Ventilation and air conditioning in the rabbi’s office

OUR RABBI MAY WELL be the biggest beneficiary of the security windows that were installed in December. I’m not talking about protection from potential attacks. I mean on a more tangible, everyday basis!

(As usual, click/tap on an image to enlarge it.)

Below the jump, this post explains why I say so.…

Disproportionately large window area

The main reason for improvement is that two walls of the rabbi’s office are exterior walls; and most of those two walls actually consist of windows. That is, windows make up an unusually large proportion of the thermal environment for anyone in that office. Not surprisingly, all that glass area (and loose window frames) used to make the room hot in summertime, and cold in wintertime.

Not any more, however. Those window panes and frames are now energy efficient. (As required by state agencies for all new windows.) In fact, they are even better insulated than the solid—but uninsulated—stucco walls. A really large surface area is thus multiplied by a truly big improvement in efficiency. Which means that the rabbi and others in that office are surely experiencing a huge improvement in thermal comfort.

Impact on mechanical ventilation, heating, and cooling

Still, the room does need to be air conditioned for many months of the year—not only for the sake of thermal comfort, but also to filter the air, which reduces the airborne transmission of disease.

Unlike the other rooms in the school building, there is no register vent located high on the wall, blowing (cooled or heated) air into the room. So I used to think that the rabbi’s office was a stuffy and forgotten corner of the building. 

This month I noticed that actually, there is indeed a register vent in that room—but it is located in the ceiling. And it works!

True, the air flow through that vent is not high; it is roughly half of what comes out of the register vents in the other rooms in that building. (I know this from a highly precise engineering-measurement technique: I held the back of my hand up to each type of vent, moving my arm back and forth to see how far away the air flow was perceptible, and compared the results. Precise enough for present purposes! 😉)

The air flow is less, yet this room is also smaller than the other rooms. And now that this office is so much better insulated and sealed, that low-flow register vent is probably finally adequate to the task of keeping the room comfortable on most days. It used to be overwhelmed by the heating load from the old windows; but my guess is that now it can keep up.

(Except, of course, when the office door is fully closed. Because while it is closed, the conditioned air cannot circulate back to its source, in order to be replenished. To that extent, the building’s design is admittedly not ideal. Yet the door needs to be propped open only half an inch in order to allow for adequate ventilation.) 

In conclusion, I do believe that the office situation is consistently better for our rabbi than it used to be. 

Feedback from Rabbi Josh (6/28/24)

“Unfortunately, your conjecture is mostly wishful thinking. Despite the improved windows and efficiency, it is not enough. In my experience it is stuffy and hot, and we haven’t yet hit the hottest days. 

“The old system is insufficient. It still needs an a/c unit.”