How to Inspect the Heating & Cooling Systems of Mobile Homes, Double wides, Trailers InspectAPedia® -
Mobile home heating & air conditioning system inspection guide
Common mobile home heating system defects
Mobile home cooling system and ductwork defects
Mobile home insulation defects and remedies to reduce heating and cooling costs
How to Inspect the heating and cooling systems in mobile homes, trailers, double-wides, multi-wides: how to spot common and dangerous defects in heating equipment incuding furnaces and boilers, inadequate heat distribution, freeze-ups, and safety hazards. How to save heating or cooling costs for mobile homes and trailers or multi-wides.
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Ver.3.5 - 04/25/07, updated through 2011 - Steve Vermilye, New Paltz NY and Daniel Friedman, Poughkeepsie NY,
Hudson Valley ASHI Chapter Seminar, Newburgh NY, January 4, 2000, NY Metro ASHI Fall 99 Seminar, Holiday Inn Crowne Plaza, White Plains NY, October
2, 1999. Readers should also see MOBILE HOME PLUMBING where we further discuss oil tanks, oil piping, and water heaters for mobile homes. Page top sketch courtesy of Carson Dunlop.
Outside heating oil tank not protected from freezing (using more expensive kerosene mix?) or use of heating tapes on heating oil lines - a possible fire risk (photo above)
Unsafe heating system chimney and vent installations on mobile homes and trailers:
Our photo (above left) shows an oil fired heating flue venting directly through the mobile home side wall and just inches from the home's windows.
Our second photo (above-right) shows a makeshift gas flue using aluminum venting (not recommended, unsafe), a too-short chimney (inadequate draft) and flimsy construction, as well as probably leaks into the home wall over the entry door.
Unsafe fire clearances and inadequate working space to maintain heating equipment are not due to the mobile home manufacturer but due to low-budget modifications such as this oil burner access through a bath vanity cabinet door (photo at left).
Warm air heat return air in a mobile home: all return air taken from crawl area
beneath living unit - one-way heat; blocked return; blocked supply; ducts
through un-heated area; NO return air, or none when utility closet door is shut! We see this design too often - it is the most expensive way you could heat your mobile home since none of the interior air is being recycled through the heating furnace.
Mobile home heat safety warning: Our photo of a mobile home warm air furnace (left) shows that someone has put paneling over the door to stop drafts - also cutting off return air to the furnace and possibly making it very dangerous if this step has also cut off combustion air from this heater.
Because the mobile home furnace is shoe-horned into a tight space it is too often the case that the system is not inspected and cleaned on schedule. Generally you will save more on reduced heating costs by having an expert clean and tune the system than you will pay for the service call.
Air filters are often ignored - change the filter monthly when the heating or cooling system are in use. A clogged air filter will reduce air flow from your heater, increasing heating costs as well as making the home less comfortable.
LP Tanks, copper gas lines are often left unsupported and exposed to mechanical
damage; also check for LP gas leaks at tanks or fittings;
Oil tanks at trailers and mobile homes - indoor-rated heating oil tanks are quite often placed outside, above ground,
in ground contact, with heat tapes (a fire hazard), often leaking, and in cold
climates, exposed to frost-risk which in turn risks loss of heat and related damage to the home
Missing or still-covered-over spark arrestor on the heating flue on a mobile home - have your heating service technician check the safety of the entire flue and chimney, including the outside components
MOBILE HOME COOLING System Defects - Air Conditioning
General Characteristics of Mobile Home Cooling Ducts
Heating or Cooling Ducts placed at one of these typical locations:
cooling ducts placed in the floor along center line of the mobile home;
cooling ducts placed in the floor along exterior walls (better heating in cold climates);
cooling ducts placed in the in trailer or mobile home ceiling (better cooling in South);
[The duct location may tip off the wind zone rating intended for the mobile home unit being inspected.]
