Publications

Sep, 2026

Conference Paper

A New Tool to Evaluate Impacts of Combining Building Envelope Improvements with Ground Source Heat Pump for Deep Building Retrofits

This study evaluates how improving building envelopes can reduce thermal loads and, subsequently, the size and cost of ground source heat pump (GSHP) systems. The building envelope enhancements analyzed include adding insulation to walls and/or roofs, minimizing uncontrolled outdoor air infiltration, and installing high-performance windows. The investigation utilizes GeoWI…

Sep, 2026

ORNL Report

GeoWISE – User Manual 1.0

Jul, 2026

Conference Paper

Sensitivity analysis of design parameters in RowWise borehole layout for ground heat exchangers

Ground source heat pump systems offer a promising pathway toward energy-efficient building heating and cooling. The performance and cost-effectiveness of these systems heavily depend on the design of the ground heat exchanger (GHE), particularly the spatial placement of boreholes used in large commercial buildings. Among various borefield layout strategies, the RowWise app…

Jun, 2026

Conference Paper

An Online Tool for Preliminary Design and Techno-Economic Analysis of District Geothermal Heating and Cooling Systems

District geothermal heating and cooling systems (DGHCS) have significant benefits for reducing energy consumption as well as building- and grid-level peak electric demand. Currently, no publicly available tools are available to effectively design and conduct techno-economic analysis of DGHCS. GeoWISE was originally developed for preliminary design and techno-economic analy…

Mar, 2026

ORNL Report

Minimum Feature Set for Mechanical Ventilation Workflow in MulTEA

This report investigates mechanical ventilation systems in multifamily buildings to specify the appropriate capabilities for integration into the MulTEA - “an energy audit tool designed to provide weatherization auditors with an improved energy simulation tool for multifamily buildings” framework. It identifies common system types, retrofit strategies, and key modeling par…

Mar, 2026

Conference Paper

The role of air sealing while ground source heat pump system retrofits in the U.S. single-family houses

Widespread commercial adoption of ground source heat pumps (GSHP) is hindered by the relatively high initial cost associated with drilling boreholes in the ground to deploy ground heat exchangers. Reducing the energy demand of buildings has the potential to reduce the required borehole length and the associated drilling costs. In single-family residential buildings, air se…

Mar, 2026

Conference Paper

The relative importance of building design parameters in reducing energy use and sensible heat release from buildings in light of forecasted future weather data and building coverage ratio

Buildings typically have a 60-to-75-year lifespan before they require significant maintenance or modifications. However, most builders evaluate the performance of their new buildings using whole-building energy simulation tools based on the current typical meteorological year (TMY) file or actual meteorological year. The energy use consumption and sensible heat release pat…

Mar, 2026

Conference Paper

A Preliminary Investigation on the Performance of a Dual-Source Heat Pump using both the Air and the Ground

Air source heat pumps (ASHPs) and ground source heat pumps (GSHPs) are the two most common types of electric-driven heat pumps in the marketplace to replace fossil fuel-based heating systems. However, the performance and efficiency of ASHPs depend on the ambient air conditions. Therefore, ASHPs usually are equipped with electric resistance heaters to provide supplemental h…

Nov, 2025

Journal

An Economic and Technical Feasibility Analysis of a Dual-Source Heat Pump Using Both the Air and the Ground

The study investigates the economic and technical performance of a novel dual-source heat pump (DSHP) compared with that of air-source heat pumps (ASHPs) and ground-source heat pumps (GSHPs). The DSHP can use both ambient air and the ground as a heat source or heat sink. It uses ambient air when its temperature is favorable for efficient heat pump operation. When the ambie…

May, 2025

ORNL Report

Simulation & Analysis of the Hydronic Shell Retrofit System as a Solution for Deep Energy Retrofits and Electrification of Large Multifamily Housing Communities in Cold Climate

Nov, 2024

Journal

Assessing the impacts of air-sealing on the sizing, operation, and economic feasibility of ground-source heat pumps for electrifying single-family houses in the US

According to recent studies and reports, in single-family houses (SFHs), air-sealing can significantly lower the thermal loads for space heating and cooling. Thus, air-sealing in SFHs could reduce the required size and cost of ground source heat pump (GSHP) systems for electrifying SFHs. This study investigated the costs and benefits of integrating air-sealing with GSHPs f…

Aug, 2024

ORNL Report

Design And Control of Thermal Storage for Ventilative Cooling in Multifamily buildings

The concept of natural ventilation is to provide a heat sink for cooling the building during the occupancy periods at night and improve indoor thermal comfort during the daytime without or with minimal need for mechanical cooling. Commonly, natural ventilation through the window or mechanical circulation of the air through the ventilation ducts are two key methods used to…