Hands-in and hands-under dryers side by side

Hands In vs Hands Under Hand Dryers: Which to Choose

A hands under dryer blows air down onto your hands from a unit mounted above them. A hands in dryer has a slot you push your hands into, and air blades strip the water off as you draw them out. Hands in models are usually quicker and tidier but cost more and need more room. Hands under models are cheaper, smaller and simpler to maintain. For most UK washrooms, the right choice depends on footfall, space and budget, not on a single winner.

Below we set out how each type works, where each one fits, what the hygiene evidence says, and how to check running costs against the UK’s own efficiency criteria.

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TL;DR

  • Hands under: compact, lower purchase price, easy to fit and service. Good for offices, small washrooms and light to moderate traffic.
  • Hands in: fast, contained, with water collected inside the unit. Suited to busy sites, though it needs more wall space and regular emptying or cleaning.
  • Efficiency: the government’s Energy Technology List sets the same bar for both types: a drying time of 15 seconds or less and no more than 4.5kWh per 1,000 cycles.
  • Hygiene: neither type beats paper towels in healthcare-style settings, and drying thoroughly matters more than the badge on the box.
  • Rule of thumb: count your daily users, measure your wall, then decide.

Table of Contents

How each type actually works

Hands under dryers

This is the design most people picture. You place your hands beneath the unit, a sensor starts the airflow, and the air pushes water down and off your hands. Some models use warm air at a gentler flow. Others use high-speed jets, often called jet dryers, that move water off the skin mechanically rather than evaporating it.

The water has to go somewhere, and with a hands under unit it lands on the floor, the wall behind or the basin area. In a small, well-ventilated washroom that is a minor point. In a very busy one it is a cleaning job.

Hands in dryers

The hands in design puts the airflow inside a housing. You insert your hands from the top, and thin, fast sheets of air (air blades) scrape water off as you withdraw them. The water is usually collected in a tray or tank at the bottom, so it does not spray around the room.

That containment is the main appeal. It is also the source of the main drawbacks: a bigger body, a higher price and a tray or internal parts that someone has to look after.

Hands in vs hands under: side-by-side

Criterion Hands under Hands in
Typical drying time Warm air models are slower; jet models can be quick Usually among the quickest on the market
Purchase price Generally lower Generally higher
Size and wall space Compact, easy to fit in tight washrooms Larger, needs clear space and a suitable wall
Water spray Water can land on the floor and wall Water is captured inside the unit
Noise Varies widely by model, so check the decibel rating Often quieter in use, but model-dependent
Maintenance Wipe-down, filter checks Wipe-down, plus emptying or cleaning the water collection
Best for Offices, small washrooms, budget refits High-traffic sites, where speed and tidiness matter

Treat the table as a guide to the category, not a promise about any one product. Always read the specification sheet for drying time, sound level and power rating before you buy.

Speed: why seconds matter more than they sound

A washroom with a queue is a washroom people avoid, and people who leave early leave with damp hands. If a dryer takes too long, users give up and wipe their hands on their clothes.

This is where the two designs separate most on a busy site. A fast hands in unit, or a quick jet-style hands under unit, keeps the line moving at a school break or a shift change. Where only a handful of people use a washroom each day, a few extra seconds make no real difference, and a simpler hands under dryer is perfectly sensible.

Efficiency: the UK benchmark both types must meet

The government’s Energy Technology List criteria for hand dryers apply to dryers where hands are placed under or into the unit. To qualify, a commercial dryer must have a standard drying time of 15 seconds or less and use no more than 4.5kWh per 1,000 cycles. The same page sets a maximum run-on time of 2 seconds after hands are removed, and standby power of no more than 2W.

Four UK hand dryer efficiency thresholds

Those figures are useful for two reasons. First, they give you a like-for-like yardstick, whichever design you prefer. Second, they expose how much a cheap dryer can cost you over time: a slow unit with a long run-on wastes electricity on every single use.

We go through the arithmetic in more detail in our guide to the hand dryer power rating that facility managers should look for.

A quick running cost check

  1. Find the rated power in watts on the specification sheet.
  2. Multiply by the drying time in seconds, then divide by 3,600,000 to get kWh per cycle.
  3. Multiply by your daily uses and by your own electricity tariff.

The sums are simple, but they change the conclusion more often than people expect. A unit with a high motor rating that dries quickly can use less energy per cycle than a lower-rated unit that takes twice as long.

What the hygiene evidence says

This is the part of the debate that gets the most heat, and it needs care. Three points hold up.

Paper towels are the standard in clinical settings. The National Infection Prevention and Control Manual recommends disposable paper towels for hand drying in healthcare. If you run a clinic, care setting or food preparation area, follow your own infection control guidance and ask your local infection prevention lead before choosing a dryer. Their advice outranks ours.

Jet dryers can disperse more microbes than towels. A pilot study in a hospital setting used a bacteriophage to stand in for microbial contamination and found lower virus contamination after paper towel use than after a jet air dryer. A separate comparison of paper towels, a warm air dryer and a jet air dryer also examined how far a virus model spread during each method. These are hospital and laboratory conditions with a deliberately contaminated starting point, so they show a risk when washing is poor, not a daily danger in an ordinary office.

Technique matters as much as equipment. A study comparing three hand drying methods highlights that people often rush and leave with damp hands, which raises the chance of transferring bacteria. Whatever you install, users need to dry thoroughly. The infection control manual also advises patting hands dry with paper towels rather than rubbing, because rubbing can irritate skin.