Common Defects
floor ducts often damaged; registers blocked or covered by carpeting
MOBILE HOME and TRAILER INSULATION and Ventilation Defects
Our photo, courtesy of Jeremias, some of our mobile home inspection and repair advice readers, shows a mobile home whose walls have been completely opened to permit:
identification and correction of all leak points
repair of rotted framing
removal and replacement of wet, moldy wall insulation
Crawl space area ventilation below mobile homes : sq ft/150 = min area and must cross vent on at least 2 sides;
PVC plastic vapor barrier placed on soil below the mobile home is recommended to hold down moisture;
Attic venting (sloped shingled roofs) - often omitted, shorter shingle life, voids warranty, etc.
Attic venting (often none or just a few spot vents in flat roofs) - condensation, leaks, related damage.
Check dryer vent routing and materials for fire hazards (blocked overheats dryer; or may collect water)
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Additional technical contributors & reference sources for this article are listed below.
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"Modular Home Construction, special defects and inspection methods" Dan Friedman, NY Metro ASHI Seminar, Holiday Inn, Crowne Plaza, White Plains NY, October 4, 1996
"Modular Home Construction, special defects and inspection methods" Dan Friedman, NY Metro ASHI Seminar, Holiday Inn, Crowne Plaza, White Plains NY, October 4, 1996
New York State: "Manufactured Homes: an installation guide for the code enforcement official," undated. [Div. of Code Enforcement & Admin. - 518-474-4073, George E. Clark, Jr., Director] - this is a guide tool, not an enforcement code or standard.
HUD State Administrative Agency (for 36 states) (NY: 518-474-4073) - for complaints
Manufactured Housing Institute, 2101 Wilson Blvd. Ste. 610, Arlington VA 22201 703-558-0400 www.mfghome.org
NYMHA, 35 Commerce Ave., Albany NY 12206-2015 518-435-9859 800-721-HOME (they want the Star Program to provide for separate assessment of manufactured homes)
Consumer Reports: www.consumerreports.org - special report 2/98
Books & Articles on Building & Environmental Inspection, Testing, Diagnosis, & Repair
Our recommended books about building & mechanical systems design, inspection, problem diagnosis, and repair, and about indoor environment and IAQ testing, diagnosis, and cleanup are at the InspectAPedia Bookstore. Also see our Book Reviews - InspectAPedia.
The Home Reference Book - the Encyclopedia of Homes, Carson Dunlop & Associates, Toronto, Ontario, 2010, $69.00 U.S., is available from Carson Dunlop, and from the InspectAPedia bookstore. The 2010 edition of the Home Reference Book is a bound volume of more than 450 illustrated pages that assist home inspectors and home owners in the inspection and detection of problems on buildings. The text is intended as a reference guide to help building owners operate and maintain their home effectively. InspectAPedia.com ® author/editor Daniel Friedman is a contributing author. Field inspection worksheets are included at the back of the volume.
Design of Wood Structures - ASD, Donald E. Breyer, Kenneth Fridley, Kelly Cobeen, David Pollock, McGraw Hill, 2003, ISBN-10: 0071379320, ISBN-13: 978-0071379328
This book is an update of a long-established text dating from at least 1988 (DJF); Quoting: This book is gives a good grasp of seismic design for wood structures. Many of the examples especially near the end are good practice for the California PE Special Seismic Exam design questions. It gives a good grasp of how seismic forces move through a building and how to calculate those forces at various locations.THE CLASSIC TEXT ON WOOD DESIGN UPDATED TO INCLUDE THE LATEST CODES AND DATA. Reflects the most recent provisions of the 2003 International Building Code and 2001 National Design Specification for Wood Construction. Continuing the sterling standard set by earlier editions, this indispensable reference clearly explains the best wood design techniques for the safe handling of gravity and lateral loads. Carefully revised and updated to include the new 2003 International Building Code, ASCE 7-02 Minimum Design Loads for Buildings and Other Structures, the 2001 National Design Specification for Wood Construction, and the most recent Allowable Stress Design.
