AC Ductwork And Your HVAC System

AC Ductwork

There’s a hidden system in your home dedicated to circulating your air. Don’t know anything about your ductwork? You’re not alone. When homes have air duct issues that can cause cold or hot spots, homeowners tend to avoid those rooms and also, avoid the problem. And when they do, without realizing it, they’ve lessened the liveable amount of square footage in their homes. It’s not a good situation.

From uneven room temperatures to excess dust, and high electricity bills, air duct issues can cause daily despair to homeowners and renters alike. What follows is a homeowner’s guide to AC ductwork; we’ll explain everything you need to know so you can rid yourself of those burdensome colds or hot spots and reclaim your rooms.

What’s An Air Duct?

Check this out – Air ducts, or HVAC ductwork, or AC ducts, are conduits that supply warm or cool air to heat, ventilate, and cool each room in your home. Air ducts are connected to the HVAC unit which filters then heats or cools your home’s air before sending it off. Air ducts are a vital part of your HVAC system, providing thermal well-being and good indoor air quality to your family.

Next, let’s see what air ducts are made of.

Types Of Air Ducts

Sheet Metal Ducting

Galvanized steel or aluminum air ducts can be round, oval, or rectangular, depending on your home and its design. Sheet metal HVAC ductwork is the most durable and is also least likely to harbor mold. Metal air ducts are practically rustproof, especially galvanized steel with its zinc coating.

Flex Duct

Simply put, flex ducts are made from a steel wire spiral, wrapped with a polymer (a bendable plastic), and surrounded by insulation. This kind of ductwork is inexpensive, lightweight, and easy to install. Flex ducts work wonders in tricky spaces where more rigid ductwork will not do. While typically a duct system won’t contain all Flex Duct, it may be used sporadically in locations where sheet metal is tough to place.

Fiberboard Duct

This type of duct has two layers: compressed resin-bonded inorganic fiberglass is encased in foil to prevent air and water vapor from penetrating. Typically, this air duct is the least expensive, prevents noise, and is already well insulated when it is first installed. The downside? The rough fiberglass surface inhibits airflow. Admittedly it’s not an incredible level of airflow stoppage, but it does make a difference in air flow.

Beware – old fiberboard ducts aren’t treated to prevent mold or mildew and should be replaced immediately. If you suspect you have old fiberboard ductwork, do not attempt to clean it. The surface damage will release fiberglass into the air and throughout your home.

How Air Flows In A Forced Air Duct System

In HVAC systems, your air goes through a cycle. A negative pressure in the ducts sucks the air in, passing it through a filter in the system. The cleaned air is heated or cooled and sent back to the areas of your house where it stays until it’s cycled again.

Return Ducts

Contrary to popular belief, almost all HVAC systems get their air from inside the building. Return ducts extract air from the living spaces back to the HVAC unit, feeding either your furnace or air handler. Return vents are usually larger than supply vents and are called grills. A filter is often installed either deep inside a return duct or right at the return grill to protect your HVAC unit from impurities.

Supply Ducts

Supply ducts blow warm or cool air to an area inside your home. Supply vents often have dampers to control the flow, called registers. Supply registers will often be installed near windows or doors to better counteract the loss of heat or cold, and two or more supply registers may be installed in larger rooms to evenly distribute your heated or cooled air.

We’ve looked at duct systems, but what happens when you air ducts aren’t up to standards?

Signs Your Ductwork Is Bad

Hot & Cold Spots

This is the ultimate tell-tale sign you have air duct issues. You’ve likely felt it before. You walk into a room and it’s too hot, or you walk down the stairs and it’s noticeably colder, often at least more than 3 degrees. If this is the case, use a thermometer to confirm what you’re feeling. Once you’re certain of the discrepancy you can call an HVAC professional from Air Check Mechanical Service. They’ll pinpoint the cause, come up with a plan, and put the plan to action.

Fair Or Poor Indoor Air Quality

There are two big signs your air quality is compromised. First, the dust collection in your house makes it look like you’ve been in a serious dust storm. Second, everyone is sneezing, especially any family members that have allergies. The main factor you should know is that dust or pollen can seep into your ductwork through holes or loose connections and infiltrate your home. Thus, the sneeze factor.

According to the National Comfort Institute, air duct problems are so common, a typical HVAC system only delivers 57% of its rated capacity. One quick call to Air Check can change that all!

High Utility Bills

Up to 30 percent of the air in your ducts may be escaping before it can do what it needs to do, i.e. heat or cool your rooms. When conditioned air leaks out or heated air is lost through under-insulated air ducts, the charges will show up on your utility bill. The scary part is you probably won’t notice unless there is a major disruption. You may eventually discover through a utility usage report that you are using way more electricity than other similar homes in your neighborhood.

Little Or No Air Flow From Supply Vent

An easy way to check for obstructed airflow is to place a piece of paper in front of the supply opening. If the paper doesn’t bend or flutter at all, something is preventing airflow. If you’re lucky, the damper on your register is closed and simply needs reopening. If that doesn’t work, you may need to call an HVAC expert.

Loud Noise

Wait a minute, doesn’t your heat pump or air conditioner make noise when it’s running? Yes, but the sound shouldn’t annoy the living heck out of you. If you hear loud rattling or whistling, you probably have loose, disconnected, or damaged air ducts. Don’t ignore it or it’ll worsen.

This has been part one of AC Ductwork and your HVAC system. Don’t forget to tune in next week for part 2!

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