Fleming Island is a consistent run and the spring and autumn calls repeat — the thermostat says 74, the house says otherwise, and nothing at all is broken. Knowing that is most of the diagnosis.
Fleming Island’s Local HVAC Company
Fleming Island HVAC & AC Repair
Upfront pricing from a crew that takes a clammy 74‑degree house seriously. The local AC company for Fleming Island, Eagle Harbor and the Plantation: air conditioning repair and installation, humidity control, mini splits and furnace repair.
Limited‑time offer
HVAC Refresh & Tune‑Up
Cannot be combined with any other offer. One per household.
Get Your Free Estimate
Tell us what’s going on — we’ll get back to you in a flash.
The Great Dane difference
Your Fleming Island AC Company, Every Month of the Year
For more than 20 years Great Dane Heating & Air has kept Jacksonville and the surrounding counties comfortable in every month of the year, including the mild ones that give people the most trouble. A family company with upfront pricing, comfort techs who treat your home like their own, and a soft spot for shelter dogs.
- 4.9★ Across 74 Google Reviews
- Licensed & Insured — FL CAC036942
- BBB A+ Accredited Business
- Installation, Service & Repair
- Heating, Cooling, Air & Ventilation
Heating & Cooling Services
What Comes With a Fleming Island AC Service Call
Florida state certified contractor CAC036942, fully insured, and accredited with the Better Business Bureau at an A+ rating. Every tech who pulls into your driveway works under that license.
Two decades across Duval County and down the west bank with it. The people who answer your call are the same people who show up at your door.
We’re a proud supporter of the Jacksonville Humane Society. Part of what you spend keeping your home comfortable helps shelter dogs here in Jacksonville find one of their own.
No cost, no pressure
Get a Free Estimate on Your System
Tell us what it’s doing. We find the real problem, give you the whole number before any work starts, and tell you straight if a repair is not worth your money.
- A full diagnosis before any quote
- The complete price, upfront
- An honest read on repair versus replace
HVAC Services — Fleming Island, FL
From First Call to AC Repair
Four simple steps — and no surprises at any of them.
Residential & Commercial HVAC — Fleming Island
Heating and Cooling Across Fleming Island
From emergency AC repair and duct cleaning to brand-new systems and mini splits — one crew across Jacksonville and Duval County.
AC Repair
Fast, honest fixes when the cool cuts out. We diagnose it right and quote it upfront — before the work starts.
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AC Replacement & Installation
Right-sized new systems with honest quotes. We help you pick what actually fits your home and budget.
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Emergency AC Repair
Broke down in the Florida heat? Call and we’ll tell you what it is likely to be, and whether it can safely wait until morning.
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Heating Repair
Warm and ready for the cold snaps. Furnaces, heat strips and everything in between.
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HVAC Maintenance
Seasonal tune-ups that prevent summer breakdowns and keep your energy bills in check.
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Heat Pump Services
Efficient heating and cooling in one system — perfect for Florida weather.
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Ductless Mini-Splits
Cool the rooms your ducts can’t reach — garages, additions, sunrooms and more.
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Air Duct Cleaning
Cleaner air and better airflow from every vent in the house.
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Indoor Air Quality
Purifiers, filtration and humidity control so your family breathes easier.
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Commercial HVAC
Installs, repairs and maintenance that keep Jacksonville businesses comfortable.
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Commercial AC Repair
When the cooling quits mid-shift, we find the real fault and give you the number before any work starts.
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Commercial AC System Replacement
Right-sized equipment for your space, quoted upfront so there are no surprises on the invoice.
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Commercial Preventative HVAC Maintenance
Scheduled tune-ups that catch small faults early — before they turn into a closed sign.
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Commercial Indoor Air Quality
Filtration and humidity control for offices, shops, salons and waiting rooms.
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Commercial Air Duct Cleaning
Cleaner air and better airflow through every vent in the building.
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Not sure what you need? Call (904) 512-0091 — we’ll sniff it out.
Heating and Cooling in Fleming Island, FL
Don’t Sweat the Dog Days of Summer
Honest techs, upfront pricing, and cool air your whole pack can agree on.
AC Replacement & Installation in Jacksonville
Old AC Out. New Comfort In.
When your air conditioner is past its prime, more AC repair isn’t always the answer. A new, energy-efficient AC installation can end the breakdown cycle, cool your home evenly, and take a real bite out of summer power bills.
Our Jacksonville team gives you the honest math on AC replacement vs. repair, sizes the new system correctly for Florida heat, and leaves the job site cleaner than we found it — just like this install.

Air Conditioner Repair & Replacement
The Months When Nothing Is Broken and the House Feels Wrong
Fleming Island has the St. Johns on one side and Doctors Lake on the other. In July that barely registers. In April and October it is the whole story.

In the in‑between months the outdoor temperature is pleasant and the dew point is not. The house needs very little cooling and a great deal of drying, and those two jobs are done by the same machine running for the same length of time. Guess which one loses.
