• Here is a link to the full explanation: https://rollitup.org/t/welcome-back-did-you-try-turning-it-off-and-on-again.1104810/

Ttystikk's vertical goodness

ttystikk

ttystikk

Well-Known Member
Sedan said:
The picture shows it very roughly, but you get the idea of how long vega works and why we won't change long vega to anything!
Click to expand...
As it happens, I have adapted my trellis panels for 9 plants on a side. I wasn't happy with the results and I think I may have made a poor compromise; if I want a lot of plants, having just 9 plants in 24 ft² isn't enough. Something to consider for the future, perhaps?
 
Last edited:
ttystikk

ttystikk

Well-Known Member
Budley Doright said:
Never said it was, it's a way to accurately (really the only way) test your theory, not by touching metal lol, oh and you asked lol. And I would just like to add that this whole thing is about the effeincy of an air handler not your misinterpretation of the laws you state. Not once have you explained how it increases the heat content of the air other than heat of compression, that never happens so not one of them. Tty I am not attacking what you are doing as I think it's a good thing. You seemed to get all attitude Judy when I said I didn't think it was necessary to change your blower position. I also said go ahead many times. It was you who became all condescending with your "its physics and not rocket science statement", your right it's not. The heat of extraction formula, as I said earlier, is just another tool you can use in your work as a "consultant" to help sell your recommendations, glad I could help :). If you want to continue this discussion perhaps you could use one of the many formulas that are available to prove your theory, I would love to see where the heat of compression comes in to play.
Click to expand...
In the intervening years between this content and today, I've completed an Associates in HVAC. I had several conversations with my instructors about this very phenomenon and we couldn't really nail down why there's such a big difference.

Window banger AC units blow air through the compressor core and while it's not as efficient as drawing sir through it's still acceptable.

Gas furnaces blow air through the heat exchanger. The difference between the 80% units and the ones putting 90% or higher is a second heat exchanger upstream of the main one, where the exhaust gas gives up that last bit of heat by condensing the moisture component of the burnt natural gas. Still blowing through, though- and that's a good thing because I'm the event of a cracked heart exchanger you want higher pressure on the house side for safety.

Having done the empirical experiment of blowing air through a running HPS fixture (think of it as an electric heater in disguise lol) and pulling it through, I can tell you that the fixture is MUCH hotter pushing than pulling.

Likewise in reverse, pulling air through a radiator full of cool water doesn't work nearly as well as pushing it. All of the water cooked air handler designs I've seen push air through, although there may be exceptions.

It seems to be a well known concept in HVAC equipment design, for whatever that's worth. How to quantify it is someone they don't teach at the community college. I'll have to do some hunting around for textbooks on HVAC design to see if this is quantified and explained.
 
You must log in or register to reply here.
Top