HVAC Contractors: How to Set Up a Home Performance Vehicle

Want to expand your HVAC business into the whole house? Better have the right wheels.

June 18, 2015
July/August 2015
A version of this article appears in the July/August 2015 issue of Home Energy Magazine.
Click here to read more articles about HVAC

HVAC contractors would do well to add insulation and air sealing to their business. They have the advantage of working in some of the same spaces as insulation and air-sealing contractors—in attics and basements, for example—so they know the territory. But the tools of the trade change when you work on the building envelope rather than on the systems, and so your vehicle setup changes too. (See “Inventory” for a complete list of the tools and materials you will need.) In this article, I discuss setting up a home performance (HP) vehicle to install cellulose and to install glass insulation. These are the first choice for most retrofit work, although spray foam has its place, as I explain below.

Trailer Versus Truck

Should your HP vehicle be a truck or a trailer? Trailers cost less to buy, but they have disadvantages. While a trailer can be used to haul insulation and other equipment, trailers generally have less volume for equipment than trucks and their uses are limited. Moving a trailer can be difficult, unless the crew has experience moving trailers, and it can be hard to park them in neighborhoods where space is limited. Finally, it may be a problem finding workers who are willing to drive the trailer to the site. Some people become unhinged when they drive a hinged vehicle.

Site-built shelves provide plenty of storage. (Jason Todd)


Well-organized sidewall jobsite and truck. (Jason Todd)

Loading bales in an extended hopper. (Jason Todd)

Pigtail for connecting to a dryer outlet.

Commercially available hose reel. (Jason Todd)

Dedicated spray foam rig with foam and spray equipment.(Jason Todd)

Thinking to save money, some contractors buy small trailers—small not only in length but also in height. Bill Hulstrunk, a technical consultant who has specialized in cellulose insulation, says that “trailer guys go out and buy the cheapest one they can, and the ceiling height is only 6 feet, 5 feet at the door.” These shorter doors can be hazardous for workers getting equipment in and out. Some insulation machines, especially those with extended hoppers, need more height as well. Storing the tools you need to perform the work and stay organized also calls for space—another reason to think big, not small. And if you decide to go with a big trailer, you will need a vehicle that has the capacity to tow it.

That being said, trailers are less likely to be the cause of a mechanical breakdown. A truck with an engine problem can be swapped out. A trailer can be dropped on site for a few days or even a week depending on the job. Should the vehicle need to leave the job site during the day, a trailer can stay behind and work can continue.

Trailers have other advantages. A trailer can be easy to load, since it is low to the ground or may even have a ramp. Since there is a separate vehicle that tows the trailer, that vehicle can be one that carries three or more people. While crews on most home performance jobs are relatively small, it may sometimes be advantageous to have more people on site.

If the trailer has forward side doors to access the area in front of the trailer, it is also possible to superinsulate this area and use it to house spray foam products that are temperature dependent. Auxiliary heat can be added in cold weather as well. This takes up significant space, though, so a trailer big enough to accommodate auxiliary heat would have to be quite large.

What Kind of Truck?

While a trailer may work for some contractors, having a dedicated truck for home performance work makes a lot of sense. Many jobs will call for a broad set of tools in addition to a fiber-blowing machine and accessories. A 16-foot box truck should provide ample room for a blowing machine, hoses, and tools, as well as the material needed to do the job. You may also need room for vacuums for existing insulation, as well as low-pressure spray foam kits. While a 14-foot truck will be easier to maneuver, the greater the capacity of a 16-foot truck may be worth the inconvenience posed by its size.

If you service a concentrated area, you might want to choose a smaller truck. If you need additional materials and tools on big jobs, you could carry them in a second truck. A forward-cab truck with a 14-foot box is more maneuverable than a truck with a larger box and provides adequate storage for most jobs. If you service big homes, homes with big attics, or suburban areas that require a long commute from your shop, you may want to think a little bigger. The cutaway-style trucks have an overhead attic, allowing for more storage above the cab. This is a great place to store additional bags of insulation.

Setup Depends on the Work You Might Do

There are two ways of retrofitting insulation in a home. One is to blow material into an open space, such as an attic. Here the goal is to move lots of material, leaving it loosely piled. The other is to compress the material within an enclosed cavity, filling areas that are impossible to get to without demolition, and reducing uncontrolled airflow through the building in the process. Dense packing walls would be an example of this.

