To assist with your Lacanche ventilation decisions, please carefully consider the following general venting guidelines.
To understand why you need a good ventilation system, read the following EPA bulletin titled "What You Should Know About Combustion Appliances and Indoor Air Pollution".
NOTES: To provide adequate ventilation for your LACANCHE, a general "rule of thumb" for determining approximate CFM (cubic feet per minute) exhaust requirement is to allow 100 CFM for every 10,000 BTU's of total range output; e.g. Cluny LG1052GE = 73,500 BTU total, so 73,500/100 = 735 CFM. Another "rule" is to allow 65 CFM for every square foot of cooktop surface. This does not take into account any gas oven output nor total burner BTU output, so a smaller number will be given; e.g. Cluny LG1052GE> 3.25 ft Wide x 2.25 ft Deep = 7.31 sq ft x 65 = 475 CFM. Anywhere between those 2 numbers would be adequate.
The "Optimum*" hood dimension we suggest is one that is actually wider than range width and as deep as the tabletop of range - large "Capture Area" - but of course this is not always possible in every kitchen design/remodel. Building Codes differ throughout the USA for gas appliance ventilation but usually they require hood width to be the same as range top width (or at least cover all gas burner assemblies). Check your Codes.
MUP (Make-Up Air): You can't exhaust air out of a home unless the same cubic volume of air can come into the home from outside to replace it. Ask your ventilation expert. Today's "tight" homes, especially in northern colder climates have special needs/guidelines for sufficient MUP. Check your Codes and ventilation experts.
Hood Mounting Height from Cooktop Surface: If the outer hood "shell" or any trim is made of Combustible Material, it MUST be 36" or greater from cooking surface (see "UL" web link). If the hood is all metal (non-combustible), then follow manufacturer recommendations on mounting height, usually 27"-30" is suggested as optimum.
Please refer to specific instructions of hood manufacturer.
Although this does not serve as an official endorsement, here are some links to common hood solutions for Lacanche: