Original data and independent reporting for the HVAC trade

Category: Homeowners

Cost guides, repair versus replace, and how to read a quote.

  • How American Homes Are Heated: The Fuel and Equipment Mix

    How American Homes Are Heated: The Fuel and Equipment Mix

    Last reviewed: August 2026 · By the HVAC Brief Editorial Team · Our sourcing and editorial standards

    The short answer

    Natural gas is the main heating fuel in 62.71 million US homes and electricity in 42.57 million, out of 123.53 million housing units. By equipment, the central warm-air furnace dominates: 53.26 million gas and 13.82 million electric.

    Heat pumps are the main heating equipment in 16.13 million homes, 13.1% of the stock, despite taking close to half of new central shipments. Equipment lasts a long time, so the stock lags the sales mix by many years.

    By fuel

    Main heating fuel Homes (million) Share
    Natural gas 62.71 50.8%
    Electricity 42.57 34.5%

    Those two account for the large majority of US homes. The remainder use propane, fuel oil, wood or other fuels, or have no heating equipment at all.

    By equipment

    Main heating equipment Homes (million) Share
    Natural gas central warm-air furnace 53.26 43.1%
    Heat pump 16.13 13.1%
    Electric central warm-air furnace 13.82 11.2%
    Steam or hot water system 6.51 5.3%

    The central warm-air furnace, gas and electric combined, is the main heating equipment in 67.08 million homes, more than four times the heat pump count. Our guide to hydronic systems covers the steam and hot water category.

    Stock versus sales

    Heat pumps hold about 13% of the installed base and near half of new central shipments. That gap is not a contradiction, it is what a slow-turning stock looks like. Any claim that heat pumps have taken over residential heating is describing sales, not homes. See our shipment share analysis.

    Why the mix is regional, not national

    National shares conceal strong geographic concentration. Gas furnaces dominate where gas distribution exists. Heat pumps concentrate in milder climates where their efficiency advantage holds through the heating season. Steam and hot water systems persist in older Northeast and Midwest housing. Fuel oil is heavily concentrated in the Northeast, which is why the heating oil price series matters far more in some states than others.

    Frequently asked questions

    How do most American homes heat?

    Natural gas is the main heating fuel in 62.71 million US homes and electricity in 42.57 million, out of 123.53 million housing units, per EIA RECS 2020. By equipment, the natural gas central warm-air furnace is the single largest category at 53.26 million homes.

    How many US homes have heat pumps?

    A heat pump is the main heating equipment in 16.13 million homes, about 13.1% of the housing stock, per EIA RECS 2020. That is far below their share of new shipments, because equipment stays installed for many years.

    Is gas or electric heating more common?

    Natural gas, by fuel: 62.71 million homes against 42.57 million for electricity. The gap has narrowed over time as heat pumps and electric systems have taken a larger share of new installations, but the installed base still favours gas.

    Why do heating systems differ so much by region?

    Gas furnaces dominate where gas distribution networks exist. Heat pumps concentrate in milder climates where efficiency holds through the season. Steam and hot water systems persist in older Northeast and Midwest housing, and fuel oil is heavily concentrated in the Northeast.

    Methodology and limitations

    All figures are EIA Residential Energy Consumption Survey 2020, table HC6.1, final data released March 2023, the current published vintage. Shares are computed against 123.53 million total housing units.

    • RECS runs every five or six years. 2020 remains current and we do not extrapolate forward.
    • Categories describe main heating equipment and fuel. Homes with secondary systems are counted by their main one.
    • National shares conceal strong regional concentration in every category.

    Sources

    1. US Energy Information Administration, Residential Energy Consumption Survey 2020, table HC6.1.
    2. Air-Conditioning, Heating, and Refrigeration Institute, June 2026 Statistical Release, for shipment share context.

    The HVAC Brief is an independent trade publication. We do not sell equipment, take manufacturer advertising, or accept payment for placement in our research. Corrections welcome.

  • What Ventilation Actually Means in HVAC (and What It Does Not)

    What Ventilation Actually Means in HVAC (and What It Does Not)

    Last reviewed: August 2026 · By the HVAC Brief Editorial Team · Our sourcing and editorial standards

    The short answer

    Ventilation is the V in HVAC and the part most often ignored, because unlike heating and cooling nobody notices it working. It means exchanging indoor air with outdoor air and filtering what circulates.

    A central system’s blower and ductwork do the circulating and filtering. Actual air exchange with outdoors happens through dedicated ventilation equipment, exhaust fans, or uncontrolled leakage through the building envelope.

    The distinction matters because a system running in fan mode is recirculating, not ventilating. Moving the same air past a filter repeatedly is filtration, and the two get conflated constantly.

    Three things people call ventilation

    Function What it does Typical equipment
    Circulation Moves air around the house System blower and ductwork
    Filtration Removes particles from circulating air Filter in the return
    Air exchange Replaces indoor air with outdoor air ERV or HRV, exhaust fans, envelope leakage

    Only the third is ventilation in the strict sense. A house can have excellent filtration and effectively no controlled air exchange, which is common in older housing where exchange happens by accident through leakage.

