Heating, cooling & ducts
HVAC installation
New HVAC systems planned from a load calculation, with ducts laid out room by room and permits planned in.
Learn more →Furnace & AC installation · Puget Sound
Heating and cooling, installed as one system.
We install a new furnace and AC or heat pump together, matched to each other and to your house, with the ducts between them sealed and sized to carry both.
- Furnace and cooling matched as a pair
- Ducts sealed and sized for both jobs
- Old equipment removed and hauled away
New furnace and AC coil installed in a basement · Seattle, WAThe problem
Why install both at once
A furnace and an air conditioner share more than a closet. The AC coil sits on top of the furnace, the furnace blower pushes air across that coil, and both use the same ducts and thermostat. When one is replaced without the other, the new piece often ends up paired with an old one it wasn't designed for. The blower may be wrong for the coil, or the controls may not work well together.
Installing them together lets us match the furnace, coil and outdoor unit as one system, size it to your house and set up controls that run it properly. It also means one disruption instead of two. For many Puget Sound homes, the cooling side is now a heat pump rather than straight AC, with the gas furnace kept for the coldest days. We'll walk you through that setup and when it makes sense.
Warning signs
When a full system install makes sense
These are the situations where replacing heating and cooling together is the sensible move.
- SIGN 01
Both units are aging together
If the furnace and AC went in together and are both getting old, replacing them as a pair avoids a mismatched system.
- SIGN 02
New furnace due, and no AC yet
Replacing the furnace is the natural time to add cooling, since the coil, ducts and controls are being worked on anyway.
- SIGN 03
AC runs on an outdated refrigerant
Older AC units that use R-22 are getting harder to service, since that refrigerant is no longer produced.
- SIGN 04
Repairs on both, every year
Furnace repairs in winter and AC repairs in summer add up. A new matched pair resets the clock on both.
- SIGN 05
The house never stays comfortable
If the system has always struggled, it may have been sized wrong. A new install is the chance to get it right.
- SIGN 06
A major remodel or addition
Adding rooms or finishing a basement changes the heating and cooling load, and the system should change with it.
Proof of work
See the difference
Drag the slider to compare. Illustrations of typical results on homes like yours.
BeforeAfterHow we do it
How we install a furnace and AC
Equipment, ducts and controls are planned together, then installed in one job.
- 01
Inspect equipment and ducts
We look at the existing furnace, AC, venting, electrical and thermostat, then follow the ducts into the attic or crawl space. Every problem gets photographed. We also note insulation levels and windows, since they affect how much heating and cooling the house needs.
- 02
Size and match the system
We size heating and cooling to the house, then choose a furnace, indoor coil and outdoor unit designed to work together. If you're considering a heat pump with the furnace as backup, we explain how that pairing runs and how it differs from a straight AC.
- 03
Remove the old equipment
We shut off gas and power, recover the refrigerant from the old AC, and disconnect and remove the furnace, coil and outdoor unit. Everything is carried out and hauled away, and the floor and pad are cleaned for the new equipment.
- 04
Install, vent and connect
The new furnace and coil go in, with venting that suits the furnace type, a new condensate drain and sealed connections to the supply and return ducts. Outside, the new unit goes on a level pad and the line set is connected, pressure tested and evacuated.
- 05
Start up and finish the ducts
We start the system, check gas pressure, temperatures and airflow, and set up the thermostat. Any duct repairs from the inspection are finished, so the new system isn't feeding leaks. You get a walk-through and photos of the new equipment and duct work.
What you get
What's included in a furnace and AC install
| Load sizing | Heating and cooling sized to your house, not to the old equipment |
|---|---|
| Matched equipment | Furnace, indoor coil and outdoor unit designed to work together |
| Removal | Old furnace, coil and AC removed; refrigerant recovered |
| Venting | Vent pipe fitted to the new furnace type |
| Duct connection | Plenums sealed to the furnace; supply and return joints sealed |
| Line set | Refrigerant lines connected, pressure tested and evacuated |
| Controls | Thermostat installed and set up for the system |
| Start-up | Gas pressure, temperatures and airflow checked |
Diagram
- 1Gas furnace
- 2Indoor coil
- 3Outdoor unit
- 4Refrigerant line set
- 5Sealed plenum
- 6Thermostat
Compare
Furnace with AC vs. furnace with heat pump
Both pairings use the same furnace and ducts. The difference is what the outdoor unit can do.
