A tenant’s attempt to stay cool turned into a frustrating utility surprise after a broken window air conditioner was replaced with a smaller unit, causing his monthly electricity bill to skyrocket. The facility itself also stood out as being particularly bad. The unit was reportedly equipped with wood, foam and duct tape, and the tenant said they could even see daylight around them. Here’s what you need to know In a post on the r/HVACAdvice subreddit, the original poster explained: “Two months ago I installed a new, smaller window unit. My electric bill jumped from $100-140/mo to $240-290/mo!” OP went on to ask the community for advice on how to address the issue. situation. Responses to the post focused on two main possibilities: weak insulation around the unit and a replacement air conditioner that may simply be less efficient. One commenter wrote: “Wood is not a great insulator. Honestly, you probably just need to fix the insulation and look at the psychic’s rating. Looks like the guy who installed it did a terrible job.” The OP then suggested that the installation may have been improvised. In response, the tenant said, “Exactly what it is, they told me they’ve never installed one before!” Part of the OP’s higher bill could have come from the replacement unit itself. If the new model has a lower efficiency rating or lacks more advanced compressor technology, it may use more electricity to provide the same cooling, and a smaller unit may also run longer if you’re struggling to keep the room comfortable. For a bill increase after an air conditioning replacement, the first things to examine are pretty simple. Look for visible openings, check for hot air around the frame, compare the specifications of the new and old units, and make sure the replacement is the right size for the room. Small leaks can increase system workload, and an undersized drive can end up running almost non-stop. Another option to reduce energy costs is to combine solar panels with appliances, including efficient HVAC systems. Where can I get more information? The Reddit thread raised two basic questions: Is the new unit inefficient or is the installation leaking cooled air? Some other cooling cost stories help put this into context, showing how thermostat settings, dry mode, and simple maintenance can change how hard an air conditioner has to work. home improvements. To see more stories like this, change your Google preferences here.