    Why tighter houses changed the problem

    Older houses leak, which provides uncontrolled air exchange at the cost of energy. As construction has tightened to reduce that energy loss, the accidental ventilation has gone with it, which is why dedicated ventilation equipment became necessary rather than optional in new construction.

    1. Exhaust fans remove air from kitchens and bathrooms, with makeup air drawn in through whatever gaps exist.
    2. Heat recovery ventilators (HRV) exchange air while transferring heat between the incoming and outgoing streams.
    3. Energy recovery ventilators (ERV) do the same and also transfer moisture, which matters in humid climates.
    4. Envelope leakage is the uncontrolled default, varying with weather and wind rather than with need.
    Filters do not ventilate

    Upgrading to a denser filter improves filtration and increases resistance across the blower, which raises static pressure and reduces airflow. It does nothing for air exchange. If the goal is fresh air rather than cleaner recirculated air, the filter is the wrong lever. See why static pressure matters.

    Frequently asked questions

    What does ventilation mean in HVAC?

    Exchanging indoor air with outdoor air, and filtering the air that circulates. It is the V in heating, ventilation and air conditioning. Running a system in fan mode recirculates and filters air but does not exchange it with outdoors, so circulation and ventilation are not the same thing.

    What is the difference between an ERV and an HRV?

    Both exchange indoor air with outdoor air while recovering energy from the outgoing stream. A heat recovery ventilator transfers heat only. An energy recovery ventilator transfers heat and moisture, which matters in humid climates where bringing in outdoor humidity would otherwise add load.

    Does running the fan improve air quality?

    It improves filtration of the air already inside by moving it past the filter more often. It does not bring in outdoor air, so it does not address anything that requires air exchange. It also consumes blower energy continuously.

    Will a better filter fix indoor air quality?

    A denser filter captures more particles but also increases resistance across the blower, raising static pressure and reducing airflow. It addresses filtration, not air exchange. Whether it is the right measure depends on whether the concern is particles in recirculated air or a need for fresh air.

    Methodology and limitations

    This page describes system functions and equipment categories. We publish no air change rates or air quality thresholds, as those are set by standards bodies and building codes that vary by jurisdiction rather than by a single federal residential requirement.

    • No ventilation rate is recommended here. Requirements vary by code and jurisdiction.
    • Equipment descriptions are generic, not specific to any manufacturer.
    • Nothing here is engineering advice for a specific building.

    Sources

    1. US Department of Energy, 10 CFR 430.32, for the SEER2 external static pressure basis referenced in the filtration discussion.

    The HVAC Brief is an independent trade publication. We do not sell equipment, take manufacturer advertising, or accept payment for placement in our research. Corrections welcome.

  • How Thermostats Actually Work, and What They Cannot Do

    How Thermostats Actually Work, and What They Cannot Do

    Last reviewed: August 2026 · By the HVAC Brief Editorial Team · Our sourcing and editorial standards

    The short answer

    A thermostat is a switch with a temperature sensor. It does not control how hard your system runs, only whether it runs. Most conventional residential equipment is single stage: it is either on at full output or off.

    That is why turning the setpoint far past your target does not heat or cool a house faster. The equipment produces the same output either way; only the run time changes.

    What a thermostat actually does

    It compares measured temperature against setpoint and closes a circuit when the difference crosses a threshold. On a single stage system that call is binary. On two stage or variable capacity equipment the control can request different output levels, which is a property of the equipment, not of the thermostat.

    Belief What actually happens
    Setting it lower cools the house faster Output is unchanged on single stage equipment. Only run time changes.
    Leaving it at one setting all day is cheaper Depends on setback depth and duration, not a universal rule
    A smart thermostat makes a system efficient It changes when the system runs, not how efficiently it runs
    The reading is the house temperature It is the temperature at that one location on that one wall
    Closing vents helps the thermostat It raises static pressure and reduces airflow

    Placement matters more than features

    1. Direct sun on the thermostat makes it read high, so the system overcools that zone.
    2. An exterior wall biases the reading toward outdoor conditions.
    3. Near a supply register the sensor reads conditioned air rather than room air, which causes short cycling.
    4. In a hallway rather than a living space the sensor controls to a space nobody occupies.
    5. Near a heat source, a lamp, a television or a kitchen, biases the reading upward.

    A poorly placed thermostat produces comfort complaints that look like equipment problems. So does a duct problem, which is why the diagnosis order matters. See ductwork and airflow.

    On smart thermostat savings claims

    The percentage savings quoted in marketing are not measured by any federal source. What a smart thermostat does is change the schedule the equipment runs on. Whether that saves money depends on your previous behaviour: a household already using setbacks has less to gain than one that never adjusted the setpoint.

    Frequently asked questions

    Does setting the thermostat lower cool the house faster?

    No. Most residential equipment is single stage, meaning it produces the same output whenever it runs. Setting the target far below your desired temperature does not increase output, it only makes the system run longer, and it risks overshooting past the temperature you actually wanted.

    Do smart thermostats save money?

    The specific percentage claims are not measured by any federal source. A smart thermostat changes when equipment runs rather than how efficiently it runs, so savings depend on prior behaviour. A household that already used setbacks has less to gain than one that never adjusted the setpoint.

    Where should a thermostat be placed?

