VMCs and heat extraction

[Théière]

I thought the motors would be ex Garrad sp25 record players [:)]

[quote user="Chancer"]

Where do you get the humidity meters from?

[/quote]

[quote user="davidb5964"]Just looked on that well known auction site and plenty to choose from .[/quote]

True, or TLC/ QVS even Toolstation used to have some in the UK

[Gluestick]

This is a mounting problem, thanks to energy conservation, double-glazed windows and serious insulation.

Older houses of course enjoyed open fires, where the chimney draught automatically drew air into the building.

Condensation is another reality of the modern house design problems. People shed moisture: their activities (Cooking, heating water, washing, showering, bathing et al) all create atmospheric humidity.

Venture into an intensive pig fattening unit and one can see. I love pork, ham, bacon and bangers, however having seen them on a project many years ago, I couldn't countenance anything porky for some years.........[:(]

The upper end "Whole of House" ventilation systems both extract excess humidity and recover heat: some good info too on this site.

E.G

Not cheap however: but then again that which actually works properly, never is!

Core problem is heat rises (natural thermocycle): and most ventilating fans are sited high up! Thus they are extracting moisture-rich air; fair enough.

However in so doing they are also extracting heat: therefore ambient room temperature drops and hits the Dew Point: result, more condensation, not less!

Rising and Penetrating damp is a whole other issue!

Best bet is a de-humidifier: or tanking.

Chancer:

Here is a good description of motor caps and how and why a two speed induction motor utilises two separate Cs.

See Here:

(N.B. Scroll circa 2/3rds down the page.)

[mogs]

I'm a bit concerned with reading this thread.

We have a new build (2011) with a VMC system but even on a low setting I find it too noisy to sleep without wearing earplugs! So consequently it's hardly used.

We do open windows when weather is good. Would it be beneficial to run the VMC during the day when it won't disturb sleep?

[Chancer]

Thanks for the link Gluestick but it was a bit above my head, mm, that should read went over my head perhaps?

Anyway i wasnt sure which one related to a VMC motor, I have always been an experimental type, playing around with things to see how they work, how to change their operation etc since I was able to walk, the VMC's were no different but it would be nice to know the science.

Heres a challenge for you, I have a Fobco pillar drill here in France I bought 30+ years ago and a Meddings Drilltru in the UK I have had for close to 20 years, both of them had the wiring ripped out, they both have switches to reverse the motor direction, both motors (brook Crompton induction) have 4 terminals with a pair of brass bus bars that could bridge any pair of terminals, I have never ever worked out how to get them to reverse which would be very usefull when tapping or drilling out broken studs with left handed drill bits.

Can you find me a diagram of how to do it, 30 years is a long time to be bugged by impotence [:(]

[Gluestick]

[quote user="Chancer"]

Thanks for the link Gluestick but it was a bit above my head, mm, that should read went over my head perhaps?

Anyway i wasnt sure which one related to a VMC motor, I have always been an experimental type, playing around with things to see how they work, how to change their operation etc since I was able to walk, the VMC's were no different but it would be nice to know the science.

Heres a challenge for you, I have a Fobco pillar drill here in France I bought 30+ years ago and a Meddings Drilltru in the UK I have had for close to 20 years, both of them had the wiring ripped out, they both have switches to reverse the motor direction, both motors (brook Crompton induction) have 4 terminals with a pair of brass bus bars that could bridge any pair of terminals, I have never ever worked out how to get them to reverse which would be very usefull when tapping or drilling out broken studs with left handed drill bits.

Can you find me a diagram of how to do it, 30 years is a long time to be bugged by impotence [:(]

[/quote]

HVAC (Heating Ventilation Air Conditioning) is the big thing these days.

Sick Building Syndrome caused umpteen problems. A modern office building needs to conserve energy, but maintain temperature and humidity  within certain tight limits. Trouble is 5,000 peeps crammed together give off a large amount of heat and moisture!

Add 5,000 PCs, servers, laptops, chargers, laser printers and photocopiers and repographic machines all pumping out Ozone and heat........

All new forced ventilation systems really need heat exchangers and humidity regulation: since they are extracting stale air and introducing fresh air from outside.

Pillar Drills: OK. I presume both older electric motors are capacitor start using a centrifugal switch? Most did, then. Capacitor Start-Capacitor Run was not common for fractional HP electric motors.

The reversing switches would probably be "Drum Switches", not "Tumbler Switches"?

The usual way to reverse rotation with induction motors is to re-wire the start windings, internally. When you have a moment, remove the covers from the small wiring box and tell me the number of wires and the terminal nomenclature. Or numbers/symbols if you like!

By swopping over the start winding connection, the motor starts its rotation in the opposite direction.

Pics of wires and terminal and inside of cover would be helpful!

Cheers.