The Coquitlam School District has been able to save $10,000
to $15,000 in annual energy costs for each of its schools
by installing CO2 based ventilation control in its Gymnasiums
and auditoriums. The school district is nestled in the foothills
of the Rocky Mountains just outside of Vancouver BC. Besides
being blessed with a mild maritime climate (5400 heating degree
days, 59 cooling degree-days), energy costs are three to five
times less than most areas in the US ($0.03 kWh for electricity
and $0.08/therm for natural gas). Despite the low cost of
energy and mild climate, the school has seen roughly a 2-year
payback (50% return on investment) on it's CO2 upgrade activity.
Typically the ventilation systems for gyms and auditoriums
are designed to provide enough ventilation for full occupancy.
In the case of Coquitlam, the gyms were only fully occupied
(300 people) during weekly assemblies. Otherwise the occupancy
of the gym average 30 people during typical gym classes. Most
of the time gyms are highly over-ventilated as is the case
for most schools.
The district first initiated a pilot project where one school
gym was outfitted with a CO2 sensor. The ventilation rate
of the gym was set for 30 people, however when assemblies
occurred, the resulting rise in CO2 levels activated the ventilation
system to ventilate at it's maximum ventilation capacity of
300 people. Since that first project the district has now
installed CO2 control in 18 schools and plans to install this
control strategy in 24 more schools. They are also now evaluating
this approach for classroom ventilation as well. According
to John McKay, Manager of Resource Conservation, "it
(CO2 control) meets the requirements for our indoor air quality
program as well as reducing operating energy costs…
so if we can save $10,000 to $15,000 per year per school in
ventilation and make every body comfortable and happy, that's
exactly where we want to go."