HVAC Installation & Replacement
Sonora & Tuolumne County
New furnace, AC, or full system — sized right and installed once.
New furnaces, air conditioners, heat pumps, ductless systems, and complete system replacements for homes and businesses throughout Sonora and Tuolumne County. We size it correctly, explain your options honestly, and put it in writing before any work starts.
New HVAC, Sized Right and Installed Once
What We Do — Installation Services
Furnace Installation & Replacement
- New gas furnace installation
- High-efficiency furnace upgrades
- Existing system removal and disposal
- Correctly sized for your home, not the old nameplate
Replacing an aging or failed furnace, we install the right unit for your home and explain the efficiency trade-offs first.
Air Conditioner Installation & Replacement
- New AC and condenser installation
- Air conditioner replacement and upgrades
- Refrigerant line-set replacement when needed
- Pad or stand replacement
From standard-efficiency replacements to high-SEER2 upgrades, installed to spec with a written estimate before work starts.
Heat Pump Systems
- Whole-home heat pump installation
- Heat-and-cool in one system
- Dual-fuel setups where they make sense
One system for year-round comfort. We'll tell you honestly whether a heat pump or an AC-and-furnace setup is the better fit for your home and fuel costs.
Complete System Upgrades
- Full furnace + AC system replacement
- Thermostat upgrades (programmable and smart)
- Ductwork modifications
- System efficiency upgrades
When it's time to replace the whole system, we handle it as one coordinated job and make sure the new equipment is matched and balanced.
System Sizing & Load Calculation
- Per-home heating and cooling load calculation
- Square footage, insulation, windows, ceilings, and elevation factored in
- Right-sized equipment, not a guess from the old system
- Ductwork capacity reviewed
Right-sizing is the single biggest determinant of long-term comfort and efficiency. An oversized system short-cycles and won't dehumidify; an undersized one runs constantly and can't keep up.
What to Expect When You Call J. Hart
Here's what to expect when you call J. Hart.
Tell us what's going on
Call or request an estimate. We'll ask what's driving the project — a failure, the age of the equipment, comfort, or rising energy bills — and schedule the soonest available time.
We assess and size the system
We calculate your home's actual heating and cooling load, look at your ductwork, and give you a written proposal with the recommended equipment and price — not a guess from the old nameplate.
You approve the work before we begin
No surprises. You'll know what it costs and what's included before we start.
We install it right, test, and walk you through it
We install to spec, start up and test the system, clean up the work area, and show you how to run and maintain it.
Planning Your Installation: Sizing, Efficiency & Cost
Replacing your furnace or air conditioner? Here's what actually matters before you buy.
Sizing
Sizing Your System Correctly
Too small
Runs constantly and can't keep up.
Too large
Short cycling, poor humidity control, less comfort.
How we size systems
We calculate your home's heating and cooling load based on square footage, insulation, windows, ceilings, Sonora's climate and elevation, and ductwork capacity. We don't just match the old system's size.
Typical sizing for Sonora-area homes
1,200–1,500 sq ft
2–2.5 ton AC
60,000–80,000 BTU furnace
1,500–2,000 sq ft
2.5–3.5 ton AC
80,000–100,000 BTU furnace
2,000–3,000 sq ft
3.5–5 ton AC
100,000–120,000 BTU furnace
Your actual needs depend on your specific home.
Why Choose J. Hart for HVAC Installation
Proper sizing, no guesswork
We calculate your actual heating and cooling needs rather than guessing. Right-sized equipment is more comfortable and cheaper to run.
Straightforward pricing
You know what it costs before we start work — written estimate, no hidden fees, no jargon.
Quality installations
Done right the first time. We test everything before we leave.
Four generations local
Family-owned since 1984. Same name on the truck, same accountability.
Licensed & insured
CA Lic #459194 · NV Lic #77957
Serving Sonora, Tuolumne County & Calaveras County
We're based in Sonora and serve homes and businesses across Tuolumne and Calaveras County.
We know the area's homes, building types, water conditions, and climate challenges — and what works at our elevation.
Not sure if we serve your area? Give us a call: (209) 533-1978
"This was the easiest, fastest, friendliest, and most professional contract job I've ever done! They helped me limp along on my old heater, then installed a new one. They sealed the area around it, took care of details, and made the necessary changes immediately."
Mona Gaskill
Heater Installation · 2025
Free Estimates on HVAC Installation & Replacement
Whether you need a new furnace, AC, or complete system, we'll evaluate your home and provide an honest estimate at no cost.
Frequently Asked Questions
Most furnace or AC replacements are completed in one day. A full system replacement (furnace and AC together) typically takes one to two days. Larger jobs involving ductwork modifications may take two to three days. We'll give you a realistic timeline before we begin.
Yes. We evaluate your home and provide a written estimate at no cost before any work starts. Call us at (209) 533-1978 or request one online.
It depends on your home's square footage, insulation, windows, and layout. We perform a proper load calculation rather than guessing. Oversized systems are just as problematic as undersized ones — an oversized AC short-cycles and won't dehumidify, an undersized one runs constantly and can't keep up.
If it's under 10 years old and the repair is minor, repair makes sense. If it's 15+ years old, needs frequent repairs, or requires a major component, replacement is usually the better investment. We'll give you an honest recommendation — and if a repair is the smarter call, see our HVAC Repair page.
We can discuss payment arrangements for larger projects. Contact us to talk about your specific situation.
For most Sonora-area homes, 15–16 SEER2 for AC and a two-stage system offer the best balance of comfort, efficiency, and upfront cost. Higher-efficiency equipment makes sense for larger homes, heavy seasonal use, or where the energy savings close the upfront-cost gap. We'll walk you through the trade-offs.
We service most major brands. For new installations, we recommend and install Bryant equipment as a factory-authorized dealer.
Yes. We service, repair, and install heat pump systems, including ductless mini-splits.
Our service area covers Sonora, Twain Harte, Columbia, Jamestown, Tuolumne, Mi-Wuk Village, Pinecrest, Groveland, Chinese Camp, Don Pedro, Sierra Village, Angels Camp, and surrounding communities — across Tuolumne County and Calaveras County.
Ready to Schedule?
We'll Call You Back Fast.
Fill out the form and we'll reach out to confirm your appointment. No holding, no runaround — just a real person who knows your trade area.
- Same-day appointments available Mon–Fri
- Upfront pricing — no surprises after the fact
- CA Lic #459194 · NV Lic #77957
- Hours: 7:30 AM – 4:00 PM, Mon–Fri