Replacement
AC installation in older Dallas-area homes
Older homes add up to four line items to an AC quote: replacing an R-22 system rather than recharging it, sealing or replacing original ducts, upgrading a small electrical panel, and sometimes a furnace near the end of its life. Ask for each as a separate, priced line so you can compare quotes and decide what to fix now.
On this page (13)
- What changes when the house is older
- If your system still runs on R-22
- Which refrigerant to replace it with
- Original ducts: inspect, test, then decide
- Electrical capacity and the panel
- The furnace under the coil
- Sizing an older house without guessing
- Attic access and the install itself
- Worked example: a 1978 ranch house
- Common mistakes with older-home installs
- What to ask every contractor
- Sources
- Questions
What changes when the house is older
A like-for-like AC replacement in a newer house is mostly a swap: new outdoor unit, new indoor coil, reconnect, test. In a house built in the 1960s, 70s or early 80s, the quote has more questions in it. The refrigerant may be obsolete, the ducts may be original, the electrical service may be small, and the attic may be hard to work in.
None of these is a reason to avoid replacing the system. They are reasons to insist on a home visit, a written scope and separate prices, because two contractors can quote the same house very differently depending on what they inspected.
| Issue | Why it matters | Published price |
|---|---|---|
| R-22 system | Production and import of virgin HCFC-22 (R-22) ended on 1 January 2020; existing R-22 systems may still be serviced with recovered or stockpiled refrigerant. | Replacement: $5,500–$16,500 for 3 tons, AC only (DFW) |
| Original ducts | ENERGY STAR estimates that about 20 to 30 percent of the air moving through a typical duct system is lost to leaks, holes and poorly connected ducts. | $1,300–$8,000 sealing or repair (Dallas); $6,000–$7,000 new ducts, about 2,000 sq ft (Dallas, undated page) |
| Small electrical panel | A larger system, or a heat pump with backup electric heat, may need more capacity. | $1,800–$3,500 for 100 A to 200 A (national) |
| Furnace near end of life | The new indoor coil usually sits on the furnace. | $4,000–$10,000 (national) |
These are published third-party ranges
Every price on this page comes from a named contractor or cost publisher, labeled Dallas, DFW or national. They are not this site’s prices or quotes. See the Dallas AC installation cost guide for the full source list.
If your system still runs on R-22
Production and import of virgin HCFC-22 (R-22) ended on 1 January 2020; existing R-22 systems may still be serviced with recovered or stockpiled refrigerant. That is why a leak in an R-22 system is expensive: the refrigerant to refill it comes only from recovered or stockpiled supply. Under EPA’s Section 608 rules, refrigerant for these systems may be sold only to certified technicians or to employers of certified technicians.
An R-22 system that is still running can be serviced. The question is whether to spend on it. A system old enough to use R-22 is also well past the point where ENERGY STAR suggests considering replacement.
ENERGY STAR says to consider replacement when a heat pump or air conditioner is more than 10 years old, and that a correctly installed high-efficiency unit can save up to 20 percent on heating and cooling costs.
You cannot simply put a new outdoor unit on an old R-22 indoor coil. New equipment uses a different refrigerant, so a replacement normally means a new matched outdoor unit and coil, and often a new or flushed line set. Ask the contractor which they plan.
- Look at the data plate on the outdoor unit. It names the refrigerant (R-22, R-410A, R-454B or R-32).
- If it says R-22, ask any repair quote to state how many pounds of refrigerant it includes and the price per pound.
- Compare that repair against a replacement quote before approving a recharge on a leaking system.
- Read the repair-or-replace guide for the decision on the parts other than refrigerant.
Which refrigerant to replace it with
Equipment made or imported since 1 January 2025 uses lower-GWP A2L refrigerants (R-454B or R-32) instead of R-410A. An EPA rule finalized in May 2026, effective 27 July 2026, removed the 1 January 2026 cutoff, so contractors may install pre-2025 R-410A systems until that stock runs out.