So what does this mean for hands in versus hands under? The honest answer is that the research compares drying methods (towel, warm air, jet) more than it compares the two housings. A hands in unit contains spray inside a body. A hands under unit leaves the airflow open to the room. Neither design removes the need to wash well first. If your washroom has a high-risk use, such as healthcare or food handling, paper towels remain the safer default, and many sites provide both.

For general washrooms, good washing is the real control. The GOV.UK hand washing guidance lays out the steps clearly, and it is worth displaying near the basin. If you also keep sanitiser in your hygiene stations, a range of hand and surface disinfectant products is easy to find online.

What the hygiene evidence says — overview diagram

Noise, space and who will clean it

Three practical questions often decide the matter before hygiene or speed do.

Noise. A loud dryer in a small, hard-surfaced room is unpleasant, and in a school, library or open-plan office it carries into neighbouring spaces. Check the sound rating on the data sheet rather than assuming a type is quiet. Our listings include models marketed as quiet, such as the Bobrick TrimLine Automatic Hand Dryer White, so it is worth comparing sound levels when you shortlist.

Space. A hands in dryer needs a clear wall area and room for users to stand square to it. In a narrow cubicle block, a compact hands under dryer is often the only workable choice. Measure the wall, then check the product dimensions and the mounting height guidance before ordering.

Upkeep. Ask who will empty or clean a water collection tray, wipe sensor windows and check filters, and how often. If the honest answer is nobody, choose the design with the least to look after. A neglected dryer of either type is worse than a plain one that is kept clean.

Which one for which building?

Offices and small commercial units

A hands under dryer is usually enough. Traffic is predictable, space is limited and a lower purchase price matters across several washrooms. Choose a unit that meets the ETL criteria above so the running cost stays low.

Schools, leisure sites and busy retail

Speed and tidiness count for more here. A fast hands in unit, or a quick jet-style hands under model, reduces queues and floor mess. Plan for more cleaning attention and tougher, vandal-resistant fittings.

Clinics, care homes and food areas

Follow your infection control guidance first. Paper towels are the recommended standard in healthcare, so a towel dispenser with a waste bin is the usual answer, such as the Bobrick TrimLine Combi Paper Towel and Waste Bin. If you mix both, keep users informed about which to use after washing.

Homes and small business toilets

A compact unit that is quiet and simple to fit will serve you well. If you are replacing an existing dryer, a plug-in model that fits a backplate can make the swap easier. For wiring and labour costs, our guide to hand dryer installation costs in the UK explains what to budget.

The environmental trade-off

Life cycle comparisons generally favour air dryers over paper towels on carbon, but the result rests on assumptions. A streamlined life cycle assessment assumes users dry their hands for a set length of time, and if people leave after a few seconds with damp hands, the benefit is less clear-cut. A review of the hygiene trade-offs makes a similar point: dryers cost less to run and have a smaller footprint, while towels need constant restocking and create waste.

In practice, the greenest dryer is one that dries hands properly in a short time and does not idle afterwards. That points you back to the ETL numbers: short drying time, short run-on, low standby draw.

Our view

We see the same mistake again and again when people ask us about washroom dryers: they compare headline drying time and price, then forget the building. A fast hands in unit in a cramped cubicle block, or a basic hands under unit in a stadium concourse, both disappoint.

Our advice is to start with three numbers: how many people use the washroom in a busy hour, how much clear wall you have, and who will look after the unit. Then check the specification against the ETL criteria, and buy the quietest model that meets your speed need. If you are fitting out several washrooms, ask about bulk pricing, because it changes the budget more than the choice between designs does.

We would rather you chose the right dryer once than the wrong one cheaply.

— Carl

Choosing a dryer from Simco Direct

We stock a range of hand dryers and washroom accessories for homes, offices and larger sites, with bulk discounts available for trade buyers and a 30-day returns policy. Browse the Simco Direct hand dryer and washroom range, or look at individual options such as the Bobrick CompacDry Automatic Hand Dryer for a budget-minded fit, the Bobrick InstaDry Jet Hand Dryer or the Bobrick TrimLine Automatic Hand Dryer in stainless steel. Check each product page for its specification before you order.

A short buying checklist

  1. Count users. Estimate daily and peak-hour uses for each washroom.
  2. Measure the wall. Allow for the unit size and for people standing in front of it.
  3. Check the ETL figures. Look for a drying time of 15 seconds or less, 4.5kWh or less per 1,000 cycles, and low run-on and standby.
  4. Read the sound rating. Compare decibel figures, not marketing words.
  5. Plan maintenance. Decide who cleans it and how often.
  6. Add towels where needed. In healthcare or food settings, provide paper towels.
  7. Ask about quantity. Multi-washroom projects can qualify for bulk pricing.

FAQ

Is a hands in dryer better than a hands under dryer?

Not always. Hands in dryers tend to be faster and keep water contained, but they cost more, take more space and need their water collection looked after. A hands under dryer suits smaller washrooms and tighter budgets. Match the choice to your traffic and layout.

Which type is more hygienic?

The research compares drying methods rather than the two housings, and it finds paper towels give the lowest dispersal in hospital-style tests. For ordinary washrooms, thorough hand washing and complete drying matter most. In healthcare or food settings, follow your infection control guidance, which favours paper towels.

How long should hands take to dry?

Under the Energy Technology List criteria, a qualifying commercial dryer should dry hands in 15 seconds or less. Keep drying until no moisture remains, because damp hands are the main reason bacteria spread after washing. Times vary by model, so check the specification.

Are hand dryers cheaper to run than paper towels?

Generally yes, since dryers avoid the cost of restocking and bin emptying, and the research notes lower operating costs. The saving depends on your tariff and how many people use the washroom. Run the kWh sum above with your own figures.

Sources

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