A Mom's Thoughts on the Nuna LUMN | Car Seat Review
As a mom of three, I've been deep in the car seat game for just about a decade. I've buckled, unbuckled, installed, reinstalled, and wiped down just about every type of seat out there. So when Nuna released their first combination seat, the LUMN, I was excited to give it a real-life test with my youngest, who’s now 4 years old. We’ve been using it daily, and in this blog, I’m sharing my honest thoughts on how it’s performing—from installation and comfort to how it fits into this next stage of car seat life.
Nuna LUMN
The Nuna LUMN is Nuna's first harness-to-booster (or combination) seat designed for forward-facing use only. Visually, it closely resembles the EXEC, featuring the same extendable leg rest for added support, but it differs in functionality by skipping the rear-facing stage entirely. The LUMN begins as a forward-facing harnessed seat and later transitions into a belt-positioning booster, with the harness system easily stowed when no longer needed. It’s built with the premium safety features Nuna is known for: an all-steel frame, reinforced belt path, Aeroflex™ side-impact protection made of energy-absorbing EPP foam, and flame-retardant-free materials. Like the Nuna EXEC, the LUMN also includes leatherette accents and a streamlined design that blends well with modern car interiors.
About Me
As a mom of three—ranging in age from 4.5 to 9.5—I’ve experienced every stage of car seats, from infant carriers to backless boosters, across a wide variety of brands. With over five years of experience in the baby gear industry, I’ve installed more car seats than I can count and have a solid sense of what makes a truly great one. Nuna has consistently been one of my top choices, primarily because their seats are incredibly easy to install—ensuring a safe, secure fit every single time. That kind of confidence in a proper install gives me serious peace of mind. And of course, I also appreciate the sleek design, plush materials, and the fact that their fabrics are free of harmful chemicals.
I was so excited when Nuna announced their first harness-to-booster seat! When my oldest outgrew her convertible car seat, she wasn’t ready to move straight into a booster, but options for combination seats were really limited at the time. I knew I wanted to keep her harnessed longer for safety. Now, my youngest, Scarlett, is 4.5 years old. She still fits comfortably in her convertible seat, but my goal is to keep her harnessed until at least age 6. In my experience, most kids aren’t mature enough to safely use a booster until they’re around 6 or 7. While many boosters have minimums of 4 years and 40 pounds, I’ve never met a 4-year-old who can reliably sit properly for the entire ride without wiggling, bending, and goofing off. Once they’re in a booster, it’s up to them to stay safe.
Scarlett's Stats
Scarlett is 4.5 years old, 41.5 pounds, and tall for her age at almost 42" tall. She currently rides comfortably in both a Nuna RAVA and Clek Foonf. The Nuna LUMN harnesses a child from 30 to 65 pounds and between 34" to 49" tall. It later transitions to a booster using the vehicle seat belt for children between 43 and 63 inches tall and up to 110 pounds. The LUMN is a great option once your child is forward facing and entering the final stage of the car seat phase. Scarlett transitioned to forward-facing when she turned 4 in October, so the timing of the LUMN's release couldn’t have been better!
First Impressions
I was so excited to receive this seat, and it came super quick! Here are my first impressions in terms of unboxing, installing, and my opinionated daughter's first thoughts!
Unboxing = SIMPLE
The Nuna LUMN arrived in a large box, similar in size and presentation to their other car seats. Just like the rest of Nuna's lineup, it featured their signature safety seal on the outside—designed to tear when opened, making it impossible to reseal without visible damage. This gives you peace of mind that the seat is brand new and has never been opened or used.
Once opened, the LUMN was in a clear plastic bag with the manual attached to the seat. The best part? It comes fully assembled with no extra parts to attach or complicated setup required. One of the reasons I love Nuna seats is how simple they are right out of the box.
I removed the manual, read through it cover to cover (always a must!), and took a few moments to familiarize myself with the seat’s features and functions. Next, I had Scarlett sit in the seat and adjusted the headrest to the proper height for her.
10/10 for unboxing
Install
Next up, installation. I know a lot of people dread installing car seats, but knowing how to install your seat correctly is absolutely crucial. If you haven’t tried installing a Nuna seat yet, you’re in for a pleasant surprise. Like the RAVA and EXEC, the Nuna LUMN uses the True Tension door system, which makes installation incredibly straightforward.
While the LUMN includes LATCH connectors, Nuna actually recommends using the vehicle seat belt for installation, and that’s because it’s virtually foolproof. It doesn’t require any Hulk-level strength like some other seats do. You thread the seat belt through, pull it tight, and the True Tension door does the rest. It really is that easy.
As I carried the seat out to my garage, I noticed it felt a little lighter than my Nuna RAVA, which was a nice bonus. I was also able to keep my vehicle’s headrest in place during installation, something that isn’t always possible with other seats. To install, I first raised the LUMN's headrest to its highest setting to easily access the True Tension door (unlike the RAVA or EXEC, where you can set the headrest before installation). Since I had already measured Scarlett’s correct headrest height, I just readjusted it after installation. It was super quick and easy thanks to the smooth sliding mechanism. Just a reminder: for forward-facing installs, you’ll want the harness straps to be even with or just above your child’s shoulders.
Once the seat belt was routed and tightened through the True Tension door, I closed it and the LUMN didn’t budge a millimeter. It was completely locked in, and that rock-solid installation felt so satisfying. No sweating, no struggle. I finished by attaching the top tether strap, which is always a must with forward-facing seats.
The only quirk I noticed was with the recline feature. Unlike the RAVA, which shows recline positions clearly numbered on the side, the LUMN has 9 recline positions but no visual indicator to show which level you’re on. While the minimalist design looks clean, I do wish there was a way to track the recline setting more easily. That said, the recline range didn’t feel drastically different between levels, so fewer positions might have been just as effective.
