Swamp cooler to central AC conversion
Done properly,this is a real project.
Converting from evaporative to refrigerated air is not swapping one box for another. It usually means new ductwork, a return air system that does not currently exist, and 240-volt power where there is none. Here is exactly what that involves, before anyone quotes you.
Free quotes Permits included Financing available
Setting expectations first
Why this costs more than a normal AC replacement
When a homeowner replaces a failed air conditioner, the ducts, the returns, the electrical circuit and the equipment platform all already exist. The new system drops into infrastructure built for it.
A conversion has none of that. Your house was built to be cooled by moving a very large volume of barely-cooled air through it and letting it escape out the windows. Refrigerated air conditioning works on the opposite principle — a smaller volume of much colder air, circulating in a sealed loop. Almost nothing built for the first approach serves the second.
So a conversion quote covers building the infrastructure as well as installing the equipment. Anyone quoting you a conversion at the price of a straight changeout has either not looked properly, or is planning to reuse things that should not be reused.
If a conversion quote looks suspiciously like a replacement quote, ask what they are doing about the return air.
Five things that make it a project
Every one of these should appear on your quote as a line you can see. If any of them is missing, it is worth asking why.
A return air system that does not exist yet
The one people never see coming
This is the biggest single item and almost nobody anticipates it. Your swamp cooler pushes air into the house, and that air leaves through open windows. The windows are the return. There is no return ductwork anywhere in the building because the design never needed any.
Refrigerated air conditioning recirculates. Air has to travel from the rooms back to the equipment through sealed ducting, and without an adequate return path the system is starved, static pressure climbs, the coil freezes and the blower wears out early. Building that return system properly — grilles, ducting, adequate sizing — is real work and it is not optional.
Supply ductwork sized for the wrong thing
Swamp cooler ducting moves a very high volume of air at low pressure, often through a single large ceiling drop rather than a distributed system. Refrigerated air needs less volume at higher pressure, distributed to each room and balanced between them.
Existing swamp cooler ducting is also typically uninsulated, because there was little point insulating a duct carrying air only slightly cooler than the attic around it. Run refrigerated air through that in a 150-degree Fresno attic and you lose a substantial share of your cooling before it reaches a room. More on duct replacement.
Electrical that was never sized for a condenser
A swamp cooler runs a small motor and a pump on a modest 120-volt circuit. An outdoor condensing unit needs a dedicated 240-volt circuit, a disconnect within sight of the unit, and enough capacity in your panel to carry it.
Many of the Fresno homes still running swamp coolers have older service panels, and some do not have the capacity available. That gets established before anything is ordered rather than discovered on installation day, and where a panel upgrade is required it is quoted by a licensed electrical contractor rather than absorbed vaguely into our number.
Somewhere to put equipment that has never been there
A central system needs an indoor air handler or furnace with a proper platform, drainage and service access, plus an outdoor condenser on a level pad with adequate clearance. Homes built around evaporative cooling frequently have no closet, no attic platform and no obvious spot for either.
Sometimes the answer is a packaged unit rather than a split system, which puts everything outside in one cabinet. That is a decision made by looking at your house, not by preference. More on packaged units.
A hole in your roof to close properly
Removing a roof-mounted cooler leaves an opening that has to be framed, decked, flashed and roofed so it does not leak in five years. This is genuinely the step where a rushed conversion shows up later, usually as a stain on a ceiling during the first serious rain.
It appears on our quotes as its own line. If it does not appear on someone else's, that is worth a direct question about who is closing the roof and how.
Worth thinking about now
What is heating your house currently?
Homes cooled by swamp coolers are frequently heated by wall furnaces, floor furnaces or a gravity system, none of which use ductwork. Which means the conversion you are considering is about to install a duct system in a house that has never had one.
That is a genuine opportunity and it is worth deciding deliberately rather than by accident. Once ducting is in place, central heating becomes straightforward and inexpensive to add at the same time, whereas retrofitting it later means paying for access twice.
It is also the moment to consider a heat pump, which provides both heating and cooling from one system and suits the Fresno climate well.
The decision, in short
- Cooling onlyLowest cost now. Keeps your existing wall or floor furnaces, which continue heating room by room.
- Add central heatingA furnace or heat pump using the same new ductwork. Costs meaningfully less done now than done separately later.
- Retire the old furnacesOlder wall and floor furnaces are frequently at end of life and worth assessing while everything else is being planned.
- We will price both waysSo you can see the actual difference rather than guessing at it.
What you actually get
Worth being clear about, because this is a significant amount of money and the benefits should be real ones.
It works at 108 degrees
Refrigerated air is not limited by outdoor humidity, so performance does not collapse on exactly the afternoons you need it most.
The house stays closed
No open windows, which means less dust, less outside noise, better security and no more explaining the system to visitors.
No added humidity
Refrigerated air removes moisture rather than adding it, which matters for comfort and for anything in the house that does not enjoy damp.
Real temperature control
A thermostat that holds a number rather than a cooler that produces whatever the outdoor conditions allow that day.
Property value and marketability
Central air is what buyers in this market expect. A swamp cooler is increasingly something a buyer prices against you.
Much less seasonal work
No pads, no pump, no spring startup, no fall shutdown, no water line to drain before the first freeze.
The honest trade-off: refrigerated air costs considerably more to run than evaporative cooling. That is worth factoring in rather than being surprised by it in August, and it is one of the things we will talk through before you commit.