For an older house this matters in one practical way: you are choosing between the cheaper remaining R-410A stock and newer A2L equipment. Both are legal to install. Ask which refrigerant each quote uses, and whether the line set is being replaced or reused, because the answer can differ by refrigerant and by the condition of the old lines.
The R-410A vs new refrigerants guide sets out the trade-off in detail.
Original ducts: inspect, test, then decide
Ducts installed decades ago were often sized for heating, run through a hot attic, and sealed with tape or materials that have since dried out. ENERGY STAR estimates that about 20 to 30 percent of the air moving through a typical duct system is lost to leaks, holes and poorly connected ducts. In a DFW summer, air lost in the attic is air you paid to cool that never reaches the room.
A new, efficient system cannot make up for a duct system that leaks or is undersized. It can also make some problems more obvious, such as one bedroom that never cools, or a system that is louder because the ducts restrict airflow.
| What the inspection finds | Usual direction | Published range |
|---|---|---|
| Joints and boots leaking, ducts otherwise sound | Seal | Part of $1,300–$8,000 (Dallas) |
| Crushed, torn or disconnected runs | Repair or replace those runs | Within $1,300–$8,000 (Dallas), depending on scope |
| Ducts too small for the airflow, or failing throughout | Replace the system of ducts | $6,000–$7,000 for about 2,000 sq ft (Dallas, undated) |
Ask for a duct inspection with every quote, and a leakage test where the contractor offers one. Ductwork sealing and replacement explains the difference between the two jobs, and the hot and cold rooms guide covers uneven temperatures.
Do ducts and equipment in one project
If the ducts are going to change, the load calculation and the equipment size should reflect the house as it will be after the duct work, not before. Doing both at once avoids sizing the system for leaks that are about to be fixed.
Electrical capacity and the panel
Older homes may be on smaller electrical service than a modern system expects. That matters most when you switch to a heat pump with electric backup heat, add a larger system, or add other loads such as an EV charger at the same time.
The contractor should look at the panel during the home visit and say on the quote whether the existing circuit and breaker suit the new equipment. If an upgrade is needed, it should be priced before you sign, not discovered on install day.
| Item | Published range | Area |
|---|---|---|
| Panel upgrade, 100 A to 200 A | $1,800–$3,500 | National |
| Meter base or service riser, if needed | Adds $500–$1,000 | National |
- Ask whether the new system can run on the existing circuit and breaker.
- If you are considering a heat pump, ask how much backup heat is planned and whether the panel can carry it.
- Ask whether any electrical work is by the HVAC contractor or a separate licensed electrician, and who pulls that permit.
The furnace under the coil
In most DFW homes with gas heat, the indoor AC coil sits on top of the furnace. If the furnace is old, replacing the AC alone can mean paying to fit a new coil to a furnace that may need replacing soon after. Older homes are more likely to be in that position.
Ask each contractor for the furnace age and condition, and for two prices: AC and coil only, and AC with a new furnace. Then you can see what doing both now costs compared with doing them separately.
| Option | Published range | Area |
|---|---|---|
| 3-ton AC only, existing ducts | $5,500–$16,500 | DFW |
| Gas furnace replacement | $4,000–$10,000 | National |
| Furnace plus 3-ton AC together | $10,500–$13,500 | National |
If you have gas and are replacing both, also price a heat pump or dual fuel; see heat pump vs gas furnace in North Texas. Atmos Energy’s Mid-Tex appliance rebate program, running 1 July 2026 to 30 June 2027 for its Mid-Tex residential customers, pays $300 for an ENERGY STAR gas furnace rated 90% AFUE or higher and $350 for 95% AFUE or higher. Applications close 12 months after purchase or installation.
Sizing an older house without guessing
Older homes may have less insulation, single-pane windows and leakier construction. That does not automatically mean a bigger system. ACCA Manual J (ANSI/ACCA 2, 8th edition) is the American National Standard for residential heating and cooling load calculation. Dallas enforces the 2021 International Residential Code and 2021 IECC with Dallas amendments, effective 12 May 2023. The IRC requires equipment to be sized from a load calculation (ACCA Manual J) rather than a rule of thumb.
