St. Pierre Church on Ice!

The new St. Pierre Fellowship Church in St. Pierre, MB required additional space for their increasing membership. The new sanctuary is designed to accomodate up to 400 people, and has a cooling requirement of up to 25 tons (300 mbh, or 88 kW) when it is fully occupied on Sunday mornings.

During the week, the building only has a few people in it and there is a peak cooling load of only about 3-4 tons (36-48 mbh, or about 10-12 kW). With a well-constructed building envelope, the peak heat loss is minimal at about 140 mbh (41 kW).

The building committee wanted to install a ground-source heating and cooling system to minimize the energy costs for the church, but was finding that the cost to install a 25 ton system was beyond their budget.  They were reluctantly leaning towards installing five 5-ton rooftop units.

Southern Comfort, the mechanical contractor, worked closely with Ice Kube Systems and MCW Consulting to design a system to provide 25 tons of cooling for Sunday morning services by integrating a fluid-to-fluid heat pump system with a CalMac thermal ice storage system.

Two Ice Kube 6-ton low temperature fluid-to-fluid heat pumps extract heat from the ice storage tank during the week, while the heat taken from the ice produces warm water for a radiant floor heating system. When the water in the ice storage tank is frozen, the heat pumps continue heating the building by drawing energy from a vertical earth loop.

As the church sanctuary warms up on Sunday morning, the heat pumps produce chilled fluid to circulate through fan coil units to air condition the building. As the cooling load increases, the chilled fluid is diverted through the frozen tank to provide additional cooling capacity.

The unique design reduced the size of the heat pumps and circulating pumps for the building. It also reduced the size and cost of the earth loop and the electrical service to the building.

From a global perspective, the peak electrical load that Manitoba Hydro must produce to service this system was reduced by over 50%. This reduces the size of the distribution system to the building and delays the building of a new generating station. 

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