Re: Window units vs. Central
Dave, in the late '40s and early '50s, I had an old army cot; not sure just where it came from, but I'd put it out in the backyard and sleep outside a lot in the hot summer time. And I sometimes helped my younger sisters move their standard double bed out in the yard to get out of that hot house.
Re: Window units vs. Central
Egon, Water with dissolved solids (minerals) sure would coat the condenser and reduce its functionality.
Condensate is essentially distilled water which is why it is OK to put through the condenser as I mentioned to Bird. If you had mineral free water available spraying it on the condenser would be OK. Just using typical tap water is NOT GOOD.
Pat
Re: Window units vs. Central
Pat:
The condensate starts out fine but due to particulate matter in the airflow things may change. [img]/forums/images/icons/grin.gif[/img] Chances are the condensate may also have sub 7.0 PH levels but this will depend on your geographic location. [img]/forums/images/icons/grin.gif[/img]
Egon [img]/forums/images/icons/grin.gif[/img]
Egon [img]/forums/images/icons/grin.gif[/img]
Re: Window units vs. Central
[img]/forums/images/icons/tongue.gif[/img] As kids we used to play in the upper deck screened in "sleeping porches" that some houses had. That's where the beds went all summer in hopes of catching a breeze. Ohterwise it was lay there and sweat. [img]/forums/images/icons/frown.gif[/img]
Re: Window units vs. Central
Yep, we weren't fortunate enough to have something like that, Dave, although my paternal grandparents did. They had a huge screened in back porch all the way across the back of the house, so that's where they slept in the summer. In fact, before television days, I guess they spent most of the day out there, too. I know they had rocking chairs, a sofa, and my grandmother's sewing maching that stayed out there. Then in later years, it was completely enclosed and a window unit air-conditioner was installed.
Re: Window units vs. Central
Egon, I guess that is something to take up with the design engineers of whoever built the units for Sears and Roebuck. At the time, late 90's, the units were the largest window units Sears sold. I bought 2 of them for an old WW II era bld that housed a team of 30 training materials developers for whom I was the co-leader. I got a friend to help me one weekend and we cut holes in the bld (corrugated galvanized metal, framing lumber, and sheetrock) and mounted the units on pedestals just outside the holes we cut.
I expected to see drain hoses or at least drain holes but finding neither we peaked in which revealed the setup. plastic reservoir to hold the condensate and a circumferential plastic ring on the tips of the fan blades. In operation there was no liquid water dripping outside. In times of really heavy humidity (we were on a point of land between the ocean and San Diego bay just a couple hundred feet from the water) the fans would sling enough water to allow some of it to make it through the condenser coil's fins as tiny droplets which you could feel once in a while. There was never enough to make a wet spot on the ground.
I don't know if the condenser fins and coil were specially coated to resist the effects of the water (if any appreciable ones) or not but I bought the extended warranty for the units and they were still doing fine when I retired having had only one service call to replace a thermostat.
Pat
Re: Window units vs. Central
Pat:
I think a good Mechanical type would shudder at the thought of a fan hitting water.
Do not fear, air and water over a fin cooler will create a different boundary layer for heat transfer. It may not be significant but it will be there.
Egon [img]/forums/images/icons/grin.gif[/img]
Re: Window units vs. Central
Egon, Reread my description of the fan. I would shudder if it were like a car's radiator fan hitting solid water but that is NOT how it is configured.
There is a circular hoop all the way around attached to the tips of the blades of the fan. As the condensate pan builds up until it touches the hoop, the hoop is wetted and carries a little water off the surface of the liquid. This water on the rim of the hoop is slung off the hoop by centrifugal force and the air currents where the droplets are entrained in the air being forced through the fins and coils of the condenser. There is a little retarding force, a small torque, acting against the fans rotation but no particular change in thrust.
I suspect a mechanical engineer would understand enough of the thermal situation to appreciate the boost this approach gives to the condenser's efficiency as well as not finding any inappropriate physics in the approach so far as water contact/transport is concerned.
I don't feel comfortable commenting on any potential deleterious effects which may befall the fins and coils due to the water somehow becoming contaminated between the time it condenses and moments later when it is expelled.
Pat
Re: Window units vs. Central
Okay on the fan situation Pat.
The otherside is still up for debate but limited by my debating skills and the undertstanding of the recipes the pertain to thermodynamics. [img]/forums/images/icons/frown.gif[/img] [img]/forums/images/icons/frown.gif[/img]
Egon [img]/forums/images/icons/grin.gif[/img]
Re: Window units vs. Central
[img]/forums/images/icons/tongue.gif[/img] Pat, I'm going to propose that in an area like "The Hole", having the condensate recovered and used as a means of evaporative cooling the condenser is going to be WAY less effective than it would be in Brawley, or Blythe, just due to the relative humidity in SDO. So I guess the question might be at what level of humidity does the mist enhance cooling of the coils and at what level does it just do strange things to the heat transfer with no real benefit. Just as in so many other things, the units are made all the same but yet applications vary. [img]/forums/images/icons/crazy.gif[/img]