Energy Savings from Residential Zoned Air Distribution Systems (CLOSED)

Update: April 2022

The final report for this project has been submitted and consisted of a market assessment of multizone equipment and key modeling results.

The market assessment of seven major manufacturers detailed the following.

• Six of the seven manufacturers have multizone equipment in their inventory.
• MZ equipment is being installed in about a quarter of new Minnesota homes and is primarily being used in higher-end new homes as opposed to retrofits.
• No Minnesota or U.S. utilities currently provide energy efficiency incentives for MZ equipment.

The modeling results identified the following.

• If spaces are being over-heated, there’s potential for space heating energy savings in new homes.
• If areas of the house are under-heated, however, a MZ system would provide better comfort but higher energy use.
• Further measurements of actual heating and cooling season temperatures in MN houses is needed to fully measure the impact of MZ systems.

Stay tuned for the final report. 

Update: October 2021

The literature identified in the study emphasizes multizone systems’ potential to reduce cooling energy loads, but with fewer potential reductions in space heating savings. Through interviews with distributors, contractors, and U.S. utilities, CEE found that energy efficiency incentives for multizone systems, which are not currently provided by utilities, would help increase market penetration. To continue this research, CEE has started modeling residential single and multizone systems and will develop two to four prototype Minnesota single-family houses. These prototypes will evaluate the change in energy use and improved comfort of both single-zone constant air volume and multizone distribution systems.

Overview

Single-zone constant air volume systems are standard in most Minnesota homes. They can lead to temperature variations and increased energy use from over-heating and over-cooling. These problems often occur in basements, on second floors, and on sunny sides of the house. Multizone variable air volume (VAV) systems offer a solution.

This white paper will explore the potential to apply newly available zoning equipment for new and existing air distribution systems. Anecdotal evidence has shown that poorly designed and implemented systems can lead to low airflow and cycling problems — the assessment will include system requirements to avoid these problems. We will use EnergyPlus models of standard Minnesota home configurations to estimate zoned system energy savings.