Diagnosing & Repairing House Structure Problems, Edgar O. Seaquist, McGraw Hill, 1980 ISBN 0-07-056013-7 (obsolete, incomplete, missing most diagnosis steps, but very good reading; out of print but used copies are available at Amazon.com, and reprints are available from some inspection tool suppliers). Ed Seaquist was among the first speakers invited to a series of educational conferences organized by D Friedman for ASHI, the American Society of Home Inspectors, where the topic of inspecting the in-service condition of building structures was first addressed.
Defects and Deterioration in Buildings: A Practical Guide to the Science and Technology of Material Failure, Barry Richardson, Spon Press; 2d Ed (2001), ISBN-10: 041925210X, ISBN-13: 978-0419252108. Quoting: A professional reference designed to assist surveyors, engineers, architects and contractors in diagnosing existing problems and avoiding them in new buildings. Fully revised and updated, this edition, in new clearer format, covers developments in building defects, and problems such as sick building syndrome. Well liked for its mixture of theory and practice the new edition will complement Hinks and Cook's student textbook on defects at the practitioner level.
"Avoiding Foundation Failures," Robert Marshall, Journal of Light Construction, July, 1996 (Highly recommend this article-DF)
"A Foundation for Unstable Soils," Harris Hyman, P.E., Journal of Light Construction, May 1995
"Backfilling Basics," Buck Bartley, Journal of Light Construction, October 1994
"Inspecting Block Foundations," Donald V. Cohen, P.E., ASHI Reporter, December 1998. This article in turn cites the Fine Homebuilding article noted below.
"When Block Foundations go Bad," Fine Homebuilding, June/July 1998
Masonry structures: The Masonry House, Home Inspection of a Masonry Building & Systems, Stephen Showalter (director, actor), DVD, Quoting: Movie Guide Experienced home inspectors and new home inspectors alike are sure to learn invaluable tips in this release designed to take viewers step-by-step through the home inspection process. In addition to being the former president of the National Association of Home Inspectors (NAHI), a longstanding member of the NAHI, the American Society of Home Inspectors (ASHI), and the Environmental Standard Organization (IESO), host Stephen Showalter has performed over 8000 building inspections - including environmental assessments. Now, the founder of a national home inspection school and inspection training curriculum shares his extensive experience in the inspection industry with everyday viewers looking to learn more about the process of evaluating homes. Topics covered in this release include: evaluation of masonry walls; detection of spalling from rebar failure; inspection of air conditioning systems; grounds and landscaping; electric systems and panel; plumbing supply and distribution; plumbing fixtures; electric furnaces; appliances; evaluation of electric water heaters; and safety techniques. Jason Buchanan --Jason Buchanan, All Movie Review
Masonry Structures: Behavior and Design, Robert G. Drysdale, Ahmid A. Hamid, Lawrie R. Baker, The Masonry Society; 2nd edition (1999), ISBN-10: 1929081014, ISBN-13: 978-1929081011
Straw Bale Home Design, U.S. Department of Energy provides information on strawbale home construction - original source at http://www.energysavers.gov/your_home/designing_remodeling/index.cfm/mytopic=10350
More Straw Bale Building: A Complete Guide to Designing and Building with Straw (Mother Earth News Wiser Living Series), Chris Magwood, Peter Mack, New Society Publishers (February 1, 2005), ISBN-10: 0865715181 ISBN-13: 978-0865715189 - Quoting: Straw bale houses are easy to build, affordable, super energy efficient, environmentally friendly, attractive, and can be designed to match the builder’s personal space needs, esthetics and budget. Despite mushrooming interest in the technique, however, most straw bale books focus on “selling” the dream of straw bale building, but don’t adequately address the most critical issues faced by bale house builders. Moreover, since many developments in this field are recent, few books are completely up to date with the latest techniques. More Straw Bale Building is designed to fill this gap. A completely rewritten edition of the 20,000-copy best--selling original, it leads the potential builder through the entire process of building a bale structure, tackling all the practical issues: finding and choosing bales; developing sound building plans; roofing; electrical, plumbing, and heating systems; building code compliance; and special concerns for builders in northern climates.