Edmunds.com | Inside Line | Auto Observer Your Account | Help | Directory
You are here:
![[F]](http://a332.g.akamai.net/f/332/936/12h/www.edmunds.com/media/townhall/webxicons/site.gif){kind=small}
Forums
Sedans Toyota Avalon Toyota Avalon Climate Control Questions
193 messages, Last post on Oct 08, 2009 at 5:22 PM
You are in the Toyota Avalon Forum. Your Hosts are pat & karens
|
The Avalons are notorious for Heating and Cooling problems and if you write to Toyota, you would not even receive a reply. As for the "fungal' problem and the stench, it is more likely that the interior cabin filter is plugged tight with pollen and debris and the stench starts there. I would change the filter which is located just under the glove box. You would find it black with moss and slime from the moisture.
|
|
|
Replying to: mashoud (Jul 10, 2008 9:06 am) As are LS400's, RX3X0's... In point of fact almost all passenger cars of asian origin since they primarily use HVAC designs, horribly FLAWED HVAC designs, by NipponDenso. I think I have read that the newer LS430's have a UV light inside the A/C plenum to belay/retard the growth of these microbes. Even worse, many US marque are now also suffering, due to this design flaw, as a result of the presence of NipponDenso in our shores as Denso US. But. Pollen filters undoubtedly help to prevent the formation of mold and mildew spores/microbes through denying them the "food" they need for growth. That isn't to say that an overage pollen filter wouldn't be a heavy contributor to bad odors. |
|
|
Replying to: rsh1 (Jul 09, 2008 8:49 am) This also means that you have to do some "digging" in order to have access to the evaporator. Amaury '08 Limited |
|
|
Replying to: wwest (Jul 10, 2008 6:27 am) I do not doubt what you’re saying about the arrangement of the heater and evaporator in a car’s HVAC, but I haven’t seen it yet. If you could prove that your arrangement is the rule-of-thumb for car’s HVAC (schematics for example), then I will learn something new and shut up. I have never, ever have a problem with foul smell in any of the car I’ve owned because I practice what I’ve explained earlier. Amaury ’08 Limited
|
|
|
Replying to: wwest (Jul 10, 2008 6:15 am) Is this the de facto arrangement for all cars? I do know that my practice of running the heater has saved me from smelling bad odors stemming from the air vents ; perhaps because of different configuration? Or because these two units are next to each other in the same compartment hence sharing the same air volume? Again, thank you from making me dig some info “new” to me. BUT let me tell you that your recommendation of leaving the windows down makes sense only IF each and every night the RH of air is about 60% or below; otherwise, with high RH values your suggestion won’t work. And I’m sure you know that is very difficult to get those 60% or below RH values outdoors during the summer season. Also the 34F temperature at the evaporator coils is more of a design value than an actual value. My house HVAC with a SEER of 15+ has always measure an average of 40F at the evaporator (with identical indoors temperatures and wet-bulb temperatures)
|
|
|
Replying to: amauhry (Jul 11, 2008 10:16 am) "If you could prove..." I have no need to go "there". |
|
|
Replying to: amauhry (Jul 11, 2008 12:44 pm) Not long after you shut your car off in the evening after a day of A/C use the HVAC plenum area will rise to EXCESSIVE RH, possibly into the level of SUPER-SATURATION. The idea is to let the passenger cabin acclimate to the "local" Rh, not leave the elevated RH or super-saturation condition exist overnight, night after night. And your home HVAC system DOES NOT have a thermistor mounted on the evaporator downstream surface to prevent the controller from allowing it to go below FREEZING. If you home's system ever has INLET airflow conducive to the evaporator freezing over you have a really serious problem. "design value rather than an actual value.." No, in a modern day automotive the HVAC system is more often used ONLY for dehumidification rather than both cooling and dehumidification. During the winter months the airflow ENTERING the automotive HVAC might readily be low enough that the evaporator would easily freeze over if not prevented from doing so by the control system. Addtionally I rather doubt that your home system has a remix/reheat mode as does almost all modern day automotive HVAC systems.
