The Big Fan

One risk is that the fan motor gets hot, and even the cable and plug get hot.

That was a big benefit of putting it outside - it is cooler, and not filling the room with the smell of hot dust.

I have slight worries that the fan may be developing a problem. Heat will accelerate that.

Other Issues

One side of the main entrance to the hall is often bolted.
3 out of 4 ceiling fans don't work
Often badminton or yoga (?) equipment is left in the passage
cars tend to park in the bike-rack !
the wall-lights don't work (bulbs?)
hand-driers in the loos don't work
urinal either leaks or doesn't flush
etc ...

Resolution ?

I think we should also try to get back to the mutual understanding with Trilogy that we used to have with William, to have the fan back outside the Exit. It is the most effective and safest place.

I have also asked if Trilogy would invest in Air-Conditioning - pricey, but no harm in asking ! It would be the ideal solution.

We should question whether they are following good advice : even though I don't think I've suggested to them the 'Man from the Council' is an impostor, Charlotte said Hayley was present with him and William, and that he was 'a proper inspector'. She may not remember what William told me he said : the fan should be in the inner end of the passage, and Ceroc Weekenders fans blow onto the dancefloor.

One way to investigate that would be to contact the Council, saying that Cripps is under new management, and would like copies of any reports from the last year or two, relating to site visits.

I believe Ceroc could request that, under the Freedom of Information Act, although that formal route has costs and delays.

However, it may not be desirable for either Ceroc or Cripps/Trilogy to ask the Council about the past - they may decide to do a thorough inspection in the future.

We could also request an ruling on the situation with the fan. The Fire Brigade may be more pragmatic than the council.

Current holding position

To maintain our working relationship, I shall comply with Cripps' demands.

I have protested that they are unreasonable in restricting us beyond what actual practical safety demands, to comply with what they perceive as 'The Rules'.

I have also suggested that they have been hampered by bad, impractical advice.
One of the dancers, who holds some responsibility for fire safety in a school says you only need a metre's clear space for a fire exit.
William said that the man that visited, supposedly from the Council, said the fan should be in the passageway - William and I agreed that it was better outside.

If we run the fan inside the cupboard, pointing in the general direction of the Fire Exit, it is about half as effective. We may be able to make do with this, if the heating is disabled completely.

There may be many small 'tweaks' that will help a little - the 'Accumulation of Marginal Gains' approach.

We may have to try an experiment (one night only) with the fan on the dancefloor, or the stage, just to convince the dancers that will only heat the hall up.

I think we should also try to get back to the mutual understanding with Trilogy that we used to have with William, to have the fan back outside the Exit.

Heating

The hall is heated by 'radiators' embedded in the walls, with fans to blow air over them.

Initially I was told they were part of a central heating system for the whole hospital site, and so Cripps had no independent control. I presumed the radiators were iron pipes with hot water flowing through them. Andy (Salsa) tells me they are electric storage heaters, and there is a switch for each of them, hidden inside a small hinged panel beside each of them. I do not know if the system has been changed, or I was just being fobbed-off through ignorance.

Strictly they will not really be 'radiating' much, except to make the walls warm. They will heat the air by direct contact as it blows over the pipes filled with hot water.

There are switches to turn the fans 'Off - Low - High'.

Even with the fans off, air within the 'radiator' will be heated and rise, so that it will flow in through the lower grille and the out through the upper grille, simply because hot air rises. (Thermal convection)

One of the Cripps staff has also turned the heaters off or on last year. I thought it was Hayley, but she may not remember it.

Experimentation

For a few months in 2012 (?), I brought two digital thermometers and a data-logger each week.
I will still have them somewhere, but they are not easily accessible or findable.

My main finding is that there is no way to make the room cooler, once it is full of dancers.
All we can do is minimise the rate at which it heats up !

This means that any unsuccessful experimentation during the evening means that the final temperature will be higher.

The most useful thing we can do is to start the evening with the room as cool as possible, by turning the heating off (!), opening the exits and using the fans to blow air in one side and out the other. This can bring the hall down close to the outdoor temperature.

Humidity

Air temperature is only one factor in human comfort : humidity is also important.

We cool by perspiration - the body produces water as sweat, which evaporates from the surface of the skin, or from clothes. When the water changes from a liquid to a gas or vapour, it absorbs a lot of energy, cooling the surface.

If there is no fan blowing hot air from indoors to outside, then not only will heat build up, but the humidity will, too. If the air is more humid, more sweat will dribble off the skin instead of evaporating. This removes much less heat from the body.

The worst case you may have experienced is in a 'sauna'. If you pour water on the hot rocks, it instantly increases the humidity so that you suddenly feel much hotter, even though the temperature changes little. The high humidity removes the body's ability to cool itself.

Another situation is at weekenders : sometimes we use 'evaporative coolers'. They blow air over a wet surface, which cools itself by evaporation. In an empty shop, where people are just sitting or walking around, without having to sweat, this can feel cooler. But when people are exercising so they have to sweat to cool down, you have already used the dry air's capacity to cool by evaporation to cool the air down : sweating will no longer have much effect in cooling the body down. The air is already nearly saturated with humidity.

