You open the summer electric bill, read it twice, and wonder what your AC did to deserve that number. If you live in Norwood, Weymouth, Somerset, Marshfield, Dedham, or Canton, you’re not imagining things. Power costs more here than almost anywhere in the country—about 30 cents per kilowatt-hour—and a system that’s even a little off turns that into real money.
The worry that comes next is usually the same one: someone is going to tell me I need a whole new system. Maybe you do. More often, not yet. Here’s what we’d try first, in the order we’d try it, starting with why the bill climbs so high in the first place.
Why Air Conditioning Bills Run High Across Plymouth, Bristol & Norfolk Counties
Massachusetts homeowners pay about 30 cents per kilowatt-hour, roughly 11 cents above the national average. Every hour your air conditioning works harder than it needs to costs more here than it would in most of the country.
Cooling accounts for around 12% of a typical American home’s yearly energy costs, and it takes a bigger bite in summer across our region. Our cooling season is also short, which creates its own problem. Your system sits idle for months, then gets asked to run flat out in the first real heat wave.
A dirty filter, a slow drain, or a loose duct in the attic that you could ignore in May gets expensive fast in July. From our office in North Attleborough to homes throughout Plymouth, Bristol, and Norfolk counties, the order stays the same: keep the system healthy, run it smarter, then look at the house around it.
Way 1: Does AC Maintenance Actually Lower Your Energy Bill?
Yes, and it’s where most of the hidden waste lives. The indoor part of your system—either an air handler or your furnace blower—pulls all the air in your house across a filter and a coil. When the filter clogs, the system strains to move air through it.
Swapping a clogged filter for a clean one can trim cooling energy use by 5 to 15 percent. Check yours monthly during the season, and change it when you can’t see light through it. It’s the cheapest fix in this whole article.
The coil and the condensate drain come next, and they’re harder to handle on your own. A dirty coil can’t pull heat out of the air very well, so the system runs longer to make up for it. A clogged drain line backs water up and can shut the system down or leave a stain on a ceiling.
The drain sits right between HVAC and plumbing. Since we do both, you don’t end up with two trades pointing at each other. That’s what a spring tune-up is for, ideally before the first hot week.
Members of our Dempsey Comfort Club get a free annual tune-up, priority service, 24/7 emergency service, and 10% off parts and labor if something turns up. Our Dempsey Maintenance Plan comes in two versions: Central AC & Gas Heat includes two visits a year, and AC & Oil Heat includes one.
Your furnace blower often moves your central AC’s air too, so the fall furnace visit and the spring AC visit work together. A tune-up should end with a plain explanation of what we found, and only a recommendation if there’s something worth recommending.
Way 2: What Temperature Should I Set My AC To?
The Department of Energy recommends 78°F when you’re home. That feels warm if you’ve been living at 70, and plenty of people give up after a day. Try 78 with a ceiling fan running, since moving air makes a room feel cooler, and come down a degree at a time if you need to.
With the rates we pay across Plymouth, Bristol, and Norfolk counties, every degree you can live with is worth keeping. When nobody’s home, ENERGY STAR guidance suggests raising the setting about 7 degrees, and about 4 degrees while you sleep. A programmable or smart thermostat handles that without you thinking about it, which is where one earns its keep.
Skip shutting the system off completely, though. A closed-up house builds humidity, and then your AC has more to fight when you walk back in.
Here’s a myth worth retiring: setting the thermostat to 65 doesn’t cool the house faster. The system works at the same pace and just runs longer to reach the lower number, so you get the same temperature for a while and a bigger bill.
Humidity matters more than most people expect. A house that’s cool but clammy makes you push the thermostat lower, which costs more. If yours feels sticky while the AC is running, that can point to a system that’s too big for the house, because an oversized unit shuts off before it pulls the moisture out.
Shades on the sunny side in the afternoon help too, and they cost nothing.
