This is the only home appliance I swear by when it’s cold one minute then hot the next – and these models will be useful year-round

We might be in October, but instead of those crisp autumn days I live for, we're in that weird time of year when it's really chilly first thing in the morning, roasting hot by lunchtime, with temperatures plummeting again when the sun goes down.

With these wild fluctuations during the day, and it not feeling cold enough to put the central heating on, it's hard to know whether you should hold off packing away the best fans for the season or bring the electric heater or oil-filled radiator out to keep things comfortable at home. Or both.

But these appliances can be sizable, and if you're anything like me, the idea of having both heating and cooling options out at the same time can make a tidy person a little twitchy.

Fortunately, there is a solution – a single appliance that offers equally effective cooling and heating.

But not all multi-functional appliances are created equal. While most fan heaters will offer a fan only mode as standard, in my experience, the fan mode isn't always that effective, especially compared to some of the best standalone fans on the market.

However there are notable exceptions that can be effective at maintaining a comfortable environment in your home at this time of year (and beyond), offering equal levels of heat and cooling functionality. And as luck would have it, they're all currently on offer as part of Amazon's Prime Day-style sale event, the Big Deal Days.

Save £100

Dyson Purifier Hot+Cool HP1: was £549 now £449 at Amazon

With three functions (heat, fan and purifier) in a single appliance, this Dyson is ideal for ensuring a comfortable home environment whatever the time of year. If you've got need for each of the functions, it works out more cost-effective than buying individual appliances of equal calibre individually. Better still, it's currently on sale at both Amazon and Dyson.

View Deal

Save £39

Duux Threesixty 2 : was £119.99 now £80.99 at Amazon

It might have fewer fan modes than the Dyson and Dreo models in this article, the fact that this Duux model has 360° air distribution means it can quickly and evenly influence the temperature in your room, whether you're looking to cool it down or warm it up.

View Deal

Save £15

DREO Smart Whole Room Heater 714s: was £99.99 now £84.99 at Amazon

Lugging a large and heavy appliance from room to room is no-one's idea of fun, so the fact that this Dreo model has an easy carry handle and weighs less than 3kgs makes it ideal for moving around your home with you.

View Deal

The Dyson Purifier Hot+Cool HP1, might be an investment (although we have spotted that both Amazon and Dyson have knocked £100 off the RRP), but it is essentially three products all wrapped up in one package. When we tested the Dyson Purifier Hot+Cool HP1, we were really impressed by both the 10 heating and cooling settings, and loved that it offered a purification function at the same time (so much so, it even appears on our round up of the best air purifiers too).

For something more compact, and affordable (at least in comparison to the Dyson), the Duux Threesixty2 is primarily a heater, but it does have two different ventilation settings. Combined with the 360° air distribution, this minimalist appliance can quickly freshen up (or warm up) your room, depending on the time of day.

If portability is more important to you, then the Dreo Smart Whole Room Heater 714S will be ideal, thanks to it's lightweight and easy carry handle. With three heat settings and three fan settings that impressed us during testing, it's clear from the get-go that this appliance absolutely wants to be seen as a heater and fan in equal measure.