### Internal DOE2 Calculations

The Home Energy Saver implementation of DOE2 executes a number of internal calculations through programming in the Building Description Language (BDL).

### 1. Heating and Cooling EIR

COOLING-EIR=#[3.412 / #[1.063 * cool_eff[]]]
HEATING-EIR=#[1. / #[0.481 * heat_eff[]]]
Based on fits of net COP (no fan) to SEER and HSPF from Fairey et al 2004 [1].

### 2. Window ventilation area

\$ Assume 1/4 of total window area opened for ventilation
\$ Assume discharge coefficient of 0.6
##set1 window_area #[window_area_1[] + window_area_2[]]
##set1 window_area #[window_area[] + #[window_area_3[] + window_area_4[]]]
##set1 frac_vent_area #[#[#[window_area[] * 0.25] * 0.6] / house_floor_area[]]

3. Lighting and Equipment power densities
\$ Lighting power density = lighting consumption (kWh/yr) X 1000 W/kW /
\$                          365 days/yr / total fractional hours in daily
\$                          lighting schedule / conditioned floor area (ft2)
##set1 lpd #[#[#[#[lights_kWh[] * 1000.] / 365.] / 6.36] / cond_area[]]
\$ Equipment power density = equipment consumption (kWh/yr) X 1000 W/kW /
\$                           365 days/yr / total fractional hours in daily
\$                           equipment schedule / conditioned floor area (ft2)
##set1 epd #[#[#[#[equip_kWh[] * 1000.] / 365.] / 12.61] / cond_area[]]

References:
[1] Fairey, P., D.S. Parker, B. Wilcox and M. Lombardi, "Climate Impacts on Heating Seasonal Performance Factor (HSPF) and Seasonal Energy Efficiency Ratio (SEER) for Air Source Heat Pumps." ASHRAE Transactions, American Society of Heating, Refrigerating and Air Conditioning Engineers, Inc., Atlanta, GA, June 2004.
http://fsec.ucf.edu/en/publications/html/FSEC-PF-413-04/index.htm