Heating & Cooling
Take the edge off your energy bills – meet the heat pump water heater
Your home’s most forgettable appliance could be wasting hundreds of dollars per year
How to Maintain an Air Conditioner
Ask This Old House plumbing and heating expert Richard Trethewey shares tips for keeping an air conditioner running efficiently
How an Energy Recovery Ventilator (ERV) Works
Richard Trethewey explains how an Energy Recovery Ventilator (ERV) replaces conditioned indoor air with fresh outdoor air without wasting energy
How to Diagnose a Frosty Air Conditioner
Ask This Old House plumbing and heating expert Richard Trethewey discusses the possible causes and solutions for a frozen air conditioner.
The Pros and Cons of a Steam Heating System
Considering steam heat? We help you weigh the pros and cons so you can decide if it is right for you.
Sizing up a Home Heating System
Richard Trethewey explains how to assess a home’s heating system – and figure out whether you’ll need to replace it
Shopping Guide: Air Purifiers and Humidifiers
By reader request, here are our picks for air purifiers and humidifiers to help you through flu and allergy season. These are sound investments for any healthy home
How to Replace a Steam Radiator
Ask This Old House plumbing and heating expert Richard Trethewey replaces a small radiator with one that’s the correct size
Improve Your Attic Ventilation with Soffit Vents
Here’s how to install soffit vents step by step to improve the airflow in your attic.
Read This Before You Buy Ductless AC
These quick-to-retrofit ductless AC systems provide unrivaled operating efficiency and room-by-room zoning comfort.
Want Central Air Conditioning? Read This Before You Install
Tired of your window AC unit? Here’s what you need to know about how central AC systems work before investing in cooling your entire house.
10 Handy Air Conditioning Tips
Beat the heat by having the cleanest, coolest, and most-efficient air conditioner on the block.
How to Install a Wall Mounted Space Heater
Ask This Old House master electrician Scott Caron warms up a chilly bathroom by installing an electric convection heater.
How to Diagnose Problems with a Hot Water Heating System
Ask This Old House plumbing and heating expert Richard Trethewey helps a homeowner figure out why one of her radiators is not working.
How to Remove an Old Fuel Tank
Before the heating system at the Arlington project house could be upgraded to natural gas, the old oil tank had to be taken away.
How to Install Room-By-Room Zoning in an HVAC System
Ask This Old House plumbing expert Richard Trethewey learns about an HVAC system that allows each room to be zoned out using smartphone technology.
All About Ceiling Fans
These air movers keep you cool and look cool doing it. Here’s how to choose a model that’s right for your space
Before You Store That Air Conditioner
Carrying it to the basement isn’t just challenging, it’s dangerous, partly because it can block your view of the steps. Here, ways to save your back—and maybe a trip to the ER
Ask This Old House: Richard Trethewey’s Greatest Hits
Over the years, This Old House plumbing and heating expert Richard Trethewey has helped hundreds of homeowners reduce their energy consumption and slash their monthly utility bills
How Thermostat Setbacks Save Money
This Old House plumbing and heating expert Richard Trethewey explains how adjusting the thermostat can reduce energy consumption and save you money.
How to Seal Leaky Ductwork
Ask This Old House plumbing and heating expert Richard Trethewey shows an innovative new way to seal ducts from the inside
How to Install an Exhaust Fan in a Wall
Scott Caron, master electrician for Ask This Old House, helps a homeowner put in an exhaust fan to rid her kitchen of smelly cooking odors.
How to Install a Whole-House Dehumidifier
Ask This Old House plumbing and heating expert Richard Trethewey shows how to control humidity throughout the house all year round.
How to Install DIY Radiant Floor Heating
Use a specialized foam panel to lock the PEX tubing in place, cover it with a sand-and-cement mix, and tile away.
How to Zone a Forced Air Furnace and Air Conditioner
Ask This Old House plumbing and heating expert Richard Trethewey shows how to divide a home's heating and air-conditioning system into different zones.
How to Install a Whole House Humidifier
Ask This Old House plumbing and heating expert Richard Trethewey shows how a professional would install a whole-house humidifier.
How to Repair a Frozen Air Conditioner
This Old House plumbing and heating expert Richard Trethewey shows how to prevent ice buildup from shutting down an air-conditioning system.
9 Things Your Home's Low Humidity Is Ruining
Keep these items in fighting condition with the help of a humidifier.
How to Install a Smart Thermostat
This Old House plumbing and heating expert Richard Trethewey shows a homeowner how to install and operate an energy-saving smart thermostat
How to Insulate HVAC Ductwork
This Old House plumbing and heating expert Richard Trethewey helps a homeowner insulate his HVAC ductwork.
How to Install a Ductless Heat Pump
This Old House plumbing and heating expert Richard Trethewey and host Kevin O'Connor install a ductless heat pump to heat and cool a room
How to Diagnose Leaks in a Steam Boiler
Ask This Old House plumbing and heating expert Richard Trethewey helps locate the leak on a steam boiler that is losing water