Here’s What to Know About Rain and Your HVAC System

Rain in Kirkland, WA

Were you aware that rain can impact the functionality of your HVAC system? It’s not something that every homeowner realizes, so it might catch you by surprise if you find yourself needing a technician after a summer storm. Here’s everything that you need to know about rain and how it can affect your heating and cooling units.

The Infrastructure of Your HVAC System

Your HVAC system is composed of three parts:

  • The outdoor units
  • The indoor units
  • The ducts or “ductwork” that run throughout your home

All three parts must remain functional for your HVAC system to work. Even though they’re interconnected, however, they’re separate systems with individual components, and each can be uniquely affected by the rain.

Your Outdoor HVAC System

These are probably the HVAC parts that you’re the most familiar with since they’re so visible outside of your home. The most common is the air conditioner condenser, but you might see heating structures outdoors, too.

Rain doesn’t generally damage these exterior HVAC units. They’re built to withstand the elements, so they’re heavy, durable, and made with waterproof metals like copper or aluminum. They’re more vulnerable on the inside since that’s where they store their electrical components, but even these tend to be insulated, and they’re further protected by the solid metal walls of their home.

When rain does start to become an issue, it’s usually because the unit has already sustained damage in some way. For example, if the soil has eroded beneath it, heavy rains can shift its position and make it tilt dangerously. If debris has been flying around in a storm with high winds, it might have dented the metal and compromised the unit’s integrity, allowing water to seep through to the wiring.

Another potential issue is caused by homeowners: tarps. They see the rain and try to cover their HVAC units with a tarp or plastic sheet to protect them. This actually does more harm than good since it traps moisture and encourages the growth of mold, rust, and mildew.

Your Indoor HVAC System

The indoor parts of your HVAC system are usually found in a basement or utility room. They include the furnace and everything within it, like blowers and evaporator coils.

Unlike their outdoor cousins, indoor HVAC units aren’t built to withstand water and other natural elements. While they’re offered some protection by their metal parts, they aren’t as sealed, fortified, or insulated.

All of this means that water can be deadly to your interior HVAC system. It can soak wires, cause shorts, rust metal, and trigger automatic shutoffs from motors and other electric parts. It’s especially troublesome when there’s standing water in a flooded basement, but even small leaks of rainwater from walls and windows can become a problem over time.

The Ductwork of Your HVAC System

The ducts of your HVAC system are spread throughout your home like veins in a body. Like other interior pieces, they aren’t waterproof, so they’re susceptible to harm from rain and other sources of moisture.

One danger of rain in your ducts is that it takes a long time to evaporate without help from the sun. After the water has been there for a while, you’ll start to get mold and mildew. Since your ducts are responsible for carrying hot and cold air throughout your home, mold spores in that air can become a genuine health hazard, as well as a nasty odor that permeates everything.

Another danger is the fact that your ducts are truly everywhere in your home. This could mean that the insulation in your attic gets soggy and ineffective. It could mean that the floor joists in your basement get soft and waterlogged. It’s a small problem that quickly snowballs into a larger, more devastating one.

The Other Dangers of a Storm

Rain is enough of a problem already, but it doesn’t usually arrive alone. Storms can bring wind, hail, sleet, snow, and more.

Any type of precipitation can lead to water damage within your HVAC system. Snow can melt; icicles can clog drains and gutters in a way that collects standing water. During a long winter, ice can be particularly tricky since it’s basically a time bomb waiting to thaw and leak. You can have a snowstorm in December and not realize the consequences of it until March.

Debris can be another major source of damage and deterioration. Big pieces of hail can dent the metal of your condensers just as easily as they dent the metal of your car. Wind can also scatter branches, leaves, and other debris all around your yard. While your exterior HVAC units are often strong enough to endure this, extremely high winds can give debris enough force to hurt. You should also be on the lookout for debris getting caught in things like filters and fan blades. They’ll reduce the efficacy of your HVAC system, forcing you to crank it up higher and higher to achieve the same results.

Last but not least, lightning can hurt your HVAC system. It’s much more common than you might think. Arcing and charring can fry exterior wiring systems or cause power surges that weaken the unit.

Potential Flooding Damage

Flooding can have a severe impact on your HVAC system. It’s a threat to both the metal and the electrical pieces, and what’s more, it can impair all three parts of your HVAC infrastructure: inner, outer, and ductwork.

With exterior units, standing water of any kind can threaten to seep through the cracks of the metal and reach the wires and coils beneath. Note that the water doesn’t have to be at an apocalyptic flood level to cause damage. Clogged gutters, poorly draining slopes, and low spots in the yard can all collect rainwater and turn into miniature floods.

Interior units are also affected by flooding. In fact, since furnaces are usually put in low-level rooms like basements, they’re more vulnerable to flooding than any other HVAC part. Ductwork can also be ruined by water damage, and to make matters even worse, it can carry water to ruin other parts of your home as well.

Warning Signs of Rain Damage to Your HVAC System

If you suspect that your HVAC system has been compromised by rain, snow, or wind, it’s time to make an inspection of your units. Here are a few common signs of damage:

  • Leaks
  • Soggy spots
  • A burning smell
  • Frayed wires
  • Dented metal
  • Strange noises when turned on

Another telltale sign of an HVAC unit in need of repair is if it doesn’t seem to be working as well as it used to be. In actuality, it’s probably working twice as hard, but you aren’t getting the same results as usual.

Don’t Let the Rain Destroy Your HVAC System

These are just a few things to know about rain and how it can weaken or even ruin your HVAC system. If you find yourself needing help after a storm, the HVAC repair specialists at Black Lion Heating & Air Conditioning can help.

In addition to HVAC repairs, our team can install and maintain all components of an HVAC system. We also provide water heater, duct cleaning, electrical, indoor air quality, and gas fireplace services in Seattle and the surrounding area. Contact us today for more information or to set up an appointment.