What cold fog and hot fog are
Fogging is a way of dispersing a product as very fine droplets that fill the room's volume and settle on surfaces, including hard-to-reach ones. There are two methods: cold fog (the generator disperses the solution without heating) and hot fog (the solution is heated into a dense aerosol cloud). Both are more effective than ordinary spraying.
How cold fog works
Cold fog creates medium-sized droplets. The cloud settles more slowly and evenly, and the product stays longer on surfaces, forming a residual (barrier) effect. The method does not heat the air and is gentle on furniture and appliances.
How hot fog works
Hot fog produces very fine droplets and a dense "smoke" cloud. It penetrates cracks, wall voids, ventilation ducts, attics, and basements better. The cloud lingers in the air longer.
Droplet size and coverage
- Cold fog — larger droplets, faster settling, focus on residual effect on surfaces.
- Hot fog — finer droplets, denser and more "volatile" cloud, focus on penetration into voids and cracks.
Where cold fog is better
Cold fog is the optimal choice for apartments: it creates a lasting barrier effect along baseboards and surfaces, smells less, ventilates faster, and is safer for finishes and appliances. It suits planned cockroach treatment well.
Where hot fog is better
Hot fog wins where pests hide in hard-to-reach places: houses, attics, basements, warehouses, non-residential spaces, wall voids. Its penetration matters with heavy infestation and complex room geometry.
Effectiveness against bedbugs and cockroaches
Against bedbugs, penetration into mattress seams, the bed frame, and baseboard cracks is valued — hot fog works well here, while cold fog gives residual protection. Against cockroaches, the barrier effect on travel routes also matters, so cold fog is often used together with gel. In both cases, fogging complements spot treatment rather than replacing everything.
What to choose for an apartment and a house
For an apartment in Chișinău, cold fog is usually enough (often combined with a barrier spray and gel). For a house with a basement, attic, and outbuildings, hot fog or a combination of methods is more often justified. The final decision is made by the specialist after inspection.