We have the same 2,400-square-foot house as two other sets of neighbors, and last month’s electric bill ranged from $280 for the family without a pool to $396 for a house with a pool. All three of us keep temperatures in the house at or above 80°F, and we all subscribe to the utility’s time-of-day pricing, so we pay lower rates for off-peak usage. In addition, we’ve all invested in regular tune-ups for our heat pumps, sunscreens for windows, and extra caulking around the house.
One set of neighbors has been looking into solar energy quite extensively, but they’ve found that, even in sunny Phoenix, the payback is in the 15- to 20-year range. That’s still not an optimal solution, so they’ve implemented numerous little things, such as turning off computers and TVs when not in use, eliminating dryer use by using a clothesline, and cooking only on the grill during summer months.
Another set of neighbors chose to use their portable evaporative cooler well into June in order to avoid turning on the air conditioning system. They’ve also placed insulation boards over west-facing windows and turned up their thermostat to an uncomfortable 83° during peak hours. And still, neither family has seen a significant decrease in their bills.
According to our utility’s Website and bill stuffers, the answer lies in replacing our 10-year-old heat pumps with higher efficiency units. In fact, it states that air conditioners represent the biggest portion of our summer electric costs and replacing a 13-year-old air conditioning unit with a new system can save 40-45 percent on the air conditioning bill. That sounds great, but I’m not sure I buy that statistic.
BAD DUCTWORK
The reason why is that in our particular house - and probably millions of others around the country - our ductwork stinks. That’s not my assessment, but rather that’s what one contractor said after taking a look at our system. (He actually said that whoever designed and installed the ductwork had obviously been smoking something.)In addition to not having enough returns, we have super-long duct runs that often go up and over 12-foot ceilings. And while vaulted ceilings may look great, they prevent access to the ductwork in about one-half of our house. We probably have major leakage problems, and all our ductwork is in an unconditioned space to boot.
Most industry sources state that ducted air distribution losses cut heating and cooling efficiency by 25-40 percent, and I’m willing to bet that we’re on the higher end of that scale. If we lose 40 percent of our energy through leaky ducts, replacing our units with higher-efficiency equipment probably won’t result in the savings touted by the utility. Interestingly enough, the utility’s Web page concerning air conditioning is mum on duct leakage. This would lead the ordinary consumer to think that high-efficiency equipment is the answer to their skyrocketing energy bills, unless a knowledgeable contractor tells them otherwise.
While I hate having $300-plus electricity bills in the summer, we’re probably not going to replace our existing heat pumps until they die. That’s against the advice of our contractor, who has been urging us to purchase high-efficiency units for the last year or so.
Cooling equipment in our area typically doesn’t last more than 10 or 15 years, and we have now entered the danger zone. But replacing the equipment still doesn’t fix our ductwork problem, for which our contractor doesn’t have a concrete answer. He said we’d probably have to tear out some ceilings in order to make repairs, but he was vague on an exact solution, apart from saying it would be expensive.
That leads me to question what we should do when our heat pumps die. Do we spend thousands of dollars in higher-efficiency equipment and ductwork repairs in order to save $100 each month in the summer? Or do we keep our existing ductwork and buy basic 13 SEER units and pay somewhat less on our electric bill than we do now?
Being in the HVAC industry, I know what the “right” answer is, but given current economic conditions, doing what’s right is becoming harder to justify.
Publication date:09/22/2008