In-Flight Carbon Dioxide CO2 & Oxygen Levels on Commercial Aircraft
AIR QUALITY on COMMERCIAL AIRCRAFT - CONTENTS: an informal study of carbon dioxide level variation during in-flight conditions on long commercial aircraft found little variation by altitude nor flight duration. Some consumers speculated to the author that poor air quality, reduced oxygen, or elevated CO2 might explain dizziness or respiratory distress experienced by some airline passengers.
InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.
Commercial aircraft air quality:
Airplane cabin IAQ, fresh air ventilation, and oxygen and carbon dioxide levels were examined by measuring CO2 and O2 levels during long flights.
This article reports the results of a limited study of the variation in oxygen levels and carbon dioxide levels during long commercial air flights in 2014. This study was made by performed by using safe, simple and accurate gas detection tube analysis to measure both oxygen and carbon dioxide levels at various points in fight.
Results suggest that the levels of these two gases in the aircraft cabin indeed varied, but not by much during long commercial airline flights at typical high altitudes.
Waters et al (2002) reported "Carbon dioxide exposures were highest on shorter and high-occupancy flights, aircraft
with greater recirculated-to-fresh-air ratio, and narrow
-bodied aircraft. In general
contaminant levels were low compared to standards. Carbon dioxide levels indicated lower
ventilation rates per occupant than
most other indoor environments."
[Click to enlarge any image]
Those authors measured aircraft cabin CO2 at
515 - 4902 ppm and reported that CO2 levels were likely to be elevated in aircraft cabins on short flights in full or nearly-full aircraft.
They also provide a succinct description of how cabin air is supplied to airline passengers:
Engine compressor bleed air is pre-conditioned, sent to the air conditioning packs, and
delivered to the cabin through a manifold that
permits mixing with recirculated cabin air.
Outside air is not filtered but the recirculation system incorporates air filtration; types and
efficiency of filters vary by aircraft.
Recirculation maintains air supply rate and minimizes
use of more costly bleed air. - Waters et al (2002)
I previously studied the rate of change of indoor CO2 in a crowded synagogue that had no functional fresh air ventilation system. During the religious service the CO2 level indoors increased significantly, possibly shifting an explanation of the apparent drowsiness of the congregants from Rabbi Arnold's sermon to the building's indoor air quality. One might ask if similarly the CO2 might increase in the cabin of a crowded airplane during a long flight - a different hypothesis than that offered by Waters et als and one that investigates the current (2014) ventilation rate on commercial aircraft.
I have received anecdotal reports of a air passengers experiencing dizziness and fainting during long air flights (Lukacher 2014) , typically transcontinental travel.
While altitude has been discussed regarding air passenger comfort anecdotal reports speculated on changes in either oxygen level or carbon dioxide level as possible contributors to the experiences of these passengers.
While altitude or other explanations for fainting and dizziness during long air flights may pertain, I wanted to investigate the cabin air quality, specifically oxygen and carbon dioxide, and to compare those results with air passenger speculations about oxygen and CO2 levels in aircraft during long flights.
Previously I have collected airborne particle samples using an adhesive air sampling cassette in order to examine in-cabin airborne particulates in the air stream from the cabin's ovehead air supply. Particulate levels down to 1u were very low: I did not find much of interest. Particulate filtration on modem aircraft appears to be quite effective at least for larger particles such as common dust, pollen, and mold spores. Very small particles such as bacteria and viruses were not studied by the author but were studied by some of the authors cited below.
In 2014, on a series of long commecial air flights including trips between Mexico and the U.S. and between the U.S. and New Zealand, the author used a simple air sampling pump made by Drager to collect periodic samples of the level of both carbon dioxide and oxygen in the passenger cabin of the commercial aircraft during those flights.
At left are the oxygen sampling tube (above) showing about 11.25% concentration of oxygen in the aircraft's cabin, and a carbon dioxide gas sampling tube after 20 pump strokes showing nearly 1500 ppm - a number that must be divided by two to obtain the actual concentration of about 750 ppm of CO2 for this measurement.
