Low energy air condition - temperature vs humidity (humidex)

[osolemio]

Those hot summers, cannot sleep at night because the air is thick of moisture. Sweating, discomfort, but you want to save the environment, so you don't use a power hungry air condition ...

Not that many realize, that if you can just dehumidify the air, temperatures up to around mid-80s can be quite acceptable. It is also better for the house, and against fungus, bacteria, cockroaches and more, if you can keep it dry.

In the same way, wind chill factor is calculated during a cold and windy day, to have an idea what the combined effect of wind and temperature does to exposed skin. Actually, your comfort level is influenced by all these factors:

• Temperature

• Humidity

• Wind

• Activity level

• Diurnal body cycle

and possibly other factors too. When you turn on a simple fan in your house, it does not cool off the air, as some think. It is actually the wind chill factor in effect. Leaving a fan on in a room while it is not occupied will normally not cool it off, unless it directs airflow over some surfaces which can absorb heat, or start a draft of ambient air.

A good example is from an aircraft cabin, especially on a long haul flight across many time zones. The desired temperature will be very different if you are either a hard working flight attendant, or a passenger who wants to sleep. Whilst the passenger could be complaining that they are too cold, even clothed and having a blanket, the flight attendant can be feeling hot from the physical work. Just ask any flight attendant working long haul flights - you can never get the temperature right to please everyone!





There is a new way of dehumidifying the air, without cooling it much, but it requires hardly any power, compared to conventional cooling or dehumidifying:


Drinking Water From Air Humidity


I could imagine an energy friendly house having a 2-way "air conditioning system":


Summer:
Ambient air is ventilated into the house, passing a high efficiency dehumidifier. A combined temperature and humidity sensor probes the air whether or not it is in the comfort zone. If needed, the humidifier will start to dehumidify, until an acceptable level is reached. Exhaust air should be by natural openings in the house, including bathrooms, kitchen and utility room, which should have window vents/vents open during summer. This flow direction ensures that moisture, fumes and smells are not drawn from these areas into the house.

Winter:
Air from bathrooms, utility room and kitchen area is ventilated out of the house, while passing a low-energy air-liquid heat exchanger. The temperature of the air should be lowered to just around freezing, and the heat extracted added to the space/water heating system. Inlet air is from window vents, to be open in the bedrooms and living room. The cold air enters the house directly now, but it makes a leaky house energy efficient. It does not matter that the air enters unheated, as long as the air LEAVING the house has the heat removed. THAT heat will be used to help heat up the cold air coming in, using the existing heating system. The fresh air from the outside is supplying the important areas of bedrooms and living room, while the air from here in turn is passed on to bathrooms, kitchen and utility room (where vents are closed). The air flow will be just as in the summer setting, and the low dewpoint of the cold winter air will provide natures own dehumidication.



Making a system like this ensures year round comfortable and fresh air, while not costing much energy. During the summer, you can sleep well at night, in dry air and knowing that you don't use excess energy for your comfort.