Your question was forwarded to the Inspector Education and Public Awareness Division of the Transportation of Dangerous Goods (TDG) Directorate within Transport Canada for response.
The answer is yes, under the Federal Transportation of Dangerous Goods (TDG) Regulations the refrigeration system may be used while the RV trailer is in transit. However, we suggest that you contact the province in which you intend to operate your vehicle to verify if they have any additional requirements. For instance, you may not be able to operate your system in a tunnel or you may be limited to two cylinders. Also, you may face other limitations when you’re on a ferry. Finally, we suggest that you verify with your trailer manufacturer to verify their position on this subject.
Here is some background information that you may find useful.
The Transportation of Dangerous Goods (TDG) Regulations are comprised of 16 Parts and 3 Schedules and can be viewed by using the following link: http://www.tc.gc.ca/tdg/clear/tofc.htm
Most exemptions can be found in Part 1, between sections 1.15 to 1.48 and they are called "special cases".
Section 1.27 exempts dangerous goods (in your case propane) in a means of transport (RV trailer) from the TDG Regulations if the dangerous goods are required for the ventilation, refrigeration or heating unit that are necessary to maintain environmental conditions. However, you may wish to verify provincial legislation to ensure that there are no additional requirements prohibiting such an activity.
For your information, I have inserted section 1.27. Also, you may view it by using the following link: http://www.tc.gc.ca/eng/tdg/clear-part1-475.htm#sec127
1.27 Operation of a Means of Transport or a Means of Containment Exemption
(1) These Regulations do not apply to dangerous goods on a means of transport that are required for
(a) the propulsion of the means of transport and that are
(i) intended to remain on the means of transport until used, and
(ii) contained in a fuel tank permanently installed on the means of transport;
(b) the safety of individuals on board the means of transport;
(c) the operation or safety of the means of transport including, while installed in the means of transport and used or likely to be used for purposes related to transport, air bags, air brakes, flares, lighting, shock absorbers or fire extinguishers; or
(d) ventilation, refrigeration or heating units that are necessary to maintain environmental conditions within a means of containment in transport on the means of transport and are intended to remain with the units or on the means of transport until used.
(2) The exemption in subsection (1) does not apply to
(a) ammunition; or
(b) dangerous goods being delivered to a destination and from which a portion is drawn off during transport for propulsion of the means of transport.
Paragraph (b) is intended to exclude from this exemption dangerous goods that are in transport on a means of transport and from which a portion is used to propel the means of transport. An example is a tank truck delivering liquefied natural gas that uses part of that load of gas to propel the vehicle.
If you have any additional questions you may contact us at TDGTraining-FormationTMD@tc.gc.ca
or you may contact a Transport Canada dangerous goods inspector in your region. They can assist you with any questions you may have. Below are the numbers for the 5 regional offices.
Atlantic Region 1-866-814-1477 or TDG-TMDAtlantic@tc.gc.ca
Quebec Region (514) 283-5722
Ontario Region (416) 973-1868 or TDG-TMDOntario@tc.gc.ca
Prairie & Northern Region 1-888-463-0521 or TDG-TMDPNR@tc.gc.ca
Pacific Region (604) 666-2955
Inspector Education and Public Awareness / Formation des inspecteurs et sensibilisation du public
Compliance and Response Branch / Direction de la conformité et mise en application
Transport Dangerous Goods (TDG) / Transport des marchandises dangereuses (TMD)
Transport Canada / Transports Canada
330 Sparks Street, 9th Floor / 330, rue Sparks, 9ième étage
Ottawa, ON K1A 0N5