The size of the old unit is not a reliable guide. It may have been sized by rule of thumb, and the house may have changed since: new windows, added insulation, an enclosed porch, a converted garage. An oversized system cools quickly and shuts off before it removes much humidity, which leaves the house cool but clammy.
- Ask whether the load calculation used the insulation, windows and duct condition as they are now, or as they will be after any planned improvements.
- Ask for the heating and cooling load figures, not only the recommended tonnage.
- Compare quotes against the rule-of-thumb band in what size AC a Dallas home needs, and read oversized AC problems.
Attic access and the install itself
Many older DFW homes put the furnace or air handler in the attic. Access can be through a small hatch, over limited decking, in an attic that gets very hot in summer. That affects how long the job takes and what it costs, and it is one reason quotes for the same equipment vary.
A contractor who has seen the attic can say whether the new equipment fits through the opening, whether the platform and drain pan need work, and where the condensate line runs. One who has not seen it is estimating.
- Clear a path to the attic hatch and the outdoor unit before the home visit.
- Ask whether the new indoor equipment fits the existing access, and what happens if it does not.
- Ask whether a secondary drain pan, float switch or new condensate line is included.
- Ask whether the platform, attic lighting or walkway needs any work for the install.
Worked example: a 1978 ranch house
Say a hypothetical single-story ranch house in Garland, built in 1978, has its original-era R-22 condenser, a gas furnace of unknown age in the attic, and the original ducts. The homeowner wants three-ton cooling. Here is how the published ranges stack up, with the caveat that the real figures come only from quotes.
| Line item | Published range | Area |
|---|---|---|
| 3-ton AC replacement, existing ducts | $5,500–$16,500 | DFW |
| Duct sealing or repair (if the ducts are sound) | $1,300–$8,000 | Dallas |
| Or new ductwork, about 2,000 sq ft | $6,000–$7,000 | Dallas, undated |
| Panel upgrade (only if needed) | $1,800–$3,500 | National |
| Furnace plus 3-ton AC together, instead of AC only | $10,500–$13,500 | National |
The useful lesson is not a total. It is that the spread between the cheapest and dearest outcome comes mostly from scope: whether the ducts are sealed or replaced, and whether the furnace is done now. A quote that is far lower than the others often has a smaller scope, so read what is included before comparing the bottom line.
Garland also has its own municipal electric utility, Garland Power & Light, rather than Oncor, so utility programs differ there. See AC installation in Garland.
Common mistakes with older-home installs
- Recharging a leaking R-22 system repeatedly. Each refill buys time at a high refrigerant price without fixing the leak.
- Upsizing to cover for leaky ducts. A bigger unit pushing air through leaky ducts still loses the air, and short cycles more.
- Signing before the panel is checked. An electrical surprise on install day is harder to negotiate.
- Replacing the AC on a dying furnace without pricing both. The coil and furnace work as a pair.
- Comparing totals instead of scopes. One quote may include duct sealing, a line set and a new drain pan; another may not.
- Skipping the permit. The City of Dallas issues mechanical permits through its DallasNow portal so that work complies with the Dallas Mechanical Code and is performed by a licensed air-conditioning contractor. See Dallas AC installation permits.
What to ask every contractor
- Is my current system R-22, and does that change your recommendation?
- Which refrigerant does the new system use, and will you replace or reuse the line set?
- Did you inspect the ducts, and will you test them for leakage?
- Does my panel have capacity for this system, and is any upgrade included in the price?
- How old is my furnace, and what would AC plus furnace cost?
- Did the load calculation account for insulation, windows and ducts as they are now?
- Does the new equipment fit through my attic access, and is a drain pan and float switch included?
- Who pulls the permit, and will the permit number be on the invoice?
