Air conditioning keeps you cool when temperatures soar. ... So how does a typical air conditioning unit work and keep you sane during the heat of summer? The basic concept is that a chemical called a refrigerant loops from inside the home to outside and back again, absorbing and casting out heat in the process
When hot air flows over the cold, low-pressure evaporator coils, the refrigerant inside absorbs heat as it changes from a liquid to a gaseous state. To keep cooling efficiently, the air conditioner has to convert the refrigerant gas back to a liquid again.
it gets warm air outside the room and it cools the warm air and then it releases the cold air inside the room
The air conditioner in a central heating and cooling system provides cool air through ductwork inside your home, by providing a process that draws out the warm air inside, removing its heat.
In a split system, the compressor condenses and circulates the refrigerant through the outdoor unit, changing it from a gas to a liquid. The liquid is then forced through the indoor evaporator coil or cooling compartment. The indoor unit’s fan circulates the inside air to pass across the evaporator fins. The evaporator’s metal fins exchange the thermal energy with the air around it. There, the refrigerant turns from liquid into vapor, removing any heat from the surrounding air. As the heat is removed from the air, the air is cooled and blown back into the house.
From that point, the condenser or outdoor unit then turns the refrigerant vapor back into a liquid, removing any heat. By the time the fluid leaves the evaporator again, it is a cool, low-pressure gas, eventually returning to the condenser to begin its trip all over again. This process continues again and again until your home reaches the cooling temperature you want, as programmed and sensed by your thermostat setting.
Having the AC run and run isn't necessarily a bad thing, as long as it does the job. Over sized systems don't run as much, but can actually cost more on the electric bill, due to higher start and run amp draw. Long cycle times on the smaller system also help dehumidify better. (Probably not an issue in San Diego)
I'd suggest having a small, supplemental system installed, dedicated to the second floor. If you have and accessable attic, it can be installed there;other options may be available, depending on the layout of the house. There's always a way, though you'll be looking at a minimum of $8-$10 grand for the install.
For the time being, let the blower on the existing system run continuously, this may help even out the temperatures a bit. On the thermostat, just switch the fan from auto to on.
Hope this helps.
20+ yrs HVAC tech.
Rotten is right, to get it nailed down to the btu, you should have a reputable hvac contractor do a heat gain calculation. After they're finished, since hvac equipment is sold in sized increments of 6000 btu, ( when between sizes, opt for the smaller choice) the end result will be roughly (as stated) 7 tons cooling capacity required. He's also right that if a closet install is practical GREAT! (that's one of the other options I mentioned)...depends on the layout of the house, types of ceilings and so on. Assuming that the original system was intended and sized to condition the entire house, you'll likely need a smaller supplemental system. (Now rotten, don't get your panties in a wad)...I'd guess around two tons or so. If you have a particular problem area that needs cooled, you can opt for a much cheaper ductless, mini split system, which would work great for one room, or one area, which you could probably have installed for somewhere in the ballpark of $3500. They work quite well.
Again, hope this helps.uncledjm14 · 10 years ago