The Big Fan in the Cupboard

Following the letter of the rules, the only remaining place for the fan is in the cupboard.

We could put the fan on the dancefloor, well away from the exits, but it would take up space, blow things around and make the hall heat up. Legal, but not useful.

By pointing the fan to blow out into the passage, at the piano, then angling it North towards the Fire Exit, we can get about half of the airflow of the best position. This might just be enough to survive, but with less comfort.

Other Standards

It would be unfair of Cripps to hold Ceroc to a stricter standard than other users, or their own staff.

Usually when we arrive, only one of the main entrance doors (which has an 'Exit' sign) is open. When they unlock one door, they do not unbolt the other. I suspect there should not even be a bolt on a Fire Exit door.

Often there are boxes of Yoga (Zumba ?) mats in the passageway, or the supports for Badminton nets.

On the 9th June, there was a stack of chairs in front of the Exit. When a member of staff had wheeled them away, he left the trolley in the passage.

Historically, burglars broke in through one Fire Exit, damaging it to such an extent that it was screwed shut for a month.

After that, Cripps put padlocks and chains through the door-handles. Sometimes they were still locked when we arrived. Once they could not find the key, so William and I spent 20 minutes sawing through the chain, during the lesson.

The Visit

A week after 'The Argument', William, then the Cripps Manager, approached me and said that a man from the council had said he was responding to a complaint, and had come out to inspect the site.

Or maybe Hayley told us that week, and I discussed it with William the next week - I forget.

The man had said
it ought to be at the inner end of the passage, blowing inwards 
(where it used to be before I found it wasn't cooling the room).

He also said that
Ceroc 'Escape' Weekenders, where an entire Pontins Holiday camp is taken over for a whole weekend of dancing used the big fans like that - blowing onto the dance floor.
I pointed out to William how the fan was on wheels, so that it would pivot out of the way with a simple push, and was no more of an obstruction at one end of the passage than it was at the other.

He agreed that what I do was as good or better than what the man suggested, and I have continued on that understanding.

I said it was odd that the man would specify the direction of airflow, and that he knew so much about national Ceroc events.

It wasn't until June 2015 that I thought about it again, with new management. I approached the Assistant Managers to discuss the use of the big fan, confident that we could come to the same understanding.

It has been suggested that that was a mistake, but the bar staff stand there all night, looking directly at the big fan in the exit, so we couldn't exactly keep it a secret.

The Assistant Mangers would not exercise any discretion, and not allow anything in or near the Fire exit routes.

Thinking again about the visit, it struck me how extraordinarily well the guy that complained had briefed the guy from the Council and how exactly their suggestions agreed, although offering no real improvement - almost as though they were clones.

Then it struck me that they might actually be the same person. The complaining dancer is into dressing-up, even as a 'female impersonator'. It would not be out of character for him to impersonate a Council Inspector. Extraordinary lengths to go to try to win an argument, though !

We could contact the Council and request a copy of the visit report. I suspect they will respond 'What visit?'

Of course it may not be good for either Ceroc or Trilogy to ask the Council if Cripps has been inspected.

The Argument

One week, I think it was in late September, one of the dancers said that it was unacceptable to have the fan outside the fire exit. I showed him how it pivoted out of the way with a simple push, but he insisted that it ought to be at the inner end of the passage, blowing inwards (where it used to be before I found it wasn't cooling the room).

See History.

He said he would report us to the Council, and then we would see.

The Big Fan Outside on the Fire Exit

Given problems with the fan being turned round by other people, and concerns with it sitting in the passage to the Fire Exit, I decided to move it along the passage and out onto the iron Fire Escape platform.

To go down the outside stairs, you would turn left outside the Fire Exit. To the right is a bit of unused space, which is large enough to contain the fan, with no obstruction to people using the fire exit.

Since the fan has wheels, it can be moved aside as easily as pushing a door.

Since the fan has fixed wheels at the right end, and castors at the left end, it naturally pivots out of the way with a simple push.

I can use the security cable, round the railings to the right to help the pivoting action, and make it impossible for the fan to move towards the stairs. It also makes it impossible for other people to turn the fan the wrong way round during the evening.

The fan could benefit from a slightly longer and thicker flex, and the fan is not rated for outdoor use. The hottest weather is rain-free, so we can consult weather forecasts, and only use the fan outside in dry weather. A roof could easily be constructed over the fire-exit, or a mini-roof over the electrical parts.


The Four Extractor Fans in the High Ceiling

Although there are four fans set in square 'chimneys' in the high ceiling, only the one at the back of the hall really works.


The 'Vent-Axia' Extractor Fan in the 'Pantry'

At the back of the hall is a small side-room, used for serving food , which has a small fan mounted in a hole in the wall.

If we are only using the small fans, then the  'Vent-Axia' extractor fan in the 'Pantry' can be switched on, to help remove warm air. Turn the knob to 'III' or '3 O'Clock'.

