By Sarah Bright
If you searched "air purifier RainMate," you probably saw it described as an air purifier — and you deserve the straight answer before anything else: the RainMate is not an air purifier in the sense that matters. It's a water-based fragrance diffuser made by Rexair (the Rainbow vacuum company). It has no HEPA filter, no carbon filter, and no published Clean Air Delivery Rate (CADR). It makes rooms smell nicer. It does not remove dust, smoke, allergens or mould spores the way a real air purifier does.
This guide explains what the RainMate actually is, what independent testing found, how the mould question shakes out, how it's sold, and what to buy instead depending on what you actually want. Short version first.
The Short Answer
What the RainMate is: a tabletop water-based fragrance diffuser ("aromatizer") from Rexair. A small fan pulls room air over a swirling water bath and returns it scented with Rainbow fragrance drops. LEDs light the water bowl (marketed as a nightlight).
What it is not: an air purifier. Independent testing by HouseFresh found it failed to remove particulate pollutants from the air in their particle-removal test — their verdict: "a pretty-looking fragrance diffuser, but it shouldn't be considered an air purifier."
If you want fragrance: the RainMate does that job; it's sold through Rainbow distributors.
If you want cleaner air (dust, allergies, smoke, mould spores): buy a HEPA air purifier with a published CADR rating matched to your room size — e.g., the Levoit Core 300 for rooms up to ~219 sq ft (AHAM-verified CADR 141 CFM smoke). Details below.
What the RainMate Actually Is
The RainMate is made by Rexair LLC, the Troy, Michigan company founded in 1936 that's best known for the Rainbow Cleaning System vacuum. Distributors list it as the "Rainbow RainMate — Aromatizer" (part no. R18014) — note the word: aromatizer, not purifier.
How it works, per Rainbow's own product description: air flows into a swirling water bath, then "clean, fresh air returns to your room" — with a few drops of Rainbow fragrance added to the water so the recirculated air carries scent. That's the entire mechanism: a fan, a water bowl, and fragrance.
Documented specifications (from distributor listings and reviews): - Type: water-based fragrance diffuser / aromatizer (part no. R18014) - Dimensions: ~10.8 × 10.1 × 10.1 inches; ~2.8 lb - Colors: ivory and black - Lights: long-lasting LEDs with low and high settings (marketed as a nightlight) - Fragrances: Rainbow offers around 14 scents (including a luxury collection — Tea Tree Mint, Mandarin Rosewood, Orange Ginger, Lavender Juniper); 2 oz bottles - Coverage claim: up to 1,200 sq ft (distributor listing — no CADR backs this; see below) - Warranty: 1-year (per retailer listing) - Maintenance: clean the basin roughly twice a month (more often if the water dirties quickly); not dishwasher safe; don't use hot water - Manual warning: do not run unsupervised (per the owner's manual, via independent review)
What It Does vs What It Doesn't
| Claim you'll see | What's actually documented |
|---|---|
| "Air purifier" | No HEPA filter, no carbon filter, no published CADR. HouseFresh's particle-removal test: failed to clear test smoke. |
| "Traps dust" | A water bath can catch some large dust particles; it does not capture fine particulates (pollen, pet dander, PM2.5). |
| "Fights odors" | Masks/adds fragrance; doesn't remove odor molecules the way activated carbon does. |
| "Covers 1,200 sq ft" | Distributor claim with no CADR or air-changes-per-hour figure behind it. A HEPA purifier's coverage is derived from its CADR; the RainMate publishes none. |
| "Good for mould" | No — see the mould section. One review roundup lists "doesn't fight germs and mold spores" as an explicit con. |
| "Humidifier" | It adds some moisture via the water bath, but it's not a rated humidifier. |
The pattern: every "purifier" claim dissolves when you ask for the number. Real air purifiers publish CADR — cubic feet of clean air delivered per minute, tested by AHAM. The RainMate publishes none, which independent reviewers flag as the first warning sign.
The Mould Question (Why "Air Purifier Mould" Led You Here)
The cluster keyword "air purifier mould" suggests some searchers hope the RainMate helps with mould. Honest answer: a water-based fragrance diffuser is the wrong tool for mould, and could make a mould problem feel solved while it isn't.
What mould needs: 1. Spore removal from air — a True HEPA filter captures 99.97% of particles at 0.3 microns, including mould spores. The RainMate has no HEPA filter and failed independent particle-removal testing. 2. Humidity control — mould grows in damp air. Adding moisture (which a water-bath device does) without dehumidification works against you. Ventilation and, where needed, a dehumidifier address the cause. 3. Source removal — no air device fixes mould growing on a wall. Clean the source; the purifier handles what's airborne.
