Charleston runs from 1700s single houses to brand-new Nexton two-stories — and the right system is different for each. Pick your home for an honest read, then explore the animated cross-section to see where everything lives.

Historic Charleston single house

Downtown, South of Broad, French Quarter, Harleston Village

No room for ducts, and the architecture is the point — condition these homes without cutting into it.

Where the equipment lives — tap a part in the drawing or the list

Best fit

Best fit

Ductless mini-splits

Most single houses have no space for conventional ductwork, and cutting plaster or piazzas to make room is the wrong answer. A wall head per floor conditions each level independently — and each head dehumidifies its own zone, which matters more than raw tonnage in a 200-year-old envelope.

Service details See how it works
Best fit

Slim-duct heat pump

Where a fully ductless look isn't wanted, a compact concealed-duct heat pump can serve two or three rooms from a closet or soffit with short runs — heating and cooling from one system through Charleston's mild winters, without touching the historic fabric.

Service details See how it works

Works well

Works well

Dedicated humidity control

Old, leaky envelopes hold moisture, so pairing the system with real humidity control — right-sized equipment that runs long, gentle cycles, plus filtration where it helps — is often the difference between 'cool' and 'comfortable' downtown.

Service details

Watch out for

Watch out for

Conventional ducted central AC

Forcing full-size duct runs into a single house usually means butchering plaster, closets, or piazza ceilings. If ducts weren't designed in, the honest answer is usually to skip them rather than oversize around them.

See how it works
Watch out for

Equipment placement rules

In the historic districts, the Board of Architectural Review expects mechanical equipment to stay out of public view — and much of the peninsula also requires flood-zone elevation for outdoor units. Placement gets designed before anything is ordered.

Ductless mini-splits Downtown Charleston service Typical pricing ranges Financing options

Pre-war bungalow & craftsman

Wagener Terrace, Hampton Park Terrace, Park Circle

The ducts were retrofitted decades after the house was built — fix the ducts and right-size the equipment.

Where the equipment lives — tap a part in the drawing or the list

Best fit

Best fit

Right-sized variable-speed central system

High ceilings and original windows mean load calculations matter. The honest read is often a smaller, variable-speed system that runs longer and wrings out humidity — not the bigger unit that short-cycles and leaves the house clammy.

Service details See how it works
Best fit

Duct sealing & home performance

These 1910s–1940s homes carry retrofit ductwork through attics and vented crawl spaces that was never designed for today's equipment. A right-sized system plus duct sealing usually beats a bigger unit — the leaks are where the comfort actually goes.

Service details

Works well

Works well

Heat pump

Charleston's mild winters suit heat pumps well, and one system covering both seasons keeps a bungalow's mechanical footprint small. It only pays off if the ducts it feeds are sealed first.

Service details See how it works
Works well

Mini-split for the converted attic

The half-story upstairs that roasts every summer rarely needs the whole system reworked — a single ductless head gives that space its own zone without touching the rest of the house.

Service details See how it works

Watch out for

Watch out for

Oversizing

The classic mistake in older Charleston homes: sizing to the leaks instead of fixing them. An oversized unit hits the thermostat number fast and shuts off before it removes moisture.
Watch out for

Old electrical before heat strips

Knob-and-tube-era wiring needs checking before electric backup heat is added — part of an honest assessment, not an afterthought on install day.

AC installation HVAC maintenance North Charleston service Typical pricing ranges

Mid-century brick ranch

West Ashley, James Island, older Mt. Pleasant

The Lowcountry's workhorse — and half its comfort problems are duct problems wearing an equipment costume.

Where the equipment lives — tap a part in the drawing or the list

Best fit

Best fit

Heat pump

Heat pumps fit ranches well: mild winters, single-story layouts, and one right-sized system for both seasons. It's the textbook match for this floor plan in this climate.

Service details See how it works
Best fit

Duct sealing or replacement with the changeout

Ranch ducts run through a vented crawl space that Charleston humidity treats as a sauna. Pairing equipment replacement with duct sealing or replacement is where the efficiency actually comes from — new equipment on rotten ducts just loses faster.

