For students only!

[Agile]

A pat on the back for the first correct answer!

Senario:-

A church with a 200 kw boiler.

Heating is turned on at 5 pm for the evening service.

When heating is switched on the temperature in the church is 10*C.

After the heating has been on for one hour the temperature has FALLEN to 8*C.

Why ?

Tony

 

[breezer]

because the parishoners have to open the door to get in, so the hot air gets out?

 

[ChrisR]

The radiators(?) introduce convection which increases the temperature stratification in the church. The upper parts warm up, but cooler air lurks at floor level.
With the air moving, there would be a small wind-chill effect.
So it depends where you put your thermometer.

 

[oilman]

...........
With the air moving, there would be a small wind-chill effect.
....................

Wind chill only applies to self heating objects that have to maintain a set temperature, it does not apply to inanimate objects like thermometers. It does not change the temperature, it just feels colder if you put your head out of a train window.

 

[htgeng]

A pat on the back for the first correct answer!

Senario:-

A church with a 200 kw boiler.

Heating is turned on at 5 pm for the evening service.

When heating is switched on the temperature in the church is 10*C.

After the heating has been on for one hour the temperature has FALLEN to 8*C.

Why ?

Tony

I would have thought infra-red heaters would be more suited to heating a church. They would be cheaper to run than a 200kw boiler too.

 

[ChrisR]

Wind chill only applies to self heating objects that have to maintain a set temperature, it does not apply to inanimate objects like thermometers. It does not change the temperature, it just feels colder if you put your head out of a train window.

That's what I thought, but no it doesn't! Will find you a quote later. Dampness in the air is important. Wrap your thermometer in a damp rag and stick it out of the train window, sort of thing.
IOW wind chill is a combination effect depending on..... .. .. .

 

[oilman]

Wind chill only applies to self heating objects that have to maintain a set temperature, it does not apply to inanimate objects like thermometers. It does not change the temperature, it just feels colder if you put your head out of a train window.

That's what I thought, but no it doesn't! Will find you a quote later. Dampness in the air is important. Wrap your thermometer in a damp rag and stick it out of the train window, sort of thing.
IOW wind chill is a combination effect depending on..... .. .. .

Fair enough, but in the case of normal temperature measurements the thermometer would be dry, so nothing to evaporate.

 

[meldrew's_mate]

How about it's a warm air unit and the fan has gone U/S, the boiler's hot but the heat's going nowhere?

My next guess is it's a Saunier Duval.

Any clues Tony, like "nothing's broken" or "all major components are OK and the pilot's lit!"

I love a whodunnit

 

[outinthestix]

Probably wide of the mark but if the heat can escape anywhere from the roof space, cold air may be drawn in through floor vents or somewhere at floor level.

 

[ACOperson]

Thermal inversion?

Is it a warm air unit?

 

[kaboom]

200kw natural draught using so much air that its pulling the cold in through the ventilation?

 

[Agile]

I did not realise that so many of the people posting here classed themselves as students. theres not one I would have thought of as a student.

I am amused by the thought of a Sonya Duval 200 kW boiler!!! Would sure cause a big floood when it leaks.

Its a warm air unit. Built in 1905 for coke! Now fired by an electro oil gas burner.

The answer is quite simple and was guessed by the volunteer admin lady at the church! I thought a student would have guessed it!

Tony

 

[ChrisR]

Fair enough, but in the case of normal temperature measurements the thermometer would be dry, so nothing to evaporate.

It's the AIR that provdes the water, that's just the point.

I did not realise that so many of the people posting here classed themselves as students.

that's because we're all still learning

The answer is quite simple and was guessed by the volunteer admin lady at the church! I thought a student would have guessed it!

Who says she's right? All the answers above say much the same thing - so if she or you think differently then you never know, you both might be wrong!

 

[oilman]

In that case, it's likely that the fans had started but the burner did not ignite. Try putting some money in the gas meter.

 

[ChrisR]

Try putting some money in the gas meter.

Aha! They can't, the collection doesn't happen until they're all singing.