Off-Gassing: Our New Heat Pump HVAC System
Channel: Sean Anderson
Date: 29/10/2023

This is a quick tour of our new heating, ventilation, and air conditioning (HVAC) system, installed in October of 2023. This system is for a large two-story home in Southern California. After many quotes and much debate about future climate predictions for our region, we opted to build our upgraded system around Bosch heat pumps. Having just installed solar, this means we our heating and cooling will be carbon emissions-free over the coming decades.

Given our goal was to 1) decarbonize our home HVAC use and 2) maintain comfortable home temperatures in the depths of winter and dog days of summer, the variable-speed heat pump system was the way to go. We initially explored in-ground heat pumps, but both our rocky property and the fact few firms even have the knowledge/expertise to install such systems pushed us to the traditional in-attic-based heat pump option.

This house was built in 2002. The original owners installed the cheapest HVAC system they could find. Not only was it noisy and an energy hog, but by 2022 it was on its last legs. One unit had completely died and the other was getting ready to kick the can.

Specifics of the installed elements here: 
1) heat pump:
  -air handler: Bosche BVA 2.0 Series (3 ton & 5 ton units)
  -air purifier: iWave-R Residential UV Air Cleaner (up to 6 tons or 2,400 CFM; model 4900-20)
  -condenser: Bosch BOVB 18 Split System Heat Pump (18.5 SEER; 3 & 5 ton units)
2) whole house fan: QuietCool QC STL PRO-6.0x
3) blown fiberglass insulation: Owens Corning Professional Loosefill Insulation System (Item Reference Number PC01; Each bat: can cover 80.6sqft @ R30 (or 46.4sqft @ R49 or 36.9sqft @ R60)

We contracted with AirWorks Heating & Cooling in Camarillo, California.

A variety of discounts for installation of heat pumps are available via various mechanisms, mostly underwritten by funding from the federal Inflation Reduction Act (IRA).