Lia kindergarten is designed to be a plus energy building. The kindergarten was opened in January 2018, and the first year has been a tune-in phase for the technical systems. The plus energy concept consist of a well insulated building envelope, a highly efficient ventilation system, a lighting system with LED-fixtures and advanced control system and a low exergy thermal energy supply based on geothermal wells and a small inverter heat pump. The energy demand is balanced with a solar PV-system

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... n the roof to achieve the plus energy definition. A lithium-ion battery package of approximately 40 kWh has been installed for peak shaving and to utilize more of the solar energy produced on the building (reducing mismatch). A lot of research, calculations and simulations has been done in the design phase for the low exergy system. The floor concrete slab with embedded heating (pex pipes) is designed for very low temperature heating (22-28 ⁰C). The floor system is reversed in the summer providing high temperature cooling (18-19 ⁰C) which also charge the geothermal wells for the heating season. The calculations and simulations has also been used to make control strategies based on model predictive control (MPC) methodology, also taking in on-line weather forecast.