Masking a musty smell with fragrance while spores remain airborne is the worst outcome: the room smells better and the problem continues. If mould is your concern, skip the RainMate and get a HEPA purifier sized to the room plus humidity control.
How the RainMate Is Sold
Worth knowing before you buy: the RainMate is sold through Rainbow's distributor network — in-home demonstrations by salespeople — rather than as a standard retail product. HouseFresh's reviewer explicitly disliked this, noting direct sales put the buyer at a disadvantage through sales pressure. You may also find units (and generic lookalikes) on Amazon and eBay at varying prices.
This matters because the demo is persuasive: the water visibly dirties, which looks like proof of purification. Dirty water proves the fan moves air through water — it doesn't prove fine particles, allergens or spores were removed. HouseFresh's instrumented test is the counterweight: visible dirt, failed particle removal.
Quick Picks
Short on time? These are our top recommendations.
What to Buy Instead
coming soon
Levoit Core 300 Air Purifier
The Levoit Core 300 is the article's one verified pick: 3-stage filtration (pre-filter, True HEPA, activated carbon) with an AHAM-verified CADR of 141 CFM (smoke), rated for rooms up to ~219 sq ft. It is the standard recommendation for bedrooms and small rooms because its numbers are published and verified — exactly the transparency the RainMate lacks.
- True HEPA 3-stage filtration captures dust, pollen, pet dander and mould spores
- AHAM-verified CADR of 141 CFM (smoke), rated for rooms up to ~219 sq ft
- 24 dB sleep mode and Energy Star certification, with filter changes every 6–8 months
Important limitation: Sized for small rooms — at ~219 sq ft of AHAM-rated coverage, larger spaces need a higher-CADR model instead.
- CADR (AHAM-verified): 141 CFM (smoke)
- Filtration: Pre-filter, True HEPA, activated carbon
- Room size: Up to ~219 sq ft
Best for: Bedrooms and small rooms where you want measurable particle removal — dust, allergies, smoke and mould spores.
Match the product to the actual job:
If you want fragrance: the RainMate does this competently — it's a decent diffuser with a nightlight. Buy it for what it is. Generic ultrasonic diffusers do the same job for less if the Rainbow branding doesn't matter to you.
If you want actual air purification (dust, pollen, pet dander, smoke, mould spores, allergies), buy a HEPA purifier with: - A published, AHAM-verified CADR — the smoke CADR should be at least two-thirds of your room's square footage. - True HEPA filtration (captures 99.97% of particles at 0.3 microns) plus a pre-filter and activated carbon for odors. - A filter replacement schedule and cost you accept — typically every 6–8 months.
One verified pick: the Levoit Core 300 — 3-stage filtration (pre-filter, True HEPA, activated carbon), AHAM-verified CADR of 141 CFM (smoke), rated for rooms up to ~219 sq ft, 24 dB sleep mode, filter changes every 6–8 months, Energy Star certified, 2-year warranty. It's the standard recommendation for bedrooms and small rooms because its numbers are published and verified, which is exactly the transparency the RainMate lacks.
For larger rooms, scale the CADR up (e.g., higher-CADR models in the same lines) — the principle doesn't change: published CADR, True HEPA, matched room size.
RainMate vs a Real Air Purifier: The Decisive Differences
- Filtration: water bath vs True HEPA + carbon. Only one has a measurable particle-capture standard.
- Published performance: no CADR (RainMate) vs AHAM-verified CADR (real purifiers). No number means no verifiable claim.
- Independent testing: failed particle-removal test (HouseFresh) vs verified CADR figures.
- Maintenance: rinse a water bowl every couple of weeks vs replace a filter every 6–8 months. The water bowl is cheaper; it also does less.
- What each is for: fragrance and ambiance vs removing airborne particles.
| Product | Key Specs | Best Use Case | Standout Feature | Amazon Link |
|---|---|---|---|---|
| Levoit Core 300 Air Purifier Our Verified Pick |
CADR 141 CFM · True HEPA · ~219 sq ft · 24 dB sleep mode | Bedrooms and small rooms | Published, AHAM-verified performance figures — the opposite of the RainMate's unverifiable claims | Check Price |
Common Mistakes to Avoid
- Buying a diffuser for allergies or asthma. Fragrance doesn't remove allergens. If breathing is the issue, you need HEPA.