Service details

Works well

Works well

Central AC with gas or electric heat

A conventional split system still serves a ranch fine where gas heat is already in place — the single-story duct layout is about as simple as residential ductwork gets.

Service details See how it works

Watch out for

Watch out for

Crawl-space duct condensation

Sweating, rusting ducts under the house are the quiet comfort killer in this housing stock — worth an actual look before any equipment decision.
Watch out for

Undersized original returns

1950s–70s return ducts often choke modern equipment. If the new system can't breathe, it can't hit its ratings — returns belong in the replacement scope.
Watch out for

Recharging an R-22-era system

Aging systems on phased-out refrigerant are usually worth replacing, not recharging — we'll show you both numbers rather than sell you a top-off.

Service details

Heat pumps West Ashley service James Island service Typical pricing ranges Financing options

Raised coastal & beach house

Folly Beach, Isle of Palms, Sullivan's Island, Kiawah, Seabrook

Salt air and flood elevation set the rules out here — the system is designed around both from day one.

Where the equipment lives — tap a part in the drawing or the list

Best fit

Best fit

Coastal-rated heat pump

Salt air is the defining constraint: standard condenser coils corrode years early on the barrier islands. Coastal-rated equipment with protective coil coatings, mounted on an elevated platform at or above the required flood elevation, is the honest starting point.

Service details See how it works
Best fit

A rinse-and-inspect maintenance rhythm

On the islands, maintenance isn't an upsell — it's what stretches equipment lifespan. Gentle coil rinses through the season plus an annual professional cleaning directly counter the salt.

Service details

Works well

Works well

Central AC with coated coils

A conventional cooling system still works at the beach when it's specified for the coast — coated coils, corrosion-conscious hardware, and platform placement designed in rather than bolted on after.

Service details See how it works
Works well

Mini-split for the ground-level room

Bunk rooms, workshops, and enclosed storage under a raised house sit outside the main system's ductwork — a single ductless head conditions that space without extending ducts below the flood line.

Service details See how it works

Watch out for

Watch out for

Standard (non-coastal) equipment

Coil corrosion is the early killer at the beach — ask about coastal warranties and coatings before buying, not after the first failed coil.
Watch out for

Flood-zone placement mistakes

Outdoor units and air handlers belong at or above the required flood elevation in VE/AE zones. Wind exposure and a hurricane-season shutdown/restart routine deserve a plan too.

Service details

AC installation Storm Center Isle of Palms service Maintenance plans Financing options

New-construction two-story

Summerville, Goose Creek, Nexton, Cane Bay, Carnes Crossroads

Builder-grade equipment cools the house but loses the upstairs-downstairs fight — zoning is the fix.

Where the equipment lives — tap a part in the drawing or the list

Best fit

Best fit

Two-zone system design

Two-story layouts often deserve zoning or a two-system design: separate trunks and a thermostat per floor stop the second story from running three degrees warmer every summer afternoon.

Service details See how it works
Best fit

Variable-speed replacement when the builder unit ages out

Builder-grade systems are built to a price, not to your bills — single-stage equipment cools the house but struggles with second-floor comfort and humidity on the swing seasons. A variable-speed replacement fixes the upstairs-downstairs fight for good.

Service details See how it works

Works well

Works well

Mini-split for the FROG or bonus room

The finished room over the garage usually sits at the far end of the duct system and shows it. Its own ductless head gives it its own zone without reworking the whole house.

Service details See how it works

Watch out for

Watch out for

Living with the builder thermostat

Builder thermostats leave efficiency on the table — schedules, staging, and humidity logic matter, especially on a system that already struggles in the swing seasons.
Watch out for

Warranties the builder never registered

Registration deadlines on factory warranties often pass before the first owner ever checks — worth confirming while the system is still young.

AC installation Summerville service Goose Creek service Typical pricing ranges Financing options

Townhome & condo

Mount Pleasant, Nexton, Daniel Island, park-circle infill

Tight mechanical closets, shared walls, and HOA rules — compact equipment picked for quiet and fit.

