Heat Recovery Ventilation System?

lynneinjapan

We had an Envirovent surveyor round a few weeks back to look at one of our tenanted properties (a 1930s 3-bed semi) where we had a problem with mould in the bathroom and front bedroom (north-facing with a bay window and cove ceiling). He guaranteed that we could solve the problem by installing one of their PIV units (cost £840 inc installation) and replacing the old extractor fan in the bathroom with one with an extract rate of at least 100 m3/hr and preferably a humidistat. They had a fan for £263 but I found another one that fitted the bill for under £20 on the Plumbworld website.

For the PIV unit I thought £840 seemed a bit steep for a glorified fan so I did some research and eventually settled on the Drimaster - was initially going to go for the Drimaster Heat so that it had an integral heater like the Envirovent equivalent, but then read on www.dryhomes.net that it was only worth getting the one with the heater if it was for a bungalow with a small hall (because it's much more efficient to heat the air via gas c.h. than electrically, so it's only worth using the heater if the air is feeding into a space so small that it causes discomfort), so I ended up going for just the basic one (cost £228 inc VAT & delivery from Dryhomes - yet to be invoiced for fitting, for which we used a local electrician, but he estimated between £150 & £200 as it involved putting in a spur off the ring main up to the loft).

Got it installed about 10 days ago and now the tenant is grumbling about the cold air it's bringing in. I should have known he would - he's not easy to please - but I feel the cold too so I do have some sympathy. Have suggested using the foam inserts to divert the air, and adjusting the fan speed, but I don't suppose that'll be good enough in this weather, so I'm now looking into the possibility of retrofitting a heater to the unit.

marshallka, how have you got on with yours?

2Sheds

I've had my Drimaster 3 yrs now and it's just packed up. Nuaire are sending out a replacement transformer, alas it 18 days until they get any in

I've fitted the Drimaster via a timer, so it comes on at 11pm and goes from a 7am, this helps stops the cold air coming in the landing which is open to the lounge, all day which is unnecessary.

The Drimaster, still works OK but only if set on 4 or above, we still get condensation on the windows and have to wipe them in the colder weather.

I called them about the 500w heater but that comes on if the temperature in the loft is 2c, so it would be 24/7 at present.

auntyS

marshallka wrote: »

Hi, well we had out "standard drimaster" fitted this week (although paid and signed for a drimaster 2000:mad::mad:). It was only when I was looking at the fitting instructions on the net (cause he never gave us any paperwork at all) and noticed that we should have a sensor installed.... I did ask them when fitting it where they were going to fit the sensor and they said it was not needed. I feel so annoyed now. You cannot trust anyone. It just that they have charged us £750 for under one hours work and I know these units are only about £250 to buy so a nice profit of £500.:mad::mad:

I don't know if this will work either as they have actually fitted it right above the second entrance door and only about 6 inches from the side wall also and have put two foams pieces along the side of the vents so only two vents working. Also the standard model has no heat recovery to it so I am going to be on the phone on monday demanding a 2000 fitted and not the one they have. My hubby is an electrician too and was so annoyed that I agreed to having ANYONE fitting it but as he works so much at the moment and revising at nights I wanted something doing quick so agreed to this being fitted.

Hello Marshallka,

Hope you see this and can give me an update on how effective the unit has been as I am having similar condensation problems in my bungalow and have been advised to install a similar system.

Thanks.

Preston_B

I know this is a very old thread...but i'm having the same problems and wondered if Marshallka could give an update if she is subscribed to the thread.

Or has anybody got a Single room heat recovery unit.....does it help with condensation??

Patrocks

Old thread but having just read it I feel it should be pointed out that the units being talked about on this thread are not heat recovery units.

A heat recovery unit does what the name suggests and recovers either the heat or cold (if using air conditioning) from the buildings air and puts it into the fresh air it is bringing in. This is a energy saving feature

The units in this thread referred to as heat recovery units do not do this they just bring outside air in. In other words they are fans or in even simpler terms they do the same job as opening windows.

The air changes these units provide will help reduce humidity but no money saving from heat recovery.

anotherbaldrick

marshallka wrote: »

Anyone got one or anything similar like the "lofty" and any advice on these much appreciated. This is to cure a problem with black mould (corners of two bedrooms, around ceiling tops of windows)and condensation. We have before had a damp specialist round and was tested for actual "damp" but none there, just the condensation and mould. Got fitted wardrobes and have to empty them in the winter. Mould grows on everything (green mould here) . We already constantly run a dehumidifier but want something better than this as the problem is still there. Thinking of replacing soffits and eaves etc but will that be a complete cure? Heard that ventilation is our only cure but not got any real feedback on these systems although reading on them they do look good.

We have one of these systems. Ours is a Vortice Promoteo HR 400. a French job. http://www.vortice.ltd.uk/product-range-390,8.html
Cannot say that I think very much of it the fan operation is confusing (as many French electrical things are) It operates via a handset zapper but you never know what it is doing.
The heat recovery element seems of no practical use. The handbook is 20mm thick and filled with useless information in 12 languages.
I have tried to clean the filters as the manual but they are stuck inside ( Thing is 12 months old).
Have tried talking to the English service agents but they are a total waste of space . the handset readout says " problem with downstream CO2 sensor". The handbook makes no mention of a sensor and the agents have never heard of it and don't know where it is fitted or what you would do about it.
Even tried to get them out to look at it but they are a one man band outfit and will not respond.
DO NOT USE THIS MANUFACTURERS UNITS


The most useful thing I find is our Velux rooflights. These are fitted at the apex of our roof and I find that opening these and some vents downstairs it causes a flue effect which circulates fresh air and is far more effective. The amount I open the rooflights depends on the weather and temperature.
This way keeps the house smelling sweet and dry.

Patrocks

To Anotherbaldrick. I followed the link you posted and the manual on that page says the humidity sensor is in the stale air outlet duct, a fault with this would display as error code ER09.

anotherbaldrick

Patrocks wrote: »

To Anotherbaldrick. I followed the link you posted and the manual on that page says the humidity sensor is in the stale air outlet duct, a fault with this would display as error code ER09.

Cheers Patrocks. That would lead me to believe that the sensor is not mounted in the unit but in the duct outside of it. Trouble is the manual and fixing instructions nowhere mention the sensor, how it would be mounted or presumably wired back into unit control box, zilch, nix, nowt, nothing, and as I mentioned when I phoned and talked to the agents they had never heard of the sensor. Yes I have got ER09 fault code. I even wonder if I have a sensor fitted at all , the installer/ operation information is so scrappy you wonder if the French are having un grand e'clat de rire

Patrocks

The literature isn't very clear is it. When I first read through I thought the sensors were internal then the error codes section refers to duct mounting. This would usually be a probe that is fitted on the outside of the duct with a wire linking back to the unit or controller. The probe is screwed to the outside of the duct but has a sensor on a thin rod in the airstream.

Now the last thing to throw into the mix is the humidity sensor shown in the accessories section of the technical data pdf. The picture looks like a ceiling mounted sensor. So clear as mud I'm sorry to say.