Poll: Does your AC work well?

[Tonywa28]

Updates:
1) dropped thermostat switching for now (thermodisc unsuitable)
2) have a nice setup for manual switching of valve, just flip from one to the other (I can post a how-to if someone wants this one),
3) switched from solenoid to electric door lock actuator (see pix) for the electric version

Actuator is a bit overpowering, so I will need to tone that down. I still need to work out the spring for this version. That's it for now.

PS - Is anyone still interested? I'm kind of carrying on for the sake of the board.


Ignore the big mounting plate. That was just to let me try lots of actuator postions to work out the most compact linkage. The final version will have a small plate

[roadrunner]

Originally Posted by Tonywa28

...PS - Is anyone still interested? I'm kind of carrying on for the sake of the board...

I'm certainly keeping an eye on your progress, and I'm sure there are a few other hot climate folks out there doing the same. If this works as expected, then...

[burgess4542]

took mine in after ac turned off after about 40 min. I could restart it after about 15 min "rest". They're replacing fan relay switch which will take about a day-add it to the list of things that have gone bad in the car-suspension on right side, door not aligned properly on pass. side, carpet rivets falling out, radio speaker just popped out, headlights not aligned-needs some sort of part, have to manually push window up while pushing power button, windshield wiper worn upon delivery (which they wanted to charge me 4), foldaway top broken (plastic part) ummmm let's see anything else i'll have to think-i'll get back with you but it's sure fun to drive!

[andykeck]

Originally Posted by burgess4542

took mine in after ac turned off after about 40 min. I could restart it after about 15 min "rest".

That sounds more like the evaporator freeze-over problem in the TSB.

[Tonywa28]

Got an electric power valve to work very reliably. No tricky wiring or relays. Just ground one terminal to make valve open, or apply 12V to same wire, valve closes meaning this can now be controlled by a SPDTsimple switch.

Even now with just the SPDT switch, you could set it to bypass, but it will drop back to normal (non-bypass) when car is turned off, back to bypass when the car starts again.
1 valve, 1 actuator, 1 switch.

So I'm now down to just getting a thermostat to switch the thing, then it will work automatically, this will likely take one relay, but overall still very simple.

Please excuse the crude baseplate in the pix. ABS is easier to protype. The final will be aluminum (and straight!!)

[KryptonGreen]

Originally Posted by Buz

My ac seems fine up to 90 degrees and humid. When you stop it definitely gets warmer.

Yeah, mine too. After seeing this thread, I put on the soft top and took a 2 hour drive with full sun load, temp 91F and 75% humidity. Inside temperature 80F, dry and comfortable. All of my cars have had the slow engine problem - KG

[®ob]

Tony, looking good.

[Eclise]

I drove mine for an hour with the AC on in humid, 90+ degree heat and I actually got cold, had to keep turning it off.

But then again, in one of my houses, I have AC in only one room and the rest of the rooms are 80+ degrees. Maybe I'm just used to the heat, LOL.

[nvrblu]

Originally Posted by Eclise

I drove mine for an hour with the AC on in humid, 90+ degree heat and I actually got cold, had to keep turning it off.

But then again, in one of my houses, I have AC in only one room and the rest of the rooms are 80+ degrees. Maybe I'm just used to the heat, LOL.

Lately, I've only been driving at night when temperatures drop below 100.

I've got a dual (split) A/C in my house. I programmed my thermostats to keep the temperature down to 80 in the AM and PM and 82 on the weekends. 85 the rest of the time. I've lived here in the desert for over 25 years so I'm used to the heat... or tired of the heat... I keep overriding the thermostat program and dropping the temperature down to 78

[lotus54]

A vacuum controlled one would be great. That way when you shut the engine off it would return to going through the heater core. Assuming the valve was made that way.
You could add a small switch that would control a vacuum solinoid inline with the vacuum water valve.

mark

Originally Posted by Tonywa28

I've spent several hours online and a couple of trips to the local commercial parts warehouse to look at heater control valves. All I found (looking through multiple catalogs) are vacuum

[lotus54]

Keep us posted. Even though it rarely gets hot here, I sometimes got to eastern Washington or Oregon, and it gets quite hot there.
I like the idea of turning off the heater core water even when not running the AC- I would think it would help keep the air going by cooler.

Mark

Originally Posted by Tonywa28

Got an electric power valve to work very reliably. No tricky wiring or relays. Just ground one terminal to make valve open, or apply 12V to same wire, valve closes meaning this can now be controlled by a SPDTsimple switch.

[DesignIt]

Originally Posted by Tonywa28

Got an electric power valve to work very reliably. No tricky wiring or relays. Just ground one terminal to make valve open, or apply 12V to same wire, valve closes meaning this can now be controlled by a SPDTsimple switch.

