Installing air conditioning in Novato, San Rafael, San Anselmo, Larkspur or Sausalito usually means one of two jobs: replacing an old system that no longer keeps up, or adding cooling to a home that has only ever had a furnace. Either way, three things decide how well the new system works - its size, the ductwork it connects to, and where the outdoor unit sits. The equipment brand matters far less than getting those right.
When a new system makes sense
- The old system is outdated. It needs refrigerant that is no longer produced, or a major part such as the compressor has failed on an older unit.
- It cannot keep up. The house never reaches the setting on hot afternoons, even after repairs and cleaning.
- Energy bills keep climbing while the way you use the system has not changed.
- Repairs are frequent. Several service calls in a few seasons are a sign the system is near its end.
- New construction or an addition. A new room, a converted garage or a second story changes the cooling load.
If your current unit simply stopped working, start with AC repair; one failed part is often cheaper to fix than you expect.
Sizing starts with a load calculation
We do not size by the old unit’s label or by square footage alone. A load calculation adds up how much heat the house gains on a design day: insulation, window area and direction, shade, air leakage, ceiling height and how many people live there. Two houses of the same size can need very different systems. A shaded home in the fog belt near the bay gains far less heat than a house with big west-facing windows in an inland valley.
Getting the size right matters both ways. An undersized system runs all afternoon and still falls short. An oversized one cools fast, shuts off early, removes little moisture and wears its parts with constant starts.
The ducts decide your options
Many older Marin homes have ducts that were sized for heating only. Cooling needs more airflow, so small or leaky ducts can leave rooms warm and the blower noisy. During the assessment we look at the duct sizes, the return air path and the condition of runs in the attic or crawlspace. That usually leads to one of three paths:
- Central AC added to the existing furnace, when the furnace and ducts are sound.
- A heat pump that replaces the furnace and adds cooling with one system.
- Ductless mini-splits when there are no ducts, or the ducts cannot be improved without opening walls.
If the ducts need work first, duct repair is part of the plan rather than a surprise later.
Where the outdoor unit goes
On hillside lots in San Anselmo, Larkspur and Sausalito, finding a spot for the outdoor unit can be the hardest part of the job. It needs clear space around the coil, a level pad or wall bracket, a short and protected line set, and a place where its sound will not carry into a bedroom - yours or a neighbor’s. Close to the water, we keep it out of direct wind and spray where we can and show you how to rinse the coil, because salt air shortens coil life.
Efficiency ratings in plain terms
Cooling efficiency is rated in SEER2: the higher the number, the less electricity per unit of cooling. In a climate where the AC runs only part of the summer, the top tiers take longer to pay back than they do in hotter regions, so we show you more than one option and what each would change.
Installation day
- The old equipment is removed and the refrigerant is recovered.
- The pad or bracket, outdoor unit, indoor coil and line set go in.
- The line set is pressure-tested and evacuated before refrigerant is released into the system.
- We set the charge to the manufacturer’s specification and check airflow, the condensate drain and the thermostat.
- The system runs through a full cooling cycle while we measure its performance.
- You get a walk-through of the controls and filter changes, and we register the warranty.
New equipment carries the manufacturer’s warranty and our work carries a labor warranty. A yearly maintenance visit keeps it that way. For local notes, see AC installation in San Rafael or in Novato.