Regardless of the area, or the age of the housing stock, a high-quality insulation job includes air sealing the attic. This will disrupt the existing insulation, often to the point where it’s a good idea to add more to cover your tracks. Compressing existing insulation is often unavoidable, and getting batts of fiberglass back in place is difficult at best. There are two approaches to treating existing attics. One is to leave the existing insulation in place, and “refresh,” and the other is to remove the existing insulation wholesale. Each approach has merits, but know that you won’t get away with just air sealing most of the time. Attics that need air sealing often can use more insulation, codes change, and some builders didn’t install enough insulation to begin with. This is a perfect time for a tune-up. No matter what HP vehicle you choose, it should have a machine capable of installing attic insulation at a distance of several feet.

Houses are insulated differently in different parts of the country. In some places, walls are seldom dense packed. This holds true especially for newer housing stock. Walls in new housing are frequently better-insulated using methods other than dense packing, and while this may not exclude some wall work, being prepared for dense packing is less important in these cases. This is not to say that you won’t use some of the same tools in attic work that you would use for dense packing. Drilling holes in framing or sheathing can be done in knee wall spaces, and gaining access to some small attics requires opening up sheathing that was installed blocking access.

Overall, the tools you will need to keep an insulation crew busy on-site differ from the tools you need to install ducts or HVAC equipment. See “Inventory” for a complete list of these tools. Carpentry and remodeling companies may be able to provide more information on tools you will need to perform a home performance job.

In areas where there is an older housing stock, you can expect to do wall work regularly. The blowing machine should be capable of pushing at a pressure sufficient to handle this type of work at a reasonable speed. You will also need to have additional tools, both to access the wall cavities and to fill them. Although cellulose and fiberglass are the first choice for most retrofit work, as I explained above, you may also be using rigid foam board, as well as other sheet materials, and perhaps even spray foam. If you use these materials, you will need the appropriate tools with which to install them. Contractors who use spray foam sometimes even have a second HP vehicle dedicated to that purpose.

How you set up for installations also depends on the amount of work you have and the number of crews capable of doing the work. It makes sense to start with one fully-stocked HP vehicle that can keep a crew of two, or possibly three, busy. Adding more crew before you purchase and stock a second vehicle may also make sense. This gives you the flexibility of handling larger jobs with an additional worker, or allowing a crew lead to go ahead and prepare for the next job. When you do decide to purchase a second vehicle, it need not be a fully-stocked truck. Consider purchasing a small truck, capable of carrying a smaller tool set to back up big jobs or to follow up on callbacks and final touches. A second vehicle might also be stocked and used as an air sealing rig; or it might be stocked and used to handle more carpentry.

What Kind of Machine?

Most installers use midsize blowing machines. These range from portable units to mounted machines that can exert greater pressure at greater speed than smaller ones. But unless you are insulating large attics, speed and size may not determine your choice of machine.

The misconception with large machines, Bill Hulstrunk suggests, is that faster is better. “If it’s a matter of dense packing, the larger machines are not going to go quicker.” He finds that unless it is a very large attic you are blowing insulation into, speed will not be an issue.

A smaller machine will also be less expensive. When we consider output, though, installation speed is determined not only by the machine, and by the worker operating it, but also by the efficiency of the crew supporting that person. While a larger truck-mounted machine with an extended hopper may not increase “output,” it is my experience that this setup allows one worker to fill the machine and walk away to tend to another task, while smaller machines require the worker’s constant attention.

Hopper extensions on the large machines are helpful for another reason. They help to keep the material in the machine. Loading a machine that can hold two or three bags at a time without a hopper extension can make quite a mess. Once the material starts to condition and break up, it becomes lighter and fluffier—more the way it will be when it is installed in the attic. The volume increases, and without a hopper extension, this material will end up all over the floor.

Hulstrunk recommends starting out with a semiportable machine like the Accu1 9300 or the Force 2—not for portability, but for electrical connections. “If you get something bigger than that,” Hulstrunk says, “then power becomes a real issue.” The midsize machines that are considered portable but are still quite heavy and are best left in place can be operated with standard household outlets. Cost may also be a consideration; the larger machines are more expensive.

