Grease filter kitchen extract

[Oz07]

What does everyone use to stop grease getting into the kitchen extract ductwork?

 

I have the following extract valves

https://www.bpcventilation.com/125mm-airflow-pvc-extract-valve

 

and its connected to a 125mm box in the ceiling with a double connection to the ductwork.

 

Are there different valves you can get with grease filter built in?

Or is it a case of bodging some grease filter inside the box and changing it every so often?

 

Be interested to see others solutions I had a quick search online but nothing obvious came up.

[Marvin]

We have the same 125 extracts with no grease. However we rarely cook greasy food and we have an extractor hood above the hob which pulls air through a charcoal filter and back out into the room at the top of the kitchen wall units. 4 years no problem with the MVHR. (we have a boost button for the MVHR in the kitchen and a humidity sensor)

[Oz07]

Yeh I have the same setup and wouldn't say we cook a lot of greasy food either. There's no problem with my unit but have you ever took the ceiling valve off and looked behind it in the kitchen? I cleaned ours yesterday and it was a bit greasy inside. I'd like to just have some kind of filter medium in there which stops it working it's way back into the duct work.

[JohnMo]

I use these on all the extract ducts

 

https://www.epicair.co.uk/products/extract-air-valve-filter-for-8960-125mm-valve-10-pieces

[Oz07]

On 18/03/2023 at 20:54, JohnMo said:

I use these on all the extract ducts

 

https://www.epicair.co.uk/products/extract-air-valve-filter-for-8960-125mm-valve-10-pieces

How do they fit just squash in around the edges? I was also recommended these https://www.i-sells.co.uk/mob/prod_detail.php?cPath=1599_178&products_id=51229&gclid=EAIaIQobChMIxriIsYSI_gIVGO3tCh2V3QxSEAQYASABEgLSnfD_BwE

I think your link is better 30 quid for 10 filters. 

 

I did think maybe i could just get some kind of filter medium behind the metal grill of the cooker hood but before the carbon filter. Has anyone modded their cooker hood in this way to trap more grease there?

[joth]

On 18/03/2023 at 20:54, JohnMo said:

I use these on all the extract ducts

 

https://www.epicair.co.uk/products/extract-air-valve-filter-for-8960-125mm-valve-10-pieces

I keep meaning to get some of these ordered.

I notice there's less than one-third priced copies available from china on eBay: e.g.

https://www.ebay.co.uk/itm/374385197240

 

Anyone tried them?

 

[SteamyTea]

1 hour ago, joth said:

I notice there's less than one-third priced copies available from china on eBay

What makes you think they may be copies?

There is a lot of badge engineering.

[sharpener]

In our kitchen above the cooker we have a 125mm extract point as part of our Villavent/Systemair MVHR system. We use bonded acetate fibre sheet which is sold by the metre in John Lewis upholstery dept for padding cushions and sofas. We cut it to a template and sew the edges to form a "hat" which goes above the  automatic fire damper mechanism. Although we do very little frying it collects a black layer of miscellaneous grot and needs changing every six months.

 

We also put discs of the same material in the bathroom extracts, they collect a lot of towel fluff and need changing once a year.

 

As a result the ductwork stays very clean and we only need to change the filters in the central plant every 3 years.

[saveasteading]

2 hours ago, sharpener said:

a "hat" which goes above the  automatic fire damper mechanism

Doesn't that reduce the suction significantly? Especially once it gets dirty.

I was looking recently at the effect of an extended duct and bends, and it was much more than I had expected.

[joth]

I'm just installing a second fan coil unit for bedroom & office cooling. It was salvaged from a restaurant refit, so is already absolutely caked in grease 🤮 but fortunately the air runs very clean through it. Anyway the inlet filter got lost at some point so I've ordered a roll of this stuff to try as a filter

https://www.ebay.co.uk/itm/202978181622

it claims G4, I'm sceptical but thought it worth a punt and better than nothing. 

 

Back to the MVHR extract vents I bought some of the no-name ones linked previously, again at 15gbp for 20 I thought it worth a punt. As Mr Tea says, they maybe straight off the same manufacture line as the genuine article.

I'm very surprised our installer didn't put these in to start with. If it works OK I'll put them on the bathrooms too. 

[Seeoda]

 I bought the conical filters to insert into the extract valves. Unfortunately, my kitchen extract is so weak at the moment I cant fit the filter there yet (just 3.5 l/s), so I only have it on a bathroom valve. I dont know what sort of flow you need to have 13 l/s after fitting, my goal flow. They catch a huge amount of dust in the bathroom anyway.

Edited May 18, 2023 by Seeoda

[saveasteading]

My easy but unscientific test is a j cloth over the grille. If it sticks it is very powerful. If not try a tissue.. if that doesn't stay put then there is a problem.

[Seeoda]

20 minutes ago, saveasteading said:

My easy but unscientific test is a j cloth over the grille. If it sticks it is very powerful. If not try a tissue.. if that doesn't stay put then there is a problem.

 

I am sure some enterprising person could correlate different objects like paper, or cloth to flow rates and make a nice bootstrap calibration method. Might not work if you have vents that screw outwards but otherwise would be good