Check the license before you sign: verify a Texas HVAC contractor. Texas requires the license number on proposals and invoices. Then line quotes up with the quote comparison tool.
Sources
- US EPA, GreenChill regulatory context (archived page) (retrieved 2026-10-20) — verify before relying on it
- US EPA, Section 608 refrigerant sales restriction (retrieved 2026-10-20) — verify before relying on it
- NAHB summary of the EPA final rule (May 2026); EPA AIM Act Technology Transitions program (retrieved 2026-09-23)
- ENERGY STAR, "When is it time to replace?" (retrieved 2026-09-23)
- ENERGY STAR, "Duct Sealing" (retrieved 2026-10-20)
- ACCA, Manual J (retrieved 2026-10-20)
- City of Dallas, "Current City Code" (retrieved 2026-09-23) — verify before relying on it
- City of Dallas Development Services, mechanical permits (Dallas Mechanical Code, Chapter 55 amendments); process and fee: verify with the City before relying on it (retrieved 2026-09-23) — verify before relying on it
- Atmos Energy, Mid-Tex Appliance Rebate Program (retrieved 2026-10-20)
- US Census Bureau ACS 2024 5-year, table B25035 (median year structure built), via Census Reporter (retrieved 2026-10-20)
- 16 Tex. Admin. Code §75.71 (Cornell LII mirror) (retrieved 2026-10-20)
- Budget Heating, AC replacement cost in Dallas (Dallas, page dated undated) (retrieved 2026-10-20)
- HVAC.com, HVAC replacement costs in Dallas, TX (Dallas, page dated 2024-05-22) (retrieved 2026-10-20)
- Voltflow, electrical panel upgrade cost 2026 (National, page dated 2026-04) (retrieved 2026-10-20)
- Budget Heating, furnace replacement cost guide (National, page dated 2026 (title)) (retrieved 2026-10-20)
- Cold Factor Heating & Air (Flower Mound, TX) (page dated 2026) (retrieved 2026-09-23)
- HVAC Services Pro (DFW) (page dated 2026-04-13) (retrieved 2026-09-23)
- HVAC Services Pro, DFW installation guide (page dated 2026-03-06) (retrieved 2026-09-23)
- HVACProjectCost.com, Dallas page (page dated 2026-08-02) (retrieved 2026-09-23)
Questions
Do older homes need bigger AC units?
Not necessarily. Older homes may have less insulation and leakier ducts, which a load calculation accounts for. Sealing ducts and adding insulation can reduce the size needed.
Should I fix the ducts before replacing the AC?
Do both in the same project if you can, so the contractor sizes the new system for the house as it will be after the duct work.
Can I keep my R-22 system running?
Yes, it can still be serviced with recovered or stockpiled refrigerant. A leak gets expensive, though, so compare any recharge quote against replacement.
Can a new outdoor unit be added to my old indoor coil?
Not on an R-22 system. New equipment uses a different refrigerant, so replacement normally means a matched outdoor unit and coil.
Will I need a panel upgrade?
Only if the panel lacks capacity for the new equipment. It is more likely with a heat pump and electric backup heat. Ask for the check at the home visit.
Is a permit needed to replace AC in an older Dallas home?
Plan on one. The permit comes from the city your property is in, and the inspection is a useful check on an older-home install. Ask for the permit number.
Next step
Free quote request
Get a quote to check against these numbers
- Tell us about the job. Service, ZIP, property and timing. The form says right away if your ZIP is outside the area.
- We check the license first. Requests go only to contractors whose TDLR air conditioning license we have matched on the state register. None is signed yet: if no checked contractor covers your ZIP, we email you and say so.
- Compare what comes back. Line the written quotes up in the quote-comparison tool.
No cost and no obligation. We are a publisher, not a contractor. Partner contractors will pay us for introductions; none is signed yet. How that works.
Request AC installation quotes
Free and no obligation. We pass a request on only to a contractor whose TDLR license we have checked and who covers your ZIP.