- Trusting "covers up to 1,200 sq ft" without a CADR. Coverage claims without air-delivery numbers are marketing. Ask for the CADR; if there isn't one, walk away.
- Using it against mould. See the mould section — fragrance masking a mould problem is worse than doing nothing, because it removes the warning signal.
- Running it unsupervised. The owner's manual says not to — it's a water + electricity device with a motor. Follow the manual.
- Expecting it to replace a humidifier or dehumidifier. It adds a little moisture; it controls nothing.
- Paying purifier prices for diffuser performance. Judge it against other diffusers on price, not against HEPA purifiers on performance.
- Reading dirty water as proof. Dirty water proves air moved through water. Only particle testing proves purification — and the published test failed.
SERP Danger Rebuttal: Bad Advice We Found in Search Results
While researching "air purifier RainMate" we checked the current results and found patterns worth flagging:
- Review pages that call it an air purifier in the headline, then list "doesn't fight germs and mold spores" and "not as effective against particles and smoke" in the cons. If the cons describe a diffuser, the headline shouldn't say purifier. Read the cons, not the title.
- "Covers up to 1,200 sq ft" repeated as a specification. It's a distributor claim with no CADR behind it. At allergy-grade air changes (4–5 per hour), a real 1,200-sq-ft room needs a CADR around 640–800 CFM — several times what typical consumer purifiers deliver. The number doesn't survive arithmetic.
- Generic Amazon knockoffs riding the name. HouseFresh noted generic water-based "purifiers" around $40 on Amazon trading on the RainMate's look. Same mechanism, same lack of CADR, less accountability.
- The dirty-water demo as "proof." Distributor demonstrations show dirty water as evidence of cleaning. It's evidence of airflow through water — the independent particle test is the evidence that matters, and it failed.
- Conflating the RainMate with the Rainbow vacuum. The Rainbow SRX cleaning system does include a HEPA neutralizer stage after its water bath — that's a different, far more expensive machine. The tabletop RainMate has no such stage. Don't let the brand's vacuum credentials transfer to the diffuser.
FAQs
Not in any measurable way that independent testing could confirm. HouseFresh's particle-removal test found it failed to clear test smoke, and the manufacturer publishes no CADR. It circulates air through water and adds fragrance — that's a diffuser's job, done fine, but not air purification.
No. It has no HEPA filter and doesn't capture mould spores; one review roundup lists "doesn't fight germs and mold spores" as an explicit con. For mould, you need a True HEPA purifier for airborne spores plus humidity control and source removal — and masking a musty smell with fragrance can hide a problem that needs fixing.
Not really — it's not a rated humidifier. The swirling water bath adds some moisture to the air, but it has no humidistat, no rated output, and no humidity control. Buy a humidifier if humidity is the goal.
Roughly twice a month — empty and clean the basin; more often if the water dirties quickly. It's not dishwasher safe, and the guidance says not to use hot water. Change the water regularly; stagnant water in any device is a bad idea.
Rainbow sells its own fragrance drops for it (around 14 scents), and the mechanism — scent carried by moving air over water — works with most water-safe fragrances. Keep the basin clean, since oils leave residue.
Rainbow sells through its in-home distributor network — the classic demonstration model. Be aware the demo is designed to sell: dirty water looks convincing but isn't evidence of particle removal. Compare against published specs (CADR) before deciding.
The Rainbow SRX cleaning system is a full-size vacuum that water-washes air and passes it through a HEPA neutralizer — a far more capable (and far more expensive) machine. The tabletop RainMate has the water bath but no HEPA stage. They're different products sharing a brand.
Final Verdict
The RainMate is a fragrance diffuser, honestly described: water, a fan, scent, and a pretty LED nightlight. As a diffuser, it's fine. As an "air purifier" — the thing most searchers are actually shopping for — it fails the only test that matters: independent particle-removal testing found it doesn't clean the air, and it publishes no CADR.
Buy the RainMate if you want a nice-smelling room. Buy a HEPA purifier with a published CADR — like the Levoit Core 300 for a bedroom — if you want cleaner air. And if mould is the problem, add humidity control and fix the source; no tabletop device, water-based or otherwise, substitutes for that.
Final Recommendations
Our Verified Pick: Levoit Core 300 Air Purifier — a real HEPA purifier with a published, AHAM-verified CADR for small rooms
Related Guides
- Best HEPA air purifiers for allergies (planned cluster article — ID TBD)
- Best dehumidifiers for damp rooms (planned cluster article — ID TBD)
Specifications verified against manufacturer, distributor and independent-review documentation October 2026; re-verify availability and current specs before purchase.
