Lofty whole home ventilation system - any good?

[joepeddos44]

The unit fitted is an envirovet whole house. I have had the filter changed, this was an external filter that wraps around 3 sides of the unit and held in place by velcro strips. They are not cheep at £45 plus vat but are supposed to last 5 yrs. I was advised to keep it running on the low setting and if I get any signs of condensation in the winter turn it up to medium until the condensation goes then set it back to low.

This unit has been used for 6 years by the previous owners and according to the engineer there is no sound of bearing wear. Newer models show a running total of the number of hours run

The main fan in the loft is in the hall next to my bedroom and I don't hear any sound from it, in the hall if you stand under the air defuser you can hear a faint noise.

I asked about current running costs which on my setting is about 1.5p a day (24 hours) but that will increase if the heating element cuts in when it gets colder

I checked the air temperature coming into the house when it was quite cold outside last week (we had to put the central heating on) and it was 14C. I gather when it gets very cold the heater element keeps the incoming air temperature at 10C

 

[pred]

What sort of roofing felt has been used in your loft, if it's the waterproof plastic stuff similar to the one Geoff Capes advertised that is your problem, it doesn't breath, it can be sorted by fitting a few air flow tiles not forgetting to make holes in the felt.

 

[joepeddos44]

Hi Pred the underside of the roof tiles has a coating of expanded foam which is probably similar to fitting a membrane to the roof that does not breath.

Plastic cladding has been fitted behind the gutters and the plastic underside have air vents but none at the front so this is something we are going to rectify this should increase the volume of air going through the envirovent fan.

In the medium term we will probably replace the roof which we new we may have to do when we bought the property.

Our builder has checked the condition of the roof and says at the moment its in a serviceable condition, some of the ridge tiles need re-pointing and a couple of tiles replaced.

 

[pred]

The foam is your problem. My advice is get your roof retiled with concrete tiles and breathable felt.

 

[joepeddos44]

Hi Pred this is on out "to do" list

 

[pred]

Hi Pred this is on out "to do" list

Your condensation problem will be solved. Or my name is not Harry.

 

[gcrow]

I just purchased a 1890s Victorian and have a horrid level of humidity in the dirt-floored cellar owing to a complete lack of ventilation. The cellar is long and narrow, split into rooms, with no ability to fit conventional airbricks in the front owing to a layer-upon-layer of council laid asphalt, one mostly bricked over vent in the middle room, and evidence of a vent in the back that was probably blocked over when an extension was added.

I need to clear this before I develop unresolvable rot. I can't (yet) do a periscope airbrick in the front myself (don't think I'm up to the task, still learning,) and there is no room for airbrick installation in the side or rear beyond that one bricked over vent hole. Even clearing that wouldn't create any draft from the front.

I've been advised that going positive pressure with ducting to enforce circulation would be a decent solution. All my research has focussed on these systems being using in lofts and houses, not so much for cellar ventilation. Any thoughts on this? Would it work, and would I be killing any chance I ever had of a warm house?

 

[michaelbailey]

check your insulation to see if the plastic has been lft on .if it has this can cause concensation

 

[gcrow]

There's no basement insulation. Walls are 1893 - no cavity and no insulation there either.

 

[Chrissyboy]

Hi

Reading these posts is like reading my own life story about 8 years ago. I tried the Nuaire Drimaster, but had to have it taken out as the bloke who fitted it wasnt a proper ventilation engineer and it turned out my loft wasnt suitable for the unit they supplied.

An envirovent guy came over and checked my house and said that we actually needed to take the air from outside as we had an airtight loft. The fact that they made their own products was encouraging also. The chap who fitted the Nuaire unit was just an electrician who knew nothing about ventilation!

I wish I had paid that little bit extra all those years ago, as the service and quality of the envirovent products are far superior, not only that they actually send their own people out to survey your home.

Envirovent also put a Cyclone in my bathroom, which has moistire tracking sensors. Nuaire offered nothing of the sort, except an old looking fan with a weird filter.

I would recommend the envirovent units any day, the customer service is second to none!

