Skip to main content
Project Info COMPLETE Project Title

Development of a Laboratory Data-Based Algorithm for Horizontal Drain Water Heat Recovery Devices, and Predictions of In-Field Performance

Project Number ET18PGE8231 Organization PG&E, SDG&E, SoCalGas End-use Process Sector Commercial, Residential Project Year(s) 2017 - 2018

Horizontal drain water heat recovery (H-DWHR) devices are products designed to recover heat from heated drain water and transfer it to potable cold water entering a building. They are counter-flow heat exchangers, similar to previously studied vertical drain water heat recovery (V-DWHR) devices, with the fundamental difference being that they are intended to be installed nearly horizontally instead of vertically. These H-DWHR devices are heat exchangers featuring a flat plate for the hot drain water to flow across, and tubes below the plate for the fresh cold water to pass through. Unlike V-DWHR devices, they employ turbulators in the cold water pipes to increase heat transfer and the resulting temperature rise in the cold water entering the building. This project evaluated H-DWHR performance and practical issues through laboratory testing of three HDWHR devices, algorithm development, and simulation studies. The three units were selected for their different lengths, representing available H-DWHR units. One was chosen because it is designed for installation in commercial kitchen dishwashers. Laboratory testing results were used to develop regressions predicting the effectiveness and energy recovery of horizontal drain water heat recovery devices as a function of flow rate through the unit. Algorithms for both V-DWHR and H-DWHR are currently being added to California Title 24, Part 6.

Project Report Document
Loading PDF Preview...
I have read and accept the Privacy Policy and Terms of Use
  • Pacific Gas & Electric Company logo
  • Southern California Edison Company logo
  • Southern California Gas Company logo
  • San Diego Gas & Electric Company logo
  • Sacramento Municipal Utility District logo
  • Los Angeles Department of Water and Power logo
  • CEC logo

Copyright © 2024 Energy Transition Coordinating Council. Trademarks are the property of their respective owners. All rights reserved.

The ETCC is funded in part by ratepayer dollars and the California IOU Emerging Technologies Program, the IOU Codes & Standards Planning & Coordination Subprograms, and the Demand Response Emerging Technologies (DRET) Collaborative programs under the auspices of the California Public Utilities Commission. The municipal portion of this program is funded and administered by Sacramento Municipal Utility District and Los Angeles Department of Water and Power.