If the large fan is sucking air out of the hall, then it would be a bad idea to try to compete with it by switching this small, weak fan on - better to leave it off, and it will 'windmill' or 'freewheel' backwards, allowing cool air to enter.

The Smaller Fans

When it was first suggested that the big fan was in the way and too noisy, I did try just to use four smaller fans.

It was just about possible to limit the temperature to a reasonable level in Spring or Autumn, but not in mid-summer.

With a fan near one fire-exit blowing cool air in, and one the other side, blowing hot air out, there was enough airflow to replace the air in the room; maybe every five minutes.

However, every 40 minutes, some helpful person would think 'that fan is the wrong way round' and turn it round, cancelling the airflow.

Even with the big fan on the corner of the dancefloor, people would often turn it round, and it became a constant struggle to keep air flowing in and out of the room.

Now we only have three smaller fans, instead of four, it will not work as well.
I used to put one fan at each end of the passage ; one blowing onto the dancefloor from the corner for people to stand in front of ; the other blowing out of the fire exit to cool the hall down.

Of course, the latter fan position would now be unacceptable, so a fourth fan would have to be put in the cupboard, facing out. Its jet of air probably would not be powerful enough to reach the fire exit.

Conflict Between the Individual and the Group

People who want to cool down will stand in front of a fan, so that the maximum airflow streams past them.

Most people think of themselves much more than of other people.
This results in a conflict between individuals that want to "Cool me!", and organisers who want to "Cool us!". It's not the same problem at all.

Energy is neither created nor destroyed, so when someone is rapidly cooling themself in front of a fan, we should consider where that heat goes.
If the fan is blowing into the room, that heat will be added to the heat already in the room.
If the fan is blowing out of the room, the heat will go outside, instead.

We advertise it as a night of dancing, not a night of standing around in front of fans trying to cool down.

If we can successfully keep the whole room cool, then the individuals won't need to cool down.
If the individuals need to cool down, then they will not be dancing, so we will have failed already.

Of course, there may be non-dancing spectators, those with a 'socialising' agenda, and the person sitting at the (draughty) door to take in money etc.
They might not appreciate the same degree of cooling as the dancers, but it will be difficult to create a separate, different micro-climate for them, so they may have to 'dress warmer'.

Direction - blowing in, or out ?

Initially, the big fan was aimed into the room, blowing at the dancers directly.

However, I found that the room would just get hotter and sweatier - the fan was just moving the air around within the room.

If you stand in a doorway and move a hand gently inwards and outwards, with fingers spread, you can feel airflow in or out, and even get an impression of the speed of airflow, since cooling of the hand will be minimum when the speed and direction of the hand equals that of the air.

With no fan, I found that the air was almost always blown from South-East to North-West, or stage-left to stage-right (teacher's point-of-view), due to the UK prevailing South to South-West winds, and the shape of the buildings..

With the fan stage-right and blowing in, I found that very little air was coming in or going out of either fire-exit.

This can be understood because the outside wind was blowing air one way, but the fan was blowing the air the other way. The two tend to cancel out.

When I turned the fan round to blow outwards, away from the dancers, it helps the natural wind-blown airflow, so a really good airflow results, changing the air in the room every minute or so, preventing heat from building up.

We could put the fan the other side of the stage, where the wind is blowing inwards, so that a fan blowing inwards also assists the airflow instead of cancelling it. However, on that side, the cupboard is between the passage and the external wall, rather than between the passage and the stage. This means that the steps up to the stage are more accessible, so this side is used for teacher and DJ access. If we had a fan in the way, it would be very inconvenient. The DJ also usually stands this side of the stage, so being close to the fan would make it hard for him to hear the music !

Noise

I suspect the fan sends more noise 'downstream' than 'upstream'.

Dust

Cripps can be a dusty venue : it is better to blow dust and grit outside, rather than towards the dancers.

Airspeed

The airspeed downstream from the fan will be much higher than upstream, since the air output from the fan is a narrow unidirectional jet, not much wider than the fan itself, whereas the air is sucked into the fan from all directions on the intake side : a much larger area than the fan itself.

So you get a gentler drift of the air towards the intake, rather than a violent jet of air on the 'out' side.
This means that plastic cups, leaflets, hair-styles etc will be affected less by the airflow.

Waste Heat

The fan motor and even the mains cable and 13-Amp plug get quite hot. Probably more of the electricity is converted to heat than to airflow - the fan is probably less than 50% efficient.
It is much better to blow that heat outside, rather than inside : we are trying to cool the room !
To put that in context, a 3000W fan maybe generates 2000W of heat, which is equivalent to the heat given off by about another 10 dancing bodies.

Humidity

If air is not flowing in and out of the hall, sweaty bodies cause a steadily increasing humidity which gets unpleasant.

History

We used to have the fan near the piano, blowing inwards.
It was right next to the door so that, in an emergency, it could be pushed aside into the cupboard.

It was not an ideal position - you would have to stop moving forwards to push it sideways, and there was a risk of it being pushed away from the cupboard door with the flow, instead of through the door, to the right, out of the way.