The data recorded included the total flight time, altitude, aircraft model and number of passengers aboard, along with the point in the flight by time and distance at which various samples were collected. The results are reported in the airplane cabin IAQ table below.
Table of Carbon Dioxide CO2 and Oxygen Levels Measured in Commercial Aircraft Cabins During Flight
Flight / Row / Date
Aircraft / Capacity
gers + crew
UA 1063 /
B737-800/900 / 145
EWR->MEX, est. Cabin Temp 70F,Tube 100/a, 10 pump strokes
Control. Cabin air samples collected @ lap height
20 pump strokes for precision
UA 718 / r8 /
2 h 40m
A320 / 120-150
MEX->SFO Control, prior to takeoff
NZ 7 / r14 /
B747 400 / 416-524
SFO->AKL dep , climbing, 20 min. into flight. Total distance 10,618 Km
8 hrs from destination, outside temp -42C
over PagoPago, outside temp -46C
NZ 531 /r10/
NZ 548 / r13/
NZ 2 / r45/
250 + crew
Traveled: 5054 Km
Total distance 10,373 Km
Over the Equator Lat 0.09S
Speed 946 KmH
35,000 ft 10,668m
UA 274 /r22/
1. Time in minutes into the total flight time
2. Dates are given in international format dd/mm/yy
3. Second reading using same sampling tube by doubling number of pump strokes for increased precision.
4.Drager gas detection tubes used: colorimetric type. Selecting the proper detection device sensitivity range is important for obtaining accurate measurement of gases in air. I used:
Carbon Dioxide level measurement: Drager Rohrchen Carbon Dioxide 100/1, certified manufacturer ISO 9001. This tube is designed for measuring CO2 levels are between 100 - 3000 ppm. Ten Drager gas pump measurement strokes are used with this tube, or the operator can use 20 pump strokes and divide the resultant measurement by 2 for increased precision. Standard deviation is +/- 10-15%. The tube colour changes from white to violet on exposure to CO2. and operates at temperature ranges from 15°C to 25°C and at humidity less than or equal to 23 mg/L (corresponding to 100% RH at 25C). An atmospheric correction factor to be applied is F=1013 / actual ATM pressure.
Oxygen level measurement: Drager Rohrchen Oxygen 5%, certified manufacturer ISO 9001. This tube is designed for measuring the level of oxygen in air in the range of 5% to 23% by volume. One pump stroke is used to perform a measurement.
Standard deviation is +/- 10-15%. The tube changes color from blue-black to white on exposure to oxygen and operates in the temperature range of 5°C to 50°C and at humidity from 0-40 mg/L. The literature includes a correction factor F = 1013hPa (14.692 psi) / actual atmospheric pressure - a factor that may be especially pertinent at high altitudes or in examining aircraft cabin conditions. The detector tube also has two reading scales, chosen based on which Drager sampling pump is used. Because this tube heats to as much as 100°C it should not be used where explosive gases may be present.
The Dräger sampling pump was leak-tested prior to use of the detection tubes by using the manufacturer's recommendations. The pump was air-flushed between measurements.
Draeger Safety Inc.
101 Technology Drive
USA, Tel: +1-800-858-1737
+1-412-787-2207, Website: http://www.draeger.com (their website was not functioning properly - Nov. 2014)
Draeger Safety Inc. (Gas Detection Systems)
505 Julie Rivers Suite 150
+1-800-375-3073. Drägerwerk AG & Co. KGaA
5. Other gas concentration in air conversions:
1 ppm CO2 = 1.8 mg CO2M3
1 mg CO2 = 0.56 ppm CO2 (at 20°C, 1013hPa)
With additional measurement reports pending, I found in-flight cabin air quality measurements of oxygen to be relatively stable, ranging from 11.2% to 12.5%.
Typical outdoor CO2 levels are between 350-400 ppm (0.035% - 0.04%) or up to 500 ppm by some sources.
