Nation Air Con

Field notes on heating, cooling & buying the job right.

Mike's field notes · working in HVAC since 1993

Heating and cooling, explained by a guy who's actually done the work.

I'm Mike. I've spent more than 30 years in crawl spaces, attics and hundred-degree backyards. This is the advice I give my own neighbors: what the work really costs, when to repair, when to replace, and how to spot a bad quote before you sign it.

Mike Sullivan, HVAC contractor Written by Mike Sullivan
HVAC contractor since 1993
Mike Sullivan kneeling beside an open residential furnace in a basement
A furnace call in a basement that looks like most basements: useful stuff, old concrete and no showroom lighting.
Real-world rangesUseful starting numbers, with the reasons your actual quote can move.
No favorite equipment brandThe install matters more than the badge stuck on the cabinet.
The money is disclosedOur matching service is free to homeowners; partners may pay us for introductions.

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Start with these guides

6 notes from the field
HVAC estimate paperwork and calculator on a worn kitchen table

How Much Does a New HVAC System Cost in 2026?

Real installed-price ranges, what moves the number and why two honest quotes can be thousands apart.

Read the cost guide →
Older furnace beside a new air handler in a basement

Heat Pump vs. Furnace: Which Fits Your House?

I install both. Here's the climate, fuel-cost and equipment-age math I'd use at my own house.

Compare the systems →
Dirty HVAC filter held beside a clean replacement at an open return grille

Why Is My AC Bill So High?

The six things I check first, starting with the $10 fix homeowners forget most often.

Run the checklist →
Very old rusted furnace in a basement

7 Signs Your Furnace Is Going Out

Short cycling, strange sounds, uneven rooms and the safety warning you shouldn't postpone.

Check the warning signs →
Rebate paperwork, calculator and handwritten notes on a kitchen counter

HVAC Rebates in 2026: What's Still Available?

The old federal credit ended. State programs, utilities and seasonal offers can still cut the final price.

Find the current programs →
Installers removing an old outdoor air-conditioning unit

How Long Does an HVAC Install Take?

A real hour-by-hour changeout, plus the shortcuts that turn a fast install into an expensive one.

See the install-day timeline →

About the fellow writing this

Why listen to me?

I started in 1993 sweeping my uncle's shop floor. Since then I've run crews, trained apprentices and sat at more kitchen tables with more estimates than I can count. I've watched homeowners get treated fairly, and I've watched them get sold equipment their house never needed.

Nation Air Con lets me help outside my own service area. We publish the guides, then connect homeowners who ask with licensed local installers. The service is free to you; contractor networks may pay us for the introduction. That's the whole model, and you can read the plain-English disclosure or our editorial standards.

Mike rinsing the coil of a residential outdoor air-conditioning condenser
A garden hose and ten honest minutes can do more good than a fancy bottle with a fancy label.

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