    On an interior wall in an occupied living space, away from direct sun, supply registers, exterior walls and heat sources such as lamps or kitchens. Poor placement biases the reading and produces comfort complaints that resemble equipment faults.

    Why does my system short cycle?

    Common causes include an oversized system reaching setpoint too quickly, a thermostat mounted near a supply register so it reads conditioned air, or restricted airflow. Short cycling reduces dehumidification and increases wear, and it is usually a sizing, placement or airflow problem rather than a thermostat defect.

    Methodology and limitations

    This page describes control behaviour rather than publishing savings figures, because no federal source measures thermostat savings at household level.

    • No percentage saving is claimed for any thermostat type or schedule.
    • Behaviour described applies to conventional residential systems. Variable capacity equipment modulates output and behaves differently.
    • Nothing here is engineering advice for a specific installation.

    Sources

    1. US Department of Energy, 10 CFR 430.32, for equipment staging and efficiency rating context.

    The HVAC Brief is an independent trade publication. We do not sell equipment, take manufacturer advertising, or accept payment for placement in our research. Corrections welcome.

  • AC Leaking Water or Blowing Warm Air: What Each Symptom Means

    AC Leaking Water or Blowing Warm Air: What Each Symptom Means

    Last reviewed: August 2026 · By the HVAC Brief Editorial Team · Our sourcing and editorial standards

    The short answer

    An air conditioner leaking water inside almost always means the condensate is not draining, not that refrigerant is leaking. Refrigerant is a gas at those pressures and does not pool on a floor.

    An air conditioner blowing warm air points at a different set of causes: loss of refrigerant charge, a compressor or capacitor fault, a frozen coil, or the system simply not being in cooling mode.

    These two symptoms account for a large share of homeowner searches and they have distinct mechanisms. Knowing which family a symptom belongs to tells you whether it is an owner-fixable maintenance issue or a service call.

    Water leaking from the indoor unit

    Cooling removes humidity, and that water collects in a drain pan and leaves through a condensate line. Water appearing where it should not means that path is blocked or overwhelmed.

    1. Blocked condensate drain. The most common cause. Biological growth blocks the line and the pan overflows.
    2. Full or cracked drain pan. Age and corrosion.
    3. Frozen evaporator coil that has thawed. Ice melting at once overwhelms the pan. This is a symptom of a deeper fault, usually low airflow or low charge.
    4. Dirty filter restricting airflow. Low airflow drops coil temperature toward freezing, which leads back to the previous cause.
    5. Improper installation slope. A pan or line that does not drain by gravity.

    Only the filter is reliably an owner fix. A blocked drain is sometimes clearable, but a coil freezing repeatedly is a diagnostic problem rather than a cleaning problem.

    Water on the floor is not a refrigerant leak

    Refrigerant leaves a system as gas, not liquid pooling indoors. A system low on charge shows up as poor cooling and a freezing coil, not as a puddle. If a technician attributes indoor water directly to refrigerant loss, ask them to walk you through the mechanism.

    Blowing warm air

    Cause Typical signature Owner fixable
    System not in cooling mode Thermostat set to fan or heat Yes
    Dirty filter, restricted airflow Weak flow at registers, possible coil ice Yes
    Frozen evaporator coil Ice visible, airflow drops, water on thaw No, find the cause
    Low refrigerant charge Gradual loss of capacity, coil freezing No, it is a leak
    Failed capacitor Outdoor fan or compressor not starting No
    Outdoor coil blocked Vegetation or debris against the unit Partly

    A system that needs refrigerant has a leak. Sealed circuits do not consume refrigerant in normal operation, so repeatedly topping up treats the symptom while venting a controlled substance. Ask for the leak to be found.

    Frequently asked questions

    Why is my air conditioner leaking water inside?

    Almost always a condensate drainage problem rather than a refrigerant leak. Cooling removes humidity into a drain pan that empties through a condensate line; a blocked line, full or cracked pan, or a frozen coil thawing all put water where it should not be. Refrigerant leaves a system as gas and does not pool indoors.

    Why is my AC blowing warm air?

    Common causes are the system not being in cooling mode, a dirty filter restricting airflow, a frozen evaporator coil, low refrigerant charge from a leak, a failed capacitor preventing the compressor or fan starting, or a blocked outdoor coil. Only the thermostat setting and the filter are reliably owner fixable.

    Does my AC need a refrigerant top up?

    A sealed refrigerant circuit should not lose charge in normal operation, so a system needing refrigerant has a leak. Repeatedly adding refrigerant treats the symptom while venting a controlled substance and leaves the underlying fault in place. Ask for the leak to be located.

    Why does my evaporator coil freeze?

    Usually low airflow or low refrigerant charge. Restricted airflow from a dirty filter or duct problem drops coil temperature below freezing; low charge does the same by dropping evaporator pressure. Freezing is a symptom of another fault rather than a fault in itself.

    Methodology and limitations

    This page describes physical mechanisms rather than publishing failure frequencies, because no federal source measures residential HVAC fault rates. Refrigerant handling context is from 40 CFR part 82 and part 84.