Bottom line: Nuna absolutely nails it with installation. I couldn’t love it more. People often say that all car seats pass the same safety tests, which is true, but a seat is only truly safe when it’s installed correctly. Nuna takes the guesswork out of it. A seat that installs securely and easily is a safer seat.
10/10 for installation
Scarlett's First Impressions
Now for Scarlett’s first impressions. Her immediate reaction? "I wish it was a color!" I had to laugh—Nuna seats are undeniably sleek and beautiful, but she’s 4, and kids love bright, fun colors. Her Clek Foonf is bright pink, and her RAVA is a dark blue (still a "color" in her eyes), so the more neutral tones of the LUMN caught her off guard at first.
But as soon as she sat in it, she was sold. She instantly loved the extendable leg rest and proudly declared to her siblings, “Look at my new seat!” It didn’t take long for the comfort factor to win her over.
9/10 (from Scarlett)
Adjustments
After using the Nuna LUMN for a day or two, I realized I needed to make a couple of small adjustments. I initially left the plush seat pad in place, since the manual says it can stay in up to 40 pounds—and Scarlett is just barely over that mark. She seemed comfortable at first, but I found it harder to reach the buckles, and her legs looked a little cramped. So, I removed the pad. Instantly, her legs had more room, and buckling her in became much easier.
Once I took the pad out, I noticed she started to slide forward a bit toward the buckle. That’s when I realized the crotch buckle needed to be moved to the closer slot (there are two options). As soon as I adjusted it, she sat up straighter and looked much more comfortable.
Everything was super easy to change, just simple buttons to undo and reattach. I especially appreciated that the crotch buckle pad is buttoned on, unlike the one on the Nuna RAVA, which constantly slips off every time she climbs out. This thoughtful detail made a big difference!
10/10 for ease of adjustments
Features I Love
After using the Nuna LUMN for over a week, I can confidently say there’s so much to love about this seat! Like I mentioned earlier, installation was incredibly simple, and most adjustments can be made without even uninstalling the seat. Huge win!
One of my favorite features is the no-rethread harness, plus the fact that it goes higher than both the RAVA and the EXEC. This is a game-changer for us since Scarlett is a tall girl, and I want to keep her harnessed as long as possible. Harness height matters! When forward-facing, the harness should come from at or above the shoulders, and once it dips below, the seat is outgrown, regardless of the listed height or weight limits. And let’s be real, most kids outgrow seats by height or torso length before hitting the weight max. Scarlett carries her height in her torso, so this is especially important for us.
The LUMN's harness height goes up to 18.5 inches—over 2 inches more than the RAVA! That means as long as she stays under 49" and 65 pounds, she can stay harnessed even longer.
Aesthetically, the LUMN might just be the most beautiful car seat I’ve seen. The leatherette details and clean lines make me smile every time I see it, which is often, because let’s face it, we see our car seats daily! I also love the open-side design. Living in sunny Southern California, I know Scarlett will appreciate the added airflow.
Another bonus? It’s slim! My other two kids use a high-back booster and a backless booster, and there’s no doubt all three seats could fit across in our Honda Odyssey.
There’s truly so much to love about the Nuna LUMN!
10/10 for features
Features Scarlett Loves
Scarlett loves the LUMN's leg rest—it's a total game-changer! She can easily sit criss-cross, stretch out, and best of all, she never complains about her legs being uncomfortable or falling asleep anymore (which used to happen on longer drives or when she’d nap in the car). This feature alone makes the LUMN perfect for road trips!
She’s also a big fan of how the seat feels. The cushiony padding is super comfy without making her overheat. In her RAVA, she’d sometimes get too warm because of the plush fabrics and higher sides, but the LUMN's more open design really helps keep her cool and comfortable.
But what she loves most? She feels like such a BIG girl in her new seat! She’s genuinely proud of it and loves showing it off to everyone.
10/10 for features for Scarlett
Things I Have to Get Used To
Honestly, I love almost everything about the Nuna LUMN! If I had to be super nit-picky, I’d say buckling the straps can be a bit more cumbersome with the extra padding in place. Also, the recline system feels a little different compared to other seats—I found that it just takes some trial and error to really get the hang of the various recline settings. The manual wasn’t the clearest in that section, either, which didn’t help.
Comparison of the Nuna LUMN to the Nuna RAVA and Clek Foonf
I genuinely love all three of these seats! That said, the Nuna RAVA and Clek Foonf offer one key feature the LUMN does not—rear-facing capability—so the LUMN falls into a different category entirely.
My RAVA has been amazing, but after using it for two kids, it’s definitely showing some wear and tear. I’m more than ready for a refresh, and the LUMN is a perfect next step. Plus, Scarlett can stay harnessed even longer in the LUMN thanks to the higher harness slots: 18.5" compared to about 16" on the RAVA. That’s a big deal for tall kiddos like her!
The Clek Foonf is another personal favorite of ours. We love its bold color options, sleek design, and how incredibly solid it feels—it’s seriously built like a tank. That said, the unboxing and installation process is definitely more involved than with Nuna seats, which are generally much more user-friendly right out of the box.
Conclusion
We all genuinely love the Nuna LUMN and think it fits perfectly into Nuna’s lineup! In my opinion, it might just be their most beautiful seat yet. Transitioning Scarlett to a harness-to-booster seat at this stage feels just right. I know she’ll be able to stay harnessed longer, and when she’s ready for a booster, we’re already set.
Overall, I’d give the LUMN a solid 9.5/10.
The only reasons for the slight deduction are the higher price point and the fact that the cupholders don’t fit her usual water bottle. Oh, and I do wish there was a pink color option!
Other Comparison Blogs
For more information on how the Nuna LUMN compares to other seats, check out these blogs:
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