Hydrovac Trucks vs. Dry Vacuum Trucks for Excavation Projects

Hydrovacs and dry vacuum excavation trucks are quickly becoming the preferred choice on construction sites for many industrial, municipal, and commercial applications. These vehicles are capable of removing large amounts of soil, rocks, and debris in a safe and timely manner. They also have the ability to excavate hard-to-reach places without causing any damage to the surrounding area.

What sets these two trucks apart?

Although they might sound interchangeable, there are distinct differences between the two. In this article, we'll take a closer look at the features of hydrovac and dry vacuum trucks, compare their differences, and help you decide which truck is right for your job. So, buckle up, and let's dive in!

What are Hydrovac Trucks?

Most vacuum trucks fall under this category. Unlike dry vacuum trucks that rely on suction power alone to remove dirt and debris, hydrovac trucks combine the power of pressurized water with a powerful vacuum to remove dirt and debris.

How Hydrovac Trucks Work

The process of using a hydrovac truck for excavation involves several steps. First, the operator uses a high-pressure water system to create a soil and water slurry. The slurry is then removed by the vacuum system and stored in the debris tank on the truck. The process is repeated until the desired excavation depth is achieved.

What are Dry Vacuum Trucks?

Unlike hydrovac trucks, dry vacuum trucks don’t use pressurized water to break up dirt and debris. Instead, these trucks rely on a powerful vacuum to collect dirt, small rocks, asphalt pieces, leaves, and other debris. Some dry vacuum truck models are equipped with a handheld air spade (instead of a high-pressure water wand) to loosen soil and break up larger materials.

Even though they're commonly referred to as ‘dry vacuum trucks’, many of these models are capable of collecting wet substances, slurries, and even liquids in addition to dry items listed above. The term ‘dry’ describes the excavation process rather than what can be collected.

How Dry Vacuum Trucks Work

A dry vacuum truck uses a powerful vacuum pump to create suction, which allows it to collect and transport various materials, such as liquids, sludge, and debris. The collected material is stored in a tank located on the truck and can either be used later as backfill or transported to a designated waste management facility for disposal.

Comparison of Hydrovac Trucks and Dry Vacuum Trucks

Hydrovac and vacuum trucks are commonly used in the construction, excavation, and waste management industries. However, while they share some similarities, there are several key differences between these two types of trucks.

Before settling on a hydrovac or dry vacuum truck for your excavation job, here are essential points to bear in mind. These should be taken into consideration before coming to a conclusion.

Purpose:

Hydrovac trucks are primarily used when thick materials like soil and sludge need to be broken down with water before removal. Vacuum trucks are mainly used when pressurized water is not required to collect debris like dirt, small rocks, leaves, etc.

Technology:

Both types of vacuum trucks utilize a powerful vacuum to suck debris into a holding tank for disposal. Hydrovac trucks combine a vacuum with high-pressure water to first break up debris and form a slurry before sucking it into the holding tank.

Speed and Efficiency:

There's no denying that hydrovacs are quicker at excavating in most soil types. However, this doesn’t necessarily mean they are always more efficient when it comes to completing the entire job.

Since dry vacuum trucks do not use water during excavation, they have the capability to dump the materials back onsite to be reused for backfilling. This can save a lot of time since the soil won’t have to be reclaimed from the slurry created by the hydrovac.

That being said, there are many jobs where dry waste is not usable for backfill. Reasons could include the excavated material is not suited for compaction or not the best option for covering utilities.

If using the excavated material as backfill then a dry vacuum truck may be your best option. If the material to be excavated is dense and full of rocks making it unsuitable for backfill then a hydrovac truck may be your best option.

Impact on the Job Site:

As we said before, hydro excavation trucks are generally faster at excavating, however the water can create quite a mess. Similarly, air excavation may not be completely clean either, as it can generate a significant amount of dust.

When working in areas with a high concentration of people extra caution is required for managing the airborne debris which can be hazardous to the public. Careful planning for each job is essential for ensuring everyone’s safety.

Properly trained and diligent operators are the key to minimizing airborne risks from either technology. However, controlling dust from dry vacuum trucks can be more difficult to manage.

Capacity:

The debris tanks on hydrovac trucks typically have a smaller capacity than vacuum trucks. Hydrovac trucks usually have debris tanks of up to 12 cu yards while dry vacuum truck tanks can have a much larger capacity of up to 20 cu yards.

Hydrovac debris tanks are generally smaller than dry vacuum trucks due to their additional water tank. This tank is used to provide the fresh water needed to create a pressurized water stream which helps to break apart soil and other materials during the hydro excavation process.

Ground Conditions:

Ground conditions should always be taken into account when digging.

In sites with light soil such as sand and gravel, and those which have been excavated previously, a dry vacuum truck is more effective than a hydrovac unit. This is because dry vacuum trucks are designed to vacuum dry materials. Their design prevents internal issues that can be caused by dust buildup.

However, hydrovac units offer a clear advantage in terms of ground conditions. They can excavate just about any soil type, whether it is muddy, hard clay, rocky, or sandy. Equipped with an onboard hot water heater, hydrovac trucks are even capable of excavating frozen ground.

Reach:

Both hydrovac and dry vacuum trucks are able to complete work in areas where access is limited. Depending on the model of the truck, this could be up to 50′ deep and at distances of 600′ away from the truck!

Safety:

Both options are considered safer than mechanical digging methods for the equipment operator and utility owner.

Even though excavating with air and/or water is ideal for delicate job environments, it is still possible for an inexperienced operator to damage lines. Proper training is the key to avoiding unsafe conditions and harm to utilities.

Choose the Right Truck for Your Job and Maximize Your Chances of Success

Both hydrovac trucks and dry vacuum trucks have unique advantages and limitations that make them suitable for different projects. When deciding which direction to go, consult an industry expert who can provide valuable insights and recommendations. The right choice can make all the difference in the success of your project.

Don't compromise on the quality of your equipment or operator. Choose Fuzion and experience the difference. Call us today at 970-539-4201 or request our services online.