An air conditioner removes water only while it is actually running. Satisfy the thermostat in four minutes and you have cooled the house and dried almost none of it. This is why a system that is working perfectly can leave a house feeling like it is not.
A strip of land with a river on one flank and a lake on the other holds moisture in the air later into the day than anywhere further inland. It is not dramatic and it is not fixable. It simply means the drying half of the job is bigger here than the cooling half suggests.
Leaving the fan on ON rather than AUTO keeps air moving across a wet coil after the cooling stops, which puts moisture the system just removed straight back into the house. It is free to change and it is the single most common self‑inflicted version of this problem.
Fleming Island Service Area
Between the River and Doctors Lake
A narrow strip with water on both sides, which is why the air here takes longer to dry out than it does five miles inland. This is where the truck actually ends up.
The largest slice of the run. Consistent housing, consistent equipment, and a lot of two‑storey plans.
Similar vintage, similar systems, and mostly the same conversations about humidity in April and October.
East‑facing streets along the St. Johns, where the damp hangs latest in the morning.
West‑facing and just as close to water, which surprises people who assume only the river counts.
The spine down the middle. Everything out here turns off it.
Shops, offices and restaurants along the highway — work we take on the commercial side.
& Tune‑Up
Limited‑time offer
HVAC Refresh & Tune‑Up
A full seasonal check‑over of the system you already have — so small problems stay small.
Cannot be combined with any other offer. One per household.

HVAC Repair & Replacement in Jacksonville
Let’s Figure This Out Together
No quote needed, no email, no phone number — just tell us what it’s doing and we’ll give you our honest read.
1How old is the system?
2What’s it doing? tick all that apply
3How often has it needed fixing?
Straight talk: If somebody tells you your system is “illegal now” because of the refrigerant rules — it isn’t. R‑410A systems can still be serviced. New equipment moved to R‑454B in 2025 and R‑410A production is stepping down, so topping off an older system gets pricier every year. That’s a reason to plan, not a reason to panic‑buy tonight.
Paw Partner
Community
The Shelter Dogs Came First
Great Dane Heating & Air is run by people who cannot be trusted around a rescue event, and the company was built with the pet population of Duval County written into the plan rather than added to it later.
That looks like rescue events, hours given to the animals still waiting, and a Rescue of the Week put in front of everyone who follows us. It is also why we are a Paw Partner Corporate Sponsor of the Jacksonville Humane Society.
Meet the Jacksonville Humane Society →
Fleming Island Families
Comfortable in April and October Too
A working air conditioner is comfort in July. The months that actually catch people out here are the mild ones, when the temperature is fine and the house still feels wrong.
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Vetted people in your home
Florida state certified — licence CAC036942 — fully insured, and BBB accredited at an A+ rating. The same small crew every time, not a rotating list of subcontractors.
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Humidity is the whole job here
Between the river and the lake the air arrives wet and stays that way, and a house at the right temperature and the wrong humidity feels worse than one that is simply warm. Filtration, purification and humidity control are the tools for that, and they are not the same tool as more cooling.
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Settings before equipment
If the answer is a fan setting and a schedule rather than a machine, that is the answer you will get. Our work is guaranteed — that is the whole point of the name on the truck.
Our work
Check Out Some of Our Work
Real installs from around Jacksonville — straight from our techs’ job sites.
Mini-split install, done right
Wiring up a new system
High-efficiency system on a fresh pad
Twin-system install
Bryant condenser on a fresh pad
Condenser replacement
New air handler, tucked in clean
Delivery day
The big teal truck
Quality inspector on duty
Our smallest biggest fan
Come say hi at the home show
Fleming Island specials
Scare Up a Fleming Island Deal
Helping Fleming Island save is one more way we give back. Mention a coupon when you call.
One per household. Cannot be combined with any other offer.
See all four offers →Reviews
Barking Good News From Fleming Island
★★★★★ 4.9 out of 5 across 74 Google reviews
Paul came out and replaced our blower motor and saved the day. He fielded my call on Sunday evening, then did the service Monday afternoon. Friendly, efficient, and professional.
After years of feeling vulnerable to dishonest HVAC companies, a neighbor put me in touch. He quickly earned my trust — quick to return calls, reasonable rates, and he’s never tried to sell me things I don’t need.
Beyond reproach. Prompt, professional, and had the problem diagnosed and repaired the same day. Integrity, honesty and great customer service.
We’ve used him for everything from small tweaks to replacing our entire unit. Quick, reliable, honest, and clean — and he beat the prices of every competitor. Yes, we priced out seven.
Fast and efficient, unbelievably affordable pricing. He quickly figures out the problem and explains it in a way anyone can understand. You automatically feel like you can trust him.
Our A/C went down and the team showed up Monday morning first thing. We had cool air flowing in no time. The crew was fast, clean, and finished under time.
They replaced our entire AC unit and did some duct work. Professional staff and excellent communication. Top quality service and work!