Carbon dioxide levels measured in-flight in the aircraft cabin ranged between 0.04% or 400 ppm and 0.1% or 1000 ppm to date in our studies and were measured at close to 0.5% or 5,000 ppm in earlier studies.
As indicated at CO2 HEALTH EFFECTS, occupants are unlikely to be affected or to notice CO2 levels under 2% or 20,000 ppm - a far higher number than in-flight aircraft cabin carbon dioxide levels.
Opinion: Perhaps to investigate or reduce air traveler complaints of dizziness or fainting we should look more closely at altitude and cabin pressures as well as other factors such as passenger hydration (drink plenty of fluids), anxiety, physical stresses before the flight (rushing, carrying bags), passenger movement & stretching during flight (avoid blood clots), the increasingly cramped seat space limitations and cramping, and aircraft cabin ozone levels.
Note: my measurements of equivalent altitude indicate that typical cabin pressures during flight give an altitude of about 7,000 feet. As I have observed simply among visitors to San Miguel de Allende, Mexico, (altitude about 6500 feet), unaccustomed people are often physically stressed at that altitude, experiencing shortness of breath and on occasion dizziness.
Opinion: An increase in respiration rate by an "out-of-breath" passenger experiencing quite understandable anxiety can exacerbate those conditions.
Bagshaw et als (2002) point out that
Commercial air carriers train their flight attendants to recognize common
of distress and to respond to medical emergencies with first
techniques, and the use of emergency medical oxygen. ... It cannot be
overemphasized that these medical kits are only for emergency use and not for
routine medical care.
In general, ... studies have consistently revealed levels of organic
substances, carbon monoxide, carbon dioxide, and airborne particles in the cabin
air well below regulatory standards and below those encountered in offices, the
street, or subway.
One exception is ozone, a substance found naturally in the atmosphere at
altitudes where most commercial aircraft fly. It enters the cabin with outside air
that is used for cabin ventilation. Ozone is a respiratory system irritant and can
cause chest tightness, coughing, and shortness of breath if exposure occurs at
high enough concentrations. In general, low levels have been found in aircraft
cabins although, in several instances, levels were measured slightly exceeding
regulatory standards. Most aircraft flying at altitudes and latitudes where high
ozone concentrations are encountered now have ozone converters which break
down the ozone before it reaches the cabin. - Bagshaw (2002)
Keep calm. Carry on.
Research on In-Flight Air Quality, Oxygen & Carbon Dioxide Levels & Other Factors
ASHRAE. 1999. ANSI/ASHRAE Standard 62-1
999. Ventilation for Acceptable Indoor Air
Quality, Atlanta, GA: American Society of
Heating, Refrigerating and Air-Conditioning
Bagshaw, Michale, DeVoll, James R., Jennings, Richard T., McCrary, Brian F., Northrup, Susan E., Rayman, Russel B. (Chair), Saenger, Arleen, Thibeault, Claude, "Medical Guidelines for Airline Passengers", Aerospace Medical Association, Alexandria VA, (2002), retrieved 26 Nov. 2014, original source: http://www.asma.org/asma/media/asma/travel-publications/paxguidelines.pdf
Brown, S. S., T. B. Ryerson, A. G. Wollny, C. A. Brock, R. Peltier, A. P. Sullivan, R. J. Weber et al. "Variability in nocturnal nitrogen oxide processing and its role in regional air quality." Science 311, no. 5757 (2006): 67-70.
Cottrell, Joseph J. "Altitude exposures during aircraft flight flying higher." CHEST Journal 93, no. 1 (1988): 81-84.
Dechow, M., H. Sohn, and J. Steinhanses. "Concentrations of selected contaminants in cabin air of airbus aircrafts." Chemosphere 35, no. 1 (1997): 21-31.
