Ask The Inspector
Air Conditioner Issues
Q: The second story of my house is much warmer in the summer months than the lower level. Why is this, and what can I do to reduce the temperature difference between the upstairs and downstairs?
A. Cooling the upstairs of a home can be difficult — especially if the HVAC air handler system is in the basement, or if no basement is present, on the first floor. Typically, hot air rises and cold air falls, so in some aspects the air handler has to work harder to pump cold air up through the ductwork systems in order to keep the upstairs of a two-story house as comfortable as the downstairs.
There certainly are alternatives available to help keep air temperatures in balance. One simple solution is to close off some of the dampers (registers) on the first floor, which will force more air upstairs and create a stronger flow of air on the second story. The first floor may not be as cool as before, but this could produce a more balanced temperature difference between the two floors.
The other alternative would be to install a secondary cooling system in the attic, if there is room, resulting in more comfortable air. The downside of this would be more of an expense for installing and maintaining two systems. Also, one system could be installed in the attic and you could install a zoning system in the ductwork. A zoned system is controlled by electronic motors on dampers within the ductwork system, which can be controlled to distribute more air to certain parts of the house depending on your comfort needs.
The Effects of Humidity
People generally talk about comfort in terms of temperature, but it’s more than that. In regulating indoor temperature, humidity is a key factor. Humidity is the amount of water vapor suspended in air at a given temperature. Relative humidity, a term often used by meteorologists, measures the water vapor the air is holding, compared to how much it could hold. The measure is expressed as a percentage.
Relative humidity is important because the human body cools itself by sweating. The faster the moisture on the skin evaporates into the surrounding air, the “cooler” and more comfortable temperatures can seem. The higher the humidity in the air, the more saturated it is with water vapor. That reduces speed at which sweat evaporates off the skin, making temperatures more uncomfortable.
Of course, air that is too dry isn’t good either. Generally, a range between 30-50 percent relative humidity is preferable. This prevents skin from drying and static-electric build-up while still allowing for evaporation of water off the skin. When comfort is considered, humidity levels are an important factor when selecting or modifying any heating or cooling system.
Snapshots From The Field
Can you guess what is wrong in this photo?
- Nearly everything
- Extension cord shouldn’t be used to run an HVAC unit
- A replacement fan shouldn’t be attached like this
- All of the above
Correct Answer 4. All of the above. In this situation, it is time to call the HVAC technician.
Ceiling fans circulate air. They do not ventilate a room or lower the temperature. They simply create a draft. That draft, or air movement over the skin, provides a wind chill effect on our bodies, making the room seem cooler. This can allow a person to set the cooling temperature on the air conditioner higher, reducing energy bills and possibly prolonging the life of the cooling equipment.
According to the U.S. Department of Energy, using a ceiling fan with an air conditioning system will allow most people to raise the thermostat temperature setting about 4 degrees without a reduction in comfort. Raising the temperature is what creates the savings, not installing and running the fan. For more energy savings, turn fans off when exiting a room. Furniture can’t “feel” the wind chill effect.
Here are a few things to consider when installing new ceiling fans:
- Ceiling fans should be installed in rooms that are at least 8 feet high
- Larger ceiling fans move more air than smaller fans
- Small and medium-sized fans will provide cooling in a 4- to 6-foot diameter area
- Larger fans are effective up to 10 feet
For best efficiency, consider the type of lights in the ceiling fans when purchasing. The fan itself may only be used part of the year; many times, lights are used every day. A single bulb can be more efficient than many bulbs and fluorescent lights are far more efficient than incandescent.
Air Conditioner Maintenance
A broken air conditioning system can mean some pretty miserable summer days. Taking steps to prevent wear and tear helps avoid some of the problems and the cost of an emergency fix. For instance:
- Check heating and cooling filters monthly. Clean or replace as necessary. More frequent replacement or cleaning will help reduce pollen and other allergens in the air.
- Use heat-producing appliances like stoves, clothes dryers and dishwashers in the evening when temperatures are cooler.
- Remove obvious obstructions, including the cover, branches and other foliage from outside condenser units. Condenser units require free air flow to function efficiently.
- Make sure all access panels are secure with all screws in place.
- Indoors, remove obstructions, including curtains and furniture from over vents.
- Schedule an annual maintenance check on all air conditioning equipment. Check with the local Better Business Bureau for companies with clean service records.
- Install programmable thermostats. Even raising the temperature a few degrees when people aren’t home can save big bucks over time on energy bills.
Be sure to keep track of service calls and what repairs were made. Remember if you feel uncomfortable with any of these items, it is important to have a professional do an annual air conditioner checkup for you. These simple checks and a single service call will help the cooling system run well all summer and possibly extend the life of the unit.
Did You Know?
The average central air conditioner unit lasts 7 to 15 years. You can extend its life and get the most out of it by having it serviced every year and by following a few simple maintenance checks.
Monthly Trivia Question
Humidity is measured with a:
Be the first to answer correctly and win a $10 Starbuck’s gift card. Submit your answer to find out if you’ve won.