1. Update on the SEEM Simulation Program Larry Palmiter and Ben Larson August 4, 2008 Ecotope Inc. Presented at Regional Technical Forum Portland, Oregon, August 5, 2008

2. SEEM Background The SEEM program has been under development since December 2003. SEEM offers state of the art modeling of heat pumps and air-conditioners including thermostat setup penalty and heat pump controls. SEEM has a comprehensive below-grade heat loss algorithm based on an international standard.

3. Features Added in the Last Year Complete psychrometrics implementation includes – Water balance on all zones: attic, crawl, and conditioned space – User input for internal water gains – Calculation of latent cooling load Complete equipment performance map for HP and A/C: – Dry, wet, and partially wet indoor coils – Predicts: sensible and latent capacity; input power as a function of outdoor temperature; return plenum temperature and humidity ratio; and indoor coil airflow rate Window areas may now be specified separately for North, East, South, and West orientations

4. Features Added (continued) Simplified R-value input for building components – Overall, air-to-air, value Multi-level buildings can now be modeled with independent input of conditioned floor area, footprint area, ceiling area, and external (i.e. cantilevered or over garage) floor area Weather site air density now used in all airflow calculations User input to adjust equipment air flow Ability to specify any day and month for tracking hourly output

5. Features Added (continued) Ground contact model update: – SEEM calculates ground heat transfer using the international standard (ISO13370:1998) which estimates the overall 3-dimensional U-value. Slab-on-grade – Full under slab insulation – Perimeter insulation with user determined depth Horizontal: Vertical: Crawl spaces, unheated and heated basements – Allows different wall types for above and below grade components – Exterior and interior slab insulation also modeled

6. Further Development of SEEM Program simulation times need to be decreased – Source code to be translated into a compiled language Inner calculation loop needs to be rewritten to accommodate new equipment types and modes of operation

7. Potential Enhancements Air handler fan operation modeling when no heating or cooling required – Continuous fan operation at full speed For comfort purposes or electrostatic air cleaners – Fan operation at reduced flow for ventilation Varying flow rates for furnace, A/C, and HP (currently only one rate) to allow for two-stage equipment Comfort control modeling for heating and cooling by reducing air flow rates Varying zonal air change rate – High ventilation rates for nighttime cooling – Cooling via ventilation if outdoor air cooler (i.e. economizer)

8. Enhancements (continued) Addition of new equipment types – Refrigerant distribution systems (mini-splits) – Two-stage equipment (furnaces, A/C, HP) – New heat pump models – Radiant floors Improved air flow modeling between zones – Conditioned space and crawl – Conditioned space and attic Improved modeling of sealed crawl space with installed options for radon mitigation