Each season of the year and the weather it brings offers challenges to be met by your home’s HVAC system and other utilities. None is harder on the water pipes than winter. The danger is not as simple as concern that the water remaining in pipes will freeze. Ice in the pipes does not cause them to rupture, contrary to popular belief. The true danger to home systems comes from frequent changes in temperature. The temperature changes are the reason pipes expand and contract and ultimately break.
What Causes Pipes to Burst?
In the wintertime the water in pipes cools and as its molecules slow down and move closer together this action increases the water’s density. The density continues to grow until the temperature of the water reaches 3.98°C (39.16°F), then it begins to expand again. Other liquids do not do this. That is because of the Hydrogen Bond of water molecules.
A water molecule is slightly polarized due to its shape. Its electrons are more likely to be located on one side of the molecule, forming an asymmetry. Water molecules are attracted to the opposite sides of other water molecules, creating Hydrogen Bonds. When water cools and the molecules move together to become denser, the competing force of the molecules attempting to align to form their Hydrogen Bonds begins to cause re-expansion. Between 3.98°C and 0°C, this bonding process wins over the desire of colder, slower molecules to get closer and its density begins to decrease.
This density decline continues until the water molecules finally freeze and expand to form ice. The ice itself does not cause a pipe to split. The ice forms a blockage that traps the expanding water molecules, causing excess pressure between the blockage and the water spigot. When this pressure gets too great for the pipe to contain, the pipe ruptures.
How Does Temperature Change Affect This Process?
Some pipes are located underground. The soil itself contracts when it is cold and then expands when the weather warms up again. When a geographic location has big swings in temperature in a relatively short period of time (such as a few days at 20°F and then temperatures climbing back into the 50°s and 60°s again) the contraction and expansion in the soil may put too much pressure on buried pipes and result in a break in a line somewhere.
Cracks and holes in the walls and basements of a structure that let in a flow of cold air where it reach and chill pipes can lead to ruptures. Northern homes are usually built with water pipes within the building’s insulation to protect them from subfreezing temperatures. Southern homes are more vulnerable as their pipes are usually located in non-insulated areas. Pipes located in crawl spaces, outside walls and attics, particularly where there are openings allow air leaks in, are susceptible to freezing. Holes where cable wires and phone lines enter can also allow cold air to affect water pipes.
What is the Solution to Protecting HVAC Systems and Home Utilities from Freezing?
Home Utility Maintenance is the key to preventing weather-related damage to pipes, and by extension, to home utilities and comfort systems. Prevent the three key causes of frozen pipes. Make sure your heating system is in tip top shape to run all winter and keep the house (and the pipes) warm. Insulate the pipes with fiberglass sleeves or foam rubber to keep them snug. Block exposure to outside frigid air by sealing cracks and holes with caulking. Open cabinet doors to allow heat into the spaces around the pipes. Turn the faucets on so they will drip and the lines remain open to relieve pressure.
Schedule a maintenance inspection by a certified HVAC technician before winter begins to examine all components of your system for any wear and tear and previous damage. Any necessary HVAC repairs should be made before the cold comes, so your system will be performing at its most efficient when you most need it.
Ask the technician to do any necessary HVAC troubleshooting now, such as insulating pipes to the humidifier if your system has one. Have A/C Maintenance done the same way before summer comes to make sure condenser coils and humidifiers are fine and their lines have not been damaged. Be proactive in caring for your HVAC and Home Utility Maintenance needs so you and your pipes stay warm in the winter.
If you want to schedule an HVAC maintenance visit, contact us today!