A short history of air conditioning https://www.youtube.com/watch?v=wD7vSnISp3g
Harry On Thu, Jul 28, 2016 at 3:54 PM, David L. Babcock <[email protected]> wrote: > My comment below is so clouded by time that it may be worthless, BUT > > When air conditioning arrived (in the 30s, 40s?) it was a trade-marked > innovation, driving all the competition under because it *conditioned* > the air, not just chilled it. It combined air cooling with dehumidifying, > with greater comfort the result. If some current air conditioners don't > dehumidify enough, well, poo on them... The trade mark got broken by > indiscriminant usage, I suppose. > > Ol' Bab, who was an engineer. > > On 7/27/2016 2:08 PM, Stephen A. Lawrence wrote: > > I'd have to guess you live in an area that isn't very humid. Otherwise you > wouldn't have to ask. :-) > > First, the books on the bookcases in the livingroom stop growing mold on > their spines if you drop the humidity. (Otherwise, here in the Ottawa > River Valley, they sure do, just sitting there during the summer.) > > Second, you stop feeling constantly sticky. > > Third, if you're hot (like, you exercise or something) instead of just > getting soaked with sweat which refuses to evaporate, you actually cool off > a bit. > > An aside: Many years ago, back in college, I repainted apartments as a > summer job. With the air conditioner running, the paint wouldn't dry (or > wouldn't dry before we left, anyway). To get it to dry fast enough to > allow us to do touchups and whatnot before we left, we consistently had to > shut the AC off. (So much for an AC drying things out.) Which leads to > our next point: > > Used in conjunction with a conventional airconditioner a dehumidifier can > make things "feel" much more pleasant. Make no mistake -- conventional air > conditioners reduce the *absolute* humidity substantially but their impact > on the *relative* humidity (which is what makes everything feel sticky) is > considerably smaller, as they reduce the temperature of the air at the same > time they remove moisture from it. Their impact on the *relative* humidity > is only as large as the difference between the internal temperature of the > air (as it comes off the evaporator coils) and the final temperature of the > air in the room (after it mixes with uncooled air). > > Some air conditioners may not cool the air significantly below the target > temperature, in which case the relative humidity may actually be raised as > a result of their operation. > > Dehumidifiers, OTOH, are designed to have a large temperature drop at the > evaporator before the air is warmed again by the condenser, and they always > reduce the relative humidity. > > > On 07/24/2016 01:59 PM, David Jonsson wrote: > > Hi > > How does dehumidifiers like this one work? > > http://www.conrad.com/ce/en/product/1377991/Dehumidifier-20-m-0011-lh-White-Blue-renkforce-HD-68W > > I assume that my personal experience of room temperature will decrease if > I run one (provided I have sufficiently high humidity). But I also realize > that the temperature of the air rises after being dehumidified. What is the > net subjective human effect? > > David > > > > > > > <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient&utm_term=icon> > Virus-free. > www.avast.com > <https://www.avast.com/sig-email?utm_medium=email&utm_source=link&utm_campaign=sig-email&utm_content=emailclient&utm_term=link> >