    • No frequency or probability is claimed for any cause listed.
    • Nothing here is a diagnosis. Symptoms overlap and correct diagnosis requires measurement.
    • Refrigerant work requires EPA Section 608 certification and is not owner serviceable.

    Sources

    1. US Environmental Protection Agency, 40 CFR part 82 subpart F, refrigerant handling and technician certification; 40 CFR part 84, hydrofluorocarbon management.

    The HVAC Brief is an independent trade publication. We do not sell equipment, take manufacturer advertising, or accept payment for placement in our research. Corrections welcome.

  • HVAC Ductwork and Airflow: The Problem Blamed on the Equipment

    HVAC Ductwork and Airflow: The Problem Blamed on the Equipment

    Last reviewed: August 2026 · By the HVAC Brief Editorial Team · Our sourcing and editorial standards

    The short answer

    Ductwork is the part of the system most often blamed on the equipment. If ducts are undersized, leaking or routed through unconditioned space, no amount of equipment capacity or efficiency rating fixes the result.

    The federal test procedure acknowledges this. SEER2 replaced SEER partly by raising the external static pressure used in testing, so ratings better reflect equipment working against real ductwork rather than a laboratory ideal.

    That change is the clearest official signal that duct resistance is a first-order variable. A system rated under the older procedure was measured under conditions gentler than most installed duct systems impose.

    What static pressure tells you

    Static pressure is the resistance the blower works against, measured across the air handler. High static pressure means the system is fighting the duct system, which reduces airflow, degrades capacity and dehumidification, and loads the blower motor.

    Symptom Often blamed on Frequently actually
    One room never comfortable Undersized equipment Duct run sizing or balancing
    House cool but clammy Equipment choice Oversizing, short cycling, or low airflow
    High bills after a new system Equipment underperforming Duct losses in unconditioned space
    Blower noise Equipment defect Static pressure above design
    Frequent blower motor failure Component quality Sustained high static pressure

    Where duct systems lose energy

    1. Leakage at joints and connections. Air that never reaches a register is conditioned air paid for and lost.
    2. Uninsulated runs in unconditioned space. Ducts in a hot attic or cold crawl space exchange heat with that space along their whole length.
    3. Undersized returns. A common and under-diagnosed cause of high static pressure, because attention usually goes to supply runs.
    4. Excessive flexible duct with sharp bends. Each bend adds resistance, and compressed flex adds far more than its length suggests.
    5. Closed registers. Closing vents to “redirect” air raises system static pressure rather than saving energy.
    The one measurement worth asking for

    Ask whether static pressure was measured, before and after any equipment replacement. If ductwork is the binding constraint, replacing equipment moves the problem rather than solving it, and the new system inherits the same limitation with a larger invoice attached.

    Why this interacts with sizing

    Load calculation determines required capacity; duct design determines whether that capacity reaches the rooms. Doing one without the other produces predictable failures. A correctly sized system on undersized ducts underperforms, and an oversized system on any ducts short cycles. See why square-footage sizing fails.

    Frequently asked questions

    Why is one room always hotter or colder?

    Usually duct related rather than equipment related: the run serving that room may be undersized, too long, badly bent, leaking, or the system may be unbalanced. Upsizing equipment to fix one room oversizes it for every other room, which introduces short cycling and poor dehumidification.

    What is static pressure in an HVAC system?

    The resistance the blower works against, measured across the air handler. High static pressure reduces airflow, degrades capacity and dehumidification, and loads the blower motor. SEER2 testing raised the external static pressure used for rating so results better reflect real installed ductwork.

    Does closing vents in unused rooms save money?

    No. Closing registers raises static pressure across the system rather than reducing the energy it uses. The blower works harder against greater resistance, airflow falls elsewhere, and any saving is offset or reversed.

    Should ductwork be replaced with the system?

    It depends on whether the ducts are the binding constraint, which static pressure measurement establishes. Reusing failing ductwork is the most common reason one quote comes in far below others, and it is a scope difference rather than a saving.

    Methodology and limitations

    The SEER2 external static pressure point references the test procedure basis in 10 CFR 430.32. Duct design procedure is ACCA Manual D, a private standard we name but do not reproduce.

    • We publish no duct sizing figures or leakage percentages, as no federal series measures them at household level.
    • The symptom table describes common diagnostic patterns, not measured frequencies.
    • Nothing here is engineering advice for a specific duct system.

    Sources

    1. US Department of Energy, 10 CFR 430.32, efficiency standards and the SEER2 test basis.
    2. Air Conditioning Contractors of America, Manual D duct design and Manual J load calculation, named as industry-standard procedures.

    The HVAC Brief is an independent trade publication. We do not sell equipment, take manufacturer advertising, or accept payment for placement in our research. Corrections welcome.

  • Boiler and Baseboard Heating: How It Works and Who Still Has It

    Boiler and Baseboard Heating: How It Works and Who Still Has It

    Last reviewed: August 2026 · By the HVAC Brief Editorial Team · Our sourcing and editorial standards

    The short answer

    Steam and hot water systems, the boiler-and-radiator or baseboard family, are the main heating equipment in 6.51 million US homes, about 5.3% of the housing stock. They are concentrated in older housing in the Northeast and Midwest.