Where the equipment lives — tap a part in the drawing or the list

Best fit

Best fit

Compact heat pump with a slim air handler

Attached homes usually give the system one small closet and one small outdoor pad. A compact heat pump with a slim vertical air handler fits both, and covers heating and cooling with a single piece of equipment — the right shape for the space and for Charleston's mild winters.

Service details See how it works
Best fit

Mini-split for the FROG or bonus room

The finished room over the garage is the classic townhome hot spot — far from the air handler, over an unconditioned garage. A single ductless head gives it its own zone without rerouting ducts through finished space.

Service details See how it works

Works well

Works well

Right-sized central AC replacement

Where the existing ducted layout works, a like-for-like replacement sized to the actual load keeps things simple — attached homes share walls with conditioned neighbors, so honest sizing often comes in smaller than the nameplate being replaced.

Service details See how it works

Watch out for

Watch out for

Shared-wall noise

Equipment placement and vibration matter more when a neighbor lives on the other side of the wall. Where the outdoor unit sits, and how it's isolated, is part of the design — not an install-day improvisation.
Watch out for

HOA equipment rules

Many associations have rules about where outdoor equipment can sit and what's visible from the street. Confirming placement against the HOA's requirements before ordering avoids expensive do-overs.
Watch out for

Choked closet returns

Slim mechanical closets often mean tight return paths. A system that can't pull enough air back can't deliver its rating — return sizing belongs in any replacement conversation.

Heat pumps Ductless mini-splits Mount Pleasant service Daniel Island service Typical pricing ranges Financing options

Read the full home-systems guide

Or skip the reading — call (843) 790-6504 and describe your house to a person who's worked in one like it.

The whole Holy City Heating & Air team and Harvey family with the wrapped service fleet in the company warehouse

About Holy City

Our roots run deep in the Lowcountry

In 2015, with over 20 years of industry experience, Tom Harvey established Holy City Heating & Air. Our technicians are seasoned professionals who are locals in the area — we live where we work.

As the team has grown, the beliefs haven’t changed: give back to the local community, care for our customers, and invest in our employees. When you call us, you know you’re getting a superior level of service — for every season.

Learn more about us

Careers — We're Hiring

Do your best work in the Holy City

Investing in our employees is one of the three commitments this company was built on. If you take the craft seriously, we'd like to meet you.

80% of medical paid
401K match
Student debt assistance

See careers & apply Meet the crew

Porch Talk

What the neighbors are saying

Pulled straight from the reviews our clients share — the kind of talk we’re proud to overhear.

A Holy City technician talking with a happy customer at their Charleston home — Real visits, real neighbors — from our Happy Customers album.

We couldn't be more pleased with Holy City! Our provider, Justin Todd went above and beyond during our maintenance visit to find out why we weren't getting heat in certain rooms. He fixed the problem and provided a very reasonable estimate for a long term solution. Also, the maintenance plan is a great value! I will recommend to all my friends and neighbors.

— Emily C.
Holy City responded quickly when I called about my heater. I was worried it was an electrical issue. Thankfully it wasn't. Richard was able to replace the part. He and Holy City were easy to work with and courteous. I highly recommend them both.

— Ashley M.
I love working with Holy City. The staff are responsive and get things done properly and quickly. Their technician Ian was knowledgeable about the issue with our units and he explained to me the problem and what to do. I highly recommend Holy City to anyone who needs a first class service with knowledgeable and friendly staff!!!

— Eve Y.
Holy City and their Technicians are awesome! We subscribe to the Annual service plan and always have professional service on the units. They go above and beyond when answering questions and help with connecting our wireless devices. Great job and highly recommended!!

— Paul F.
Excellent company! Great communication and prompt service. Technician was thorough with his diagnostic testing! He showed a level of professionalism that has won me over plus their quote was much less than half the price of their competitor!! Will be calling them for all of my future HVAC needs!!

— Larry J.
Anthony was an excellent technician. He was personal and most polite. I was quite impressed with his plumbing knowledge and expertise. I will request him for all my plumbing needs. Also, my thanks for the quick response to my service needs.

