryer. He was told that crews could build between one to two bores a day, with a potential duration of 12 days at most. 

While trustees gave their informal nod to the system, which was first discussed by the council on April 21, it still must be voted on as part of the village’s budget for the 2027 fiscal year. It will thus be part of this fall’s budget hearing, Communications Manager Josie Clark said Wednesday. 

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