    They work differently from forced air: a boiler heats water or makes steam, which circulates to radiators or baseboard units that heat rooms by radiation and convection. There is no ductwork and no blower, which is why these homes usually have no central air conditioning path.

    How common they are

    Main heating equipment Homes (million) Share of stock
    Natural gas central warm-air furnace 53.26 43.1%
    Heat pump 16.13 13.1%
    Electric central warm-air furnace 13.82 11.2%
    Steam or hot water system 6.51 5.3%

    Forced air dominates nationally, but that national picture hides regional concentration. Steam and hot water systems persist where the housing stock predates forced air, which is why a contractor in New England sees them constantly and one in Arizona almost never.

    How the system works

    1. The boiler heats water, or boils it to steam, using gas, oil, propane or electricity.
    2. Distribution carries hot water through pipes by circulator pump, or lets steam rise through pipes by pressure.
    3. Emitters, cast iron radiators, baseboard convectors or radiant floor loops, transfer heat into rooms.
    4. Return brings cooled water or condensed steam back to the boiler.

    Because heat moves through water rather than air, these systems respond more slowly than forced air and hold temperature more steadily. They also cannot deliver cooling, filtration or ventilation, which is the practical trade-off.

    Why this matters for cooling retrofits

    A house with hydronic heat has no ductwork to reuse, so adding central air means installing a duct system from scratch. That is the single largest reason ductless mini splits are common in this housing stock. See how mini splits work.

    Fuel matters more here

    Boiler systems are disproportionately oil-fired in the Northeast, which ties running cost to a volatile fuel. Residential heating oil averaged $4.01 a gallon in the 2025/26 season. Our heating oil price index tracks the weekly series.

    Frequently asked questions

    How many US homes use boiler or baseboard heating?

    Steam and hot water systems are the main heating equipment in 6.51 million US homes, about 5.3% of 123.53 million housing units, per EIA RECS 2020. They are concentrated in older housing in the Northeast and Midwest rather than spread evenly.

    What is the difference between a boiler and a furnace?

    A furnace heats air and a blower distributes it through ductwork. A boiler heats water or makes steam, which circulates through pipes to radiators or baseboard units. A boiler system has no ducts and no blower, so it cannot provide cooling, filtration or ventilation.

    Can you add air conditioning to a house with baseboard heat?

    Yes, but there is no existing ductwork to reuse, so the options are installing a duct system from scratch or using ductless mini splits. That absence of ducts is the main reason mini splits are common in hydronically heated housing.

    Is baseboard heating expensive to run?

    It depends on the fuel the boiler burns and local prices, not on the emitter type. Oil-fired systems are common in the Northeast and expose households to a volatile fuel price. Electric resistance baseboard, a different product from hydronic baseboard, has its own cost profile tied to electricity rates.

    Methodology and limitations

    Installed equipment figures are EIA Residential Energy Consumption Survey 2020, table HC6.1, final data released March 2023. Heating oil prices are EIA series W_EPD2F_PRS_NUS_DPG.

    • RECS 2020 remains the current vintage for equipment data; the 2024 survey’s heating and cooling tables are due in spring 2027 See what the 2024 survey release covers.; we do not extrapolate it forward.
    • The steam and hot water category groups several emitter types and fuels.
    • National shares conceal strong regional concentration in this category particularly.

    Sources

    1. US Energy Information Administration, Residential Energy Consumption Survey 2020, table HC6.1.
    2. US Energy Information Administration, weekly heating oil series W_EPD2F_PRS_NUS_DPG.

    The HVAC Brief is an independent trade publication. We do not sell equipment, take manufacturer advertising, or accept payment for placement in our research. Corrections welcome.

  • What Is a Ductless Mini Split? How It Differs From Central Air

    What Is a Ductless Mini Split? How It Differs From Central Air

    Last reviewed: August 2026 · By the HVAC Brief Editorial Team · Our sourcing and editorial standards

    The short answer

    A ductless mini split is a split system without ducts: an outdoor compressor connected by refrigerant lines to one or more wall, ceiling or floor units that condition rooms directly. Most are heat pumps, so they heat and cool.

    They are rated on SEER2 and HSPF2, the same federal measures as ducted central systems, not on the CEER scale used for window units. Split system heat pumps carry a national minimum of 14.3 SEER2 and 7.5 HSPF2.

    The name causes confusion. “Ductless” describes the distribution, not the technology. Mechanically a mini split is the same refrigerant cycle as a central system, with the air handler moved into the room instead of sitting in a plant space feeding ductwork.

    How a mini split differs from a central system

    Feature Ducted central system Ductless mini split
    Distribution Ductwork to registers Indoor heads in each conditioned space
    Zoning Whole house, or zoned with dampers Per head, inherently zoned
    Duct losses Real, especially in unconditioned space None, there are no ducts
    Efficiency rating SEER2 and HSPF2 SEER2 and HSPF2, same scale
    Federal minimum, split heat pump 14.3 SEER2, 7.5 HSPF2 14.3 SEER2, 7.5 HSPF2
    Regional AC standard applies Yes for air conditioners Not to heat pumps

    Where they make sense

    1. Homes without existing ductwork. Adding ducts to an older house is often the largest single cost in a retrofit. Mini splits remove that line item.
    2. Additions and conversions. A garage, attic room or extension that the existing system was never sized to serve.
    3. Rooms the central system cannot satisfy. Rather than upsizing the whole system for one problem room, which oversizes it for every other room.
    4. Where duct losses are severe. Ductwork running through an unconditioned attic loses energy that a ductless system never incurs.

