On Demand Ventilation

For space heating; would it be possible to preheat the air using solar arrays on the roof? Could these same arrays also serve to "shade" the collecting area in the summer reducing solar heat gain?

For cooling: What is being done with the air conditioning condensate? Could it be used to cool the intake air during the summer through evaporative cooling? Or used to increase the efficiency of the heat dissipation? If the condensate is misted or allowed to evaporate into the heat exchange feed air would it increase the thermal conductivity and thermal capacitance of the air passing over the fins? (By fins, I mean the metal used to dissipate the heat into the atmosphere.)

Gavilan

Good point..It seems to me that HVAC is incredibly crude.

They throw up buildings in short order with little insulation and less thought. Then just throw money at it trying to keep it warm or cool! The whole thing need planing at trick one.

Then in the UK if you try and build anything that doesn't look like a 1950's house a load of dim witted locals moan that it's 'not in character'... see if it's 'in character' when the North Sea sweeps 'em out of their complacent Nimby suburban smugness.... Oh yes they'll be laughing on the other side of their faces when they are paddling their bath like a canoe above the flooded remains of their 4x4 ...

(Ah..I needed that )

Del

For space heating; would it be possible to preheat the air using solar arrays on the roof? Could these same arrays also serve to "shade" the collecting area in the summer reducing solar heat gain?

Sure its possible and has been done, but not necessarily with a reasonable payback. That's the big problem with solar, big investment, big maintenance, and long payback. Buildings requiring ventilation need it all the time, not just when the sun is shining.

For cooling: What is being done with the air conditioning condensate? Could it be used to cool the intake air during the summer through evaporative cooling? Or used to increase the efficiency of the heat dissipation?

This has been done for years on small window A/C units. A slinger ring around the condenser fan drops into a sunken portion of the AC unit's platform where the condensate runs. The slinger ring picks it up and throws it on the condenser, excess can then drip out the back.

Larger A/C systems could possibly benefit from it but by the time it was implemented, it would be more of a nuisance than it was worth, otherwise, the manufacturer's would have been doing it long ago. They don't even do that on any commercial rooftop units.

New advances in Air Conditioning efficiency come from better lubricating oils, high tech metals with less friction and better heat transfer, thinner walled copper and thinner fins ( less durable though ) And of course variable speed technologies.

If the condensate is misted or allowed to evaporate into the heat exchange feed air would it increase the thermal conductivity and thermal capacitance of the air passing over the fins?

Maintenance is already painfully high on mist or steam type humidifiers using pure potable water that's been run through an additional filter, compare that to skanky condensate dripped from a filthy evaporator coil. How would you like to dip your tongue down in an evaporator drainpan? Just imagine how long your spray nozzles would work. You'd also be poisoning the building occupants with air-borne bacterias etc.

Could the future be CCHP

http://en.wikipedia.org/wiki/Trigeneration

Deseng

I installed a small fan connected to a fresh air grille and ducted it up to a dedicated AC air handler in a school classroom where there were 33 computers (classroom training). The fan was controlled by a CO₂ monitor. It works great! My son is the teacher at this high school and he hears the little fan kick on intermittently about 15 minutes after class begins.

The trouble is, the "el-cheapo" CO₂ monitors have a limited life span and require re-calibrating. This one is in a year and still working like "day-one".

Hey I lick the CO₂ monitoring concept...I've not heard of that before.

It could be usefull...Mrs Cat insists on having the bedroom windows open all night ans it's Bloody Freezing. Maybe it's another project beckoning?

Del