|
|
|
Replying to: wwest (Jul 11, 2008 4:59 pm) Why do you want my house’s HVAC to have a thermistor? I’m quite sure that the TXV valve my system has does the job a whole lot better and efficiently, since it monitors the Freon R22 state across the evaporator, self-adjusting the fluid’s pressure (hence its temperature) accordingly. The remix in your “remix/reheat”mode is not practical for home application; first, most home are not made of glass; second, even if they were, there would be no need to instantly defog the “windshield” of such houses as would be in a moving car, say, during winter; third, …. Properly sized residential HVACs significantly lowers RH levels with the use of AC during the summer, and their heated, dry air “dehumidify” even more during the “dry” winter. Most residential HVACs, especially those with an SEER of 10 or higher, are more efficient than automotive HVAC’s, where efficiency is sacrificed for compactness. About your “reheat” mode? Yes, my 6-ton HVAC is always in recirculated (summer) or reheat (winter) mode; I couldn’t think of my electric/gas bills if this monster had a “fresh” air intake mode; ain’t just practical for home HVACs. Amaury ’08 Limited
|
|
|
Replying to: amauhry (Jul 14, 2008 8:18 am) Even with clothes freshly out of the washer you can hang them outside to dry and the disparity between even 100% Rh and the wet clothes will result inthem being dry within a few hours. The point is that even 100% relative humidity does not equate to prevention of enough evaporation to reduce the level of moisture wherein the A/C plenum getting below the level in which it would support microbial growth providing even a small level of convection airflow is made available. Forced airflow, even better. "Do you want my house's HVAC to have a thermistor?" No, my point was that automotive systems, wherein absent "control" the evaporator might freeze over, your "house's" HVAC will likely never "see" that threat. "The remix in your "remix/reheat" application is not practical for home application;" Well, not only is it PRACTICAL, the remix/reheat method is currently in daily use in many homes, for the very same reason for which it is used in automobiles. Most are standalone DE-humidifiers but some more upscale homes actually use central heating and cooling in combination, simultaneously, to both cool and dehumidify the home and increase human comfort levels. Obviously the highest level of dehumidification would be attained with the evaporator operating at the lowest possible temperature thereby oftentimes requiring the use of the reheat/remix application/method. And the actual numbers, temperature range, for microbial grown is 65-75F. And IMMHO automotive A/C system efficiency could be quite significantly improved (along with FE) via ALWAYS using recirculate and somehow bypassing the reheat/remix mode during the cooling season when there is no THREAT of/from windshield fogging, INTERIOR windshield fogging anyways. During the summer months, cooling season, I always set my automotive A/C system to the maximum cooling level (it then automatically switches to recirculate) wherein the reheat/remix vane/door remains firmly SHUT, and then I manually adjust the blower speed to meet my cabin cooling needs.
|
|
|
Replying to: wwest (Jul 14, 2008 10:11 am) You should know better. Air conditioning not only cools but dehumidifies (removal water molecules from the air) at the same time, or did you forget about the dripping water from window A/C units? Where do you think that water is coming from? In my 6-ton unit, it is a continuous flow of water through a ¾-inch black PVC pipe connected to a drain. So why the need of heat, especially in the summer, to remove house humidity when the A/C does it better and cheaper by itself? I’d feel sorry for those home owners with such an option on their HVAC system not because of their wasted money (in case they’re filthy rich) but because of their ignorance. There’s no need for this combined heat/cold mode for a home, and such an option would be redundant and a waste of energy both on the cold and heat side. Amaury ’08 Limited
|
|
You are here:
Forums
Sedans Toyota Avalon Toyota Avalon Climate Control Questions
New? Join Now!
Forum Tools
Search Forums
Browse by Vehicle
2010 Toyota Avalon
Browse by Board
Browse by Topic
Today's Chats