How we run a conversion
Typically two to four days on site depending on scope, planned in advance so you know what is happening and when.
1
Before anything is quoted
Assessment and load calculation
We measure the house, calculate the actual cooling load rather than guessing at tonnage, look at the attic and the roof, check your electrical panel capacity, and establish where equipment can physically go. This is what makes a conversion quote reliable instead of optimistic. How sizing is done.
2
Before work starts
Design, written scope and permit
Duct layout and return placement designed, equipment selected, everything written out as a fixed scope you approve. We pull the mechanical permit and prepare the energy compliance documentation. More on permits.
3
Day one
Removal and roof closure
The cooler comes off, the water line is capped, and the roof opening is framed, decked, flashed and made weathertight the same day. We do not leave a roof open overnight.
4
The bulk of the work
Ductwork, returns and equipment
Supply ducting installed and insulated, the return system built with properly sized grilles and ducting, the equipment platform constructed, condenser pad set, line set run and the electrical circuit installed.
5
Final day
Commissioning and verification
Deep vacuum verified with a micron gauge, charge confirmed by superheat and subcooling, total external static pressure measured, airflow balanced room by room and the temperature split checked. Then we show you the readings.
6
After
Inspection and closeout
Inspection scheduled and attended by us, energy compliance documentation registered, permit closed, equipment registered for warranty, and your paperwork handed over complete.
What it costs
Published, because you deserve to plan before you call
A full evaporative-to-refrigerated conversion in the Fresno area typically falls in the range below, including equipment, ductwork, the return air system, electrical, roof closure, permit and inspection.
- Home size and load — the calculated tonnage and the number of rooms to serve.
- Ductwork scope — whether any existing ducting is genuinely reusable, which is uncommon.
- Return air complexity — how many returns are needed and how accessible those paths are.
- Electrical — whether your existing panel has capacity or an upgrade is required.
- Heating decision — cooling only, or central heating added on the same ductwork.
- Equipment tier — efficiency rating and whether staged or variable-speed equipment is chosen.
Financing is available, and for a project of this size it is worth discussing early rather than at the end. Your firm price follows the on-site assessment and comes as a written fixed scope.
Conversion questions
How much does it cost to replace a swamp cooler with central air in Fresno?
Typically $12,000 to $22,000 for a full conversion including equipment, ductwork, the return air system, electrical, roof closure, permit and inspection. The range is wide because the scope genuinely varies — home size, how much ducting is needed, return air complexity, whether your electrical panel has capacity, and whether you add central heating at the same time.
Why is a conversion more expensive than replacing an existing AC?
Because a replacement drops new equipment into infrastructure that already exists, and a conversion has to build that infrastructure. Your home has no return air ductwork, since the swamp cooler used your open windows as the return. Supply ducting sized for evaporative airflow is generally unsuitable and usually uninsulated. There is no 240-volt circuit for a condenser. And a roof opening needs closing properly.
Can you reuse my existing swamp cooler ductwork?
Occasionally in part, but usually not. Swamp cooler ducting is sized for a much higher volume of air at lower pressure, is frequently a single large ceiling drop rather than a distributed system, and is typically uninsulated because it never needed to be. Running refrigerated air through uninsulated duct in a 150-degree Fresno attic loses a substantial share of your cooling before it reaches a room. We assess it honestly and tell you what is genuinely usable.
What is return air and why does it matter so much?
Refrigerated air conditioning recirculates air, so it must travel from your rooms back to the equipment through sealed ducting. A swamp cooler does not recirculate — it pushes outside air in and that air leaves through open windows, so the house has no return ductwork at all. Building an adequate return system is the single largest item people do not anticipate, and without it the system is starved, static pressure climbs, the coil freezes and the blower fails early.
Will my electrical panel handle it?
Sometimes, and sometimes not. An outdoor condenser needs a dedicated 240-volt circuit and a disconnect, and many Fresno homes still running swamp coolers have older panels without spare capacity. We check this during the assessment rather than discovering it on installation day, and where an upgrade is required it is quoted by a licensed electrical contractor as a visible line rather than buried in our number.
Should I add central heating at the same time?
It is worth pricing both ways. Homes with swamp coolers usually have wall or floor furnaces and no ductwork, so a conversion installs a duct system where none existed. Adding central heating while that ducting is going in costs considerably less than retrofitting it later, since you only pay for the access once. A heat pump can handle both heating and cooling from a single system.
How long does a conversion take?
Typically two to four days on site depending on scope, with the roof opening closed and made weathertight on the first day rather than left open. Permits and equipment ordering happen before we start, so the on-site time is the actual work rather than waiting around.
Will my electric bill go up?
Yes, and we would rather say so now than have you discover it in August. Evaporative cooling is remarkably cheap to run because it is essentially a fan and a pump. Refrigerated air conditioning uses a compressor and costs meaningfully more. What you get for that is cooling that works at 108 degrees, a closed house and real temperature control. It is a genuine trade-off and it is worth going in with your eyes open.
Start with an honest assessment
Free quote, a proper load calculation, electrical capacity checked, and a written fixed scope with every line visible.
Prices shown are typical ranges for the Fresno area and are not quotes. Your firm price follows an on-site assessment and load calculation, and is provided as a written fixed scope. Electrical panel upgrades, where required, are performed by a licensed electrical contractor and quoted separately. Financing is provided by third-party lenders subject to their approval and terms. California Heating & AC Repair is operated by Craftline Renovations, Inc. · CSLB License #999179 · Licensed and insured.