Federal Air Regulation (FAR). 1996. Title
14 Code of Federal Regulations, Chapter I–
Federal Aviation Administration, Department
of Transportation, Part 25–Airworthiness
Standards: Transport Category Airplanes, S
ection 831: Ventilation,
as amended June 5,
Harding, Richard. "Cabin air quality in aircraft." BMJ: British Medical Journal 308, no. 6926 (1994): 427.
Hocking, Martin B. "Passenger aircraft cabin air quality: trends, effects, societal costs, proposals." Chemosphere 41, no. 4 (2000): 603-615.
Hocking, M. B. "Indoor air quality: recommendations relevant to aircraft passenger cabins." American Industrial Hygiene Association 59, no. 7 (1998): 446-454.
Hodgson, Michael. "Low relative humidity and aircraft cabin air quality." Indoor Air 11, no. 3 (2001): 200-214.
Lee, Shun‐Cheng, Chi‐Sun Poon, Xiang‐Dong Li, and Fred Luk. "Indoor air quality investigation on commercial aircraft." Indoor Air 9, no. 3 (1999): 180-187.
Lindgren, T., and D. Norbäck. "Health and perception of cabin air quality among Swedish commercial airline crew." Indoor Air 15, no. s10 (2005): 65-72.
Lindgren, Torsten, and Dan Norbäck. "Cabin air quality: indoor pollutants and climate during intercontinental flights with and without tobacco smoking." Indoor air 12, no. 4 (2002): 263-272.
Lindgren, Torsten, Dan Norbäck, Kjell Andersson, and Bo-Göran Dammström. "Cabin environment and perception of cabin air quality among commercial aircrew." Aviation, space, and environmental medicine 71, no. 8 (2000): 774-782.
Malmfors, Torbjörn, Daniel Thorburn, and Arne Westlin. "Air quality in passenger cabins of DC‐9 and MD‐80 aircraft." Environmental Technology 10, no. 6 (1989): 613-628.
Mangili, Alexandra, and Mark A. Gendreau. "Transmission of infectious diseases during commercial air travel." The Lancet 365, no. 9463 (2005): 989-996.
Muhm, J. Michael, Paul B. Rock, Dianne L. McMullin, Stephen P. Jones, I. L. Lu, Kyle D. Eilers, David R. Space, and Aleksandra McMullen. "Effect of aircraft-cabin altitude on passenger discomfort." New England journal of medicine 357, no. 1 (2007): 18-27.
Nagda NL, Rector HE, Zhidong L
2000. Aircraft cabin air qua
lity: A critical review of
past studies. In
Air Quality and Comfort in Airline Cabins
, ASTM STP 1393, NL Nagda,
ed. West Conshohocken PA: American So
ciety of Testing Ma
terials, pp 215-235.
Nagda, Niren L., Harry E. Rector, Zhidong Li, and David R. Space. "Aircraft cabin air quality- A critical review of past monitoring studies." Air quality and comfort in airliner cabins (1999): 215-239.
Nagda, Niren L., Michael D. Koontz, Arnold G. Konheim, and S. Katharine Hammond. "Measurement of cabin air quality aboard commercial airliners." Atmospheric Environment. Part A. General Topics 26, no. 12 (1992): 2203-2210.
Nagda NL, Fortmann RC, Koontz MD,
Airliner Cabin Environment:
Contaminant Measurements, Heal
th Risks, and Mitigation Options
. US Department of
Transportation, Report No. DOT-P-15-89-5.
Washington, DC: Govt Printing Office.
Pierce WM, Janczewski JN, Roethlisberger B,
1999. Air quality on commercial
. Vol. 41, pp 26-34.
Proussaloglou, Kimon, and Frank S. Koppelman. "The choice of air carrier, flight, and fare class." Journal of Air Transport Management 5, no. 4 (1999): 193-201.
[Do air travel passengers consider aircraft cabin air quality when choosing an airline?]
Rankin WL, Space DR, and Nagda NL. 2000. Pa
ssenger comfort and the effect of air
Air Quality and Comfort in Airline Cabins
, ASTM STP 1393, NL Nagda, ed.
