Yeah, what you're saying makes sense now that I think about it. I think the hood sits pretty flush against the weather strip so it probably isn't the warmer air getting pulled in through the inlet screen and the holes on the front side of it make sense for the purpose of water drainage. The additional heat has to be coming from somewhere though and it might well be the firewall. I definitely see wire harnesses coming out of there but I haven't got a close enough look at any seals or insulation around them at the firewall. And even if the seals are intact, I'm not so sure that there wouldn't be heat transfer to the cabin side of the firewall and the ducting anyway. I definitely should keep in mind that the car is 22 years old (turning 23 in April) like you said but I can get pretty obsessed about making sure things are working the way they are supposed to. For what it's worth I took some photos of the water valve in the fully open and fully closed positions. I searched what some of the symptoms of a bad valve are and it was stuff like no heat from the vents, inconsistent heat, coolant leaking around the valve, and stuff like that and that is not a problem in my situation so hopefully the valve itself is OK. I have no problem getting heat when I want it and my coolant level is consistent. I've still been too lazy to take the air intake assembly off (plus I don't have a garage and it's cold out and the neighbors might think I'm crazy) and access the valve to be able to verify if the cable is in adjustment or not but I think it's definitely still worth a try just to be sure. So I can't say there's nothing I can do about the additional heat until I verify that first but I have a feeling that it might just be a natural heat transfer that is out of my control or some deteriorated seals at the firewall. I will say that actually driving with ventilation only (as opposed to being stationary when I was taking the temperature readings) alleviates some but not all of the additional heat. I've seen a few other threads about this topic elsewhere online and the conclusion usually is that the ducting experiences heat gains from the warm air in the engine compartment. Some cars worse than others I guess. On a positive note, it sounded like they were able to at least temporarily solve the problem by running the AC enough to get the ducts cooled down and then switch the AC off for ventilation only, most likely needing to run the AC again once the duct heat built up again. If nothing else, if I really wanted to experience the fresh air, I could just lower the windows. The only problem is the drag that produces at higher speeds.

 

Hello, I have a random question regarding the ventilation system of my 1997 Honda Accord Special Edition. I was reading about the flow-through ventilation system under the heating and cooling section of my owner's manual and it mentions that in fresh air mode the system "draws in outside air, circulates it through the interior, then exhausts it through vents near the rear window." So my question is where can I find these rear window exhaust vents and is it possible that they can become clogged with debris? I have looked for them but I haven't found anything near the rear window resembling a vent, so what am I missing? I mainly just want to know for curiosity's sake but also to potentially improve my ventilation if there's debris in them that I can clear. Thanks!

 

I have a '97 also. I've not been able to find these vents, not on this Accord nor on any other make sedan, whose owners' manuals will say the same.... Since I can't find them I don't worry about them getting plugged

 

Going off your pics, it looks like the valve is moving full stroke. We changed one on my son's Civic, as he thought the valve wasn't working, and it looked a lot like yours, swing full stroke between open and closed. On his, we still haven't figured out why it doesn't get hot air into the car yet, although we're going to look at the dampener controls and motors now that we finally have a FSM for it. At one point I thought it might have a clogged heater core, due to it not having the correct kind of coolant in it, but we flushed it (both ways) and it came out clear.

 

Those vents to get air out might actually be in the trunk. Air gets into the trunk through the fabric material on the package shelf, then those vents are low on the side and covered up by the part of the bumper-skin that wraps around the quarter panel. Look down low along the sides of the trunk near where the bumper-skin reaches the rear wheel arches.

 

Well after several months, I have made another observation about the ventilation temperature situation that might be worth noting. Now that it is summer I have been using my sun shade to reflect the sun from coming in the windshield and getting the dash and everything super hot. So my observation is that when I don't use the sun shade and everything is super hot, I experience air coming out of the vents in ventilation mode that is significantly higher than the outside temperature. However, when I do use the sunshade and the dash doesn't get nearly as hot, the air coming out of the vents is not as hot as when I didn't use the sun shade. I should also mention that I did these tests without the engine running and just the blower on full speed so I could isolate this cause (temp **** all the way to cold and intake selector to fresh air too of course). So I guess my takeaway from this is that the sun can influence this behavior as well as the engine bay heat. The dash getting super hot must have a way of getting the ducting hot as well. It's also possible that even the hood getting heated by the sun could have an influence since the inlet screen is situated under the hood when the hood is closed. Maybe it pulls in a mix of pure outside air and air that is warmed by the heat from the hood but I could definitely be wrong about that. I have no doubt that Honda designed it that way with a purpose and not by accident. I just don't know what that purpose is. I've seen some pictures of the late 70's and 80's Accords with the vent placed on top of the hood and I always thought that made more sense for ventilation so naturally I wonder why the design changed. Regardless, I have been using the AC now (in recirculate) and it is keeping me cool so this isn't so much of an issue as it was when I wanted to bring cooler outside air in when it was spring. I just thought this was an interesting observation and worth pointing out even if it seems obvious.