How a home's heating, cooling and air work.

How it works

Chicago winters are long and cold. In a normal year, January averages 25.2°F. So heating does most of the work in a Chicago home. Most homes use one of three kinds. A furnace heats air, and a fan pushes the warm air through ducts to each room. It is the most common kind. A boiler heats water, and pipes carry the hot water or steam to radiators. A heat pump moves heat from the cold outdoor air into your warm house. In summer it runs the other way and cools the house.Source: National Weather Service, Chicago · U.S. Department of Energy

When something is wrong

Most equipment shows signs that it is wearing out long before it stops. Some rooms stay too cold. The furnace runs all the time but can't heat the house. The energy bills keep going up. A dirty air filter makes the system work harder to move air. It can raise your energy costs and wear the equipment out early. Soot on the equipment or a vent, or a strange burning smell, is a sign to have it looked at. So is a burner flame that stays yellow at the tips. These are good things to tell us when you ask for a visit.Source: ENERGY STAR · U.S. Consumer Product Safety Commission · U.S. EPA

Before you call

A few checks take a minute. Make sure the thermostat is set to heat, and set higher than the room. If it runs on batteries, change them once a year. Look at the air filter. If it looks dirty, change it, and make sure it fits snugly with no gap for air to slip around it. If the house is still cold after that, ask for a visit.Source: U.S. EPA

How it works

Most central air is a split system. Refrigerant carries heat out of the house. The cold coil inside takes heat and moisture out of the air. Outside, a fan blows outdoor air over the hot coil, and the refrigerant gives its heat up to the cooler outdoor air. Some ductless air conditioners are split systems too, often called mini-splits.Source: U.S. Department of Energy · U.S. EPA

When something is wrong

When cooling falls off, airflow is a common cause. Airflow problems can cut a system's efficiency by up to 15 percent. Too little air can let the inside coil ice over. Too much air can leave the house damp. Dirty coils make the system run longer and cool less. Too much or too little refrigerant also wastes energy and wears the equipment out sooner. Only a technician certified under EPA Section 608 may add or remove refrigerant. Tell us what you notice: warm air, ice, water, or rooms that never cool.Source: ENERGY STAR · U.S. Department of Energy · U.S. EPA

Before you call

Make sure the thermostat is set to cool, and set lower than the room. Change the filter if it is dirty. Keep leaves, dirt and snow away from the outdoor unit so it can move air. Inside, a drain carries away the water the coil takes out of the air. A plugged drain can cause water damage and make the house more humid.Source: ENERGY STAR

Fresh air

Ventilation trades stale indoor air for fresh outdoor air. Bringing in more fresh air lowers the pollution inside. Bathroom and kitchen fans that blow air outdoors take out moisture and dirty air where they start. The best ways to clean indoor air are to remove what makes it dirty and to bring in clean outdoor air. Filters and air cleaners help, but none of them removes everything.Source: U.S. EPA

Humidity and mold

Keep the humidity inside between 30 and 50 percent. A humidity gauge, sold at most hardware stores, tells you where you are. Air that stays too humid helps mold grow, and mold can cause allergies and asthma. When warm, wet air touches a cold surface, water forms. Dry anything wet within 24 to 48 hours. If you see water where it shouldn't be, or smell something musty, tell us.Source: U.S. EPA

Filters and ducts

The filter in your heating and cooling system cleans the air only while the system runs. Use the best filter your system's maker recommends. A technician can tell you which one your system can take. Many makers say to change it every 60 to 90 days. Cleaning the ducts is not part of yearly care. EPA says to clean them only when needed. Standing water or debris in a duct needs attention right away.Source: U.S. EPA

The price

$39.99 for the visit, the same for every home and every kind of work. You agree to it before anyone comes. The technician finds the cause and tells you what they found. Then they price any repair, line by line, from our price list. Nothing more happens until you say yes to each line.

What gets checked

A check-up looks at what keeps a system safe and working well: the thermostat and its settings, the controls, the electrical connections, the moving parts, the drain, the airflow and the refrigerant. Only a technician certified under EPA Section 608 may handle refrigerant.Source: ENERGY STAR · U.S. EPA

Age and signs

Think about new equipment when a heat pump or air conditioner is more than 10 years old, or a furnace or boiler is more than 15. Other signs are repairs that keep coming and bills that keep going up. Rooms that are too hot or too cold can come from the equipment, but also from the ducts or the insulation, so those are worth checking first.Source: ENERGY STAR

The right size

Bigger is not better. A system too big for the house turns on and off in short runs. It never runs long enough to work well or to dry the air, and it wears out sooner. The right size comes from a load calculation such as ACCA Manual J. It looks at the home's insulation and floor area.Source: ENERGY STAR

Each season

Have the furnace or boiler checked in fall, before the cold. Have the air conditioner checked in spring. In the months you use them most, look at the filter once a month. A regular schedule can cut heating and cooling costs by 10 percent or more, and helps the equipment last longer. In winter, keep snow off an outdoor unit. In summer, keep leaves and plants away from it.Source: U.S. Department of Energy · ENERGY STAR

The thermostat

A programmable or smart thermostat can lower the heat or the cooling while you sleep or are away. Put it on an inside wall, away from vents, lamps, doors and sunlight, so it reads the room itself.Source: U.S. EPA · ENERGY STAR

What it is

Carbon monoxide has no color and no smell. It comes from burning fuel. A furnace, boiler or water heater that isn't working right can let it into the house. So can a vent or flue that is rusty, cracked or blocked. Its signs are like the flu: headache, dizziness, weakness, an upset stomach and confusion. Babies, older people and anyone with heart or breathing problems are more sensitive to it.Source: CDC · U.S. Consumer Product Safety Commission · U.S. EPA

Keeping safe

Have your heating system, water heater and any other gas appliance serviced every year, even when they are new. Make sure gas appliances vent the right way.Source: CDC · U.S. EPA

If you smell gas, your CO alarm sounds, or anyone feels sick, leave and call 911 from outside.

AirLogic is not an emergency service.