West Conshohocken PA: American Societ
y of Testing Materials, pp 269-289.
Rayman, Russell B. "Cabin air quality: an overview." Aviation, space, and environmental medicine 73, no. 3 (2002): 211-215.
Ryan, P. Barry, John D. Spengler, and Paul F. Halfpenny. "Sequential box models for indoor air quality: Application to airliner cabin air quality." Atmospheric Environment (1967) 22, no. 6 (1988): 1031-1038.
Spengler, J. D., and D. G. Wilson. "Air quality in aircraft." Proceedings of the Institution of Mechanical Engineers, Part E: Journal of Process Mechanical Engineering 217, no. 4 (2003): 323-335.
Spengler J, Burge H, Dumyahn T,
1997. Environmental Su
rvey on Aircraft and
Ground-based Commercial Transportation
Vehicles. Report of May 31, 1997, Boston
MA, Harvard School of Public Health.
Thibeault, C. L. A. U. D. E. "Cabin air quality." Aviation Space and Environmental Medicine 68 (1997): 80-82.
Wang, Jun, and Sundar A. Christopher. "Intercomparison between satellite‐derived aerosol optical thickness and PM2. 5 mass: Implications for air quality studies." Geophysical research letters 30, no. 21 (2003).
Waters, M. A., T. F. Bloom, B. Grajewski, and J. Deddens. "Measurements of indoor air quality on commercial transport aircraft" [PDF] In Indoor air 2002: proceedings of the 9th international conference on indoor air quality and climate, Santa Cruz, California, pp. 782-787. 2002. Abstract: Exposures to cabin environmental contaminants were measured on 36 commercial transport
aircraft. The objectives were to characteri
ze levels of contaminants and evaluate the
relationship between flig
ht factors such as aircraft size
, occupancy, ventilation, and flight
length, and environmental parameters. Monito
ring was conducted at two coach locations for
the duration of the flight for
VOCs, nitrogen oxides, CO, CO2
, temperature, relative
humidity, total particulates, and barometric pressure.
Five-minute average concentration
ranges were: CO
515-4902 ppm; O
<0.05-0.24 ppm; CO <0.2-
2.9 ppm; nitrogen oxides
<0.05-2.0 ppm; and total pa
rticulates <0.028-0.197 mg/m
. Gate-to-gate average
concentrations of VOCs we
re: toluene <3-130 ppb, limonene
<3-12 ppb, and ethanol <0.8-2.4
Carbon dioxide exposures were highest on shorter and high-occupancy flights, aircraft
with greater recirculated-to-fresh-air ratio, and narrow-bodied aircraft. In general
contaminant levels were low compared to standards. Carbon dioxide levels indicated lower
ventilation rates per occupant than
most other indoor environments.
Zhang, Yuanhui, Yigang Sun, Aijun Wang, Jennifer L. Topmiller, James S. Bennett, and RW BESANT. "Experimental characterization of airflows in aircraft cabins, Part II: Results and research recommendations. Discussion." ASHRAE transactions (2005): 53-59.
Zitter, Jessica Nutik, Peter D. Mazonson, Dave P. Miller, Stephen B. Hulley, and John R. Balmes. "Aircraft cabin air recirculation and symptoms of the common cold." Jama 288, no. 4 (2002): 483-486.
Continue reading at CARBON DIOXIDE - CO2 or select a topic from closely-related articles below, or see our complete INDEX to RELATED ARTICLES below.
Try the search box below or CONTACT US by email if you cannot find the answer you need at InspectApedia.
Ask a Question or Search InspectApedia
Use the "Click to Show or Hide FAQs" link just above to see recently-posted questions, comments, replies, try the search box just below, or if you prefer, post a question or comment in the Comments box below and we will respond promptly.
