Hiyer, today I'm just going to show you, what we call a test rig it just shows you how a
fan can perform with a bit of resistance. So when you fit a fan any ducting, bends,
flexible ducting and grills will all add resistance. Flexible ducting is the worse because it's
highly resistive. But this is just showing you maybe a length of rigid ducting and a
90 degree bend and then some resistance that might be from a grill, so this could be a
ceiling mounted fan with a 90 degree bend on the back and then going to outside or it
could be sort of through the wall with a bit ducting on it and then a grill. I'm just going
to show you first our Silent 100 fan, so this is the EnviroVent Silent 100 a standard axial
fan, but you'll see if I put the fan on the rig here so what'll happen is, it will actually
push the globe up showing you the fan copes quite easily with that resistance so it's
drawing the air in and pushing it all the way up. So it's showing you how strong the
fan is and how it will cope with that little bit of extra resistance that you may get from
the installation. If I take the fan off, the globe drops back down so it's a nice simple,
simple effect showing you how the fan can perform. One of the other fans I've got here,
again this is our EnviroVent 100 but this is what we call the Design it's got this nice
front cover on now what I'm about to show you here, isn't showing you the fan is not
very powerful, it's showing you just how this grill can affect the performance of the fan,
so this fan is ideally only suited to go through straight through a wall if you start ceiling
mounting it, although it could be ceiling mounted it is IPX rated there's no issues
with that you are going to reduce the performance of the fan and just by having this front cover
on you'll see just by having that on, it doesn't move the globe. But if I just gently move
that away the globe moves, just showing you that if you've got a fan that's on a ducted
system although it looks nice it's not coping with that extra resistance. So this fan wants
to be mounted straight through a wall or on a short length of ducting - maybe a metre
of rigid ducting something like that. If you start installing it into a complicated system
or a lot of flexible duct it's not going to cope with it you need to go to the other fan.
So although it's a nice looking fan it's got the nice stripe on there, lovely front cover
straight through a wall - yes any other way then you know maybe just double check with
ourselves to make sure it would be suitable. What I'm also going to show you now - just
as i've got them here i've got another fan here, the first thing you notice here, this
is a one of your lower-end fans sort of something you maybe get as a budget fan what we call
it, it's not one of ours so hence I've just tapped it up so you can't see the manufacturer
but the first thing you'll notice there's a lot of noise coming from the fan. So it's
quite a noisy fan but also just by putting it on the back of there it's not coping with
that resistance, so straight away it's not doing anything with the fan and just to show
you I can put our Silent 100 back on and the globe will lift up, so although the fan you
know I'm not saying that the fan is no good again it's probably only ideal straight through
a wall if you're putting it on a complicated system or any length of ducting with a bend,
this fan is going to be no good. I'm also just going to show you one more fan,
I'll just turn that one off, got one more here so again this fan little bit bigger,
little bit wider but again you'll see with this fan it just can't cope with that resistance
on the system so what you've got here because the ball is not moving up the air is actually
coming back out of the fan, so if you get any fans were the air is coming back out it's
not generally the fan you can't wire it up the wrong way so the motor spins the other
way - most of these fans will have an AC motor some will have an EC motor on them or they
may have a DC but if you wire it the wrong way the motor isn't going to spin the other
way the air is coming back out because it can't push it through the system. So it's
coming back out so your not going to get rid of that moisture so it's quite important that
you get a nice, good, powerful fan that'll cope with the system you've got i.e. if you've
got a long length of ducting maybe two metres of flexible ducting anything like that you
need a powerful fan that will cope with it. That's sort of it on the fans, i've got one
more I'm just going to show you - now this is a slightly different fan this is what we
call our ECO DMEV, this is a continuous running fan so it's designed to run all the time,
just bear with me a second while I turn that fan off. Just so you can hear me, so this
is continuous running, now it's designed to run at a low rate all the time and would come
under system 3 of the building regs and it'll go to a higher rate when required. Although
it's running all the time it's very energy efficient, doesn't cost a lot to run and it
is actually better for ventilation at being a continuous system but as I say what I'm
going to do, I'm going to put this on there and what you'll see with this fan although
it's running at a low rate, it's quite an intelligent fan - it's what we call a constant
volume fan so it's detected that resistance on the system and it's automatically speeding
itself up to cope with that. Which is a really good feature because if you've got wind blowing
back down or the ducting is quite a complicated system this fan is still going to achieve
the airflow it needs to do to meet building regulations rather than without the constant
volume technology you may reduce the airflow it's not going to meet regulations or it might
not cope with that resistance , so it's going to do that and I can take it back off and
it'll drop back down again and what I can do the fan is quiet but I do have a button
here, I can boost it up to it's higher rate it's still coping with that resistance on
the system and again I just take it off there - it's really good. That's it really, just
showing you our test rig, again we have other fans we can test on there but it's a really
good simple way of just testing the performance of a fan and how it copes with that resistance
- that's it from me hopefully i'll see you soon.