The larger machines that are truck-mounted do require a greater power load. For example, the 2300 series Krendl machines that a number of contractors use need a 30-amp breaker to operate. These machines have a voltmeter installed to ensure that they will receive a constant 230 volts. If machines are underpowered, the lower voltage could damage the motors.

Having a generator on board, or at least available, is not a bad idea. “A lot of our locations have and use a generator when necessary,” says Dave Abrey, director of quality assurance for GreenHomes America. “If there is an electric dryer, we can usually plug in there. We have been looking at Cool Machines as well, because we can use a smaller generator.”

The ability to draw sufficient power from the home varies by region. Newer residential areas, where people use a lot of electrical appliances, such as clothes dryers, usually have appropriate breakers. Depending on local codes, and on whether you have an electrician on board, your crew may have to use specialized extension cords to connect to a dryer plug.

Finally, bear in mind that a truck-mounted machine takes up space. GreenHomes America has used many different machines, starting with Accu1 9300 and Force 2, followed for some time by the Krendl 2300 with an extended hopper. Recently, though, Abrey has found that the “Cool Machine, compared to similar Krendls, is 10 inches thinner, leaving more room onboard for moving around”—an important factor.

Location and Accessories

There needs to be storage space for bags of insulation. A typical job may need 20 to 60 bags of cellulose or fiberglass. Brought to the front of the truck, these bags can be stacked and held in place with a load bar. Most installers store the blowing machine near the back door of the truck, since that makes it is easier to access and load during production. Hose connections are made here, and the fresh-air intake for the machine, if it is not permanently installed in the truck body, can be extended by a piece of flex duct out the back door.

There should be enough hose to work around the home as well as up into the attic. Most machines start with a 3-inch takeoff. Commonly attached to that is 100 feet of hose reduced to 2.5 inches and then to 2 inches for the last 50 feet or so. This hose can be used to fill an attic or other open space. To work on walls, the hose is reduced further to 1½ inches or 1¼ inches for the last 50 feet. This should be a firm but flexible hose that allows the installer to push back on the cavity and the installed material.

One hundred fifty feet of hose takes up a bit of space, and there are a few options. Reels make storage tidy and hose handling a fairly simple task. Some reels sit on the floor and can be tucked under shelving when not needed.

Another option is to mount the reel on the wall. These wall-mounted reels are narrower, and they provide a bit more room to move around on board; they also keep the hose off the floor and out of the way. Either option leaves the built-in storage space available for other uses.

Hulstrunk has also seen the larger hose stored in a plywood box with a 6-inch hole. The box measures 2 x 4 feet, making it a little larger than a floor hose reel. This can be an inexpensive way to hold the hose in place.

For wall work or other enclosed cavities, a smaller hose is needed. A 2-inch swivel can be left on the end of the main hose. Smooth-walled reducer fittings can be left on the ends of 2-inch, 1½-inch, and 1¼-inch flex hose, so they will be readily accessible and not easily lost. Dense-pack hose can be hung from a hook, or coiled and stowed in a bin or a special tube mounted on the wall or roof of the truck. I like using 4-foot PVC pipe fastened near the ceiling. If the truck has barn-style doors off the back, the pipe is fastened right up to the ceiling. If the truck has garage-style doors, the pipe is fastened lower and near the wall. The advantage of storing the dense-pack hose straight is that this will help the installers, since they will not be fighting as much of a curve in the wall cavity. “If you are constantly wrestling with the curve of the hose, it makes it a lot harder,” says Hulstrunk. For slopes, he recommends a smooth-walled 2-inch hose similar to the smaller wall hose, since the standard 2-inch hose with ribbing will get caught on things within the cavity, or on the material that is placed over some cavities to enclose them.

Vacuuming Out

Some installers are getting a lot of insulation removal work. Not all installers do this work, and it adds to the cost of the job, but it provides many benefits to the homeowners. Some installers are using vacuums to clear out the attic first. “Guys that are using them are such fans,” Hulstrunk says, “they would never quote out a job without vacuuming or removing whatever is in place.” The benefit is that the air sealing goes quickly and easily, since there is nothing in the way, and this naturally leads to greater air leakage reductions.