    Where they make less sense is a house with sound existing ductwork and a system due for replacement. There the ducts are a sunk asset, and the case rests on zoning rather than on avoiding duct installation.

    The sizing rule still applies

    Per-head sizing is where mini split installations most often go wrong. Each head serves a space with its own load, and the same oversizing failure mode applies: an oversized head short cycles and dehumidifies poorly. See why square-footage sizing fails.

    Frequently asked questions

    What is a ductless mini split?

    A split system without ductwork. An outdoor compressor unit connects by refrigerant lines to one or more indoor heads mounted on walls, ceilings or floors, which condition rooms directly. Most are heat pumps, providing both heating and cooling, and they are rated on SEER2 and HSPF2 like ducted central systems.

    Are mini splits heat pumps?

    Most are. A mini split heat pump runs the refrigerant cycle in both directions so one machine heats and cools. Cooling-only mini splits exist but are less common in the US residential market. Federal minimums for split system heat pumps are 14.3 SEER2 and 7.5 HSPF2.

    Is a mini split more efficient than central air?

    Both are rated on the same SEER2 and HSPF2 scale, so the rating comparison is direct. The structural difference is duct losses: a ducted system loses energy through ductwork, particularly in unconditioned attics or crawl spaces, while a ductless system has none. Whether that advantage is decisive depends on the specific duct system.

    How many indoor units can one outdoor unit run?

    Multi-zone systems connect several indoor heads to one outdoor unit, with the number depending on the equipment. Each head serves a space with its own load, so per-head sizing from a room-by-room calculation matters as much as total capacity.

    Methodology and limitations

    Efficiency minimums are from 10 CFR 430.32(c)(5) and (c)(6). Equipment descriptions reflect standard configurations rather than any specific manufacturer’s product.

    • We publish no installed cost. No federal series measures HVAC installed prices.
    • Federal minimums are floors. Many products exceed them.
    • Whether a mini split suits a specific house depends on a load calculation for that house.

    Sources

    1. US Department of Energy, 10 CFR 430.32, efficiency standards for central air conditioners and heat pumps.

    The HVAC Brief is an independent trade publication. We do not sell equipment, take manufacturer advertising, or accept payment for placement in our research. Corrections welcome.

  • Should You Replace Your HVAC Now or Wait? What the Data Says

    Should You Replace Your HVAC Now or Wait? What the Data Says

    Last reviewed: September 2026 · By the HVAC Brief Editorial Team · Our sourcing and editorial standards

    The short answer

    Nothing in the federal data suggests waiting saves money. Equipment producer prices are up 60% since 2019, rose in 21 of the 31 month-over-month comparisons since January 2024, and August 2026 is the highest reading in the series.

    The incentive picture also got worse, not better. The 25C credit worth up to $2,000 on a qualifying heat pump expired for property placed in service after December 31, 2025.

    If your system is working, waiting is a reasonable choice. If it is failing, waiting is a bet, and the published data has not rewarded that bet for several years. Here is what each factor actually says.

    What the price trend says

    Producer prices for HVAC equipment manufacturing rose from an index of 203.0 in 2019 to 324.8 in August 2026, up 60%. Consumer prices rose 31% over the same period, so equipment inflated at roughly twice the general rate.

    More to the point for timing: the series has risen in most recent months and the latest reading is its highest since 2019. There is no published federal forecast of a decline, and we do not make one. See our price index analysis for the drivers.

    What changed on incentives

    Factor 2025 2026
    Federal 25C credit on a qualifying heat pump Up to $2,000 $0
    What controls eligibility Placed in service by Dec 31, 2025 Not available
    State and utility rebates Unaffected Unaffected

    Installation date controls, not purchase date, so equipment bought in late 2025 and installed in 2026 does not qualify. Details in what the 25C expiry costs.

    What waiting does and does not change

    1. Does not lower the price. No published data supports a decline, and the trend has run the other way.
    2. Does not restore the tax credit. 25C expired by statute for post-2025 installations.
    3. Does narrow refrigerant options over time. Pre-2025 R-410A inventory is finite, though it remains federally installable with no end date.
    4. Does risk an emergency replacement. A failure in peak season removes your ability to compare quotes, which is the one lever you fully control.
    5. Does preserve capital. The real argument for waiting. If the system works, money not spent is money kept.
    The one thing worth timing

    Not the market, the season. Comparing quotes properly requires time, and time is exactly what you lack when a system fails in August or January. If replacement is coming within a year or two, doing it outside peak season is the controllable advantage. The price trend is not.

    Frequently asked questions

    Should I replace my HVAC now or wait?

    Nothing in the federal data supports waiting for lower prices. Equipment producer prices are up 60% since 2019, rose in 21 of the last 31 month-over-month comparisons, and August 2026 is the series high. The 25C credit worth up to $2,000 also expired for installations after December 31, 2025. If your system works, waiting preserves capital; if it is failing, waiting is a bet the data has not rewarded.

