After moving into a newly built house, a Wisconsin homeowner said the air conditioner was already causing concern, running for hours and sounding worse the longer it stayed on.

Here's what to know

In a post on Reddit, the homeowner said the airflow felt decent only within the first foot from the vents.

They also wrote, "Yesterday it took 4 hours to drop 4 degrees (74 to 70)" even though the outdoor temperature was about the same, and said the condenser "sounds like an old school diesel engine idling."

Despite those complaints, the HVAC installer reportedly said a one-degree-per-hour cooldown was normal and could not send a technician for more than a week.

The homeowner said the 2,200-square-foot, two-story home has a 60,000-BTU furnace paired with a 3-ton coil and a 2.5-ton AC unit, and that the house was supposed to perform 30% better than the high-efficiency rating.

If you're dealing with similar comfort problems, upgrading your heating and cooling system is one of the best ways to save money on your utility bills and protect yourself from rising energy costs. Palmetto's Comfort Plan network can help you find efficient heating and cooling solutions for your home and connect you with vetted installers.

More background

Replies suggested more than one possible cause.

One commenter wrote, "That condenser noise plus it getting worse the longer it runs really sounds like a charge issue to me," while another said, "You have no speed on the cooling blower pin. put purple, or blue there."

In a newly built home, better insulation, tighter construction, and efficient equipment are supposed to help keep cooling bills down. But if the system is not commissioned properly, those expected savings can disappear quickly, leaving behind higher costs and rooms that still feel muggy or unevenly cooled.

What can be done?

Commenters cautioned the homeowner against changing fan speeds without first getting a proper inspection. On a system that may be undercharged or improperly configured, DIY adjustments can make the problem harder to diagnose and may even lead to more expensive damage.

Documenting indoor and outdoor temperatures, photographing the equipment and wiring, and requesting a full commissioning check can help identify the issue. That should include refrigerant charge, static pressure, blower settings, and duct leakage — the kinds of details that can show whether the problem is a relatively simple fix or a more serious mismatch.

If that conversation leads to an upgrade, Palmetto is another option worth considering. If you're not ready to pay up front, the Comfort Plan includes $0-down options that can lower your heating and cooling costs by up to 50%, and Palmetto Comfort Plans include 12 years of free maintenance.

Homeowners can also pair solar panels with electric appliances, including efficient HVAC systems, to cut utility costs even further. EnergySage makes it easy to find the best solar system and installer for your home and budget, saving you up to $10,000 on installations.

One commenter summed up the concern this way: "Get someone with gauges out there before you touch fan speeds, an undercharged system will trash the compressor over time and that's way more expensive than a slow cooldown."

Where can I learn more?

This Wisconsin homeowner's complaint about weak cooling and rising energy use touches on issues that come up in plenty of other AC troubleshooting stories, too. Things like clogged drain lines, dirty components, and insulation gaps can quietly sap performance and push bills higher.

• On TikTok, one homeowner found a simple drain-line cleaning helped the AC run noticeably better.

• A homeowner found cleaning the air-conditioning unit sharply improved cooling and cut wasted electricity.

• An expert warned poor insulation at home leaves an AC working harder for less comfort.

Each of these examples highlights a different way airflow, maintenance, or insulation problems can make an AC seem like it's failing. If your system is running too long or making strange noises, these stories can help narrow down what's worth checking before costs creep up.

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