Ironing Out the Details of Laundry Drying Time

BY MICHAEL O'BRIEN, LAUNDRY AND WAREWASHING MANAGER

Michael has nearly a quarter century of experience in the foodservice and warewashing industry.

Here’s a subject that doesn’t get much attention from laundry facility managers—drying time. “Drying time” is not an event like “party time.” It is how long your drying cycles are set for. Many facilities have one setting that never varies from load to load or season to season. That practice misses an important opportunity to improve. Tailoring your drying times to match the load can cut labor and utility costs.

I’ll get the bad news out of the way first. You really need to read your dryer manual. All of them, if you have more than one. There! That wasn’t so awful, was it? You don’t have a manual? Almost all manufacturers now offer manuals online for free downloading. Just read it!

Why is it so important? Because I don’t have an answer about these settings for every laundry room out there. Your manual will tell you the maximum load the dryer can take, and will give estimates for temperature level and drying time based on the weight of the load and the type of fabric. Pay close attention to all this, but don’t make it too complicated.

TIP #1 - Break down your load types into two or three settings that are posted on the wall —“Cotton Towels 25 minutes at 160 degrees," and so on.

One of the keys to economical and efficient drying has nothing to do with dryers at all. It has to do with your washers, specifically the extract step at the end of the formula. When you think about this, you realize just how important it can be.

TIP #2 - Linens with excess moisture left in them from the spin cycle will take much longer to dry, or won’t really dry at all. On the other hand, high speed extractions use a lot of electricity, so there’s no point in continuing to spin laundry that’s as moisture-free as its going to get.

What’s the happy medium? Are you going to have to read your washer manual as well? Actually, I highly recommend reading all of your manuals, but you don’t have to do that to figure this one out:

TIP #3 - I use the “pencil stream” method I was taught in the misty depths of time when I was first learning about laundry (the 80’s). As a laundry programmer, I was told to put a 6 or 7 minute spin cycle on a test load, and then observe the stream of water coming out of the drain while the extraction was in progress. When the stream of water from the drain becomes smaller than a trusty #2 pencil, it has spun as much as it needs to. You note how long that is, then go back and use that number for your extraction time.

Back to drying time. There are some basic rules of thumb to follow.

GUIDELINE #1 - First, even though this may seem counter-intuitive, you don’t want the linens to dry all the way. Why not? Well, there are lots of reasons to avoid over-drying. For instance, once the linens dry completely, the nap becomes abrasive, and continued tumbling causes the fibers to wear each other off. You get a lot more lint, and your linens get thin and have to be replaced sooner than would be necessary if you managed differently.

What you want is just a tiny bit of humidity left in the air when you open the dryer door. The linens themselves should feel dry to the touch. This will also help eliminate wrinkles when the linens are folded and stacked.

Fast Fact: “Hand” is a term you might hear from an experienced laundry professional, as in, “this has a nice hand to it." This refers to how the linens feel when you run your hand across them. Do they feel dry and crackly? Are they stiff, or still damp? Or do they have the nice, warm, soft feel that makes you want to lie down on them or use them to dry off? That’s the “hand” we’re looking for.

So excessive drying time is what causes wrinkles? It is one possible source. For polyester blend fabrics, which are very common now, wrinkles can occur if the linens are heated or cooled too rapidly inside the washer. This happens if you go straight from a cold step to a hot step with no intermediate warm step, or vice versa.

GUIDELINE #2 - Another common problem from over-drying is excessive static, especially during winter when building heating systems suck most of the moisture out of the air. Laundry workers often ask for more fabric softener when this happens, when what they really need to do is cut 3-5 minutes off of their drying time. Adding too much fabric softener can actually make fabrics water-repellent and much harder to clean the next time around.

GUIDELINE #3 - The final really great, don’t-forget-about-this reason for not over-drying is that over-drying is a potential cause of laundry room fires. Bone-dry cotton towels rubbing lint off of each other in a gas-heated dryer can lead to a lot of trouble, especially if the lint traps aren’t kept clean or if even a little bit of grease is not washed out of a kitchen rag before drying. So, one last time—read the manual!