The short answer
We size a new AC for your specific Los Altos home with a room-by-room load calculation, check whether the existing ducts can carry cooled air, and plan the outdoor unit placement before quoting. For many homes a heat pump is worth comparing, since it cools in summer and heats in winter.
Plenty of houses in Los Altos were built for a climate where air conditioning felt optional. Summers on the west side of the Santa Clara Valley are dry and usually gentler than in the hotter southern and inland parts of the valley, yet a string of warm afternoons can still leave upstairs bedrooms stuffy well into the night. ClearSky Heating & Cooling drives about ten miles west from San Jose to plan and install central cooling across the 94024 ZIP code. Our approach starts with your house, its rooms, windows, attic and ductwork, rather than with a catalog. The goal is a system that is sized for how Los Altos actually feels in July, fits the lot without bothering anyone next door, and works with the heating equipment you already have or plan to switch to.
A Load Calculation Beats Copying the Old Nameplate
The most common installation mistake we see is simply matching whatever capacity was there before. That older unit may have been oversized from day one, or the house may have changed since: new windows, added insulation, a converted garage, a second-story addition. An oversized air conditioner reaches the thermostat setting quickly, shuts off, and repeats, which wears parts and leaves rooms clammy because the coil never runs long enough to pull moisture out.
Instead, we measure. Square footage is only one input. We look at window area and orientation, attic insulation depth, ceiling heights, and how much afternoon sun lands on west-facing walls. In a west-valley climate the correct answer is often a smaller, steadier system than people expect, and a variable-speed compressor can make a noticeable difference in comfort during the mild-but-warm stretches that make up most of a Los Altos summer.
Adding Cooling to a House That Never Had It
If your home has a forced-air furnace but no AC, the ductwork is the big question. Ducts sized only for heat can be too small for cooling airflow, and older runs in an attic or crawlspace are frequently leaky, crushed, or poorly insulated. Cold air lost into a hot attic is money spent on cooling nothing.
We inspect the supply and return paths, test static pressure, and tell you plainly whether the ducts can be reused, need sealing and a few upgraded runs, or should be replaced. Homes without any ducts are not out of luck: ductless mini-split systems can cool a few key rooms with small refrigerant lines and wall or ceiling heads, and they avoid opening walls.
- Ducts reusable as is: we seal joints and rebalance dampers
- Ducts partly undersized: we upgrade the problem runs and add a return if needed
- Ducts in poor shape: we price a replacement alongside the equipment so you see the whole picture
- No ducts at all: we lay out a mini-split option room by room
Placing the Outdoor Unit with Neighbors in Mind
Condenser placement matters more than most homeowners realize. The unit needs clear airflow on all sides, a level pad, a short and protected line set, and a spot that keeps compressor noise away from bedroom windows, both yours and the neighbors'. Side yards in many Los Altos neighborhoods are narrow, so we measure clearances before recommending a model rather than after.
Quieter variable-speed condensers are worth considering when the only workable location sits close to a fence line. We also check local setback and permit requirements as part of the planning, so the paperwork is handled before the installation crew arrives.
What Installation Day Looks Like
Most straightforward replacements finish in one day; a first-time install with duct work can take longer. Here is the usual order of work so you know what to expect when the truck pulls up.
- Protect floors and set up a clear path to the attic or crawlspace
- Recover refrigerant from the old system and remove the existing equipment
- Set the new condenser on a level pad and install the matching indoor coil
- Run or flush the refrigerant lines, pressure test, and pull a deep vacuum
- Charge the system to manufacturer specs and verify airflow at the registers
- Set up the thermostat and walk you through the controls and filter location
Thinking Ahead About Your Furnace
Your new air conditioner will share a blower and ducts with whatever heats the house, so it pays to think about the furnace at the same time. Under Bay Area Air District rules, gas furnaces manufactured from 2029 onward must meet a zero-NOx standard, which in practice steers replacements toward heat pumps. Those rules do not require you to replace a furnace that still works.
If your furnace is getting older, a heat pump installed now can handle cooling today and take over heating later, sometimes with the gas furnace kept as backup. We will lay out both paths side by side. For incentives, we check BayREN and your local clean energy provider for whatever is currently offered and confirm it before including it in a proposal.
More services in Los Altos
- AC Repair in Los Altos
- Heating Repair in Los Altos
- Heat Pump Installation in Los Altos
- Furnace Repair in Los Altos