Load calculation and sizing
Equipment is sized to the house, not to the old furnace label. Oversized systems short cycle and cost more.
Swapping a gas furnace for a heat pump in Fairfax? HAXX runs a load calculation, reviews the panel and pulls the Town of Fairfax permits for the install.
Serving Downtown Fairfax, Fairfax Manor, Oak Manor, Deer Park and the Cascades and the rest of Fairfax. Share your address to confirm availability.

A heat pump replaces a furnace and AC with one system for heating and cooling. Good results come from sizing, layout and electrical planning done before equipment is ordered.
Equipment is sized to the house, not to the old furnace label. Oversized systems short cycle and cost more.
Keep existing ducts when they are in good shape, or go ductless where ducts are missing, leaky or impossible to run.
HAXX electricians review the panel and service before the install, so a surprise panel upgrade does not appear mid-project.
Mitsubishi Electric and American Standard systems, among others, matched to the home and budget.
HAXX pulls the mechanical and electrical permits and meets the city inspector.
We point you to the rebates your address qualifies for and provide the equipment documentation programs ask for.
Fairfax requires all-electric new buildings and adopted local reach codes with the 2025 building code update. On an existing home, the Building Division can say which measures apply to your project.
A shaded canyon house and a sunny ridge house need very different capacity. HAXX sizes from a Manual J style load calculation, not from the old furnace label.
Steep or narrow lots limit pad locations. HAXX plans line set length, condensate routing, clearances and noise before the permit is drawn.
HAXX applies for the mechanical and electrical permits with the Town of Fairfax Building Division and attends the inspection.
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“Thorough diagnostics of A/C system, identified and repaired the issue quickly!”
“Service was performed well and on time. Service person was highly skilled and provided easy to understand options to deal with the issue. Price for diagnostics was reasonable and easy to pay online.”
“Our commercial building had several HVAC problems, and their team carefully diagnosed each unit, explained the available options, and never pressured us into unnecessary replacements. They worked hard to repair what could be repaired and kept us informed throughout the process.”
Existing equipment, home layout and what you want to improve.
Sizing, airflow, equipment placement and electrical needs.
Options, exclusions, permit requirements and any eligible incentives.
Confirm equipment, scheduling and handover details with HAXX.
A closer look at recent heating and cooling work by HAXX.

On site during a commercial VAV box repair: access above a suspended ceiling, equipment and the work in progress.
Explore recent projects
Heat pump installation.

Outdoor heat pump installation.

Heat pump air handler installation.

Heat pump air handler service.

Lennox ac installation.

Compressor replacement.

Mitsubishi leak detection.

Leaking coil replacement.
Fairfax's all-electric rule covers new buildings. For additions and alterations, the Town's reach code adds requirements, so confirm with the Building Division what applies to your remodel.
Yes. A heat pump install needs Town of Fairfax permits and inspection. HAXX prepares the application and meets the inspector.
Yes. Bay Area winters are mild, and correctly sized heat pumps heat comfortably through them. Sizing and duct condition matter more than the brand.
Most single-system replacements take one to three days on site. Permits, equipment lead times and any electrical work add to the overall timeline.
Share the property, equipment and questions you have in mind.
(408) 901-8315
Call HAXX to discuss your property and scheduling.
