Air conditioners can create a lot of water because they remove moisture from the air. To get rid of this, they have a [usually plastic] drain pipe that comes out of the side of the air handler. Over time, algae can block this pipe and, when it does, the AC won’t work. In fact, some condensate drains have a float switch that won’t let the AC run if water backs-up. Water can also puddle around the unit or flood the area. To deal with condensate problems, please see Air Conditioner Leaks Water, below.

American design standards are legislated in the Uniform Mechanical Code or International Mechanical Code. In certain states, counties, or cities, either of these codes may be adopted and amended via various legislative processes. These codes are updated and published by the International Association of Plumbing and Mechanical Officials (IAPMO) or the International Code Council (ICC) respectively, on a 3-year code development cycle. Typically, local building permit departments are charged with enforcement of these standards on private and certain public properties.


A programmable thermostat is a must-have in today’s state of AC technology. Programmable thermostats allow you to set temperatures for various times throughout the day and automatically lower the temperature when you most need it to help you save money and manage your cooling without constantly hovering over the dial. In this article, we’ll walk you through installing a programmable thermostat in your home.
Air conditioner equipment power in the U.S. is often described in terms of "tons of refrigeration", with each approximately equal to the cooling power of one short ton (2000 pounds or 907 kilograms) of ice melting in a 24-hour period. The value is defined as 12,000 BTU per hour, or 3517 watts.[32] Residential central air systems are usually from 1 to 5 tons (3.5 to 18 kW) in capacity.
Ductwork pinging or popping. If you hear a pinging or popping sound coming from metal ductwork, this may be caused by thermal expansion or by air blowing past a loose flap of metal. Track along the duct runs, listening for the sound. If you find it, make a small dent in the sheet metal to provide a more rigid surface that’s less likely to move as it heats and cools.

The cost to replace your gas furnace will vary based on the type and size of furnace you select, labor and installation costs, and any repairs your HVAC system may need. Nationally, average HVAC prices for a heating specialist range between $1,800 and $2,500. It’s important to select the right size gas furnace for your heating needs. A furnace that’s too small won’t heat your house properly, while a furnace that’s too large will run inefficiently, cycling on and off and likely breaking down sooner. HVAC specialists calculate your exact heat needs by measuring your home and incorporating variables such as the regional climate and your home’s level of insulation. Retail pricing for gas furnaces can range from $650 up to $3,000 and more. The higher the AFUE (annual fuel utilization efficiency) rating of the furnace, the more efficient it is at turning fuel into heat and the lower your carbon footprint and utility bill will be. HVAC installation costs are often based on an hourly rate and can range from under $50 to over $100 per hour, depending on the company and the furnace being installed. Higher-end furnaces cost more to install because they require added labor and expertise. For a typical installation, it might take two HVAC installation pros one day or less to remove your old furnace and replace it with a new one.

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