A Toxic Gas Testing Plan: A Gas Sampling Plan for Residential and Commercial buildings lists some of the toxic indoor gases for which we test, depending on the building complaint and building conditions
Gas Exposure Hazard Levels: for Toxic Gas Exposure to Ammonia, Arsine, Arsenic, Bromine, Carbon Dioxide, Carbon Monoxide, Hydride, Ozone - allowable exposure levels and hazard levels
Formaldehyde: US EPA. UFFI (Urea Formaldehyde Foam Insulation) was previously considered a hazard (formaldehyde outgassing).
Subsequent research virtually closed concern regarding this material; however formaldehyde appears to remain a health concern for sensitive individuals.
Ozone Warnings - Use of Ozone as a "mold" remedy is ineffective and may be dangerous.
Sampling for gases in air such as VOC's, MVOC's, toxic chemicals, and combustion products.
Unfortunately no single test or tool can detect all possible building contaminants. We use methods and equipment which can test for common
contaminants. If the identity of a specific contaminant is known in advance we can also test for a very large number of specific contaminant
gases in buildings.
We use gas sampling equipment provided by the two most reliable companies
in the world, Draeger-Safety's detector-tubes and Drager accuro� bellows pump, the Gastec� cylinder pump
and detector-tube system produced by Gastec or Sensidyne, and
we also use Sensidyne's Gilian air pump. For broad screening for combustibles and a number of other
toxic gases and for leak tracing we also use Amprobe's Tif8850. All of these instruments, their applications, and sensitivities (minimum detectable limits) for specific
gases are described in our Gas Sampling Plan online document.
 Per Levéen, email comments 23 May 2009
. Mr. Levéen is with Telia, the leading mobile telephone operator in Sverige (Sweden). By telephone Telia (not Mr. Levéen) can be reached at
90 200 or From abroad at +46-771-99 02 00
Lukacher, Joanne, personal communication to author, June 2014, Poughkeepsie, NY.
Dr. Roy Jensen, Department of Chemistry, Grant MacEwan College, Edmonton, AB for technical review and critique 8/23/07.
Dr. Jensen notes that if we increase the CO2 level in air in an enclosed space from
its normal level of about 0.03% (we counted it as starting at 0) to a level of 1.4%, we obtain a corresponding
decrease in the oxygen level from its normal level (at sea level) of about 20.9% down to 19.5%, for a 6.7%
reduction in the amount of oxygen available. The amount of oxygen lost is 6.7 % (1.4/20.9 * 100 %). Our earlier version of this document was incorrect in
 Stephen Fisher,
Australian and New Zealand Sales Director,
K.D.Fisher & Company, Pty., Ltd.
18 Benjamin Street, St. Mary's,
Adelaide, South Australia, 5042,
Ph: (08) 8277-3288 (Int): +61-8-8277-3288
Fax: (08) 8276-4024 (Int): +61-8-8276-4024
E-mail: firstname.lastname@example.org [by email, Feb 2012] Quoting from the company's website
KD Fisher & Co. Pty. Ltd., Safety and Welfare: OHS & W training facilities located on premises; Gas detection monitoring & consultation; Safety & Security products; Electric components, Power & switchgear products, Electrical/Electronic service & engineering
Mr. Fisher adds "Our company is family owned, and employs 30 personnel, and has been specifying, and designing gas detection systems, using "bought in" detectors from overseas manufacturers, and developing sampling systems to allow the most proficient system for many applications, including jet fuel leakage detection systems for military aircraft hangars, and tanker parking shelters, for the Australian Dept. of Defence. "
[3-a] "Dangers of Carbon Dioxide, Health Effects of Carbon Dioxide Gas", K.D. Fisher & Co. Pty, Ltd., 18 Benjamn St., St. Marys, Adelaide, South Australia 5042, website: www.kdfisher.com.au, Tel: 08-8277-3288. Offices in Sydney & Melbourne.
This document consists of selected reproductions from the CCOHS (Canada's National Occupational Health & Safety Resource) with minor Australian applications & modifications, and cites the InspectAPedia carbon dioxide gas hazards article found above on this page.