| Factor | Furnace + AC | Furnace + heat pump |
|---|---|---|
| Cooling | Outdoor unit cools in summer | Outdoor unit cools in summer |
| Heating | Furnace does all the heating | Heat pump heats most days; furnace backs it up |
| Gas use | Gas used all heating season | Gas used mainly on the coldest days |
| Controls | Standard thermostat | Controls set up to switch between the two |
| Good fit | You mainly want summer cooling | You want to lean on electric heat |
Puget Sound homes
Full-system installs in Puget Sound homes
Many homes around Seattle got their furnace and AC as a set, and both are now reaching the same age. In Eastside tract homes from the 1980s and 1990s, the furnace in the garage often has an AC coil added later and an outdoor unit that has been through a lot of rain. Some older Seattle homes still have a furnace converted from oil sitting in the basement, with no cooling at all. Each of these is a good candidate for replacing heating and cooling together.
The climate pushes the design. Long, mild heating seasons favor a heat pump doing most of the work, with a gas furnace stepping in on the coldest mornings. Short summers that can still turn hot mean the cooling side has to be right, not an afterthought. And because the ducts in so many local homes run through attics and crawl spaces, the duct work is part of the install, not something left for later. We plan all three together, from the first inspection.
Pricing
What shapes the price
A full system is quoted after the inspection, with each part of the job listed.
- FACTOR 01
Equipment type and size
Furnace size, AC or heat pump, and single-stage or variable-speed equipment all change the cost.
- FACTOR 02
Venting and gas changes
Moving from a standard furnace to a condensing one can mean new vent routing and a condensate drain.
- FACTOR 03
Duct condition
Sound ducts get sealed at the furnace. Leaky or undersized runs need replacing before the new system starts.
- FACTOR 04
Electrical and placement
A new circuit, a disconnect, or moving the outdoor unit to a new spot adds to the job.
- FACTOR 05
Permits
Furnace and AC installs generally need a mechanical permit, which we pull for you. Fees vary by city and county across the region.
Great service. I highly recommend this company. Wish I would have found them years ago... Isaac, Kareem and Irving were professional, courteous, and friendly. Pricing was clear and there were no surprises. Very happy with our experience.
FAQ
Furnace and AC installation: questions we hear
Still unsure? Call (800) 674-4933 and talk it through with us.
Should I replace my furnace and AC at the same time?
If they're both aging, usually yes. The AC coil sits on the furnace and shares its blower, so a new AC on an old furnace, or the other way around, can leave you with a mismatched system. Replacing both lets us match the parts, size them together and do the duct and venting work once. If one unit is still young, replacing only the other can make sense.
What is a dual-fuel system?
It's a heat pump paired with a gas furnace. The heat pump handles cooling and most of the heating, and the furnace takes over when it gets cold enough that gas is the better choice. In the Puget Sound's mild winters, the heat pump can run most of the season. Many homeowners like keeping gas as backup while leaning on electric heat.
How long does a furnace and AC installation take?
A straight swap of furnace and AC in the same locations often takes a day or two. Changing the venting, moving the outdoor unit, adding electrical or replacing ducts adds time. We give you a schedule with the quote, and we plan the work so you're without heat for as short a time as possible.
Can my old ducts work with new equipment?
Often, yes. If the ducts are sound, sealed and sized well enough, they can serve a new furnace and AC. Cooling usually needs more airflow than heating, so undersized returns and crushed runs show up quickly. We check the ducts during the inspection and include any repairs in the quote, so you know before install day.
What size furnace and AC do I need?
That depends on your house, not the size of the old equipment. Older systems were often oversized. We look at square footage, insulation, windows and layout, then size heating and cooling to match. Getting the size right is a big part of a system that runs quietly, heats evenly and doesn't short cycle.
What happens to my old furnace and AC?
We take them away. The refrigerant in the old AC is recovered before it's disconnected, as required, and the equipment is carried out of the house and hauled off. The furnace area and the outdoor pad are cleaned, so the new equipment goes into a clean spot.
Related services
Often done together
Heating, cooling & ducts
Furnace replacement
Straight advice on when to replace, then a furnace sized to your house, with venting and ducts done properly.
Learn more →
Heating, cooling & ducts
Air conditioner replacement
Aging AC or heat pump replaced with a matched system, with the coil, line set and ducts checked.
Learn more →
Heating, cooling & ducts
Air duct replacement
Damaged, leaky and rodent-fouled duct runs pulled and replaced, with sealed joints and photos of the work.
Learn more →Let's see what's going on up there.
Book a free inspection. We'll photograph your attic and crawl space and walk you through what we find, before you decide anything.