filter life

[lizzie]

I am changing my filters a lot....its not me being oversensitive to my need for clean air either the mvhr system gives me alerts.  I know its environmental and also weather related to some degree.  I am not in a built up environment and have fields all around and high up on a ridge so windy too.

 

My filters last on average about 8 weeks, manufacturers say average is twice a year change.

 

Got an alert yesterday and today I have just changed this filter (F7) after 47 days, so a little over 6 weeks and its filthy....see pic....dirty one and a new clean one for comparison.

 

I know some of you buy filters from alternative suppliers cheaper but I have not found one that makes them to fit my system.  Any web sites to try?

 

On another note the change to the enthalpy exchanger has made a big difference to the comfort levels in the house.

[Jeremy Harris]

First off, filters can look dirty when they are still working OK, they tend to quickly get a thin layer of dark muck over them, long before they become clogged.  Our filter alarm time is settable in the control unit for the MVHR, and I have it set for 6 months, which seems fine.   Might be worth looking to see if the filter change alarm frequency can be changed on your unit, as 8 weeks seems to be a very short time to me.  The extract side filter on our system rarely gets very dirty, but the finer intake one does.  I can usually vacuum clean the intake filter once, then replace it at the second filter change of the year, which seems to work OK (it won't tolerate being vacuum cleaned more than once).  The extract filter lasts longer, and can be lightly vacuum cleaned three or four times before needing replacement.  Our filters look very similar to yours, I'd go so far as to say I think your intake filter uses exactly the same filter material.

 

I found that the price of the filters from Genvex in the UK was very high, and also found that they weren't a common size, so I couldn't buy cheaper replacements.  Luckily I found Jasun Envirocare, who can make batches of custom made filters to exactly the same specification as the OEM ones, but for a fraction of the price.  I just gave them the exact dimensions of the filters, and the filtration standard, and they quickly made a batch of new filters, that look to me to be indistinguishable from the genuine Genvex ones, other than having a different label.

 

 

[ragg987]

As per @JSHarris, I tend to vacuum mine at 3 months and replace at 6. They do look pretty bad at 6.

 

I purchased mine from http://www.filterworld.eu/

About 1/3 of the UK price but high postage if ordering 1 or 2 sets, so I ordered 5 sets. I also had a quote from Jasun, they were more expensive.

 

Is your alert time-interval based or something else? Our Airflow alarm is set at a time interval, but it is conceivable your is e.g. measuring a pressure drop?

 

Also, from your photos it looks like your F7 is trapping some large stuff (is that plant material)? I would expect either you intake duct wire mesh or the G4 prior to the F7 to capture these, thus the F7 has only the finer stuff to filter.

[lizzie]

Thanks both - looked at the filterworld site but they dont seem to do my filter - no mention of my brand of machine.  Will try Jasun and see if he can offer anything more competitive.  I don't think they are anything special so maybe he can.

 

Will investigate settings on filter change alerts thanks.

 

I have tried vacuuming without huge success might give me another week or so at best but it definately affects the pressure when filter is dirty.

 

My F7 is on the the intake I have a G4 on the extract...that is a bit dirty but nothing like the intake as you would expect. I think I could get away with replacing that half as often again as the intake if pushed.

 

On intake and extract I have an open vent with a sort of cowl over and some very large mesh sides both on the outside wall.

 

 Thats all there is between outside and F7 so that is getting everything.  I dont have any option to put any other filter in before the F7.  Its high up so hard to get a decent pic from ground level.

 

Maybe because of the fields my air is very dusty and lots of insects?  It costs me about £75 every 6 weeks or so for filters at the mo...seems expensive so was trying to find a more cost effective route but if thats it then thats it I guess.

 

 

[Gone West]

2 hours ago, lizzie said:

I am changing my filters a lot....its not me being oversensitive to my need for clean air either the mvhr system gives me alerts.  I know its environmental and also weather related to some degree.  I am not in a built up environment and have fields all around and high up on a ridge so windy too.

 

My filters last on average about 8 weeks, manufacturers say average is twice a year change.

 

Got an alert yesterday and today I have just changed this filter (F7) after 47 days, so a little over 6 weeks and its filthy....see pic....dirty one and a new clean one for comparison.

 

I know some of you buy filters from alternative suppliers cheaper but I have not found one that makes them to fit my system.  Any web sites to try?

Does your system give alerts at irregular intervals or do you set a date for the alert for example in 3 or 4 or 6 months time. My first filter change was at 3 months and since them I clean them at 3 months and change them at 6 months so I have set my alert to 3 months. My filters are G4 and F7 and I buy mine in bulk from Filtershop. I tried Jason Envirocare but they were only marginally cheaper than Total Home Environment.

https://www.wtw-filtershop.nl/c-1862769/combi-185/

[lizzie]

19 minutes ago, PeterStarck said:

Does your system give alerts at irregular intervals or do you set a date for the alert for example in 3 or 4 or 6 months time. My first filter change was at 3 months and since them I clean them at 3 months and change them at 6 months so I have set my alert to 3 months. My filters are G4 and F7 and I buy mine in bulk from Filtershop. I tried Jason Envirocare but they were only marginally cheaper than Total Home Environment.

https://www.wtw-filtershop.nl/c-1862769/combi-185/

It is set for 180 day alerts - 6 monthly thats the system default however the level of contamination in the filter seems to over ride this if necessary and this is what appears to be happening. TBH these days I am checking them monthly at the end of the month anyway but I didnt do the check at the end of March as I only had the exchanger changed on 12th and new filters in then.  I would have checked next week but the alert came first.  Guess I just have extra dirty air LOL.

