BETAC

Building Envelope TAC

Energy Efficiency Technology Assessment: Drain Water Heat Recovery Evaluation

July 14, 2017

The objective of this project is to investigate and assess the energy efficiency, effectiveness, and performance of vertical, sloped and horizontal DWHR systems for MURB applications. BETAC will be working with Gary Proskiw, Manitoba Hydro, and Manitoba Housing on this project.

Background

Drain-water heat recovery (DWHR) systems recover heat from a building’s wastewater and use it to preheat the fresh incoming water, thereby reducing the overall domestic hot water (DHW) load.

All new Part 9 (residential) construction in Manitoba, as part of the province’s review of Section 9.36 of the National Building Code (other than for houses with slab-on-grade or crawl space foundations), now require a DWHR system. Their introduction into mid/high-rise multi-unit residential buildings (MURBs) has been extremely limited.

Our Research

The majority of information and testing available for DWHR performance was developed for vertical installations. However, the accessible portions of the drain lines in MURBs are predominately horizontal or sloped at 45°.

  • Therefore, BETAC will conduct a series of laboratory trials to evaluate the heat recovery performance of typical DWHR units installed in vertical, horizontal and sloped (45°) configurations with the use of Red River College’s plumbing workshop.
  • Surface temperatures and in-line temperatures will be monitored to permit better correction between the two variables for use in future field screening applications.