According to an e-mail from the hostal itself, Hostal La Macarena does not have air condiitoning, even though its website says it does, as well as some guide books (like Lonely Planet Madrid and Rough Guides Spain).
This place has plenty of good recommendations from books and the web, but I found myself a little taken aback at their e-mail responses. I sent a note in English asking about a room and received a reply, in English, saying that the room did not have air conditioning. So then I replied, pointing out that their website said all rooms did, and suggesting they might want to correct it. I put in the paragraphs from the website in English and Spanish where it talks about the amenities all their rooms have, and asked if the other information was correct. I get a reply only in Spanish!
Finally, I sent an e-mail saying I would still take the room if it had a balcony (because I didn't want an interior room in Madrid in August without air conditioning!), and now he hasn't replied at all!
I re-read what I wrote above, and maybe it isn't as bad as it first seemed to me. I did close my last note by saying something like "if you don't have a room with balcony, then thanks anyway", so maybe he thought he didn't need to say anything more. I still think it would've been polite to send an acknowledgment.