AC vs evaporative cooler: ratio of (BTUs/hr)/electric watts

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Discussion Overview

The discussion centers on comparing air conditioners and evaporative coolers, specifically focusing on the ratio of cooling output (BTUs/hr) to electrical power consumption (watts). The conversation explores the operational principles of both systems, their efficiency, and the challenges in quantifying the performance of evaporative coolers.

Discussion Character

  • Debate/contested
  • Technical explanation

Main Points Raised

  • Some participants note that evaporative coolers do not provide BTU ratings, possibly due to the variability in their performance based on environmental conditions.
  • One participant shares personal experience, stating that evaporative coolers work effectively in dry climates but are less efficient in humid areas.
  • Another participant mentions that evaporative coolers operate using minimal electricity compared to traditional air conditioners, which require more power due to their complex refrigeration cycles.
  • There is a suggestion that while evaporative coolers do not technically "cool" air, they can provide sensible cooling under specific conditions, which can be calculated from performance tables.

Areas of Agreement / Disagreement

Participants generally agree on the limitations of evaporative coolers in humid conditions and the differences in power consumption between the two cooling methods. However, there is no consensus on the quantification of cooling output for evaporative coolers, as it remains a contested topic.

Contextual Notes

The discussion highlights the dependence of evaporative cooler performance on environmental humidity and the lack of standardized BTU ratings, which complicates direct comparisons with air conditioners.

techniker
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Hi

Air conditioner vs evaporative cooler: ratio of (BTUs/hr) / electrical watts

I know evaporative coolers do not state BTUs/hr. I do not know why.

Did anyone try them and record time taken to cool.

I found this example, but I do not know if it is practically relevant:

https://www.google.com/url?sa=t&rct...e4yanAg2CCVEok3BD4cTSg&bvm=bv.128153897,d.bGs

I just read the last line “In this example, the cost of electrical cooling is about 7 times greater than the cost of evaporative cooling.”
 
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Evaporative coolers, aka 'swamp coolers' work in dry air (only). As the humidity increases, evaporation decreases, and the resultant heat removal due to evaporation decreases.

I imagine it is difficult for manufacturers to make meaningful claims about heat removal for swamp coolers.

I grew up with a swamp cooler in AZ, it worked great in the dry air. I live in Dallas now, and it would be a waste of electricity here.

A swamp cooler runs a fan and a small water pump (really small), so it basically uses as much electricity as a fan. Electrical coolers run a high pressure pump that moves freon in a closed system through two phases (gas / liquid), this takes a lot more power than just blowing air past / over wet pads that have water dripping on them, which is what a swamp cooler does.
 
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Strictly speaking, direct evaporative coolers don't do any cooling, so there's that...

Griddle is also correct; evaporative cooler output is highly dependent on the input conditions, and therefore very inconsistent. So the vendors don't give general BTU ratings.

But you could pick a specific set of conditions and calculate sensible cooling provided. Much of the info can be gotten from a performance table.
 
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OK Thanks a lot
 

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