Air Conditioning

Air conditioning service.

Interstate Heating Co. is your #1 HVAC contractor in Sussex, WI, and the surrounding communities. We are the leading company for all of your air conditioning needs. If you need repairs, maintenance, or a brand new system installed, the technicians at Interstate Heating Co. are the qualified and professional crew for the job.

We provide the highest quality service for your air conditioner. We also aim to educate and inform our customers. Informed decisions are good decisions. We want you to feel confident we are qualified to perform the service for which you are hiring us.

How Much Money Can a New Air Conditioner Save You?

Our SEER2 (Seasonal Energy Efficiency Ratio 2) energy savings calculator can help determine how much you could save on your utility bills. Simply enter your current unit’s SEER value and compare it to a newer, more efficient SEER2 unit. You can even customize it to better match your home’s system for a more accurate calculation.

SEER2 Energy Savings Calculator

{{ seerOld }} SEER vs {{ seerNew }} SEER2

{{ annualSavingsPercent() }}%

{{ seerOld }}
{{ annualElectricalCostOldUnit() }}
Annual Cost
{{ seerNew }}
{{ annualElectricalCostNewUnit() }}
Annual Cost

Estimated 15-Year Savings:*
${{ projectedSavings }}

{{ year }} {{ state }} average residential electricity retail price of {{ price }}¢/kWH**.
*Based on an average annual utility rate increase of {{ avgUtilityIncrease }}%.

This calculator does not guarantee actual costs or savings and is only to be used for educational purposes.

Customize to Your Home

Adjust these settings for a more accurate calculation:




Rate (¢/kWH)


Average Annual Cooling Hours***

Historical Comparison

{{ state }}'s electricity prices compared to {{ yearFifteenYearsAgo }}.

{{ yearFifteenYearsAgo }}


{{ priceFifteenYearsAgo }}¢/kWH

{{ yearTenYearsAgo }}

{{ differenceTenYears }}

{{ priceTenYearsAgo }}¢/kWH

{{ yearFiveYearsAgo }}

{{ differenceFiveYears }}

{{ priceFiveYearsAgo }}¢/kWH

{{ year }}

{{ differenceCurrentYear }}

{{ price }}¢/kWH

** Data from U.S. Energy Information Administration
*** Data from 2002 EPA study

** Data for Canadian cities from
*** Data from

Air Conditioning Basics

The four main components to your air conditioner are:

Condenser: The condenser is the outside metal unit and where the gas from the compressor is condensed into a liquid. The gas entering the condenser is very hot. The temperature is then lowered, so the gas can convert back to a liquid.

Compressor: The compressor is inside the condenser. It circulates the pressurized refrigerant, to concentrate the heat, and changes the low pressure gas to high pressure.

Evaporator: The evaporator is the part of the system inside the home. In simple language, it absorbs the heat from your home.

Expansion Valve: The expansion valve controls the amount of refrigerant in your system.

All of these pieces are connected by a copper tube that handles refrigerant, creating a closed loop. Heat is collected in the evaporator, sent outside to the condenser. The heat is removed, and the cool air is recirculated back into your home.

AC Facts

An Air Conditioner Doesn’t Create Cool Air.
What happens in the AC process is actually the removal of heat from the air. Your AC uses a chemical called refrigerant to remove heat and transfer it outside. The warm air runs through the lines and coils in your unit and goes from liquid to gas and back again. During this process, the refrigerant removes the heat and transfers it elsewhere so that when the air comes out the other side, it is cool.

Your AC Will Remove Humidity.
Lower humidity helps the overall comfort level in your home by making you feel cooler, even if the temperature is the same.

Your Air Filter Needs To Be Checked And Replaced Every Three To Six Months.
(depending on the manufacturer’s recommendations)
A dirty air filter restricts your air flow, which reduces efficiency, costing you money, and over time can put stress on your unit and could cause a costly repair.

Maintenance, Maintenance, Maintenance.
Your air conditioner needs regular checkups to keep it running in tip-top shape. Having regular annual preventative maintenance will bring your system longer life and fewer breakdowns over all.

The Seasonal Energy Efficiency Ratio (SEER) measures air conditioning and heat pump cooling efficiency, which is calculated by the cooling output for a typical cooling season divided by the total electric energy input during the same time frame. A higher SEER rating means greater energy efficiency.

At Interstate Heating Co., we provide all the services you need to keep your AC running in top-notch shape. Call us at 262-246-4772 for repairs, maintenance, or new-system installation.

“Our Technician Chris was prompt and diagnosed and fixed the problem with our ac very efficiently. He was informative, courteous and friendly. Great customer service.”
- Jeanette J.
“Interstate installed a new air conditioner 4 days after a technician was here to evaluate the problem. Installation went smoothly and there have not been any problems yet. The installers worked during the rain and did a great job of cleaning up afterward. Enjoying my new air conditioner!”
- Karen H.
“Our 6 year old central air system stopped producing cold air. We called at 8:00 AM on a Sunday and the technician arrived in an impressive 45 minutes. Fortunately all that was required was a new capacitor and we were back in business. Casey, the technician could not have been more pleasant or competent. Fast, terrific service. Thank you.”
- Tom L.
“Needed to replace a 26 year old air conditioner and was able to make that happen in 4 days! They also credited my initial service call to the total price of the unit which I was thankful for. My only wish was to have an actual brochure to compare replacement units, to actually see the features and the prices (I am old school in that regard!) rather than looking it up online. Many people my age are not as comfortable with that!”
- Karen H.
“Dylan. the technician, came to our home to do a yearly check of our air conditioning system. He was a true professional, courteous, and answered all our questions. We were very impressed with his knowledge. He didn't mind that my husband followed him around because he likes to be informed and understand what was happening and what Dylan was finding along the way. We will always request Dylan for any future needs we may have. Thank you.”
- Cynthia R.
“The technician showed up on time to service our A/C, furnace and Aprilaire. He was thorough and respectful. We’ve been a customer for many years and highly recommend Interstate Heating.”
- Neil A.

Need Air Conditioner Service?

Contact the experts at Interstate Heating Co.

Call us at 262-246-4772!