    Will HVAC prices go down in 2026?

    There is no sign of it in published federal data, and we make no forecast. The producer price index for HVAC equipment reached its highest reading since 2019 in August 2026 and has risen in most recent months. No federal agency publishes a price forecast for this equipment.

    Is there still a tax credit if I wait?

    Not federally. The Section 25C Energy Efficient Home Improvement Credit applies to property placed in service before December 31, 2025, and installation date controls rather than purchase date. State and utility rebates are separate programmes and are unaffected by the federal expiry.

    When is the best time of year to replace an HVAC system?

    Outside peak heating and cooling season, because that is when you have time to compare quotes properly. An emergency replacement in August or January removes the one lever you fully control. The federal data offers no basis for timing the price itself.

    Methodology and limitations

    Equipment prices are BLS series PCU333415333415, indexed to its 2019 annual average, with month-over-month counts computed from the monthly series since January 2024. Consumer prices are CUUR0000SA0. Credit terms are from the IRS.

    • We publish no price forecast. No federal agency forecasts this series and past direction is not a prediction.
    • Producer prices are not installed prices. The pass-through to a specific quote varies.
    • Nothing here is financial or tax advice.

    Sources

    1. US Bureau of Labor Statistics, Producer Price Index series PCU333415333415 and Consumer Price Index CUUR0000SA0, via the BLS Public Data API v2.
    2. Internal Revenue Service, Energy Efficient Home Improvement Credit.

    The HVAC Brief is an independent trade publication. We do not sell equipment, take manufacturer advertising, or accept payment for placement in our research. Corrections welcome.

  • How Often Should HVAC Be Serviced? What Is Established

    How Often Should HVAC Be Serviced? What Is Established

    Last reviewed: August 2026 · By the HVAC Brief Editorial Team · Our sourcing and editorial standards

    The short answer

    The common advice is annual servicing, once for cooling and once for heating on a system that does both, but no federal agency sets or measures a required interval. It is manufacturer and trade guidance, not regulation.

    The one maintenance task with a clear mechanism behind it is the air filter. A restricted filter raises static pressure across the blower, which is exactly the condition SEER2 testing was changed to represent more honestly.

    We separate what is actually established from what is repeated. That distinction matters here because maintenance advice is also a sales channel, and the interval you are told often matches a service plan rather than a measurement.

    What is established and what is not

    Claim Status
    Restricted filters raise static pressure and reduce airflow Established mechanism, and the reason SEER2 testing raised external static pressure
    Refrigerant circuits should not lose charge in normal operation Established. A system needing recharging has a leak
    Annual professional servicing is required Trade and manufacturer guidance, not federal requirement
    Maintenance extends equipment life by a specific number of years Not measured by any federal source
    Maintenance saves a specific percentage on bills Not measured by any federal source

    The tasks that have a mechanism behind them

    1. Change or clean the filter on schedule. The interval depends on filter type, pets and occupancy, not on the calendar alone. This is the one task with a direct, well understood effect on airflow.
    2. Keep the outdoor coil clear. Vegetation and debris restrict heat rejection, which the equipment cannot compensate for.
    3. Check the condensate drain. A blocked drain causes water damage, which is a failure mode independent of equipment performance.
    4. Have refrigerant charge verified rather than topped up. A system low on charge has a leak, and repeatedly adding refrigerant treats the symptom while venting a controlled substance.
    5. Have static pressure measured at least once. If ductwork is the constraint, no amount of servicing the equipment fixes it.
    On “maintenance saves you money” claims

    The percentage savings figures attached to maintenance plans are not from federal measurement. The defensible version is narrower: restricted airflow measurably degrades performance, and a refrigerant leak both costs money and worsens as refrigerant prices rise under phasedown. Those are mechanisms, not a percentage.

    Frequently asked questions

    How often should HVAC be serviced?

    Common trade guidance is annually, or twice yearly on a system that both heats and cools, but no federal agency sets or measures a required interval. It is manufacturer and industry advice rather than regulation. Filter changes are the task with the clearest mechanism and should follow filter type and household conditions rather than a fixed calendar.

    How often should I change my HVAC filter?

    It depends on filter type, pets, occupancy and how much the system runs, so no single interval applies. The mechanism is well established: a restricted filter raises static pressure across the blower and reduces airflow, which is the condition SEER2 testing was revised to represent more accurately.

    Does HVAC maintenance really save money?

    The specific percentage savings quoted with service plans are not measured by any federal source. What is defensible is narrower: restricted airflow degrades performance, and a refrigerant leak costs more as prices rise under federal phasedown. Treat percentage claims as marketing unless a source is named.

    Does my system need refrigerant topped up each year?

    No. A sealed refrigerant circuit should not lose charge in normal operation. A system that needs refrigerant has a leak, and repeatedly adding refrigerant treats the symptom while venting a controlled substance. Ask for the leak to be found rather than the charge to be topped up.

    Methodology and limitations

    We publish no service interval or savings percentage because no federal source measures either. The static pressure point references the SEER2 test procedure change under 10 CFR 430.32. Refrigerant handling context is from 40 CFR 84.

