Have you ever noticed: non A/C ventilation after car is warm blows warm?
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Joined: Sep 2007
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From: CA
Have you ever noticed: non A/C ventilation after car is warm blows warm?
Question about interior ventilation with A/C off.
Conditions: cool air outside, car engine is warm (normal operating temperature); car has been parked with engine off for, say, twenty minutes; ventilation system is set to a temperature below outside temperature, even all the way to LO; you restart and drive off with interior ventilation on, outside air, fan blowing at mid-level (to face and body), but A/C (airconditioning) OFF.
Observation: lots of WARM air flows out of the ventilation system. Cool air will flow instantly when A/C is turned on, but the question is in regard to ventilation with A/C OFF.
My Guess: I think this is happening because the ventilation system draws air through ductwork that becomes heat-soaked by the engine compartment when the car is parked with a warm engine. This does not occur when the engine is stone cold.
Does your ISx50 act this way, too?
Conditions: cool air outside, car engine is warm (normal operating temperature); car has been parked with engine off for, say, twenty minutes; ventilation system is set to a temperature below outside temperature, even all the way to LO; you restart and drive off with interior ventilation on, outside air, fan blowing at mid-level (to face and body), but A/C (airconditioning) OFF.
Observation: lots of WARM air flows out of the ventilation system. Cool air will flow instantly when A/C is turned on, but the question is in regard to ventilation with A/C OFF.
My Guess: I think this is happening because the ventilation system draws air through ductwork that becomes heat-soaked by the engine compartment when the car is parked with a warm engine. This does not occur when the engine is stone cold.
Does your ISx50 act this way, too?
Last edited by tom_s; Jul 18, 2008 at 06:05 PM.
Lexus Test Driver
Joined: Jul 2007
Posts: 1,125
Likes: 1
From: ca
i dont know why but in my old honda.. with ac off i turn the **** to cool.. cool air wil vent through but if its cold and i want warm i just turn the ****.... it works with most of my older cars.. never tried it in my lexus though....
Question about interior ventilation with A/C off.
Conditions: car engine is warm (normal operating temperature); car has been parked with engine off for, say, ten minutes; ventilation system is set to a temperature below outside temperature, even all the way to LO; you restart and drive off with interior ventilation on, fan blowing at mid-level (to face and body), but A/C OFF.
Observation: lots of WARM air flows out of the ventilation system. Cool air will flow instantly when A/C is turned on, but the question is in regard to ventilation with A/C OFF.
My Guess: I think this is happening because the ventilation system draws air through ductwork that becomes heat-soaked by the engine compartment when the car is parked with a warm engine. This does not occur when the engine is stone cold.
Does your ISx50 act this way, too? Thanks in advance for your response.
Conditions: car engine is warm (normal operating temperature); car has been parked with engine off for, say, ten minutes; ventilation system is set to a temperature below outside temperature, even all the way to LO; you restart and drive off with interior ventilation on, fan blowing at mid-level (to face and body), but A/C OFF.
Observation: lots of WARM air flows out of the ventilation system. Cool air will flow instantly when A/C is turned on, but the question is in regard to ventilation with A/C OFF.
My Guess: I think this is happening because the ventilation system draws air through ductwork that becomes heat-soaked by the engine compartment when the car is parked with a warm engine. This does not occur when the engine is stone cold.
Does your ISx50 act this way, too? Thanks in advance for your response.
Lexus Champion
Joined: Jun 2006
Posts: 2,795
Likes: 0
From: California
also to observe, what is your pathway set to when you turn the car on, is it recirculate or fresh air? as i have this particular problem of the car choosing to close off outside air if the car has been sitting.
Question about interior ventilation with A/C off.
Conditions: cool air outside, car engine is warm (normal operating temperature); car has been parked with engine off for, say, ten minutes; ventilation system is set to a temperature below outside temperature, even all the way to LO; you restart and drive off with interior ventilation on, outside air, fan blowing at mid-level (to face and body), but A/C (airconditioning) OFF.
Observation: lots of WARM air flows out of the ventilation system. Cool air will flow instantly when A/C is turned on, but the question is in regard to ventilation with A/C OFF.
My Guess: I think this is happening because the ventilation system draws air through ductwork that becomes heat-soaked by the engine compartment when the car is parked with a warm engine. This does not occur when the engine is stone cold.
Does your ISx50 act this way, too?
