How manufactured homes can leak energy, and what you can do about itBy Brian Sloboda
Manufactured homes, sometimes dubbed mobile homes, often log higher energy bills than traditional wood-frame or modular homes. Manufactured homes come as singlewides, doublewides and triplewides. Doublewides and triplewides require a crossover duct to provide air flow between the sections — a major culprit in air leaks that mean wasted energy. Also, homes that sit on jack stands or blocks allow air to flow underneath.
But residents can take steps to help manage energy costs and increase comfort. It may take a couple of weekends and even a few hundred dollars, but basic repairs can yield significant savings in the long run. Savings of up to 50 percent have been reported in manufactured homes that have been properly sealed and had old electric furnaces replaced with new electric heat pumps.
Here are the most common culprits of energy loss and ways to remedy them:
Belly board problems — In most manufactured homes, the belly board holds the insulation in place under the floor and serves as a vapor barrier. Plumbing that runs under the floor is on the warm side of the insulation to keep it from freezing in winter. However, the belly board can be damaged by animals or deteriorate over time, allowing the floor insulation to become moisture laden or to simply fall out, exposing ductwork and dramatically increasing energy losses. Often there is also long-term water damage from leaky pipes, toilets and showers that has compromised floor, insulation and belly board integrity. These problems must be addressed prior to basic weatherization. Replacing the belly board and repairing leaky plumbing should be the first thing on your "to do" list.
Air leakage/infiltration — Infiltration of excessive outside air can be a major problem. Specific problems include deteriorated weather stripping; gaps in the "marriage wall" that joins multiple units making up the home; holes in the ends of ducts; gaps around wall registers and behind washers and dryers; and unsealed backing to the electrical panel. Addressing leakage is a dirty job and requires crawling under the home and into the attic. Gaps can be filled with weather-stripping and insulation.
Crossover ducts — Sealing the ducts that run under the sections making up your mobile home will result in tremendous energy savings and increased comfort. Crossover ducts are often made of flexible tubing and are therefore prone to collapse and are easy for animals to chew or claw into. Crossover ducts made of thin sheet metal can leak air heated or cooled air, which is what happens when ductwork connections are made with duct tape. Repairs are generally easy, using either special duct sealant or metal tape found at most home improvement stores.
Lack of insulation — Insulation levels and associated R-values in walls, floors and ceilings in manufactured homes can be woefully inadequate. If it is easily accessible, adding additional insulation to ceiling and floors will help. However, avoid major renovations, often not justified, just to add insulation.
Uninsulated ductwork — Wrapping your ductwork leads to energy savings. Find insulation specifically made for ductwork at hardware stores.
Single-glazed windows and uninsulated doors — Most manufactured homes come with single-glazed windows and uninsulated doors. Replacing the windows with double- or triple-glazed windows or adding storm windows will help to make the home more comfortable. An insulated door will also help. However, these solutions can be very expensive. At a minimum, you should add weather stripping to doors and windows. Also, a window film kit is a cheap and easy-to-install upgrade that will help keep winter winds at bay.