What's the best way to improve a stale smelling house

Do any of your windows have a lock facility, where you can open them slightly and lock them in that position. I use this on my windows when I’m out or at night for safety.

How about an air purifier?

Surely this isn't sustainable long term? Literally only being home 7 hours means less than 7 hours sleep every night. That's not okay. And time to eat? Shower?

Do you live a long way from work? Is this long term?

Open windows when you are home, even for half an hour.
Price's Candles 'Open Window' candle or reed diffusers. The whitebone has a light scent.
Dehumidify regularly.

Scented things will mask it for an hour or two. Clean carpets and rugs professionally regularly incl other upholstery I.e sofas and curtains.

air out when home.

have you got a good extractor in the kitchen which is doing the job?

Scented things will just make it worse.

For us the worst culprit is old food in the fridge. Before you go away, make sure you've cleared the fridge, it makes a huge difference.

Then windows open in every room when you're back.

Edit- I misread as you being away for work ie overnight. Still a minimalist fridge will help a lot

Zoflora or bleach down your plug holes..

Splash of zoflora in an inch of water in your sink. Or bleach.

Take food waste straight to the outside bin.

My hallway can be a bit whiffy due to boots and trainers that have been on the allotment/farm so I use one of those plug ins in there and flick it on as soon as I come home.

One of those air freshers that run off a battery that you can set a timer on.

Make sure you air it well when you are home. Keep everything clean in the kitchen, elbow grease spray is good for stripping the greasy layer off things, tops of cupboards/fridge are usually grotty and dusty and greasy.

I would get a dehumidifier for the kitchen , leave as many windows open on the latch as you can and invest in some really decent reed defusers , I’d recommend the Jo Malone.

When you ARE home, windows open at nearly all times. A very clean house also smells markedly less stale too, so I'd consider a big declutter so that it's very easy to mop and dust round everything regularly. I have a lot of plants and I think that makes a small difference to air quality too. Pure oil electric diffusers are very good. Absolutely no to artificial sprays and smells/plug ins etc as it just smells stale and rank half an hour later and accumulates crap in your air. I mop with a few drops of eucalyptus or rosemary in my mopping water. I line my drawers with liners and have cedar balls with my clothes. I hang bedding outside at the weekend (duvet) for a good air too unless it's wet outside. I put a kettle of hot water and a tablespoon of bicarb in my sinks monthly. I use vinegar (buy massive containers online) to clean with. It all adds. Good luck.

When you ARE home, windows open at nearly all times. A very clean house also smells markedly less stale too, so I'd consider a big declutter so that it's very easy to mop and dust round everything regularly. I have a lot of plants and I think that makes a small difference to air quality too. Pure oil electric diffusers are very good. Absolutely no to artificial sprays and smells/plug ins etc as it just smells stale and rank half an hour later and accumulates crap in your air. I mop with a few drops of eucalyptus or rosemary in my mopping water. I line my drawers with liners and have cedar balls with my clothes. I hang bedding outside at the weekend (duvet) for a good air too unless it's wet outside. I put a kettle of hot water and a tablespoon of bicarb in my sinks monthly. I use vinegar (buy massive containers online) to clean with. It all adds. Good luck.

Febreeze bathroom are good little air fresheners I have them dotted about and when they've 'ran out' I use them as drawer/wardrobe fresheners and they still smell nice weeks later.

Chefs candle is good for food smells, often on offer in Waitrose