Way 3: Before You Replace Your Air Conditioning, Check the House Around It
This is where a lot of articles tell you to buy a new unit. We’d rather you look at three other things first. A typical home can lose 20% or more of its cooled air through leaks, holes, and poorly connected ducts, so air you paid to cool ends up in an attic or a wall cavity.
Thin insulation and drafty rooms make the system fight the house all day. Mass Save offers home energy assessments that look at exactly this, and sealing and insulating are often the least expensive way to bring cooling costs down.
A good Home Comfort Advisor will check your ducts and airflow before talking about equipment at all. Only after that does it make sense to ask whether the equipment itself is the problem.
Should I Repair or Replace My AC?
Age matters, but it isn’t the whole story. A unit past ten years or so tends to use more energy, and that’s when replacement starts to make sense. A filter, a capacitor, a drain, or low refrigerant, though, can make a young system act old.
Ask whoever diagnoses yours to tell you which it is, and to put repair and replacement options in writing side by side. If you’re only given one option, get a second opinion.
If replacement is the answer, sizing matters more than most people think. Bigger is not better. An oversized system cools the house fast, shuts off, and never runs long enough to pull out humidity, so you get that clammy feeling plus extra wear on the equipment.
The right way to size it is a Manual J load calculation, which looks at your insulation, windows, and layout rather than the size of the old unit. Every AC installation we do includes a free in-home consultation and a Manual J load calculation. A high SEER number doesn’t guarantee savings either, because a poorly installed system can underperform a lower-rated one that’s installed correctly.
We back select new HVAC system installs with a written 10-year labor warranty at no additional cost. It covers our workmanship, while the manufacturer covers the equipment. Because that says “select,” ask us which systems qualify.
On rebates, the rules have shifted. The federal heat pump tax credit ended December 31, 2025. As of January 1, 2026, heat pumps using the older R-410A refrigerant no longer qualify for Mass Save rebates, and eligible equipment uses R-32 or R-454B. Mass Save rebates can still offset a heat pump or mini-split upgrade, but amounts change, so we confirm what your home qualifies for before you decide anything.
Can I Get Efficient Air Conditioning in a Boiler Home With No Ductwork?
This one comes up constantly around here. Plenty of older New England homes were built with boilers and radiators and no ducts at all. If you heat with a boiler or oil in Dedham, Canton, Plymouth, or anywhere else across Plymouth, Bristol, and Norfolk counties, you’ve probably had this conversation.
Central AC would mean building duct runs through finished walls, which is a big job, and plenty of homeowners decide it isn’t worth it.
Ductless mini-splits and heat pumps are the usual answer. A mini-split cools room by room, so you aren’t cooling an empty bedroom at two in the afternoon, and there are no ducts to leak. A heat pump also heats in winter, which is part of why Mass Save rebates apply to them.
Mass Save has rules about equipment and installers, and we walk you through them up front. Mini-splits need care too. Filters need washing and coils need cleaning, so a clogged mini-split in the bedroom is the same problem as a clogged central system, just smaller.
If your house is a mix, with ductless in some rooms and central air in others, one visit that covers all of it is worth having. We work on oil and gas furnaces, boilers, heat pumps, air handlers, and plumbing, so a visit doesn’t have to stop at the AC unit. And if the honest answer is that your setup is fine and you just need a new filter, we’ll tell you that. Same-day service is available for when it isn’t that simple.
Lower Your Air Conditioning Costs in Plymouth, Bristol & Norfolk Counties: Where to Start
Start small. Change the filter, get the tune-up on the calendar, and settle on a thermostat setting you can live with. Then look at the ducts and insulation before anyone talks about equipment.
If a replacement does turn out to be the right call, it should be sized to your home with a real load calculation, with the options written down. Your bill won’t drop to what you’d pay in a cheaper-power state, but it can come down more than you’d expect, and you’ll know why.
If you’d like a Home Comfort Advisor from Dempsey Energy to take a look at your system, or you want to hear how the Dempsey Comfort Club works, reach out. We’ll tell you what needs doing, what can wait, and what you shouldn’t spend money on.
