Being married to an HVAC technician is great for exactly one reason in July: I get free advice about staying cool. The downside is that he says things like "your return air is starved" at the dinner table.
Our rented duplex doesn't have central air. We have one portable AC unit in the bedroom where the twins sleep and a collection of fans. Last week's heat wave pushed the inside temperature toward 88 in the afternoon, and I finally sat Dan down and asked him to explain, like I'm not married to him, what renters can actually do.
Everything below is renter-friendly. Nothing requires drilling, permission from the landlord, or a big purchase.
1. Keep the heat out before it gets in
Dan's first point was that cooling is mostly about blocking heat, not fighting it after it's already inside. Sunlight through windows is the biggest source of heat in a small place like ours.
- Close blinds and curtains on sun-facing windows by mid-morning. For us that's the west side, so they go down around noon.
- If your curtains are thin, a cheap set of blackout curtains on a tension rod makes a noticeable difference. We spent about $38 on two panels for the living room.
- Reflective window film that clings with water (no adhesive) is another renter option. It peels off when you move out.
2. Use the night air, then seal up
Here in the East Bay, even in a heat wave, it usually cools off at night. Dan's routine:
- Once the outside air is cooler than inside, open windows on opposite sides of the house to get a cross breeze.
- Put a box fan in one window facing out to push hot air out, and let cooler air come in the other side.
- In the morning, before it heats up, close every window and blind. You're trapping the cool air.
This one surprised me. I'd been leaving windows open all day "for air," which was just letting the hot air in.
3. Make the portable AC work smarter
If you have a portable unit or a window unit, Dan says most people are losing half its efficiency without realizing it:
- Clean the filter. Ours slides out. He rinses it every two weeks in summer. A clogged filter makes the unit work harder and cool less.
- Seal the window kit. Those plastic window panels that come with portable units leak around the edges. A strip of foam weatherstripping fixed ours. About $6.
- Keep the exhaust hose short and straight. A long, saggy hose heats up and radiates warmth back into the room.
- Cool one room, not the house. Close the door to the room with the AC. Trying to cool a whole duplex with one portable unit is a losing game.
4. Reduce the heat you make inside
I didn't think about this at all until Dan pointed at the oven. Cooking, the dryer, the dishwasher's dry cycle and even old incandescent bulbs all add heat. During the heat wave, we:
- Did no-cook dinners (I wrote about our favorites last month).
- Ran the dishwasher and laundry after 8 p.m., which also helps with time-of-use pricing on our PG&E plan.
- Air-dried the dishes with the door cracked open overnight.
5. Fans cool people, not rooms
This is Dan's favorite thing to say. A fan doesn't lower the temperature, it just moves air across your skin so you feel cooler. So:
- Turn fans off in empty rooms. They're just using electricity.
- Set ceiling fans (if you have them) to spin counterclockwise in summer, which pushes air down.
- For a quick boost, put a bowl of ice or a frozen water bottle in front of a fan. It's a little silly, but the twins love watching the ice melt.
6. Keeping little ones comfortable
For the twins, we keep it simple: light cotton pajamas or just a diaper and a thin sleep sack, lots of water during the day, lukewarm baths before bed, and the AC set around 76 in their room. Dan says setting it lower than that mostly just makes the unit run nonstop. If you're ever worried about your kids in the heat, call your pediatrician's advice line. They've been really helpful for us.
What it cost us
All in, we spent about $55 this summer: blackout curtains, weatherstripping and a second box fan we found secondhand for $12. The inside temperature on hot afternoons dropped from around 88 to the low 80s in the main room, and the twins' bedroom stayed comfortable all week.
Dan still wants to talk to me about return air. I'm going to let him. He earned it.
