Project Summary
VENTILATION
COOLING CONTROLLER STRATEGIES
Murray Milne, UCLA
99-28
The objective of this
project is to test the feasibility of an intelligent natural ventilation
cooling controller that can minimize air conditioning costs for homeowners.
The greatest potential source of FREE cooling energy in most
California climates is outdoor air. The
problem is simple when cool outdoor air is available to flush overheated
buildings. However when daytime temperatures are too hot, the problem is more
difficult. Fortunately, in most
California climate zones even during the hottest days the night-time
temperatures are usually quite comfortable.
The controller's task is to know how much night-time air should be
brought in to cool down the building's interior mass so that it can 'coast'
comfortably through the next day, and not overcool so that heating is needed
the following morning. This controller
should also know if it is using more fan energy then it is recovering in
cooling, or if wind-driven natural ventilation is available. Our studies have shown that the need for air
conditioning can often be completely eliminated in many climates if the
building is carefully designed and if a smart controller can be developed to
harvest this free resource.
No such product exists on the market today. In fact there is little demand for this type
of controller because California homeowners do not understand the benefits of
managed ventilation cooling. The market
is undeveloped because no one has yet figured out how to make very much money
from ventilation cooling. This means
this is a classic case of the need for public interest energy research. But if our "proof of concept" of
this controller is successful it will also help to create new demand for
sensors, actuators and quieter, more efficient fans.
The potential impact is immense. Assuming residential air conditioning in California uses roughly
0.3QBtu (Quads), and if this project leads to the elimination of just one air
conditioner in a thousand, then it could save over 100,000 Mwhr per year (more
than 100 times the cost of this proposal).