 

Will have a look at filtershop thank you.

[Gone West]

1 minute ago, lizzie said:

Guess I just have extra dirty air LOL.

Do you know if you have insect screens in the air intake to the F7 filter.

[lizzie]

Just now, PeterStarck said:

Do you know if you have insect screens in the air intake to the F7 filter.

Not as far as I am aware.  I only have that metal box with mesh sides (see earlier pic) on the outside wall and an open pipe straight into the manifold.  There is nothing else for me to access filterwise other than the two in the machine.

[Gone West]

1 minute ago, lizzie said:

Not as far as I am aware.  I only have that metal box with mesh sides (see earlier pic) on the outside wall and an open pipe straight into the manifold.  There is nothing else for me to access filterwise other than the two in the machine.

If there is a way to fit a fine insect screen, which is easily accessible for cleaning, it might help reduce the larger crud on the filter. There does seem to be a lot of what look like weed seeds trapped on the filter.

[lizzie]

4 minutes ago, PeterStarck said:

If there is a way to fit a fine insect screen, which is easily accessible for cleaning, it might help reduce the larger crud on the filter. There does seem to be a lot of what look like weed seeds trapped on the filter.

Yes there always is a lot of large stuff trapped.  Think it might mean trying to get something on the outside wall behind that metal box if there was to be any pre filter.  Think that will be beyond me though I'm not good on ladders. Thanks.

[Gone West]

2 minutes ago, lizzie said:

Yes there always is a lot of large stuff trapped.  Think it might mean trying to get something on the outside wall behind that metal box if there was to be any pre filter.  Think that will be beyond me though I'm not good on ladders. Thanks.

Would it be possible to fit something on the inside of the ventilation unit where the intake duct enters.

[lizzie]

24 minutes ago, PeterStarck said:

Would it be possible to fit something on the inside of the ventilation unit where the intake duct enters.

That could be worth investigating although getting the foam pipes on and off to clean it would be quite a task as they are now all glued together because they kept falling apart! Maybe something inside would work easier.  I will investigate. Thank you.

[vivienz]

Do you think that your filter life is shorter because your MVHR was blasting at a high rate until recently? It would be logical to see how this would clog them more quickly.

[lizzie]

4 minutes ago, vivienz said:

Do you think that your filter life is shorter because your MVHR was blasting at a high rate until recently? It would be logical to see how this would clog them more quickly.

That was what I thought previously but this latest filter was put in in the day all the work resetting the vent rates and changing to enthalpy was done so that theory doesnt hold.  The filthy filter in the picture is the one installed on that day 12th March....47 days ago!  I think my windy location next to fields must be impacting, just so glad all that muck not going into my lungs..........and to think we picked this plot being high up, not surrounded by other buildings and for clean air!  

[vivienz]

I wonder if it got clogged by all that Saharan sand that came up with the warm weather at easter. Either way, all that stuff is better off in the filter than your lungs, Lizzie.

[ragg987]

If the f7 is the first filter, that could be where the issue lies. In our system the f7 is the third line of defense.

 

We have an insect mesh on the inlet, then a g4 and finally the f7. I tend to wash the mesh every year and replace the others as a set.

 

It might be worth adding a fine stainless steel mesh to the inlet to capture the bigger crud. I reckon you could wrap a strip around the perimeter.

[lizzie]

4 minutes ago, ragg987 said:

If the f7 is the first filter, that could be where the issue lies. In our system the f7 is the third line of defense.

 

We have an insect mesh on the inlet, then a g4 and finally the f7. I tend to wash the mesh every year and replace the others as a set.

 

It might be worth adding a fine stainless steel mesh to the inlet to capture the bigger crud. I reckon you could wrap a strip around the perimeter.

Ah around the square box outside.....good thought that could work!

 

Yours sounds very sophisticated with all those filters rather than just the one I have.

[dpmiller]

old pair of tights stretched over the F7 as a prefilter?

[Jeremy Harris]

Just now, dpmiller said:

old pair of tights stretched over the F7 as a prefilter?

 

That, seems like an idea very well worth trying to me!  Unconventional, but it has to be worth a try.

[Cpd]

I use high quality dust mask when working near fine sawdust or anything dusty, I have a big box of pre filters and have two of these inserted before the main filter, when the front one is dirty I chuck it and put the one behind to the front and a new one at the back. The main filters last for years this way. When I one day get my mvhr built I will use the same principle of at least one good cheap pre filter before the main filter and maybe a set of tights to ! 

[lizzie]

Guys love the old tights idea...genius thank you!