The Green Way to Cool a Home
It has become a standard feature in American homes and apartments over the past 20 years, to the point where people will not even consider buying a home without central air conditioning or without wall units (if you have a loft or apartment space). Running air conditioning units increases a homes electrical usage by as much as 40% in the summer time. So how do you cool a house other than air conditioning?
Air Movement
The largest reason for discomfort in the summer is hot, stagnant air. Air movement is essential to cooling down any space. This is usually down through duct work distribution. As you can see from the diagram below, the air cycles through the duct work and past the evaporator coil (which is cool) and allows the air to consistently move cooling the entire space down to your thermostat set point. Because this system works so well, it is by far the most popular. So How can this kind of system be mimicked?
Whole House Fan
A whole house fan is an industrial power fan than is installed between the ceiling and the attic. The fan is wired to your thermostat just like the furnace of air conditioning system. There is also a manual start/stop switch on the fan. When the thermostat trips, the fan starts, pulling the warm air out of the house and into the attic where it is released through the attic ventilation areas.
Using this system to cool usually requires at least one window to be open at opposite ends of the house to create a cycled air movement. The air is then pulled in from outside and cycles through the windows you have opened. If you do not wish to cool a space, simply leave the windows closed and shut the door.
This system costs about $1000 for the fan and the electrical work. A normal central air conditioning system for a house with duct work is about $2,000. Without duct work, it averages between $5,000 and $8,000 so the initial saving up front is substantial. Also service work is significantly easier since there is very little equipment involved.
Because you are using a fan to use air movement to cool a space, the temperatures will not get as low as it would with a central air conditioning system unless you have used green building methods when building your home or some simple tips to help in the cooling process. By utilizing some green methodology and a whole house fan system, you may never miss air conditioning again!
Cautions
Whole house fans require more attic ventilation that the average house. If you are installing an attic house fan, make sure that you utilize a ridge vent as it will allow the hot air from the house to escape properly. Gable vents should also be present.
Do not start a house fan with the firepalce damper open. It will suck air down the chimney making a very large mess.
Remember that the design of the whole house fan is for cooling purposes only. There is no reason to suck the heat out of a house in the winter time.
Extra Tips
To really keep the temperature down in the summer time naturally, here are a few simple tips:
1) Blinds do wonders to keep out the UV heat of the sun. Adding blinds to the sunny rooms in your home will keep the temperature nominally cooler.
2) Using ceiling fans is a must in the summer time to circulate the air in your house. If you do not have ceiling fans in your bedrooms, this is a worth while investment for comfort, especially at night.
3) Keep the windows open at night when it is cooler and run turn on your ceiling fans. It is surprising how comfortable your space will be by performing this simple trick.
Whole house fans are a green method in cooling and also very cost effective saving hundreds of dollars a year on cooling costs. These fans also last for 30 years or more allowing you to continue to enjoy and save money with this type of product.