thanks for the reply. I am totally new to the swamp cooler stuff. I just moved to el paso and bought a house with what they told me was a swamp cooler. the thermostat looking thing has pump only, high cool, low cool, low vent, high vent and off. so i am thinking its a swamp cooler. it also has a rubber hose running from the water faucet to the cooler on roof. i know nothing about swamp coolers. but when my son has it at high cool at night it is feezing upstairs and it is blowing warm/hot air downstairs. furnace....i have no idea even where to start to find out if i do or not. where do i check for that? auto damper.....? cookie sheet damper....? sorry guys......newby here. thx.
Okay, it's a swamp cooler.
This animation shows how a swamp cooler works (animation requires Flash).
http://www.mineralarts.com/images/coolerFlash.swf
The swamp cooler
only cools. It pulls in air from the outside and runs it through an evaporative cooler and into the house. If the house is too cold, don't run the cooler. It probably uses the same ducts as your furnace. The hot air is coming from your furnace. Don't run the cooler and the furnace at the same time.
Since you are in El Paso, I assume you have no basement which means the furnace is probably in a closet or possibly in the garage.
Dampers: First, find your furnace. Look at the duct work coming out of the furnace. Usually the air intake is at the bottom and the outlet duct that blows the hot air into the house is at the top. Look for a slot in the outlet duct work that might hold a damper sheet (looks like a cookie sheet). If the there is such a slot and the damper is in place, take it out. It is blocking the flow of hot air from the furnace into the house ductwork. If there is no slot, you may have an auto-damper.
Next, look at the ductwork leading out of the swamp cooler. Look for a similar slot for a cookie sheet damper. If the slot is there, find the damper sheet and put it in the slot. We know it isn't in place now because cold air is blowing into the house. If there is no slot, you probably have an auto-damper. Auto-dampers open and close based on air pressure created by the swamp cooler fan and the furnace fan. If the swamp cooler is running, the damper next to the cooler opens and the damper near the furnace closes, allowing cold air into the house and preventing moist air from getting into your furnace. If the furnace is running, the fan from the furnace opens the furnace damper and closes the swamp cooler damper allowing hot air into the house and preventing it from blowing outside through the swamp cooler.
When you run the swamp cooler and furnace at the same time, both auto-dampers are open and the parts of the house closest to the swamp cooler get cold air and the parts closest to the furnace get hot air. Leave all the swamp cooler setting in the off position and the thermostat set to a high enough temperature to get the furnace running and see what happens.