RTU replacement programs
Like-for-like and heat pump conversions under the 2025 Title 24 rules, with curb adapters fabricated in our shop so the crane day is one day.
Commercial HVAC · California
Commercial HVAC contractor for California GCs.
Rooftop unit replacements, VRF systems, VAV and make-up air, installed by our own crews and commissioned to Title 24. From a single 5-ton RTU swap to a 200+ ton multi-tenant office, one team carries it from load calc to TAB report.
Interactive 3D
Commercial HVAC in 3D.
Interactive models of the equipment on this scope, drawn in code from what we install every week. Drag to rotate.
Packaged rooftop unit on a curb - the workhorse of California retail, office, and QSR. We set, pipe, wire to the disconnect, start up, and balance.
What we deliver
New installation, system replacements, retrofits, and emergency service for office, retail, restaurant, and light industrial. We size, install, and commission.
- Rooftop Units (Trane, Carrier, Lennox, Daikin, York)
- VRF & VRV Systems (Mitsubishi, Daikin, LG)
- Variable Air Volume (VAV) & Constant Volume
- Mini-Split & Multi-Zone Systems
Project size: $50K (single RTU swap) to $4M (multi-floor mechanical TI). Typical schedule: 4–16 weeks from contract to substantial completion.
Full scope, process & specs
Sierra Mechanical installs, replaces, and services commercial HVAC systems across California - from 5-ton retail spaces to 200+ ton multi-tenant office complexes. We work directly with general contractors, property managers, and end-users on new construction, equipment replacement programs, and mechanical retrofits.
Our crews are factory-trained on the major equipment lines (Trane, Carrier, Lennox, Daikin, Mitsubishi VRF) and certified for refrigerant handling under EPA 608. Every project includes proper load calculations (Manual N for commercial, Title 24 compliance docs for California), engineered submittals, and full commissioning with start-up reports delivered to your closeout package.
For tenant improvement work, we coordinate with your structural, electrical, and plumbing trades from day one. Our project managers attend your weekly OAC meetings, push RFIs through promptly, and hand over O&M manuals + as-builts on substantial completion - not three months after the certificate of occupancy.
Load calc + equipment selection
We size to actual loads, not rules of thumb. Manual N for commercial, with Title 24-T24 software docs.
Submittals + permits
Stamped drawings, equipment cut sheets, control diagrams. We pull our own mechanical permits or coordinate with your design team.
Install + start-up
Self-performed by our W-2 crews. Factory start-up by manufacturer reps. Refrigerant pressure test, evacuation, and charge.
Test + balance + closeout
TAB by NEBB/AABC certified third party. O&M manuals, as-builts, training session for the operator.
- Make-Up Air Units (Greenheck, RuppAir, Captive-Aire)
- Building Automation / BMS (BACnet, Niagara, Honeywell)
- Indoor Air Quality / IAQ (UV-C, MERV 13+, ERV)
- TAB Coordination (NEBB / AABC certified)
- LEED-Eligible Equipment & Refrigerant Compliance
- Title 24 Energy Compliance
- Refrigerant Recovery & EPA 608
When GCs call us for commercial hvac.
New construction & shell
Design-assist from basis of design, equipment procurement and expediting, and factory start-up coordinated with the manufacturer rep.
VRF & multi-zone office
Mitsubishi, Daikin, and LG VRF for office and medical TIs where zoning and efficiency matter more than first cost.
Controls & BMS tie-in
BACnet and Niagara integration with the landlord system, demand controlled ventilation, and FDD where Title 24 requires it.
Codes & standards we build to
- 2025 California Mechanical Code (CMC)
- Title 24 Part 6 (2025) energy standards
- ASHRAE 62.1 ventilation
- EPA Section 608 refrigerant handling
- NEBB / AABC test and balance
Job flow in 3D
How a commercial hvac job moves.
Same six stages on every Sierra job, from takeoff to the TAB report. Scroll to walk through it; drag to look around.
- Estimating
Plans & takeoff
Budgetary number in 4 business hours. Itemized hard bid in 5 days.
DeliverablesBid · scope sheet · alternates
- Pre-construction
3D coordination
Clashes with structure and other trades are solved on screen, not in the field.
DeliverablesShop drawings · submittals · Title 24
- Rancho Cordova shop
In-house fabrication
CNC-cut, formed, and welded to SMACNA and NFPA 96. Never outsourced.
DeliverablesDuct · hoods · fittings
- Logistics
QA & delivery
Leak-tested, tagged to the drawing, and delivered on your install date.
DeliverablesTest records · tagged pallets
- Self-performed
Field install
Our own W-2 crews, with a PM in your OAC meetings every week.
DeliverablesRTU sets · rough-in · look-ahead
- Turnover
Start-up & closeout
Start-up, NEBB/AABC test and balance, O&M manuals, and as-builts.
DeliverablesTAB report · O&M · as-builts
Commercial HVAC questions.
What size commercial HVAC projects does Sierra Mechanical take on?
From a single rooftop unit swap around $50K up to multi-floor mechanical packages around $4M. Typical schedules run 4 to 16 weeks from contract to substantial completion.
Which HVAC equipment brands do you install?
Our crews are factory-trained on Trane, Carrier, Lennox, Daikin, and York packaged equipment and on Mitsubishi, Daikin, and LG VRF systems. We also install Greenheck, RuppAir, and Captive-Aire make-up air units.
Do you handle Title 24 compliance on HVAC replacements?
Yes. Every project includes load calculations, Title 24 compliance documentation, and commissioning. On rooftop unit replacements we check whether the 2025 heat pump requirements apply before equipment is selected.
Who performs test and balance?
TAB is performed by a NEBB or AABC certified third-party agency that we coordinate. Start-up reports, the TAB report, O&M manuals, and as-builts go into your closeout package.
Next step - takeoff & budgetary pricing
Bidding commercial hvac? Send the plans.
Budgetary number in 4 business hours. Itemized hard bid in 5 business days. One PM from takeoff to closeout.