Very few places swing the way this valley does, and almost nobody designs a house around it. That swing is free cooling if you set the building up to take it — and it is the reason this shop exists.
Vacaville sits between the Vaca hills and the Delta. On a typical summer day the afternoon runs into the high nineties or past a hundred — and then, most evenings, air moves in off the Delta and the temperature falls a very long way before morning.
That daily swing is the single most useful thing about this climate, and most houses are set up to ignore it completely: sealed shut, running the air conditioning at eleven at night against outdoor air that is already cooler than the thermostat setting.
The shape matters more than the numbers: a long hot peak, a sharp transition in the evening, and many hours when outside is cooler than inside.
This is a description of a pattern, not a forecast or a measurement of your house. Some evenings do not cool off, and smoke season closes the windows entirely. What we do is set the house up to take advantage of the evenings that do — which here is most of them.
Most HVAC companies here only sell you the first half.
Between roughly noon and seven, nothing else will do. The system has to be correctly sized for the real peak load, the ducting has to be able to carry the air, and the attic it runs through has to not be working against it.
That is ordinary HVAC work, done properly: a load calculation from the building, static pressure measured before equipment is specified, and duct leakage dealt with rather than ignored.
Once the outside air drops below the inside air, running a compressor is buying something the weather is offering for nothing. A whole-house fan moves that cooler air right through the building in minutes.
It also flushes the attic and the building's thermal mass, which is what makes the following afternoon start from a lower point.
Not cooling, short cycling, icing up, tripping the breaker, or running from noon to midnight. Diagnosed on readings before a part is quoted.
Sized from the house and the real peak, not from the old data plate. Permit, Title 24 and inspection handled.
Sized, sited and installed with the attic venting checked first — which is the step that is most often skipped and most often causes the disappointment.
Static pressure, leakage, return sizing and register balancing. Where most comfort complaints actually originate.
Furnace service, heat-exchanger and combustion checks, replacement, and heat pumps covering both seasons on one machine.
One visit in spring, before five months of hard running. The cheapest hour on this page and the most likely to prevent a July failure.
There is a version of this pitch that oversells whole-house fans, and we would rather not make it. A fan does nothing at two in the afternoon, nothing on a smoky day, and nothing on the nights that stay warm.
What it does is remove the compressor from several hours of every evening that does cool off, which in this valley is most of them. That is a genuine and worthwhile saving, and it is a different claim from the one usually made.
An arrival window you can plan around, and a message before we set off.
Readings at the equipment, at the return and at the registers — plus the attic, which in this valley is part of the problem.
Repair and, where relevant, replacement side by side, with ventilation priced separately so its value is visible on its own.
Old parts shown to you, packaging taken away, system left running while we are still there.
We are on Peabody Road in Vacaville. Fairfield, Suisun City and Dixon are fifteen minutes away, Davis and Winters a little further, and the rest of the list is inside forty.
It is a large fan mounted in the ceiling that pulls air out of the house and pushes it into the attic, so opening a few windows draws cool outside air right through the building. In Solano County it works unusually well, because the evening air genuinely does drop a long way below the afternoon peak. It is not a replacement for air conditioning — it is a way of not running the air conditioning for several hours a day.
On a smoky day, when you want the windows shut and the filtration running. On a humid evening, when you would be pulling moisture in. And on the handful of nights each summer when it simply does not cool off. A fan is a tool for the nights that do cool, which here is most of them — but we will tell you plainly that it is not every night.
Usually not. It is more often airflow — a return that is too small, ducting that has been crushed or disconnected in the attic, or a single thermostat downstairs deciding when everybody has had enough cooling. We measure airflow at the registers on both floors before recommending anything, because replacing equipment does not fix a duct problem.
Sized to the actual load, which is calculated from the building rather than from its square footage. It is worth being careful here: oversizing is common and it causes short cycling, poor dehumidification and a system that wears out early. A correctly sized system running longer beats an oversized one running in bursts.
Yes. Equipment changeouts in California generally require a permit and Title 24 documentation, and Solano jurisdictions do inspect. We pull the permit, schedule the inspection and hand over the closed permit with the job.
Spring is when this work is cheap, available and worth the most.