Analysis
 Comparing Ventilation Rates

The results of the data collected by the blower door test and the CO₂ monitor were different by a factor of two. This could be for many reasons, such as outside air speed, pressure difference or the assumptions made when calculating the correlation factor.

ASHRAE Standard
The ASHRAE Standard for hotel bedrooms is 30 cfm/room.

In room 417 the data shows that it was under ventilated in the CO₂ test and about right in the blower door test, while the other two rooms seem to be over ventilated.

An under ventilated room is not acceptable during any season, while an over ventilated room is undesirable in the heating season but is desirable in the summer.

Ventilation

All of us want fresh air wherever we are, but there is a balance game once we are inside of a building.

Can we have too much fresh air? No, but inside we also want to feel thermally comfortable. The balancing game is the quest for energy efficiency and fresh air. These two are sometimes in conflict as the more outside air that is taken in means the more energy that must be used in order to bring the air up to a thermally comfortable level.

As shown by the equation:

Heating Load = UA Windows + UA walls +UA Ceilings + UA Floors + Air Infiltration Load

Air Infiltration Load:

C x Volume of air (CFM) x [delta]T (°F)= Heat loss (btu/hr)
(Where C = 1.1)

this is a factor that includes density and specific heat of air and a time conversion.

As a result, architects tried to minimize the amount of air infiltration in order to save energy, which led to sick buildings because they did not have enough ventilation.

In order to combat this problem ASHRAE between 1972 and 1989 made a recommendation that buildings have at least 5 cfm per person. ASHRAE realized that this rate was too low. They have since revised the recommendations. The new ASHRAE Standard for hotel bedrooms is 30 cfm/room.

Cooling Season

Research has shown that by using natural ventilation it is possible to skew the comfort level, thus reducing the energy load on buildings since no air conditioning is needed at these times. Since the transom windows have been blocked in the rooms, a way should be found in order to keep the air velocity at a high enough rate in order for the occupants comfortable.
 

Heating Season

During the heating the best method is to control the ventilation rate so not to use excess energy. The two room that were over ventilated, if projected to be the average over ventilation for half of the rooms at the YMCA, would see a savings of:

(80 rooms total) / 2 = 40 rooms