 GAS EXPOSURE EFFECTS, TOXIC Toxic Gas Exposure Hazards and Test Protocols including links
to our toxic gas exposure screening and gas testing protocols.
 "Table Z-1 Limits for Air Contaminants, 1910.1000 Table Z-1" OSHA standard for air contaminant limits (http://www.osha.gov/pls/oshaweb/owadisp.show_document?p_table=STANDARDS&p_id=9992) - includes for CO2, Carbon dioxide.........| CAS No. 124-38-9 | 5000 ppm | 9000 mg/m3 limits for carbon dioxide as an air contaminant.
 Klemens C. Baczewski PE, email correspondence, 4/29/2009 discussed correct CO2 calculations.
 Taylor, Lewis G. and G. Oscar Kreutziger, The Gaseous Environment of the Chick Embryo in Relation to Its Development and Hatchability, 1968 (printout does not include the Journal)
 Holloway and Heath, 1984 Ventilatory Changes in the Golden Hamster..., Laboratory Rat...., Comp. Biochem. Physiol., Vol. 77A, No 2, pp. 267-273
 Bruggeman et al. 2007 Acid-base balance in chicken embryois...incubated under high CO2 concentrations... Respiratory Physiology and Neurobiology 159:147-154
 De Smit et al, 2006 Emryonic developmental plasticity of the chick: Increased CO2 ... Comparative Biochemistry and Physiology, Part A 145: 166-175
 Bar-Ilan, Amir and Jacob Marder, Adaptations to Hypercapnic conditions in the Nutria..., Comp. Biochem. Physiol. Vol 75A, No 4, pp 603-608, 1983
 "Health Effects of Carbon Dioxide Gas", CCOHS, Canadian Centre for Occupational Health and Safety, web search 02/15/2012, original source: http://www.ccohs.ca/oshanswers/chemicals/chem_profiles/carbon_dioxide/health_cd.html
Carson, Dunlop & Associates Ltd., 120 Carlton Street Suite 407, Toronto ON M5A 4K2. Tel: (416) 964-9415 1-800-268-7070 Email: email@example.com. The firm provides professional home inspection services & home inspection education & publications. Alan Carson is a past president of ASHI, the American Society of Home Inspectors. Thanks to Alan Carson and Bob Dunlop, for permission for InspectAPedia to use text excerpts from The Home Reference Book & illustrations from The Illustrated Home. Carson Dunlop Associates' provides extensive home inspection education and report writing material.
The Illustrated Home illustrates construction details and building components, a reference for owners & inspectors. Special Offer: For a 5% discount on any number of copies of the Illustrated Home purchased as a single order Enter INSPECTAILL in the order payment page "Promo/Redemption" space.
TECHNICAL REFERENCE GUIDE to manufacturer's model and serial number information for heating and cooling equipment, useful for determining the age of heating boilers, furnaces, water heaters is provided by Carson Dunlop, Associates, Toronto - Carson Dunlop Weldon & Associates Special Offer: Carson Dunlop Associates offers InspectAPedia readers in the U.S.A. a 5% discount on any number of copies of the Technical Reference Guide purchased as a single order. Just enter INSPECTATRG in the order payment page "Promo/Redemption" space.
The Home Reference Book - the Encyclopedia of Homes, Carson Dunlop & Associates, Toronto, Ontario, 25th Ed., 2012, 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. Field inspection worksheets are included at the back of the volume.
Special Offer: For a 10% discount on any number of copies of the Home Reference Book purchased as a single order. Enter INSPECTAHRB in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.
Special Offer: Carson Dunlop Associates offers InspectAPedia readers in the U.S.A. a 5% discount on these courses: Enter INSPECTAHITP in the order payment page "Promo/Redemption" space. InspectAPedia.com editor Daniel Friedman is a contributing author.
The Horizon Software System manages business operations,scheduling, & inspection report writing using Carson Dunlop's knowledge base & color images. The Horizon system runs on always-available cloud-based software for office computers, laptops, tablets, iPad, Android, & other smartphones