But....

The A/C compressor load may be as low as 300 watts at times. The electric drive is of a solid state variable frequency type so the compressor need only run fast enough, "just" fast enough to keep the cabin near the desired comfort level.

Whereas due to the requirement of intermittent operation, running, the ICE driven compressor must be of constant high volume and likely with a substantial liquid refrigerant reservoir.

 

I feel this is a stong reason why. What is longetivity ownership of the 2 brands? I mean I'm a Ford Family man, my parents only drove Fords, My Wife's family is the same. In fact a few of the 70's Ford's purchased new are sitting in the back field now after finally being retired after 20-30 years.
Looking down the road how man old Ford's do you still see driving, how many Toyota's?

So I plan on keeping this car to "plant" in the back yard also, so if that means choosing between ICE on at lights to stay cool, so be it.

 

Well, as long as you promise to recycle the battery pack.... we don't want anyone accusing us of causing more harm than good!

 

Here in Arizona moderate discomfort at a light is not possible. A big problem is when going from light to light in the city the recovery is not enought to lower the temperature for the next light. I just wish there was a temperature sensor so that at short lights the ICE would stay off and for longer lights it would come on when the temperature gets to a settable level of uncomfort. That way the recovery time would be less, but there is still some savings of gas.

JG

 

Why not wire a relay into the brake light circuit and use the relay contacts to hold the A/C clutch circuit open as long as the foot brake is applied...?? At long lights simply switch to the e-brake.

But.

Most modern day automotive A/C systems run the A/C compressor all year around and often pretty much independently of cabin temperature. The "job" of the A/C compressor is to provide enough liquid refrigerant to keep the A/C evaporator as near to ~35F as is possible. So anytime the liquid refrigerant is exhausted ("high" side pressure is low) the A/C compressor will run to replenish the supply.

So all system airflow is first cooled by the evaporator to as close to 35F as the blower speed allows. The cabin temperature is controlled downstream of the evaporator based on how much of the previously cooled airflow is diverted to flow through the heater core and then remixed with the cooled potion before outflowing into the cabin.

Your A/C, today, has two "masters". A/C is used both for cooling and for dehumidifying the cabin atmosphere in order to prevent or belay instances of windshield or window fogging. With the OAT significantly below your cooling comfort setting the A/C continues to be used for dehumidification functionality.

So in reality the better way to use those relay contacts might be to interrupt the heater core flow pump motor and thereby make the A/C FULLY efficient.

In my case, '01 AWD RX300, I purchased and installed a manual water flow shutoff valve at Home Depot so the heater core is totally non-functional during the warmer months.

 

Just want to throw a quick point out there in support of electric A/C. It has been shown that the battery operates more effeciently in warmer temperatures. When do you need A/C? Hmmm, same time of the year you have better battery performance (with the exception of defrost in northern climates).

I, like many, was disappointed that the climate control in the 2008 Mariner did not solve the A/C in EV mode dilemna. I don't understand why the automotive industry refuses to allow for programmable margins in things like climate control and speed control.

 

I seem to recall a previous thread about how to install a shutoff valve on the FEH. It was very detailed, maybe with pictures, maybe by GaryG. I searched extensively and can't find that thread. Anyone know what I'm referring to? Thanks.

 

You post is/was confusing.


You already have manul control of the A/C.
You already have an "Auto" setting for the A/C ( more so in 2008 ).

There is no switch or relay needed.

The A/C compressor only runs:
a) you have the dash A/C switch turned on
b) you have the dash defogger / defroster turned on
c) the battery is too hot ( over 87'F ) and commands A/C to run
d) the first 0.5 second of each key-turn to lubricate the compressor

The A/C does not run "all year" and "all season" just to dehumidify the air.
Only if the driver wishes it to.

-John

 

Engineering wise there is very little likelihood that any modern day electronically controlled automatic climate control system that actually allows you to set the target cabin temperature does not use, rely, upon the A/C compressor capability all year around when in automatic mode.

But, yes, you can turn the A/C compressor function off each and every time you initially start the FEH/MMH and/or each time you depress the "auto" PB.

It is also highly unlikely that you can disable (other than my suggested method) the A/C compressor in defrost/defog/demist mode, full or partial.

 

I got it here:



this is the link: https://www.greenhybrid.com/discuss/...55/index3.html


Posted by Salsbr

Has anyone else tried this?