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 or worn AC for a heat pump in Union City? HAXX sizes the system room by room, checks the panel and pulls the city permit.
Serving Decoto, Alvarado, Holiday Park, Casa Verde, West View Estates and the Union City Station District and the rest of Union City. 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.
Union City enforces the 2025 California Building and Energy Codes. A heat pump replacing an existing HVAC unit is permitted through the Building Division, and the city asks for a CF1R energy compliance form.
Many Union City tract homes have had window, insulation or room changes over the years. HAXX sizes from the house as it is today, not from the old unit's label.
A heat pump draws a large 240-volt load. HAXX reviews the panel during the estimate so any electrical work is known before install day.
Ava Community Energy runs an online incentive finder that lists rebates and tax credits by ZIP code and household. Check current terms with each program before you sign.
Rated 4.8 across 515+ reviews on Housecall Pro, Google and Facebook. Read more reviews.
“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.
Replacing an HVAC unit needs a permit from the Union City Building Division. The city's contractor application lists HVAC replacement and asks for a CF1R form. HAXX prepares the paperwork and meets the inspector.
It depends on your household and the equipment. Ava Community Energy's incentive finder lists current options by ZIP code. Confirm eligibility with each program before you commit.
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.
