HVAC Installation in Janesville, WI
A new system here will heat from October through May and cool from June through August every year. Tell us about the house, and a licensed contractor who covers Rock County will get in touch.
Tell us about the job
It takes about a minute.
What a system in Janesville has to handle
Your new furnace will run from October through May, 8 months a year, with winter nights averaging 16°F from December through February. A system sized right for that cold has to hold the house through the coldest nights, not just the mild ones on either end of the season.
The air conditioner takes over for the other 3 months, June through August, when afternoons average 81°F. Eleven months out of the year, this house needs either heat or cooling, so both sides of the system get real use. Rock County has seen 17 winter storms and 78 damaging wind events over the past ten years, and 18% of Wisconsin households lost power for at least 24 hours in 2024. Most furnaces need power to run the blower and controls, so a system built for this area has to hold up to what the weather here brings, not just the temperature.
- 8 months
- October through May, your system heats
- 3 months
- June through August, it cools
- 16°F
- the average winter night it heats against
- 81°F
- the average summer afternoon it cools against
NOAA nClimDiv, 1991–2020 normals
Wisconsin requires contractors to register with the state.
That registration puts the business on file with the Department of Safety and Professional Services. Nobody tested the contractor's HVAC knowledge to get it, and there's no license behind the name. Rock County and its cities cannot layer on their own HVAC license on top of that registration, so the state record is the only one that exists anywhere in Wisconsin.
For a job like this, the protection that matters comes from the permit, not the registration. Installing a furnace, air conditioner or heat pump is work most local building offices in Wisconsin require a permit for, with an inspection once it's done. That inspection is what checks the gas connections and the rest of the installation against code, since a mistake there is the dangerous part of the job. The registration says who the business is. The permit and inspection are what say the work itself was done right.
Sources: Wisconsin Legislative Reference Bureau · Wisconsin Department of Safety and Professional Services
- When should I replace my HVAC system?
- Replace it when repairs start coming often, or when the unit is old enough that the next breakdown is a real risk. A furnace working hard for 8 months a year here has more wear behind it than one in a milder climate, so age matters more than the calendar might suggest. If your system is limping along with a temporary fix, or a technician has told you parts are getting hard to find, that is your sign. Waiting for a full breakdown in the middle of winter, with lows averaging 16°F, means days without heat while you wait on a new system.
- Should I replace my furnace and air conditioner at the same time?
- If both are old, yes, it usually makes sense to do them together. A furnace and AC installed at the same time are matched to work as one system, and replacing one while keeping the other means the newer unit is paired with worn equipment it wasn't designed around. It also means only one round of labor and one disruption to your home instead of two. If one unit is much newer than the other, replacing just the failing one is reasonable.
- What happens during an HVAC installation?
- A contractor removes the old equipment, sets the new furnace, air conditioner, or both in place, and connects them to your ductwork, gas line or electrical circuit, and the vent or flue. They test the system afterward, running it through a full cycle to check airflow, ignition, and shutoff. Any duct or venting problems found during the work get addressed as part of the job, since a new unit connected to bad ductwork won't perform the way it should. A contractor can walk you through the specific steps for your home and equipment.