A degree-day method for residential heating load calculations specifically incorporating the utilization of solar gains

Conference · Sat Sep 01 00:00:00 EDT 1990

OSTI ID:6393572

Lucas, R G; Pratt, R G

A simple and well known method of estimating residential heating loads is the variable base degree-day method, in which the steady-state heat loss rate (UA) is multiplied by the degree-days based from the balance temperature of the structure. The balance temperature is a function of the UA as well as the average rate of internal heat gains, reflecting the displacement of the heating requirements by these gains. Currently, the heat gains from solar energy are lumped with those from appliances to estimate an average rate over the day. This ignores the effects of the timing of the gains from solar energy, which are more highly concentrated during daytime hours, hence more frequently exceeding the required space heat and less utilizable than the gains from appliances. Simulations or specialized passive solar energy calculation methods have previously been required to account for this effect. This paper presents curves of the fraction of the absorbed solar energy utilized for displacement of space heat, developed by comparing heating loads calculated using a variable base degree-day method (ignoring solar gains) to heating loads from a large number of detailed DOE-2 simulations. The difference in the loads predicted by the two methods can be interpreted as the utilized solar gains. The solar utilization decreases as the thermal integrity increases, as expected, and the solar utilizations are similar across climates. They can be used to estimate the utilized fraction of the absorbed solar energy and, with the load predicted by the variable base degree-day calculation, form a modified degree-day method that closely reproduces the loads predicted by the DOE-2 simulation model and is simple enough for hand calculations. 6 refs., 6 figs., 2 tabs.

• Research Organization: Pacific Northwest Lab., Richland, WA (USA)
• Sponsoring Organization: DOE/NE
• DOE Contract Number: AC06-76RL01830
• OSTI ID: 6393572
• Report Number(s): PNL-SA-17704; CONF-900833-13; ON: DE91004078
• Resource Relation: Conference: ACEEE summer study on energy efficiency in buildings, Pacific Grove, CA (USA), 26 Aug - 1 Sep 1990
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
14 SOLAR ENERGY
RESIDENTIAL BUILDINGS
HEATING LOAD
CALCULATION METHODS
CLIMATES
ENERGY CONSERVATION
HEAT LOSSES
SOLAR ENERGY
SPACE HEATING
TEMPERATURE EFFECTS
BUILDINGS
ENERGY
ENERGY LOSSES
ENERGY SOURCES
HEATING
LOSSES
RENEWABLE ENERGY SOURCES
320100* - Energy Conservation
Consumption
& Utilization- Buildings
140901 - Solar Thermal Utilization- Space Heating & Cooling