#745: Gaseous Water, Garage Insulation, and Using AI for HVAC Sizing

Beware of 'COVID projects' where contractors may have overextended their capabilities, leading to poorly executed work like HVAC systems in unconditioned attics or crawlspaces.

When renovating, consider the entire building envelope, especially with concrete slabs that extend to the exterior, as they can act as thermal bridges.

For ductwork in unconditioned spaces like garages, proper air sealing and insulation are crucial to prevent energy loss and indoor air quality issues.

Be skeptical of bubble wrap insulation for ductwork; its R-value claims often assume an impossible-to-achieve airspace.

AI tools like Chat GPT and Claud can be useful for initial HVAC load calculations and cross-checking, but they struggle with complex tasks like interpreting floor plans for ductwork routing.

In high-performance homes, manual J calculations are critical, and contractors may need to adjust inputs to accommodate smaller, more efficient equipment to avoid short cycling.

Interior window shades can significantly reduce solar gain and improve comfort, even if they don't block heat as effectively as exterior shading, aiding smaller HVAC systems.