High-performance homes require better HVAC design strategies than code-built homes. Builders can more easily understand high-performance needs by familiarizing themselves with basic HVAC design concepts and strategies.
The first step is conducting a room-by-room load calculation.
Local climates determine whether a building’s HVAC system is designed to first meet cooling or heating needs. Heating-dominant climates require heating needs to be addressed before cooling, and vice versa. Load calculations are based on the coldest and hottest days of the year to ensure systems provide comfort at both extremes. In any climate, high-performance homes have significantly lower cooling and heating requirements than code-built homes, so the best options for them might be very different than a code-built home.
Split-ductless systems, for example, provide both cooling and heating in one highly efficient system, and are a great solution for high-performance homes. The systems are energy-efficient; come in a range of capacities; offer a variety indoor unit options; and can combine multiple indoor units using one outdoor compressor system.
Step two in HVAC system design is selecting the right size system. Undersized systems do not adequately cool or heat, while oversized systems unnecessarily increase cost and often short cycle.
If ducted systems are used, determining ductwork design can be challenging. In high-performance homes, efficient ductwork needs to be inside the conditioned space. Ductwork run outside of conditioned space results in energy penalties and an increased risk of condensation. One benefit to using split-ductless systems is the elimination of ductwork challenges.
Builders are encouraged to look for an HVAC contractor who specializes in high-performance new construction. During the design process, teamwork between the builder and the HVAC contractor is essential. Other allies helpful in the HVAC design process are energy raters and HVAC manufacturers committed to helping high-performance builders find better HVAC strategies.
Mitsubishi Electric Trane HVAC US understands that high-performance builders and HVAC contractors need help with new strategies as the cooling and heating loads for residential new construction continue to be lowered. Over the last few years, Mitsubishi Electric Trane HVAC US has introduced its Performance Construction Team to provide continued support in this area. Find more information about the Performance Builder Program and the Performance Construction Team here.