Mike and the team were very professional, friendly, and knowledgeable. The price was not unreasonable. So happy we found this company — we know we will be taken care of in the years to come.
Just had Great Dane install a new A/C in my home. Mike came to my home, saw what I had, and I told him what I wanted installed. There was absolutely no sales pressure.
Mike came out and gave an estimate with no fluff, which is what I like. He was honest and professional. The team that installed the unit worked well together and the work performed was stellar!
From the blog
Straight Answers From a Jacksonville Air Conditioning CompanyWhat We’d Tell You About HVAC in Jacksonville, FL
No fluff and no scare stories — the same answers we give on the phone, written down so you can try the free fix first.
Airflow Why Your AC Freezes Up in a Florida Summer
Ice on an air conditioner in ninety-degree weather looks like a contradiction, but it is ordinary physics. Your evaporator coil is supposed to run…
Repair How to Reset Your AC After a Power Outage
The power flickers, comes back, and the AC does not. Before you decide it is broken, understand what it is probably doing: waiting on…
Humidity Why Your House Feels Sticky at 74 Degrees
Cooling and drying are two different jobs, and a system can do the first while skipping the second. Start with the free fix, then…
FAQ
The Questions We Get Most
The questions Jacksonville asks us most — straight answers, no jargon.
It is 74 in the house and it still feels damp.
That is the signature complaint out here and it is usually not a fault. In the mild months the system reaches the set temperature almost immediately and shuts off, and since it only removes water from the air while it is actually running, the humidity never gets dealt with. The house is the right temperature and the wrong dryness.
It only happens in spring and autumn.
Which is exactly what you would expect. In July the system runs long enough to dry the house as a side effect of cooling it. In April and October it barely has to run at all, so that side effect disappears while the outdoor air is still carrying plenty of moisture. The equipment has not changed; the season has.
Would turning the temperature down fix it?
It makes the house cold and damp instead of mild and damp, and it costs you money to get there. Run time and airflow are the levers that actually matter, and where the load is genuinely too low for the equipment, dedicated humidity control does the job properly. We would rather measure than have you experiment with the thermostat.
Is a dehumidifier worth it, or is that overkill?
In a house between two bodies of water with a system that is comfortably sized, it is a fair question rather than an upsell. Where adjusting how the system runs gets you there, we will do that first because it costs nothing. Where the load genuinely is too low for the equipment to dry the house, a whole‑house dehumidifier is the right tool and a bigger air conditioner is the wrong one.
Would a variable‑speed system help with this?
It can, and for a straightforward reason: equipment that can run at part load runs for longer at lower output, and longer run time is what removes moisture. It is not the only answer and it is not free, so it deserves a proper comparison rather than being presented as the obvious upgrade.
The whole neighbourhood is around the same age. Should I be planning?
Planning, yes. Replacing on somebody else’s timetable, no. A community built inside a few years does arrive at these decisions together, but yours has its own readings and they are the ones that matter. We will tell you honestly where it sits.
Should the fan be set to ON or AUTO?
AUTO, almost always, and it matters more here than most places. Leaving the fan running continuously blows air back across a wet coil after the cooling has stopped, which re‑evaporates moisture the system just removed and puts it straight back into the house. It is one of the most common causes of a damp‑feeling home and it costs nothing to change.
What is the $99 HVAC Refresh & Tune‑Up?
A full seasonal check‑over of the system you already have — measurements taken, the parts that genuinely foul cleaned, and a straight answer about what needs attention and what does not. Out here it is also when we look at how the system is set to run in the mild months, which is where most of the complaints come from. Cannot be combined with any other offer, one per household.
What humidity should the house actually be at?
Comfortable is a range rather than a number, and what people notice is the difference rather than the reading. The useful thing is measuring it in a few rooms rather than guessing from how it feels, because a house that is genuinely fine and a house that is genuinely damp feel much more alike than the numbers suggest.
Do you come out to Fleming Island?
Regularly. Fleming Island, Eagle Harbor, the Plantation and the streets along US‑17 are inside the normal service area at the same pricing as anywhere else we go. Great Dane is licensed in Florida as CAC036942, which you are welcome to look up before you let anybody into the house.
Will you tell me if I do not need the work?
Yes, and out here that is frequently the answer, because the most common complaint we get has no fault behind it at all. You will be told what is happening and why, and what the cheapest thing that helps actually is.
Anything worth checking before I call?
Three things that cost nothing. Check whether the fan is set to ON rather than AUTO, because that alone explains a lot of damp houses. Look at the filter, since a collapsed one starves the system. And note whether the problem is the temperature or the feel — those are two different calls and knowing which saves us both time.
Done Right the First Time
Honest, upfront pricing and work we stand behind 100% — that’s the Great Dane guarantee.
Serving the Jacksonville, FL area
HVAC Service Near You
Fast, honest HVAC service across Jacksonville, Duval County and the surrounding Northeast Florida communities.



