Stay Cool With Hot Prime Day Deals on Air Conditioners: up to 20% Off Portable ACs, Window Units

When you buy through our links, Insider may earn an affiliate commission. Learn more.

It's barely mid-July and it's already been a hot summer. If you've been suffering through the heat without air conditioning, Amazon Prime Day, which ends tonight, is here to offer some relief. We're seeing great discounts on top air conditioner brands during the sale, including a few deals on picks from our guides to the best air conditioners and best portable air conditioners.

We weeded through hundreds of Prime Day air conditioner deals remaining on day two to pull together these recommendations. While we haven't tested every air conditioner below, we are only highlighting discounts from reputable brands that we have hands-on experience with.

Our favorite deal so far is 10% to 20% off Midea air conditioners. The Midea U (20% off at Amazon when you clip the coupon on the page) won the "best energy-efficient" pick in our AC guide. It has a unique design that allows you to open the window on cooler days without having to take the unit out — a great feature if you live somewhere with variable weather during the summer. Below you'll also find deals from popular brands like GE, Frigidaire, and Whirlpool.

Window AC vs portable AC: We think a window AC is best for most people; they're more energy efficient, better at cooling, and less expensive upfront. However, if you have atypical windows that can't fit a traditional unit, a portable AC might be a good option. Check out our guide to portable air conditioners versus window air conditioners for a more detailed breakdown.

Wall units: While window and portable ACs are the best options if you rent, if you own your home you may consider a wall unit. Wall ACs come in two styles: through-the-wall units and ductless mini-split units. We don't generally recommend a through-the-wall AC unless your home already has a sleeve for one. Ductless mini-split air conditioners are a good alternative to through-the-wall ACs and a great option for homes that want the experience of central air without installing the ductwork. These units consist of a wall-mounted air conditioner that connects to a small condenser stored on the outside of your home. You'll still need to drill through the wall (and should consult professional installation), but it's much less expensive than installing central air.

Energy efficiency: Energy efficient units are not only better for the environment, but also keep your cooling costs low. All of the window AC picks in our best air conditioner guide are Energy Star* certified, but portable units are less likely to have this designation.

Btu: Btu is the cooling power of your air conditioner. While it may be tempting to purchase an air conditioner with as high a Btu as possible, that isn't always the best option. If you get a unit that is too big for your room, it will cool too quickly without removing the moisture, leaving a cold, clammy environment. Alternatively, an AC that is too small will be overworked, boosting your energy bills. Use the table below (from the Energy Star website) to determine what Btu your room requires:

You might opt for a slightly larger Btu if the room you're looking to cool has a ceiling more than 8 feet high, is very sunny, or it's a kitchen. Keep in mind it's common for model numbers for the same units to vary by one or two digits. This usually denotes different Btu ratings and colors.

Sign up for Insider Reviews' weekly newsletter for more buying advice and great deals.You can purchase logo and accolade licensing to this story here.Disclosure: Written and researched by the Insider Reviews team. We highlight products and services you might find interesting. If you buy them, we may get a small share of the revenue from the sale from our partners. We may receive products free of charge from manufacturers to test. This does not drive our decision as to whether or not a product is featured or recommended. We operate independently from our advertising team. We welcome your feedback. Email us at [email protected].