OAR 330-070-0062: Passive Solar Space Heating AEDs

(1) Installations of passive solar space heating systems must comply with all applicable state, county or local codes and regulations. (2) The estimated first year energy savings for the system must be the net usable energy produced under average environmental conditions in one year. (3) Passive solar space heating systems must produce energy savings equal to not less than 20 percent of the annual energy used for space heating in the dwelling to be eligible for a tax credit. Such systems must: (a) Have sufficient solar access not jeopardized by future buildings or tree growth; (b) Provide usable heat for the heated space; (c) Provide adequate thermal storage for solar heat gained; (d) Prevent overheating of the heated space that requires mechanical space cooling; and (e) In addition, sunspaces must: (A) Have no backup heating device; and (B) Be able to be isolated from the heated space. (4) Determination of annual performance must be based on one of the following approved methods: (a) Using the department's prescriptive passive solar heating path to achieve 20 percent savings. (b) Annual hourly simulation using an approved energy modeling software (e.g.: Energy-10). (c) Monitored data from system before and after installation of AED. (5) Costs eligible for passive solar space heating systems include: (a) The cost for thermal storage; (b) The cost of movable window insulation that is part of a passive system. It must tightly seal on all sides of the window. It must also have an R- value of at least three; (c) The cost of south-facing windows, if the requirements of section (4) of this rule are met; and (d) The cost of passive heat distribution components. (6) The department will use data supplied by the applicant to determine the amount of the tax credit. [Publications: Publications referenced are available from the agency.]