MAISY RECS Hourly Loads & Emissions Databases

Question 6. If Metered Data is Critical for NWS Loads, Why Do You Use EPlus Engineering Analysis to Calculate Space Heating and Air Conditioning loads?

Short Answer: Weather can vary significantly from one year to the next so developing “typical “meter-based weather sensitive load profiles would require 8760 load data for many years, which does not exist. Space heating, AC and ventilation electricity use is determined primarily by outdoor weather temperatures and does not reflect the random load patterns of non-weather sensitive loads. Fortunately, many years of weather data are available to develop typical weather profiles for more than 900 locations across the US. These weather data are applied to develop MAISY RECS weather-sensitive hourly loads.

Longer Answer: MAISY RECS Residential Hourly Load Databases apply EPlus engineering analysis to calculate space heating, air conditioning and ventilation loads (weather sensitive loads or WS loads). EPLUS is a US Department of Energy engineering heat load model that calculates hourly kW use for space heating, air conditioning and distribution based on dwelling unit, occupant characteristics and weather data.

EPLus model simulations from more than 900 weather stations are used to develop weather-sensitive hourly load estimates for “typical meteorological year (TMY)” data. TMY data reflect typical hourly data for actual days in individual months based on an analysis of historical data. This database reflects typical hour to hour variation in outdoor temperatures. This approach is superior to modeling WS loads based on average daily temperatures as averages dampen hour to hour variations that are important in estimating peak kW impacts of weather. Simulation results are calibrated to individual RECS record space heat, air conditioning, and ventilation (fans and pumps) annual kWh estimates and dwelling unit floor space.

Related MAISY Topics