 

[garymz]

Hi all,
I am a property landlord and have several properties all experiencing condensation and mould in various degrees. Frankly, a lot of the problems are caused by tenants drying clothes indoors etc.

Anyhow, having read such great reviews about PIV and having some feedback from other landlord friends about how effective they were, I looked into it.

Due to the cost of installation given I have a few properties, it seemed to me, that it essence, these systems are just basic fans with a filter (ok some have a humidity sensor or a small heater at extra cost) but that’s not my point.

So, I bought an in-line extractor fan (and reversed it, for input of course!) the Hydroponics Grow Room Tent type which also came with a huge carbon filter and is very quiet. I ducted this in to an adjustable diffuser vent in the hall and wired up to some electric with an on/off button -total cost for parts £49.99. This is opposed to £280.00 for the unit from a vent company or £900.00 inclusive of fitting. (I fitted myself -not difficult set up)

Result - a gentle input of air that is not cold, even in winter, yes it is cool air but not cold, and complete elimination of mould and condensation overnight. Also, it just smells so much fresher in the property.

So my point is: yes for me it works 100%, but at the end of the day, it is just a simple fan that inputs continuous filtered air – nothing special. For those that are capable, and it is not a difficult install, you could save an absolute fortune fitting a fan yourself. If you can fit an extractor fan in your kitchen you can fit one of these. If it is located in a loft it really is a piece of cake to set up. The trickiest part was getting the electric to it.

cheers

Gary

 

[SimonH2]

I think you've missed the point slightly - mostly this thread has been about MVHR, Mechanical Ventilation with Heat Recovery. Rigging up a continuous supply that's preheated is (as you point out) trivially easy and cheap to do. However it adds to running costs and in the case of my previous tenants in the flat I can absolutely guarantee that anything using electricity would have been turned off to cut down the bills (I had to give them a S21, amongst other things they had made every single surface in the flat go mouldy).

Still thinking about the details, and I'll start a thread here when I get underway, but I'm currently at the stage of collecting offcuts of Correx from a local sign company. The intension is to use this to make a heat exchanger - making up for the correx's less than ideal thermal properties by having plenty of surface area. Add a couple of fans, some ducting, and some PUR insulation (plus the obligatory gaffer tape !) and I reckon it should work.
This is for my SOs house which has a significant tendency to be damp (the gas cooking doesn't help).

 

[garymz]

Hi,

Just mentioning an alternative to MVHR which is a cheap and easy way to resolve condensation issues with minimal fuss. However, I guess when it comes to tenants, they need to be managed effectively.

It costs £2.30 per month to run the vent and I have reduced all the rents by £5.00 per month to cover this. My tenants are now clear that any condensation that occurs due to turning off the PIV, will be liable for redecoration costs and have signed a disclaimer to that effect. Its a simple solution both ways. However, by all accounts they are happy that there is no longer a problem.

Gary

 

[ayrforce1]

I`m new on here so best wishes to all.
We had an envirovent system installed , by our landlord. It is the in -cupboard type install with a vent to the kitchen and one to the hall, and has a heater. We are in a flat and our clothes are dried indoors as no drying area or room are provided.
Would anyone know the running cost of these heated units, we are 3 up and the supply vent pipe for the unit is on the front of the building which regularly get very high winds, and we certainly don`t get the gentle breeze effect that others speak of.
My other issue would be ventilation . We have trickle vents on the windows and I know that there is a vent behind the kitchen units, a regular source of very cold air at this time of year. Our shower room / toilet has no window and the extractor fan was removed when the envirovent was fitted, so when we shower or even run a tap where exactly is the condensation supposed to go. Also of course the unavoidable toilet smells.
I can`t say if the unit is making a difference, my solution some time previous was to move all wardrobes and clothing away from exterior walls and that made a difference.
No financial incentives , from my landlord to keep the unit running, but I did get a rent increase , yes increase.
Many thanks.

 

[krisrt]

GARYMZ that is a great idea and has made my mind up to which route im going to go down.

Could you post up which fan you used or just the spec of the fan you used?

thanks kris