Low Temperature Space Heating Systems Dr. Evgueniy Entchev CMX 2012 Learning Forum March 22, 2012

Drake Landing Solar Community  Largest Solar Community project in North America  Location Okotoks, Alberta - 20 km south of Calgary  Subdivision of 52 homes space and water heated by solar

End-user space heating utilization system The designed system must be able to :  Provide comfort while utilizing renewable source  Work with fluid incoming temperature from 65 o C – 35 o C  Provide heat recovery from the exhaust house air Return Plenum Supply Plenum Heating Coil HRV Blower HW out Tw1 Tw2 Ta1 Ta2 HW in Ta6 Ta7 Ta3 Ta4 Ta5 Fresh air To outside House exhaust air Preheated air temperature

Air Handler To achieve the required versatility - vary 3 parameters  Air flow  Water Flow  Water Temperature

Design of low temperature AH  Ability to vary the air flow as a function of the incoming fluid temperature  Use baffles to provide an ~ even air distribution over the coil  Use high efficient blower motors - ECM to save energy  Re- design the heating coil to get as max heat as possible at given air flow velocity

Design of low temperature AH  Use highly insulated stratified tank  Use high efficient DC water pumps  Vary the water flow as a function of the outdoor temperature to preserve the stratification in the tank

Design of low temperature AH  Use at least 3 control set points 35 o C, 50 o C, 65 o C  Use AI learning algorithms to optimize the system operation and comfort delivery  Utilize as many modulating devices

Thank You!