— Paulette S.
My experience with Holy City and Lamar was wonderful. He was thorough and explained everything to me step by step. He truly cared to make sure my HVAC issue was diagnosed properly and fixed. I highly, highly praise and recommend Holy City for all your HVAC needs. You will be glad you chose them!

— Helen the S.
Mark came today to service my system, which was installed a year ago by Holy City Heating and Air, LLC. Mark was courteous, came exactly when scheduled, performed the maintenance helped me understand my thermostat, and just was excellent. This is a great company and cares about customers satisfaction after the installation was done. I chose a high-efficiency Daikin system and my family is very pleased with everything a year after it was installed!

— Mark M.
Matt the “Comfort Consultant” was super helpful, and attentive and answered all of our questions in a timely manner. The install crew was fast, on time, professional, and very clean and considerate when it comes to the house, attic, and yard. I would 100% recommend them to anyone who needs help on their HVAC units and Ductwork.

— David G.
I cannot say enough good things about this company. They are responsive and very knowledgeable. Gideon was able to get our system up and running when another company reported extensive work needing to be done. Needless to say, they saved us a ton of money. Very happy with my experience.

— Brad O.
Hunter and TJ did a great job for us! They are very knowledgeable, professional, and personable. They took the time to really listen to my concerns and our plumbing symptoms and as a result correctly and quickly diagnosed the problem. Which by the way no other plumber had been able to do. The moral of the story: call Holy City Heating and Air, LLC first!

— Mo F.

Testimonials published by Holy City Heating & Air. Read or leave a Google review

From our customers

Thank y’all for trusting us with your homes

A few of the customers across the Lowcountry who’ve trusted Holy City with their comfort — in their own words.

Thank you, Ashley M.

heating repair

“Holy City responded quickly when I called about my heater.”
Thank you, Emily C.

maintenance visit & heat diagnosis

“Went above and beyond during our maintenance visit.”
Thank you, Paulette S.

plumbing service

“I was quite impressed with his plumbing knowledge and expertise.”
Thank you, Mark M.

Daikin system maintenance

“I chose a high-efficiency Daikin system and my family is very pleased.”
Thank you, David G.

HVAC installation & ductwork

“The install crew was fast, on time, professional, and very clean.”
Thank you, Mo F.

plumbing diagnosis

“They took the time to really listen … and quickly diagnosed the problem.”
Thank you, Brad O.

HVAC repair

“Gideon was able to get our system up and running … saved us a ton of money.”
Thank you, Larry J.

HVAC diagnostics

“Their quote was much less than half the price of their competitor!”

Read the full reviews →

Friends & Family Membership

Maintenance that pays for itself

Every HVAC system needs maintenance — it’s how you keep it efficient, comfortable, and out of trouble in Charleston’s climate. Members get priority treatment and meaningful savings, starting at $21 a month.

See the membership

20% off

equipment repairs
Half-priced

service fee
Priority

service scheduling
From $21

per month

Bosch Comfort Pro
Mitsubishi Diamond Dealer

Brands we install & service

One of the top Daikin Comfort Pros in the nation.

The Comfort Pro distinction is Daikin’s dealer standard — and it comes with the Daikin Comfort Promise: if we haven’t met your expectations within a year of your installation, we come back and make it right at no cost to you.

12-year parts limited warranty on registered systems
Daikin-trained installation team
Humidity-smart inverter systems

Browse the Daikin catalog Learn what Comfort Pro means

Also under services

We work with Bosch & Mitsubishi a lot

Beyond Daikin, our team installs and services Bosch and Mitsubishi systems across Charleston and the Lowcountry — heat pumps, ductless mini-splits, and whole-home comfort equipment. Bring us the brand you have (or the one you want); we’ll size it honestly and stand behind the work.

Bosch
Mitsubishi
Daikin Comfort Pro

Ask about your system

Residential & Commercial — it’s on the van

Charleston businesses run on comfort too

Storefronts with doors open to July humidity, historic buildings that were never built for ductwork, restaurants where the kitchen fights the dining room — commercial comfort in the Lowcountry is its own trade, and it’s where our founder started. Multi-zone Daikin VRV, packaged systems, server room cooling, and maintenance planned around your business hours.

