Home PIV units - Anyone got one?

[Koldov]

you can notice a temperature difference going onto the landing but since the doors are closed it doesnt affect us. Ours cuts out if the air that is drawn in is too cold - we notice the condensation build up when this happens.

 

The heater would prevent this though, I thought that might have been the point of it?

[Koldov]

I have the heated version(had a very good discount) i have never used it. Running costs are too high to run the heater all day every day.

 

I think others have intercepted the recommended electrical supply (fused spur) and have it on a timer. We only get condensation on the windows overnight really so could have it set to only run then...?

[stevewill6]

I think others have intercepted the recommended electrical supply (fused spur) and have it on a timer. We only get condensation on the windows overnight really so could have it set to only run then...?

 

Yeah thats one way to do it. From memory i think its only a 300w heater element probably enough to take the chill off the air?

 

Me and my dad installed it in 2018 i think. My dad got one the same time. Apart from the temperature shut off its run 24/7 since then. I do have the remote for it but forgot to pair it when we installed it and its to high to reach without a ladder.

 

I also tried washing the filter in the washing machine on a delicate wash, it worked quite well. maybe get away with doing in one more time before buying replacements.

Edited March 31, 2023 by stevewill6

[KK20]

The heater would prevent this though, I thought that might have been the point of it?

 

 

No, the heater is on the output not the input. Input is via two large fabric filters, the heater goes via a collar on the output before the ducting.

[Koldov]

No, the heater is on the output not the input. Input is via two large fabric filters, the heater goes via a collar on the output before the ducting.

 

Yes, I had seen that.

 

I just presumed it might be configurable...? As in you could keep it on a bit longer when the temperature drops in the loft as it was heating the air it was blowing out a bit.

 

Seems a bit odd (if not pointless) if it is going to shut off on cold nights when the condensation would be bad and you need it on...

[KK20]

it seems to work. I have no idea what the temperatures are set to, there are a couple of variable resistors. I live in the lakes, it gets cold up here but over the years this thing has worked for us.

[nicholab]

PIV units are great they should be left to run 24x7. We had the heated one I would say walls felt warm and house seemed to heat up quicker.

[titch]

Do these have any cooling effect in the summer?

 

Notice any quicker drying of clothes?

 

Does it make heating the house any better?

 

Would it work ok with a wood stove downstairs? It's not going to blow the hot air out of the house?

 

Trying to see if it offsets any of its own costs anywhere else around the home.

[Andrew_C]

Do these have any cooling effect in the summer?

 

Notice any quicker drying of clothes?

 

Does it make heating the house any better?

 

Would it work ok with a wood stove downstairs? It's not going to blow the hot air out of the house?

 

Trying to see if it offsets any of its own costs anywhere else around the home.

 

 

No cooling - your loft is always going to be warmer than outside, especially if it is sunny.

 

It will help with drying, but it went in asap when we moved in so can't really compare.

 

It does help with heating in that the air in the stairs doesn't stratify.

 

It will to some extent push warm air out, that's the plan. It does this instead of trying to extract air.

[nicholab]

Do these have any cooling effect in the summer?

 

Notice any quicker drying of clothes?

 

Does it make heating the house any better?

 

Would it work ok with a wood stove downstairs? It's not going to blow the hot air out of the house?

 

Trying to see if it offsets any of its own costs anywhere else around the home.

 

Heating fells more effective and walls feel warmer when I had a PIV.

[KK20]

drying? A little I suppose, it isnt so much the drying but the vapour left behind. There isnt a massive airflow coming from the vent, the system is supposed to build up a little pressure so that the vapour will keep moving and be expelled rather than settle and condense. It doesnt really extract warm or cold air such as an expelair in the bathroom and it doesnt work as a circulating heat exchange vent. We have a dehumidifier in the utility/drying room and that works well when we are drying clothes, we use that alongside a heated clothes horse - those cost little to run compared to a tumble dryer.

[Koldov]

Well, I finally pulled the trigger on this one about a month ago (just the basic one, loft controls/no heater)... and it works!

 

Even on the couple of minus degree nights we've had recently, there's only been a couple of mm or so condensation on the main bedroom window, which previously would have been full window and dripping. No condensation on any other windows, which would normally be in a similar state.

 

However, although I'm really pleased with the results, I've got to say it is actually making the landing considerably cooler (even 'cold' according to the OH) and therefore kicking off the heating overnight. It's on 3 at the moment and really noticed the condensation building back up when I tried it a 2 for a couple of days.

 

The heating overnight is set a 17 degrees which I think is just about manageable and I keep the thermostat in the bedroom to ensure that. Unfortunately we leave bedroom doors open due to dogs whining and scrabbling at them if they can't get in to cuddle up!

 

I could leave the thermostat downstairs, but in a recent trial one night this allows the PIV to blow cold air in all night upstairs meaning we wake up to about 14 degrees (and this was before the really cold nights we are getting into now)...

 

Reading a bit about it, I see a lot of people turning the heating off overnight and wondering why you would have it on anyway when you're in bed. Although I used to do that so I understand, I'm not sure the OH wouldn't appreciate it as she gets up at 06:00 to walk the dogs and now I think with the heating off overnight the PIV would really just make the upstairs gradually colder and colder.

 

I also had started keeping the heating on overnight due to the cold/damp problems we were experiencing and it did seem to help, but maybe with the PIV now I don't have to worry about that...?

 

What do you all have your heating set to overnight?

[KK20]

we moved our thermostat to the living room and away from the door., it DID used to be on the landing (which was not a good idea). Depending on the layout of your house just keep the doors closed around the vent. we didnt notice a temperature difference in the other rooms only on the landing where the vent was.

[Andrew_C]

What do you all have your heating set to overnight?

