Integration of Sustainable Systems in a Residential Home
Authors: Small Dorothy S. 
Published: October 2010

In today’s world, it has become ever more important to design homes and buildings with considerations that will reduce the total energy requirement and reliance on fossil fuels. Energy conservation is the first important consideration. The construction and appliance components that reduce energy consumption will be presented. Various systems are being included in the design of this off-grid 100% renewable home. The home will incorporate: passive solar design; solar hot water for radiant heat and domestic hot water; woodburning heat with backup hot water coils for domestic hot water and radiant heat; a hybrid electric system with PV and windmill sources and backup diesel generator (modified to use vegetable oil); a rainwater collection system; a graywater treatment system and blackwater treatment. The heating and air conditioning system combines the efficiency of radiant heat with evaluated tube solar hot water technology. A heating coil is incorporated in a masonry heater as the backup. The sizing considerations of the systems are discussed along with the description of methods to discharge excess hot water. Passive solar building design has been a focal point of the home. The heat gain has been considered as the heating system has been designed. The domestic hot water is discussed to compare the demand vs. production of hot water vs. storage. The practices of the homeowner to minimize the need for air conditioning and the design features that improve the conditioning of the air in the summer are presented. The integration of electrical generation will utilize PV, windmill and diesel generator backup (that will be converted to vegetable oil). This combination is used to take benefit of the wind potential while there are periods of little or no electricity generated from the PV system. The size of the systems has been optimized to balance the cost of production vs. storage. The sizing criteria are presented with the optimization calculations for each of the systems. The system design of a rainwater collection system is presented describing the rain water available, the size of the collection area, and the storage capacity. Equipment considerations are discussed with pre and post storage treatment of collected water. A graywater treatment system is designed to take advantage of the passive solar orientation of the home. The system incorporates graywater management practices, sizing of filtration and discussion of placement of components of the system. A blackwater system is also incorporated in the design of the home. The considerations of various systems are presented along with the sizing and utility requirements. The effective design of a 100% off-grid renewable home must first consider the efficient use of all energy. Secondly, the integration of systems is complex and requires the flexibility of the operations of the systems to produce a range of potential capacity to ensure comfort. The systems incorporated in this design are automated to an extent that is practical, however, monitoring of the systems must be conducted to ensure proper operation.