Classromm IAQ
Classromm IAQ
(OP)
Dear fellows:
I just finished the installation of some ductless mini split systems in a local elementary school. Everything working fine so far. Now, some school members are worried about flu transmission due to air recycling. Any idea on how to provide some additional sanitation to the air inside besides proper unit maintenance? Any suggestions welcome.
Thanks!!
I just finished the installation of some ductless mini split systems in a local elementary school. Everything working fine so far. Now, some school members are worried about flu transmission due to air recycling. Any idea on how to provide some additional sanitation to the air inside besides proper unit maintenance? Any suggestions welcome.
Thanks!!





RE: Classromm IAQ
RE: Classromm IAQ
RE: Classromm IAQ
Unless you're using a DOAS with radiant cooling, as GMcD recommends, all systems have recirculation.
Flu transmission through air recirc is more of an issue when you have common returns connecting multiple spaces, not when you have a mini-split in the room taking room air and swiriling it around, exactly like a ceiling or desk mounted fan would.
RE: Classromm IAQ
I must said that the classrooms do have an independent outside air injection system, including a pre-cooling coil, which is suppose to keep proper ventilation rates. I believe that board members are more concerned about in-room flu spread, not really about cross contamination from the other classrooms. And this concern originates from the fact that the 15 year old inefficient 3-ton AHUs that used to supply air conditioning to these classrooms, had an UV lamp system installed on their ductworks. I think that these ceiling hung mini-split evaporators have some room in the return section, which can be used to install some very compact mini UV lamps? Does any of you guys know about such lamps ?
Thank you!!
RE: Classromm IAQ
Take the "V" out of HVAC and you are left with a HAC(k) job.
RE: Classromm IAQ
Fundamentally, if the concern was germ-spreading, the whole air system should have been changed out to a low level displacement ventilation system using the 400-600 cfm of minimum ventilation air you have anyway (15-20 cfm per person with 30 people). Do the math- I bet you that taking the dedicated ventilation air quantity, cooling it to 64F, and supplying at floor level, will do your cooling needs while providing 100% flow-through outdoor air. If you have solar cooling loads, then use exterior shading to eliminate it, and then the only cooling load you have left is a portion of the people and equipment, since heat from the lights goes away into the 100% exhaust air stratified layer. Think about it next time you have another school retro-fit.
Local climate conditions will dictate what amount of humidification or de-humidification you'll also need.
RE: Classromm IAQ
This is not to downplay the problem, but surely somebody has studied it and result in subsequent code restrictions.
RE: Classromm IAQ
When's the last time you saw a UV lamp on a ceiling fan? Same idea here, you're just recirculating air in the space.