Commercial AC repair & installation
Commercial heating
Daikin VRV multi-zone
Server room cooling
Commercial geothermal
Maintenance on your hours

Commercial Service Call (843) 790-6504

Call support until 9 PM — a real person answers.

Where We Roll

From South of Broad to Summerville, we’re already in the neighborhood

Sullivan’s Island salt air, Daniel Island new-builds, Mount Pleasant family homes — our technicians cover the communities we call home. Find local notes, neighborhoods, and answers for your area.

View all service areas

A wrapped Holy City Heating & Air service van parked in a Charleston residential neighborhood — You’ve probably already seen the van on your street.

Financing

Comfort now, on a payment that fits

We partner with Goodleap, a home-improvement financing specialist offering a wide variety of loan and repayment options. A short application tells you whether you qualify.

Explore financing

Homeowner Education

Humidity, salt air & hurricanes — handled

Browse the Learning Center

Frequently asked questions

What areas does Holy City Heating & Air serve?

We serve Charleston, South Carolina and the surrounding Lowcountry — including North Charleston, West Ashley, Mt. Pleasant, Summerville, Goose Creek, and the sea islands from Daniel Island to Edisto. See our service areas page for local details.

What are your hours?

Our office runs Monday through Friday, 7 AM to 7 PM, and we provide call support until 9 PM every day — so a real person answers whenever your system quits.

What services do you offer?

Air conditioning repair and installation, heating, heat pumps, ductless mini-splits, indoor air quality, plumbing, water heaters, and maintenance plans for the whole system.

Do you offer financing?

Yes — we work with Goodleap, a home-improvement financing specialist with a wide variety of loan and repayment options. A short application tells you whether you qualify.

Is there a maintenance plan?

Our Friends & Family membership includes twenty percent off equipment repairs, half-priced service fees, and priority service, with plans starting at twenty-one dollars per month.

Rainbow Row's pastel historic houses on East Bay Street in Charleston, South Carolina

Y’all deserve to be comfortable.

Schedule an appointment with us today — or call and talk to a real person, until 9 PM.

Schedule Service Call (843) 790-6504

Charleston’s trusted heating, cooling & plumbing experts

Pick a door on our Rainbow Row

What’s your system doing?

From the Battery to the ’burbs, every comfort trade

AC Repair

AC Installation & Replacement

Heating Repair & Installation

Heat Pumps

Ductless Mini-Splits

Indoor Air Quality

Plumbing

Water Heaters

HVAC Maintenance & Tune-Ups

Energy Audits & Home Performance

Lowcountry homes aren’t one style — neither are their systems

Historic Charleston single house

Where the equipment lives — tap a part in the drawing or the list

Best fit

Works well

Watch out for

Pre-war bungalow & craftsman

Where the equipment lives — tap a part in the drawing or the list

Best fit

Works well

Watch out for

Mid-century brick ranch

Where the equipment lives — tap a part in the drawing or the list

Best fit

Works well

Watch out for

Raised coastal & beach house

Where the equipment lives — tap a part in the drawing or the list

Best fit

Works well

Watch out for

New-construction two-story

Where the equipment lives — tap a part in the drawing or the list

Best fit

Works well

Watch out for

Townhome & condo

Where the equipment lives — tap a part in the drawing or the list

Best fit

Works well

Watch out for

Our roots run deep in the Lowcountry

Do your best work in the Holy City

What the neighbors are saying

Thank y’all for trusting us with your homes

Maintenance that pays for itself

One of the top Daikin Comfort Pros in the nation.

We work with Bosch & Mitsubishi a lot

Charleston businesses run on comfort too

From South of Broad to Summerville, we’re already in the neighborhood

Comfort now, on a payment that fits

Humidity, salt air & hurricanes — handled

Why Is My AC Freezing Up?

Why Is My AC Running but Not Cooling?

Repair or Replace? How Charleston Homeowners Should Decide

Frequently asked questions

Y’all deserve to be comfortable.