Are Split Air Conditioners Harmful to Human Health?

How does and air exchange unit effect this issue?

there is no air exchange unit in the split air conditioner.if it is there then it will improve the situation.thanks

siva

Some governments (USA) require air exchange units installed in new residential and commercial buildings and to some extent building that maybe extensively remodeled.

siva1943,

Your question, "is this good for the health of the occupants?" does not have an absolute answer.

It would really depend upon the use and occupant density of the conditioned space.

People produce contaminants (i.e., bioeffluent), primarily carbon dioxide and water vapor, as well as some VOCs in perspiration. In adidition, furnishings, equipment & processes in the conditioned space also can contribute to the airborne contaminant level.

While it is true that a split AC unit has no provision for supplying any outside air for dilution ventilation, typical building construction is fairly porous, and depending upon the vintage of the construction, there is a significant, measurable air exchange rate with the outdoors, ranging from <0.1 air change per hour (ACH) to about 4.5 ACH. These are USEPA estimates for residential construction, with all windows closed.

For non-residential construction, the EPA estimated air exchange rate is even higher - ranging from 0.19 ACH to 8.69 ACH.

Therefore, even if an AC unit has no provision for drawing in outdoor air, some outdoor air will enter into the conditioned space, via natural infiltration/exfiltration.

In closing, you will note that I use the term "Outdoor Air", as opposed to "fresh air". Living and working in NYC, I can assure you that THERE IS A DIFFERENCE BETWEEEN THE TWO!

(Sometimes you actually want to keep the outdoor air outside!)

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Just my $0.02...