Straight Talk Articles

Hot Tips on Keeping Cool for Less
May, 2019

Dear Pat and Brad: We moved into our home last spring. It’s pretty new and seems well-insulated in winter. But it was hot last summer so we had to run the AC a lot, and the electric bills were a killer. Do you have any ideas how we can cool our house this summer without going broke? – Brandon


Dear Brandon:

We’ve discussed in past articles some of the easiest ways to make your home more efficient, like reducing solar gains, insulating and ventilating the attic, and sealing air leaks. (See the May 2018 article on our website.) You may need to focus on inefficiencies in your cooling system. But before we address that, let’s look at some other possible problems.

  • Do you have freezer or a second refrigerator in the garage?  This can be a major power sucker, especially if it’s old and you live in a warmer climate. (1)

  • Do you have a well? Your pump may be sucking you dry as you use it more in summer. Start by looking for leaks in the system, and if necessary, reduce irrigation.

  • How about a swimming pool? It may be time to overhaul or replace the pump. If the pump is in good shape, try putting it on a timer.


If you have central air conditioning (AC) or heat pump, make sure your filter has been changed or cleaned recently.  The next step is to call in an HVAC contractor for a tune-up and a complete assessment of the system.   A tune-up can improve the efficiency and extend the life of the unit.  The tune-up includes cleaning the condenser coil, a check of the refrigerant levels and a good look at the pump and electrical contacts.    Talk to the contractor about the efficiency of the AC unit.  If it’s old it may be cost-effective to replace even if it’s still functional.

The ductwork is as important as the AC unit, so make sure the contractor you choose is capable and willing to provide an expert assessment.  A real pro will know how to measure the air flow at each supply and return register. If you’re not getting cool air to the rooms that need it, the contractor may be able to make some modifications to the ductwork.

Leaky ductwork could be your problem.  If the ducts are in unconditioned areas like the crawl space or attic it’s especially important to make sure they’re sealed and insulated. It will also help to seal ducts that are in conditioned spaces.  Some HVAC contractors can do a duct-blaster test to measure duct leakage.  Discuss whether you should ever close any supply registers.  Most experts prefer that supply registers are always open.(2)

If you cool with window AC units, there are a few things you can do to maximize your cooling while keeping costs as low as possible.

  • Use window AC units in rooms that can be closed off with a door, to make the cooling as effective as possible.

  • Make sure you have the right sized unit for the size of the room. A unit that’s too big will cool the room before the humidity has been lowered, which will make it feel less cool,(3) while a unit that’s too small will have to work too hard, causing a shorter life span—and it may not do the job.

  • Use an electric fan or ceiling fan to help distribute the cold air throughout the area you are cooling.

  • Turn off the AC unit when no one’s in the room.

  • If your window AC unit isn’t cooling properly, it may need replacing. Look for an ENERGY STAR-certified unit to get make the most of your cooling dollars.


Of course, the simplest way to save money on your Air Conditioning is to not use it. As much as possible, keep your activities to rooms that are easily cooled. Try to spend the summer eating outside. If you have a basement, think about setting up a second bedroom down there where it’s cooler. Think of it as a summer hideaway!

This column was co-written by Pat Keegan and Brad Thiessen of Collaborative Efficiency. For more information on energy efficiency myths, please visit the May 2019 more information page.



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That old fridge or freezer in your garage could be taking a bite out of your wallet. Photo: whyamiKeenan, creative commons