  Heating, Ventilation and Air conditioning (HVAC) systems account for
approximately 40% of the total energy used by buildings in the USA. To reduce
this consumption States enforce minimum energy codes that currently range from
strict (ASHRAE 90.1-2016) to relaxed (ASHRAE 90.1-2007) with some states
following no particular standard. To reach as close as possible to net zero
carbon and energy, each statewide energy code requires different levels of
interventions for each code minimum building. This paper presents a collection
of potential HVAC retrofits to transition each State's current code minimum
buildings towards the goal of net zero to achieve a carbon free future by 2050.
The study shall use a large array of code minimum criteria and climate zones
covering the 48 contiguous United States to determine the most successful
interventions at reducing the energy use of buildings meeting today's energy
codes. Office use type has been selected for the study as they account for 18%
of total buildings and close to 19% of the total commercial floorspace. A
number of interventions will be applied to this use type that will vary based
on current code and climate zone; however, a common theme will be
electrification through the use of heat pump technology. Each intervention will
be scored based on energy and carbon savings, along with level of difficulty
and cost. The study not only provides a comprehensive transition guideline
toward the net zero energy and carbon but also predicts the future project
opportunities.
