PIV questions

[AlanB1976]

Hi all
I have a couple questions if you don't mind. I've read quite a few posts but haven't seen the answers (please point me to one if I missed it that has the answer).

1. Heated version electricity use. I read that using the PIV in winter can cause the house to get cold, specifically where it enters. So I thought the heated version would be best but can anyone tell me if that would result in an increase in cost, taking into consideration that the overall heating should come down due to lower humidity? With energy costs these days it might be that I just have to deal with wiping condensation and tackling mould rather than not eat due to the costs

2. Is there a "best" type brand or type out there. I see a lot go for Nuaire and a couple other makes but I've also read that you should get an intelligent one that shuts off when the humidity/CO2 levels are good, temperature in loft is high, etc. . I didn't see the Nuaire ones saying they did that. They said they had sensors but not that it managed around them. So, is there a better type or brand to get?

Thanks
Alan

 

[pcaouolte]

The heated version will use about 400 watts so cost about 16p per hour to run at todays' electricity prices. However, it will only run at 400 watts when it is cold in the loft, so when the outside temperature is about 6 degrees C or lower.

Most of the time the heater will not be used and the PIV will use about 8 watts so cost about 1p to run for 3 hours.

The Nuaire ones are good quality, I have no experience of other makes. The heater is activated automatically when the loft air is cold and the whole unit shuts down when the loft is very warm to avoid making your house even hotter in the summer. Extra controls are available to measure humidity levels but these add a significant amount to the cost. In my experience no extra controls are needed, just leave the unit on all the time and it will be fine.

 

[pcaouolte]

Just to add, the heater doesn't make the air warm that is coming into your hallway or landing, it just takes the very cold edge off it. You are essentially introducing a mechanically powered draught into your house, the hall/landing will be colder after the PIV is fitted. You are not likely to notice a temperature difference in any other room.

The PIV should do a good job of reducing the humidity in your home. They can certainly help to solve condensation and mould problems.

 

[AlanB1976]

Thanks for the replies. Really appreciate it.

The heated version will use about 400 watts so cost about 16p per hour to run at todays' electricity prices. However, it will only run at 400 watts when it is cold in the loft, so when the outside temperature is about 6 degrees C or lower.

Just a question on what you mentioned above. If it is cold outside (like the cold snap we had before Christmas), will it run at 400w 24 hours a day (costing almost £4 a day)? And if so, is it possible to put a timer on the heater or something similar?

 

[pcaouolte]

It very rarely runs at 400 watts all day. Even in the winter the sun shining on the roof warms up the loft enough to shut off the heater.

You shouldn't have any method of automatic control with a PIV which includes a heater. Switching the unit off and on with a time switch could reset the overheat cut out if it had activated, which could present a safety risk, the instructions specifically say that you should not do this.

 

[Odds]

If your loft is full of dust will the piv unit recycle that through the house?

 

[RandomGrinch]

If your loft is full of dust will the piv unit recycle that through the house?

They have some pretty sizeable filters on them:

...and they don't run like a vacuum cleaner!

 

[Odds]

They have some pretty sizeable filters on them:
View attachment 291715
...and they don't run like a vacuum cleaner!

I asked specifically because i've thought about having one installed to reduce the condensation that accumulates, during winter especially, throughout the house but the loft is a dustbowl full of bunnies and spiders - how often would the filters have to be changed after heavy use, do you think?

 

[pcaouolte]

The filters normally need replacing every 5 years. It is possible to clean them up a bit using a vacuum cleaner or an air line if your loft is unusually dusty.

 

[Johnytuono]

Hi all
I have a couple questions if you don't mind. I've read quite a few posts but haven't seen the answers (please point me to one if I missed it that has the answer).

1. Heated version electricity use. I read that using the PIV in winter can cause the house to get cold, specifically where it enters. So I thought the heated version would be best but can anyone tell me if that would result in an increase in cost, taking into consideration that the overall heating should come down due to lower humidity? With energy costs these days it might be that I just have to deal with wiping condensation and tackling mould rather than not eat due to the costs

2. Is there a "best" type brand or type out there. I see a lot go for Nuaire and a couple other makes but I've also read that you should get an intelligent one that shuts off when the humidity/CO2 levels are good, temperature in loft is high, etc. . I didn't see the Nuaire ones saying they did that. They said they had sensors but not that it managed around them. So, is there a better type or brand to get?

Thanks
Alan

We have the heated version of the Nuaire. We live in a 3 bedroom terraced house with a fairly low landing ceiling where the PIV is situated. We have had the unit on speed 4 since installation BUT I turned off the heater (as I believe it doesn't do THAT much anyway) but I didn't tell my wife and she (we in fact) have learned to live with it. Yes you can feel a slight breeze (it is on 4 mind you) when going to the loo in the middle of the night but the advantages of the unit have been great. We regularly had RH at 74% downstairs and that's with not drying clothes on the rads etc but now, after 5 weeks, the RH as I type is 55% with a room temp of 18c, yes 18c definitely feels warmer with drier air ( we do bump the temp up to 19c in the evenings though), outside temps have been -1 to -6 here. It circulates all the heat that is higher up, in fact downstairs just went to just below 16c overnight the other day, and this is in an old victorian terraced house ! I don't think that's bad. I'm thinking of turning the speed down to 3 as we don't want too dry humidity. I wish we'd got one years ago ! Also, we used to have condensation on our bedroom window after the night activities (breathing ! cheeky ) especially with the window closed, now, nothing not even in the freezing weather. The only place we get about 1cm of condensation is the far window of the kitchen (about 17ft away) but it's usually far, far worse than that ( I also put it down to us always brewing up and the steam hitting it).
Hope this helps.
Edited to add :
Yes, the landing IS cooler but we can't feel it in any other room even with undercut doors (either that or leave them ajar)
At first I thought it wasn't doing anything, then I noticed that slowly the RH levels were coming down after about 3 weeks.
IMO it's nice to have the heated option as you can't retrofit the heater but tbh I don't think it's needed, a lot is in the mind.