Basement Ventilation

RayEdison

Hi,

I was wondering if anyone had experience of ventilating a basement.

The basement is done up - combined living/kitchen area, bedroom and bathroom (both with doors).

There's no ventilation at present. No air bricks or trickle vents. Running a dehumidifier to keep the humidity level down.

I've looked at positive input ventilation. Envirovent and Nuaire do wall mounted units. I'd go for one of them but the dimensions of the units don't easily fit where they would need to go.

I've also come across the Elta Mori HR fan. Similar principle but on a smaller scale (would fit much better where I need it). It alternates between extracting air and supplying air. The heat from the extracted air is saved and used to heat the supplied air from outside.

My initial thoughts were that the Elta fan wouldn't shift as much air as the PIV unit but looking in more detail at the performance figures they're not too different.

On the highest setting the Mori HR 150 fan is able to attain an airflow of 17 Litres per second. The envirovent wall mounted PIV unit can get up to 19 Litres of airflow per second on its highest setting (+ a bit more if using the temporary boost setting but I'm ignoring this for comparison purposes).

I don't know how much difference 2L/s would make but I would consider 2 fans spaced apart in the open plan kitchen/living space if required.

I've found it very difficult to find any significant reviews of PIV units/basement ventilation etc so just wondered what others here thought about the above.

coffeehound

RayEdison wrote: »

I've found it very difficult to find any significant reviews of PIV units/basement ventilation etc so just wondered what others here thought about the above.

The thing with PIV is that it does not provide any way for air to exit the living space and so it relies on there being existing routes for the stale air to exit the rooms.

In the case of a basement there may be no provision at all for air to exit. However, if there is an existing extractor fan in the bathroom, then the PIV will help it to do its job.

The MHRV system on the other hand contains both the inlet and outlet for air movement and so is better suited to a basement that has no other ventilation provision.

Fire_Fox

I have a middle floor leasehold flat that is so 'landlocked' it has some similarities to a basement flat (eg. no cross ventilation). I open windows to let condensation out and diesel fumes in! So I have been geeking out on my options.

Some questions ...
Are you referring to a leasehold flat? When the kitchen and bathrooms were done done why no extractor fans? How far is it from the possible site(s) for a PIV or MHVR unit?

RayEdison

That’s a very good point about air not being extracted with a PIV unit alone.

I was thinking the stale air would find its way out through gaps but this is realistically just going to go up through the gaps around the ceiling spot lights and up through the ground floor flooring!

The MHRV unit does make more sense therefore.

I’ve had a decent envirovent humidity controlled extractor fan put into the basement bathroom. This replaced a very cheap looking fan.

Even with this I don’t think it’d work with the PIV as the bathroom door is usually kept shut to prevent too much condensation and moist air leaking out into the rest of the basement.

RayEdison

Fire Fox:

It’s the basement in the house I own. Mainly used as guest accommodation. Basement conversion happened before I bought it. Bathroom had a cheapish extractor fan. Kitchen/living area is almost ground level (has double glazed windows looking out) but the house is built on a bit of an incline so the back of the basement is totally underground.

The kitchen has an extractor good but not ducted outside. Just filters the fumes.

There’s only one aspect of the basement which faces an external wall. Terraced property so can’t ventilate off to the sides. It’s here that I’d sit the unit. The dimensions of the PIV units I’ve found are too bulky to sit comfortably against the walll and the distance might be too great for the ducting (internal to external wall) based on the installation manuals I’ve read.

The unit would push air into the open kitchen/living area and hopefully circulate it into the bedroom which isn’t too far. I might need two MHRV units but could start with one. They’re about £265 each without installation!

RayEdison

Forgot to mention - it’s freehold