With the blowing machine, insulation, and various other necessary tools, there is not much extra storage on a typical HP truck. The vacuum itself may fit on board, but the truck will not be large enough to hold the material that is removed. Large demo bags can be used, but an enclosed dump trailer or dumpster will still be needed.

Temperature-Sensitive Materials

The largest spray foam kit on board for a typical job will likely be two-part foam in propane grill sized cylinders. This will not take up too much room on the truck but will need to be kept warm in colder weather. You may want to invest in shop-built insulated devices with heating blankets or boxes to keep the material warm. Temperature is also an issue with foam guns as well as caulk. Making storage portable or a space available that can be heated can help facilitate jobs. It may be that some materials will need to come into the shop when the weather gets cold. Again a trailer can have a dedicated room toward the front, but at a cost of sacrificing space on board for other material.

learn more

Contact the author though his company website or by email.

For more on insulation and other home performance materials and equipment:


Cellulose Insulation Manufacturers Association

Cool Machines


J&R Products


North American Insulation Manufacturers Association

Spray Polyurethane Foam Alliance

Spray Foam: A Cure-All Solution?

Cellulose and fiberglass insulation are the first choice for most retrofit work, as I explained at the beginning of this article. However, some contractors see spray foam as a cure-all solution. This is understandable. Spray foam air seals well, has a high R-value, and applies quickly. I often see installers and contractors, when recognizing the size of the job ahead of them, immediately get out the spray foam rig. Spray foam appears to do every thing we need it to do, and some feel that a second truck should be dedicated to spray foam. After some time in the business, the thought tends to dissipate. Let’s look at what spray foam is and isn't.

Two types of spray foam delivery system, and not many more types of spray foam, are commonly used in retrofit. With a dedicated truck or trailer, an insulation contractor would use a high-pressure system such as Graco. This self-contained system heats, monitors, mixes, and delivers the chemicals to the installer via a heated hose. The temperature-sensitive chemicals are stored in 55-gallon drums. This poses problems for storage and handling.

The spray foam itself may be open cell or closed cell. Regardless of the type of foam used, a high-pressure system is expensive, and it requires a dedicated and knowledgeable crew. Since it is designed to achieve high production rates, a high-pressure system should be used only for large jobs. Many spray foam installers prefer to spray a minimum of 1,000 board feet. (A board foot, a unit more commonly used to designate rough lumber, is 1 square foot 1 inch thick. If you were installing 2 inches of spray foam on a wall, it would be 2 board feet for every square foot.) This speaks to the time and effort involved in setting up the job. Most HP jobs are less than 1,000 board feet. Examples are insulating a band joist in a basement or a knee wall in an attic. Home performance work may include insulating a crawl space or a basement, or an attic with an exposed interior wall. But much of the spray foaming that we might want to do would consist of small jobs.

The personal protective equipment (PPE) required for high-pressure jobs also limits the work that can be done. Full coverage from overspray and an outside air hood restrict the installer’s movements, and crawling around in tight spaces is even more difficult when you are suited up this way.

Smaller, portable delivery systems that you can carry into a home easily are good for sealing attics and many small penetrations. They are also less expensive than high-pressure systems. While the lower cost of a portable system may seem enticing, it’s the expectation of volume that is keeping that cost down.

If you install all types of insulation, you may find enough work to justify buying a spray foam delivery system. This would include jobs sealing new construction, and deep energy retrofit work, where lots of spray foam is needed; and it would include using spray foam to supplement smaller jobs as well. The setup of a truck to perform this kind of work has some of the same elements you might find on a fiber truck. One-part guns, weatherstripping, and light carpentry are all possibilities.

Generally a spray foam truck is a back-burner item for a new HP contractor. It may be many years before it makes sense for you to buy one. Meanwhile, find a few good subcontractors who understand what you are trying to do, and who can maintain a high standard. Use those subcontractors for any small spray foam jobs, and set up your HP truck to install cellulose and fiberglass insulation.

Jason Todd is president of Energizengage Consulting, which helps contractors, utilities, and energy efficiency program implementers understand, streamline, and optimize their involvement in the Home Performance industry. He has trained and supported numerous HVAC contractors who are expanding their business models to include the whole house.

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