Learn
How it works
A handful of ideas explain almost everything your heating and cooling does. Knowing them makes a technician's words easier to follow and a new system easier to choose.
In this section
- Your home's system as a whole
How heating, cooling, air and controls fit together in one home
- How cooling and heat pumps move heat
The refrigeration cycle, and why your outdoor unit blows warm air
- How gas appliances burn and vent
Combustion air, flues, vent categories and condensing furnaces
- Airflow and ducts
Supply and return, static pressure, leaky ducts and when duct cleaning helps
- Efficiency ratings
What AFUE, SEER2, EER2 and HSPF2 mean and how to read them
- Sizing heating and cooling
Why size matters, load calculations and short cycling
- Refrigerants and the rules
R-22, R-410A, newer refrigerants, certification and leaks
Other sections
- Heating and cooling systems
What each piece of equipment does, and how to tell which kind you have.
- Care through the year
What to check before winter, before summer and in between.
- Chicago homes
The climate, the city's rules, older homes, permits and help with bills.
- Safety
Gas, carbon monoxide, venting, warning signs, asbestos, lead and mold.
- Choosing and paying for work
Repair or replace, hiring well, what affects cost and how to pay.