There are a number of things to consider when you’re looking into hiring an air duct cleaning company, and when you should is a little up to you.

What do I mean by that? Well, you don’t need to hire one every month or every few. Typically speaking, you can wait a good amount of time in between cleanings. However, the best way to tell is just by feeling it out yourself.

You’re in your home every day, and you’re very familiar with the air conditions. That should make it pretty easy for you to tell when things are going downhill. But we’ll get into what you can do to keep tabs on everything and really have a sense for when you need to call in some professionals.

Without wasting any more of your time, let’s get into it.

Mold.

You’re surely aware of the negative effects that can spring from inhaling too much dust. But mold is another story entirely. Mold is capable of spreading through your home at a shocking pace. Everywhere it goes, it brings the risk of exacerbating allergies or respiratory issues.

Mold typically presents itself when your system has taken on an excessive amount of moisture. This frequently happens when you live in a humid climate, but it can really happen anywhere.

You may be able to spot mold on the vent covers. If it’s not there, don’t take that as a sign that your home is free and clear. Mold can be deep in the ducts making it almost impossible to detect, but keep in mind that mold often comes with a strong, musty odor as well.

If you have mold in your home, don’t wait or try to clean it yourself. Contact a professional.

Rodents or Insects.

This is easier to detect than mold, and it comes with similar risks. Rodents and insects in your home can cause or spread illness to the members of your household. They often leave droppings or nests deep within your system. If your vents are infested with them, it’s a serious concern.

As we said, these are much easier to detect. A few common signs are droppings around the vents, chewed-up materials, or bad smells.

Try to get on this problem as soon as possible once spotted. A duct cleaning won’t sway rodents and insects if they’re left alone too long.

Freshly built home or renovation.

When a home is undergoing any sort of construction, there’s always a dense amount of dust or particulates built-up. It’s impossible to keep it out of the duct system most of the time.

You certainly don’t want to be inhaling all of that construction debris. So having a duct cleaning will ensure that your home looks new on the inside and on the outside.

Dust.

If you constantly find dust in your home, no matter how often you clean or how many people come through, there may be a problem.

Your home could be the cleanest one in the world, but it would still have dust, dirt and a whole variety of other contaminants in the ducts. You could even see dust coming out of your vents when the HVAC kicks on.

If you can see the dust on the air supply and return vents, investigate further. Remove a vent cover or filter and look into the duct system. If you see dust or dirt on the inside and outside, your ducts most likely need to be cleaned.

Get help if you have these problems.

Assuming that you’ve noticed even one of these problems, it could be time to look at a company.

However, it’s important to get the right help that you need. When you look for a company to clean your air ducts, you can keep a few things in mind to make sure you’re in good hands.

Ask how long the company has been in business—experience matters when dealing with HVAC systems.

Ask for some references. A reference can go a long way in supporting a companies claims.

Ask for proof of liability insurance. If they have both of the previous things, then it’s unlikely you’ll need it, but it’s nice to have the confirmation.

Simple questions like these will help a lot. If they answered yes to all three, then keep asking away! Never be shy when asking questions about a service that you’re about to pay for. We hope that you’ll take our advice and consider having your air ducts cleaned sooner, not later.