Abstract: A micro-combined heat and power (mCHP) system includes a liquid cooled variable speed genset that is located to the exterior of a building and that is provides heat and power to the interior of the building. The genset may be configured to output an electrical supply of between approximately between 500W and 40 kW. A coolant loop may extend from the exterior genset to the interior of a building and is configured to reclaim heat from one or more sources of waste heat at the engine, generator, oil and/or exhaust. The reclaimed heat is then transferred, directly or indirectly, to the air flow path of a building heating system. In one embodiment, the reclaimed heat is transferred to a liquid circuit via a liquid-to-liquid heat exchanger and thence to the cold air intake of a forced air furnace via a liquid-to-air heat exchanger. A thermostat may control heat transfer from the mCHP to the heating system.