When I purchase any mobile home for renovation, I always climb under the home to see what kind of shape the ductwork is in. If it isn’t in good condition I will repair or replace it. Why? Because hundreds of wasted dollars can be lost in energy costs by old and leaking ductwork.
So how much does it cost to replace the old ductwork in a mobile home? This isn’t an inexpensive project:
- Typical cost is about $35 – $55 per linear foot
- Typical single-wide with 60-foot ductwork length would be from $2,100 to $3,300
- Typical double-wide with 110-foot ductwork length would be from $3,850 to $6,060
- Clean, Seal and Reinsulate can often cost less than $1,000 if done yourself
There seems prohibitively expensive. Continue reading to see some workarounds to replacing the ductwork if you have old, damaged and leaking ductwork.
What Is My Mobile Home Ductwork Made From?
Ductwork in a mobile/manufactured home is typically made from a thin, pliable galvanized sheet metal. This is a lightweight material that is easy to work with and is great to use for a mobile home.
Since mobile/manufactured homes sit off of the ground with a type of crawl space beneath, the vast majority of ductwork systems exist beneath the home. It is nestled in with the insulation just beneath the floor.
Why Is It So Expensive To Replace Mobile Home Ductwork?
Just like the blood veins carry blood from your heart to all locations throughout your body, the ductwork in your home carries the heated or conditioned air from the HVAC unit and distributes it throughout your home. There are usually air registers in every room that connects with the main ductwork to let air into that part of your home.
In order that each room in your home receives the right amount of air for that room, different sized arteries come off the main ductwork so that it channels different volumes of air as needed for larger and smaller rooms. There is quite a bit of engineering that goes on to make sure the system works properly for the home. This adds to the cost of replacement.
The ductwork in a mobile home is contained within the insulation under the floor of the house. This means that in order to change the ductwork, the insulation needs to be removed and then reinstalled; this adds to the cost.
What Can Happen To My Mobile Home Ductwork Over Time?
Since almost everything known to man deteriorates with the passage of time. Metal ductwork is no different. Since it is made of very thin sheet metal, all sorts of issues can occur.
The seam is where it is especially vulnerable and this can often end up splitting over time. As the material is constantly subject to expansion and contraction with the heating and cooling, this has a tendency to stress the seam which may split and get small holes in it.
More common is settling and movement. This can cause various pieces of the ductwork to separate from each other. When this happens, holes open up which allows insects and rodents access to the interior of the home.
Also, any leakage from split seams or holes makes the HVAC system operate very inefficiently causing wasted energy and expensive utility bills.
Replacing The Mobile Home Ductwork
It is not an easy task to remove and replace the ductwork. The insulation will first be opened up and removed from around the existing ductwork. Usually, there will be at least a couple of technicians required to do the job. It is difficult at best since they are working in a very small, dark and confined area.
The old ductwork detached from the floor registers is removed and then dismantled. Once all of the old ductwork is removed, new pieces are then installed that are of the same size as the old pieces that were removed.
After installation and connection to the floor registers, the insulation is replaced.
What Are Alternatives To Replacing The Ductwork?
I’ve seen only a few cases where the entire ductwork needed replacing. More common are leaks caused by the separation of ductwork components from one another and from the registers.
Cleaning, sealing and insulating the mobile home HVAC ductwork is usually much less expensive than a full replacement.
Clean, Seal and Insulate The Old Ductwork
This is a job best done when replacing the floor insulation in your mobile home. In an older home, the floor insulation often deteriorates due to humidity, water leaks, dirt, rodents, snakes and almost anything else that might be under the home.
Replacing the old underfloor insulation can often be a significant source of energy savings. HUD as a great PDF available “Manufactured Homes: SAVING MONEY BY SAVING ENERGY“.
Page 12 of that PDF states the following:
“Leaky ducts are common in older manufactured homes and can dramatically increase heating and cooling bills. It is not uncommon for an older duct system to lose 20% of the heated or chilled air to the outside. If your annual heating and cooling bill is $2,000 and your ducts are leaky, you could be spending $400 every year to heat and cool the outdoors.”
What are some of the indications you might notice?
Page 12 of the PDF:
“Almost all homes can benefit from duct sealing. If you answer YES to any of these questions, your home may be especially in need of duct sealing: • Was your home built before 2000?
• Are the heating and cooling air distribution in your home uneven—that is, do some rooms get a lot of air from the registers, while others don’t get enough?
• Is it difficult to heat or cool your home, even after having performed heating and air conditioning system maintenance?
• Does a visual inspection reveal a deteriorated crossover duct (see next page)?”
The PDF has some great information on the “how to” of sealing your mobile home ductwork. This will also be the topic of later post.
How can I tell when my mobile home underbelly insulation needs replacing? Common problems with underbelly mobile home insulation include:
- Double-Wide Mobile Home Ductwork – Ductwork in a double-wide mobile home is often very similar to a single-wide. Each unit has a main duct that runs the length of the unit. Between the two units, there is a crossover duct tying them together.
- What Are The Mobile Home Ductwork Supplies Needed? – Often, the specific parts used in mobile homes differ from those in a site-built home. Mobile Home Depot offers pages of all the parts needed on their website.
Can I install a single HVAC unit outside of the home and remove the air handler from inside the mobile home?
Yes, I have done this in a number of mobile home renovations. You get a much quieter operation by moving the condenser and air handler to the main unit outside of the home. This also frees up additional closet space inside of the home where the old unit resided.