Conditions: cool air outside, car engine is warm (normal operating temperature); car has been parked with engine off for, say, ten minutes; ventilation system is set to a temperature below outside temperature, even all the way to LO; you restart and drive off with interior ventilation on, outside air, fan blowing at mid-level (to face and body), but A/C (airconditioning) OFF.
Observation: lots of WARM air flows out of the ventilation system. Cool air will flow instantly when A/C is turned on, but the question is in regard to ventilation with A/C OFF.
My Guess: I think this is happening because the ventilation system draws air through ductwork that becomes heat-soaked by the engine compartment when the car is parked with a warm engine. This does not occur when the engine is stone cold.
Does your ISx50 act this way, too?
Just noticed this tonight. Really hot today in SoCal got in car at 7:00 PM real hot inside garage had climate control set to Lo air felt like heater was on, eventually got tired of waiting for cool air so I turned on A/C button.
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Lexus Champion
Joined: Feb 2006
Posts: 2,553
Likes: 0
From: San Diego, CA
ok guys, a quick physics lesson here. It is physically impossible, regardless of where you set the temperature, to get cooler than ambient air coming through the vents without the AC compressor engaged. If it's 100 degrees outside, you've set the temp to 60 degrees, the compressor is off, you will get air that is ATLEAST 100 degrees. And that's assuming the engine bay is cool and isn't adding any additional heat. This phenomenon isn't limited to Lexus, it's physics, the way the world works and applies to ALL cars.
The only variance from car to car would be how well the ducts are insulated from the engine bay. Some systems may introduce less heat form the engine bay than others, but NONE will be cooler than ambient.
Waiting for cool air on a hot day with the compressor off??? Where exactly are you expecting this cool air to come from?
The only variance from car to car would be how well the ducts are insulated from the engine bay. Some systems may introduce less heat form the engine bay than others, but NONE will be cooler than ambient.
Waiting for cool air on a hot day with the compressor off??? Where exactly are you expecting this cool air to come from?
Last edited by Ramon; Jul 17, 2008 at 01:13 AM.
I think that's what the OP is trying to figure out. Whether or not the IS' climate control system adds a lot of heat to incoming air. I don't think he asked if it was possible to get cooler than ambient without AC. He mentioned that when the air outside is cool, the air coming in through the vents is warm and wanted to know if that was due to the heat from the engine.
ok guys, a quick physics lesson here. It is physically impossible, regardless of where you set the temperature, to get cooler than ambient air coming through the vents without the AC compressor engaged. If it's 100 degrees outside, you've set the temp to 60 degrees, the compressor is off, you will get air that is ATLEAST 100 degrees. And that's assuming the engine bay is cool and isn't adding any additional heat. This phenomenon isn't limited to Lexus, it's physics, the way the world works and applies to ALL cars.
The only variance from car to car would be how well the ducts are insulated from the engine bay. Some systems may introduce less heat form the engine bay than others, but NONE will be cooler than ambient.
Waiting for cool air on a hot day with the compressor off??? Where exactly are you expecting this cool air to come from?
The only variance from car to car would be how well the ducts are insulated from the engine bay. Some systems may introduce less heat form the engine bay than others, but NONE will be cooler than ambient.
Waiting for cool air on a hot day with the compressor off??? Where exactly are you expecting this cool air to come from?
Pit Crew
Joined: Apr 2010
Posts: 186
Likes: 1
From: MN
Hi Everyone,
This morning I noticed that it was cold outside yet the air coming through my vents (climate control was off and on FRESH AIR) was very warm. I thought this was odd and decided to turn on the climate control (Auto). I noticed right away that the temp was ALL the way up to HI. I turned it back down to something like 68 and then shut the climate control off. I immediately felt a drop in the temp of the air coming in from the outside. It seems that the climate control...even in the off position may affect the temp of air coming in from the outside when you have the climate control off and using fresh air.
This morning I noticed that it was cold outside yet the air coming through my vents (climate control was off and on FRESH AIR) was very warm. I thought this was odd and decided to turn on the climate control (Auto). I noticed right away that the temp was ALL the way up to HI. I turned it back down to something like 68 and then shut the climate control off. I immediately felt a drop in the temp of the air coming in from the outside. It seems that the climate control...even in the off position may affect the temp of air coming in from the outside when you have the climate control off and using fresh air.
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