With ever increasing energy costs anything that can be done to reduce the monthly power bill makes good sense....When it comes to energy, less is more.
In a typical Phoenix area residence, heating and cooling energy consumption accounts for 50% of your monthly electric bill.
Power costs are a function of: utility rates; system design; system installation; system operation; and system maintenance.
Utility rates are usually the sum of "demand" charges (instantaneous maximum energy requirement) and "energy" charges (kilowatts of power). Most utility companies have "time of use" plans which relate both demand and energy charges to the time at which it is used. Overall power company demand for energy is lower at nights and on weekends when commercial customers are closed. .. this leaves the utility with excess generating and transmission capacity which it can afford to sell at reduced rates. (Sometimes as much as 50% less.)
By doing laundry doing "off-peak" hours, you can reduce the rate you pay for about 8% of your energy...If you heat water electrically, this jumps to 27% of your energy. If you have a pool, operating the pump during "off-peak" hours reduces the rate on another 6% of your energy.
Sometimes, a single air conditioning system serves both upper and lower levels of a home. Since warm air rises, year 'round the upper levels may always be warmer than the lower levels. Solutions to this is checking air balance (see below), or possibly the installation of ceiling fans to enhance air circulation and level off the temperatures throughout the home.
It is not unusual to find easily correctable defects in the manner in which air conditioning systems are installed. A few to look for include:
Improper Air Balance
The ideal situation is to re-circulate air distribution to each area in proportion to the cooling/heating load of the space. Many contractors improperly balance a system, leading to over conditioning some spaces while under conditioning others. The result is uncomfortable conditions in one area, requiring extra hours of system operation in an attempt to obtain the desired space temperatures.
The cure is to rebalance air flows throughout the home. (In two story homes operating on a single system, this may be difficult to accomplish without some form of zone control.)
Studies by California power companies have found that 20% or more of the energy used to heat and cool a typical residence is lost through duct leakage. Ducts improperly installed or sealed waste energy. The simple solution is to perform a duct leak test, and if leakage appears to be above an acceptable minimum, correct the deficiency.
The thermostat installed in the majority of homes is usually of the non-programmable variety which many owners use as an "on-off" switch.
Replacing a standard thermostat with a programmable stat can pay for the replacement in relatively short time. Program the stat to provide for temperature set-back if the space is not occupied, and AC unit operating hours are reduced. Refer to Alliance "Comfort Zone" for details on "Smart Thermostats".
Improper system maintenance can significantly contribute to energy costs. Systems overcharged or undercharged, and dirty filters, evaporators, or condensers all contribute to excess energy costs and unnecessary equipment wear. The following graph reproduced from the EPA Energy Star website illustrates the importance of air conditioning system tune up and maintenance
Residential Energy Use
Air Conditioning & Heating
Pool & Other