Vacuum cleaner

General Features

Upright, Cylinder or both

Many vacs will do the job of both types, but some dont.

Wet and dry

Enables hoover to suck up water without fusenpoppenspitzensparkzappen.

Blow and suck

Power take-off

Mains power socket outlet on the machine for running power tools so that the vacuum switches on when the tool is operated, and switches off (sometimes after a few seconds delay) when the tool is switched off.

Cable retract

Retracting cable makes it easier to carry. No hands are needed for the cable. Looks neat too.

Tool storage

Machine shop vacs

Vacs intended for machine shops have 2 features for high debris volume:

a 2 bag arrangement where the top bag filters, and the debris then drops into the bottom collection bag.
wide bore hose, enables use of longer hose runs

Some also have power take off.

Filter Types

Cloth Bag

A cloth filter eliminates the cost of bags, and is less likely to clog than paper.

The bag must be emptied, which can be messy.

Performance is middling.

Old cloth filters generally need a thorough clean to restore full suction power.

Paper bag

The bag is disposable, making emptying more or less mess free.

A new paper bag every time means ongoing expense

Paper filters clog very rapidly on building dust.

Cyclone

Cyclones are good for building dust

Some cyclones have additional filters that must be replaced from time to time.

Cyclone vacs with no other filter lose no suction at all due to the filter. In contrast, the back pressure produced by paper & cloth bags is significant, and worsens considerably as the pores clog.

This is partly but not 100% true for cyclones with additional cloth filters, as those filters will give some airflow resistance that increases over time. The presence of the cyclone filter means that much less clogging occurs, but they will still clog eventually.

Dysons have gained a poor reputation for reliability as well as price. Other makes don't generally seem to suffer the same frequent problems.

DIY Cyclone

DIY cyclone filters are easy to make, and can be added to any existing hoover or air filtration system.

http://www.internode.co.uk/cyclone/

http://www.woodcraft.com/articles.aspx?articleid=408

http://codesmiths.com/shed/workshop/techniques/cyclones/

Water

These uncommon vacs use a tub of water to trap the dust.

Presumably the water needs emptying after each use.

Reviews

Earlex WD1000 Combi Vac

Earlex WD1000

Earlex website

PROS:

cheap
blows as well as sucks (useful sometimes)
wet and dry

CONS:

really needs the wet+dry filter (£10 from Wickes)
filter needs cleaning: sometimes tapping or brushing off dust will do, from time to time washing and drying it, especially after sucking up lots of fine dust
mixing wet with fine dust quickly blocks the filter: it is better to empty the canister and remove the filter to sucking up mainly water (flooded floors etc)
when sucking up lots of water it can spit out (often filthy) water from around the motor housing as well as the blow orifice: workarounds are to station the machine outdoors, or putting a dustsheet over it to catch the spray
the filter just pushes onto its housing and can slide down, especially if the cleaner is bumped on the floor, resulting in clouds of dust being blown out of the machine
the filter has a tinplate body which eventually rusts through requiring replacement even if the filter material is still serviceable
no carrying handle
tends to tip over if pulled by the hose
hose just pushes into orifices and can get blown out when fitted to the blow orifice
short mains cable
no cable, hose or tool storage

Available from Screwfix, Wickes and others.

Earlex WD1200P Combi Power Vac