Off - MrsC has only just stopped opening a window at night.

 

I'm going to be looking at the location of the sensor over the W/E. It is currently in an unheated room which has the door closed (MissC at Uni).

[jmak]

Well, I finally pulled the trigger on this one about a month ago (just the basic one, loft controls/no heater)... and it works!

 

Even on the couple of minus degree nights we've had recently, there's only been a couple of mm or so condensation on the main bedroom window, which previously would have been full window and dripping. No condensation on any other windows, which would normally be in a similar state.

 

However, although I'm really pleased with the results, I've got to say it is actually making the landing considerably cooler (even 'cold' according to the OH) and therefore kicking off the heating overnight. It's on 3 at the moment and really noticed the condensation building back up when I tried it a 2 for a couple of days.

 

The heating overnight is set a 17 degrees which I think is just about manageable and I keep the thermostat in the bedroom to ensure that. Unfortunately we leave bedroom doors open due to dogs whining and scrabbling at them if they can't get in to cuddle up!

 

I could leave the thermostat downstairs, but in a recent trial one night this allows the PIV to blow cold air in all night upstairs meaning we wake up to about 14 degrees (and this was before the really cold nights we are getting into now)...

 

Reading a bit about it, I see a lot of people turning the heating off overnight and wondering why you would have it on anyway when you're in bed. Although I used to do that so I understand, I'm not sure the OH wouldn't appreciate it as she gets up at 06:00 to walk the dogs and now I think with the heating off overnight the PIV would really just make the upstairs gradually colder and colder.

 

I also had started keeping the heating on overnight due to the cold/damp problems we were experiencing and it did seem to help, but maybe with the PIV now I don't have to worry about that...?

 

What do you all have your heating set to overnight?

16°C overnight 18° daytime. ASHP heating

 

Difficult to prove absolutely, but as far as I could tell, having 2° setback for nighttime uses less electricity than 3° due to the increased energy required to raise the temperature. And that doesn't take account of the cheaper night rate - it might be cheaper to run at a higher temp overnight when electricity is cheaper - but I don't actually want the house any warmer at night.

[nicholab]

I found a PIV helped the house feel warmer. Wall less moisture on them less moisture in the air to heat up. I did have a heated outlet on mine.

[Aprice]

Has anyone fitted one of these to help with condensation in the loft, it's currently pretty much raining inside ours.

 

Wondering if fitting one of these is going to help with stopping that?

[jmak]

I don't think it will help in the loft - as I understand it, the idea is that it brings drier air from the loft into the house. If you have condensation in the loft, you probably need more ventilation in the loft. There are different roof designs - the simplest problem to fix would be that the existing ventilation is blocked. A common cause is that loft insulation has been topped up and is more covering the vents in the eaves.

[Koldov]

I don't think it will help in the loft - as I understand it, the idea is that it brings drier air from the loft into the house. If you have condensation in the loft, you probably need more ventilation in the loft. There are different roof designs - the simplest problem to fix would be that the existing ventilation is blocked. A common cause is that loft insulation has been topped up and is more covering the vents in the eaves.

 

Absolutely this...

 

It 'might' help in that it will help pulling air in from outside increasing air flow in the loft and moving damp air, but if there isn't sufficient ventilation in the eaves of the roof (or tile vents etc.) it won't.

[Andrew_C]

I'm going to be looking at the location of the sensor over the W/E. It is currently in an unheated room which has the door closed (MissC at Uni).

This has stopped the stairwell getting so cold.

[Danp]

I had a PIV fitted in March and not long afterwards it got too warm for it to be on. For the last 6 weeks or so it's been on 24/7 and I can see what a difference it has made. Every morning I was wiping the inside of windows as they all had pools of water on them. Now, nothing.

 

One thing I have noticed is that the cover of the PIV that's in the hall gets condensation on it, which makes sense as the unit is blowing cooler air into a room where it has heat rising against it.

 

Also have issues with condensation in the loft, really need to sort the air flow out up there.

[jinnantonnixx]

Has anyone fitted one of these to help with condensation in the loft, it's currently pretty much raining inside ours.

 

Wondering if fitting one of these is going to help with stopping that?

 

You really want good air flow in the loft.

 

If yours has been 'membraned', you might want to consider gizmos called 'lap vents' which are plastic spacers that open up a channel between membranes. I fitted these in my loft and it's definitely helped with loft condensation I was experiencing. It also helps my PIV to get fresh air.

 

 

Another important consideration with a PIV is making sure you loft hatch is sealed. Otherwise the PIV is pulling air through the loft hatch instead of outside and this will get you nowhere.

[mole]

If you've moisture in the loft there could be warm air getting into it from down in the house then condensing.

[Koldov]

I've recently moved house and unfortunately (for various reasons) decided to leave the PIV behind... I say unfortunately because in the new house I have had to start wiping down windows again every morning!

 

So, I'm on the lookout for another one... as it's a bungalow and options for both suitable location and distance from living areas are limited I'm going to go with the heated version this time.

 

I've looked at the heated version of my previous one and it is the Nuaire Drimaster Dri-Eco-Heat HCS, which seems to retail at roughly £450... however, whilst searching around to get a better price I've also seen a comparable model Vent Axia PureAir PIV Unit with Heater with comes in at £100 less.

 

Both seem to get OK reviews, the main difference being the Nuaire one has controls in the diffuser. Seems like a no-brainer to go for the Vent-Axia one, am I missing something?

 

EDIT: And now I've found a Manrose one for another £50 less than the Vent-Axia, I know we're possibly going down the quality scale here but...

Edited November 26, 2024 by Koldov

[PotNoodleTech]

Just bare in mind a heated version using up to 400w running 24/7 is going to send your leccy bill up 2 - 3 quid a day