    • No federal requirement sets a residential HVAC servicing interval.
    • Manufacturer warranty terms may require documented maintenance. That is a contractual matter between you and the manufacturer.
    • Nothing here is engineering advice for a specific system.

    Sources

    1. US Department of Energy, 10 CFR 430.32, efficiency standards and the SEER2 test basis.
    2. US Environmental Protection Agency, 40 CFR part 84, hydrofluorocarbon management.

    The HVAC Brief is an independent trade publication. We do not sell equipment, take manufacturer advertising, or accept payment for placement in our research. Corrections welcome.

  • AC Repair Costs: Why No Reliable National Figure Exists

    AC Repair Costs: Why No Reliable National Figure Exists

    Last reviewed: August 2026 · By the HVAC Brief Editorial Team · Our sourcing and editorial standards

    The short answer

    No federal series tracks what a capacitor, compressor or coil replacement costs, so every price range published on this topic is a vendor survey or a contractor estimate. We do not publish one, because we cannot verify it.

    What is measurable is the direction of the inputs. Producer prices for HVAC equipment are up 60% since 2019 and contractor wages are up meaningfully over the same period, so parts and labour have both moved.

    This page tells you what determines the bill, which repairs change the replace-or-repair calculation, and how to sanity check a quote without a national average that does not exist.

    Why no reliable national figure exists

    Cost element Measured federally?
    Component at the factory Partly. BLS PPI covers equipment manufacturing, not individual spare parts
    Distributor and contractor parts markup No
    Diagnostic and labour time No. BLS publishes wages, not job pricing
    Refrigerant, where a repair needs it No residential price series
    Service call minimums No

    Four of five elements are unmeasured. A published range for a capacitor replacement is describing one sample of contractors at one moment, which is why the ranges you find disagree by multiples.

    The repairs that change the decision

    Component repairs sort into two groups: cheap parts that fail routinely, and expensive failures that push you toward replacing the system.

    1. Capacitor. A common wear part. Failure stops the compressor or fan starting. Replacement is a small part plus a short visit and does not change the case for keeping the system.
    2. Contactor. Similar category. Electrical wear item, routine replacement.
    3. Blower motor. Middling. Worth weighing against system age and refrigerant type.
    4. Evaporator or condenser coil. Expensive, and on an R-410A system it means recovering and recharging a refrigerant being phased down.
    5. Compressor. The failure that most often makes replacement the better option, because the part, the labour and the refrigerant all land at once.
    The refrigerant question changes repair economics

    Any repair that opens the refrigerant circuit on an R-410A system commits you to a refrigerant under federal phasedown, which will get more expensive across the remaining life of the equipment. That does not make the repair wrong, but it belongs in the comparison. See what the R-410A rule actually says.

    How to sanity check a repair quote

    1. Ask for the part and the labour separately, the same discipline that applies to a full replacement quote.
    2. Ask what failed and why. A capacitor that fails twice in two seasons is a symptom, not a part problem.
    3. For any refrigerant-circuit repair, ask what the system is charged with and what that refrigerant costs to source now.
    4. For a compressor or coil, ask for the replacement quote alongside the repair quote. That is the only way to compare properly.
    5. Get the diagnostic in writing before authorising work.

    Frequently asked questions

    How much does it cost to replace an AC capacitor?

    No federal source publishes component repair prices, so any figure you see is a vendor survey or contractor estimate rather than measured data. A capacitor is a small wear part plus a short service visit, and it is at the inexpensive end of HVAC repairs. Ask for part and labour separately to judge a specific quote.

    How much does an AC compressor replacement cost?

    Not published by any federal series. A compressor is the failure most likely to make full replacement the better economic choice, because the part, the labour and the refrigerant recovery and recharge all arrive together. Ask for a replacement quote alongside the repair quote before deciding.

    Why do repair cost estimates vary so much online?

    Because none of them come from measured data. Four of the five cost elements, parts markup, labour time, refrigerant and service minimums, are not tracked by any federal series. Published ranges reflect one sample of contractors at one moment and differ by region, season and equipment.

    Is it worth repairing an old air conditioner?

    It depends on which component failed and what refrigerant the system uses. Cheap wear parts rarely justify replacement. A compressor or coil failure on an R-410A system commits you to a refrigerant under federal phasedown, which belongs in the calculation alongside the repair price.

    Methodology and limitations

    We publish no component price range because no primary source supports one. Input direction is from BLS producer price series PCU333415333415 and BLS Current Employment Statistics for NAICS 238220. Refrigerant status is from 40 CFR 84.54 and EPA final rule 91 FR 31284.

    • No federal series prices individual HVAC spare parts or repair jobs.
    • The ordering of repairs from cheap to expensive reflects the components involved, not measured price data.
    • Nothing here is a quote or an estimate for any specific job.

    Sources

    1. US Bureau of Labor Statistics, Producer Price Index series PCU333415333415; Current Employment Statistics, NAICS 238220.
    2. 40 CFR 84.54 and EPA final rule 91 FR 31284, for refrigerant phasedown status.

    The HVAC Brief is an independent trade publication. We do not sell equipment, take manufacturer advertising, or accept payment for placement in our research. Corrections welcome.