Everyday Indoor Comfort Situations and Decisions

Permanently changing conditions

This guide presents some simple actions that could be taken in various indoor situations. Based on rules and preferences, these decisions may be taken in a different way or at a different time but they offer a good starting point for considering what is to be done and why.

Keep in mind that changing indoor conditions to reach a specific comfort level requires time and this is major reason that decisions should be made preemptively rather than on the spot. One major advantage of preemptive decisions is that they create less stress on people and equipment and also require less energy consumption.

Default target

When in doubt about any specific approach, always target the lowest humidity you can reliably achieve using natural or forced ventilation, without leading to serious personal discomfort due to it. Even if the temperature may be higher or lower than desired, on the moment, the situation is easily manageable.

Keep in mind that dry air is the easiest to cool or dry and that just about any human activity increases humidity. Indoor air temperature is also, generally, regulated by the space, objects and occupiers, in less than 1 hour with no external intervention.

Slowly increasing humidity

Relative humidity should be ideally kept below 65%. When values reach 60% some preemptive measures should be considered.

Natural ventilation by opening a window should be considered. During rain or humid times, as seen on local weather stations or on the internet, dehumidifiers or air conditioning devices should be started with a target of 50% humidity.

Quickly increasing humidity

Particular to bathroom and kitchens, it means that before reaching 55% relative humidity preemptive measures should be considered. Keep in mind that both hot showers and baths release as well as boiling water generate massive amount of humid air that is very hard to control.

Natural ventilation by opening a window should be considered. During rain or humid times, as seen on local weather stations or on the internet, dehumidifiers or air conditioning devices should be started with a target of 40% humidity or continuous until reaching this value.

To reduce the impact of humidity that can be very difficult to keep in check, it may be useful to start dehumidifying on continuous mode around a half an hour before starting any intense activity in bathrooms and kitchens and keeping it on around a half or an hour after such activity is finished to reduce lingering effects.

Slowly dropping temperatures while using windows or forced ventilation

Slowly dropping temperatures do not have a major adverse effect, even if they are slightly discomfortable on the spot. When humidity seems to drop less quickly than temperature, the effect of natural ventilation is reduced but still present until temperature begins to drop less quickly.

When temperature and humidity drops less quickly, air circulation is also slower and natural ventilation, by opening a window, tends to have less of an effect on indoor air quality.

Note that forced ventilation can be much more effective at improving indoor air quality even if the temperature and humidity does not drop much from the initial state.

Quickly dropping temperatures while using windows or forced ventilation

Such a condition signals that air exchange is the best at this moment and it reinforces the benefits of exchanging the air with the one outside.

Care should be taken so that persons can cope with such a momentary condition. If this is not the case, partition air exchange should be considered, meaning that ventilation should be reduced in certain areas and kept at the same strong rates in unoccupied areas that do not interact with these occupied spaces.

Slowly dropping temperatures

Trends toward lower temperatures may lead to discomfort. A specific value should be set at which remedial action should be taken, particularly if the air is not currently warmer or cooler air conditioned.

A set temperature should be established by accord that would result in starting indoor heating equipment at a specific power output.

If heating is already started, adjustments proportional to the difference between actual and desired temperature should be applied.

Slowly increasing temperatures

Trends toward higher temperatures may lead to discomfort. A specific value should be set at which remedial action should be taken, particularly if the air is not currently warmer or cooler air conditioned.

A set temperature should be established by accord that would result in either natural, forced ventilation or air cooling by using conditioning devices. Sometimes, with warmer and humid exterior air the only choice is to keep closed air circulation in warmer areas and force it through in nearby cooler rooms or shaded areas.

Shading an area under direct sunlight can alleviate some of the sun's heating impact and exterior solutions are much more effective than interior ones.

If cooling is already started, adjustments proportional to the difference between actual and desired temperature should be applied.