Even now with just the SPDT switch, you could set it to bypass, but it will drop back to normal (non-bypass) when car is turned off, back to bypass when the car starts again.
1 valve, 1 actuator, 1 switch.

So I'm now down to just getting a thermostat to switch the thing, then it will work automatically, this will likely take one relay, but overall still very simple.

Please excuse the crude baseplate in the pix. ABS is easier to protype. The final will be aluminum (and straight!!)

Excellent! I'm very interested in the outcome of your project. I like the simplicity of the single switch, but if you can get thermostat to control it, that's even better. Keep us updated on your progress. This could go down in Lotus history as the "Tony AC mod".

Thanks,
John

[ready4-1]

I really don't get the variation of performance experienced here.... I have had no problem at 96 degrees and 80% humidity. The vents blow cold air on me and although the cabin may be slightly warmer, in the airflow I am completely comfortable. Much power robbing from the engine though...

[Flash G]

I think a lot of the variance in temperatures inside the car depends on several factors.

Here in L.A. the past few days it's been between 90 - 105 degrees depending on what part of the city you're in. I noticed that when I take the car directly out of my garage and turn the A/C on, It blows nice and cool even in 100+ weather.

The problem is when the car has been sitting parked in 100+ degree weather all day. When I get in the car, the A/C just isn't powerful enough to cool the car down - no matter how long I drive. The A/C in my other cars can easily cool down the interior of the car in 100+ degree temps within 10 to 15 minutes.

My point is - if you park outside on a really hot day, the A/C in these cars will never get comfortably cool, as other cars do.

[nvrblu]

I've only parked my Elise outside in the heat for extended periods a couple of times. I use a car cover and it helps a lot to keep the interior cool. The car I drive to work most of the time is parked in the sun (or a little bit of shade if I can get one of the "good" spots) and the interior temperature reaches 130 F to 140 F on a typical, hot Arizona day (105 F to 115 F). I just roll down the back windows and run the A/C full force for the first 2 or 3 minutes of driving and it helps a lot to cool down the interior... maybe this would work with the Elise?

[Tonywa28]

I have a couple of observations and opinions about the variance found in the thread concerning AC performance.

1) The AC is undersized for the southern or other very hot and/or humid parts of the US. This opinion is also held by 3 different Lotus techs and one customer service advisor at the two dealers I have information on. Weak AC for the US market is something the European cars have struggled with for decades. Several aftermarket companies used to exist that just made Porsche 911 air conditioning upgrades. I never have heard of a general lack of heating in a European car. They design with their own climate in mind. So do we.
2) The higher the humidity, the tougher it is to feel cool. So the high humidity areas struggle the most. so DC, NYC, probably Chicago etc also have issues.
3) The fan path through the manifold in the car seems to be somewhat restricted. I noticed this by running the AC with the hose removed between the evaporator unit and the vent manifold. There's plenty of air coming out of the unit, but it seems weaker at the vents in the car. Compare it to a GM product. My GMC van blows like a hurricane at the highest settings and is so cold it will give you a headache.
4) I also theorize that the poor air flow contributes to any icing problem on the evaporator.
5) Radiator tubes in the sills contribute to cabin be heated as you drive. Just that much harder for the AC to perform well. Feel your side sill by your knees after an hour drive.
6) Blend motor and door - I suspect that the actuator that opens and closes the vent door that mixes the cold and hot air may not get the blend door to seal tightly. This allows some hot air into the car under all climate settings. I believe this is the most likely reason that the heater core bypass helps at all. This could certainly vary from car to car if it's marginal.
7) There seems to be an inordinate amount of "pinched O rings" found in these systems. I find it very hard to believe that there are so many out there. My car supposedly has had that problem twice (along with one compressor failure). An acquantaince was just told he had multiple O ring problems found after his third trip in for bad AC. They are also replacing his condenser (first replacement of one of thoses I've heard of).

I'm not drawing any big conclusions here, I'm just distilling what I've observed down to what I believe are the contributing issues.

[xtn]

I am very interested in this project. If you reach a point that you could sell a kit with reasonably thurough instructions, I would be all over it. Or if not a kit, then at least a complete listing of parts and part numbers along with instructions.

I'm not very capable, design wise, but I can dang sure follow instructions. I'm even willing to contribute towards an "R&D fund," if it will help keep this project on track. Do you accept Paypal?

xtn

[Tonywa28]

Okay, there seems to be a good amount of interest. I should get the packaging down this weekend. I've bought some more parts and will try to put together 2 or 3 for testing by other folks. Rob and John A. have been keeping in close touch, so they're my first guinea pigs if they are interested.

John,
I can put yours in if you like. Shoot me an email when your car comes back from the dealer.....how's that rental Jeep Liberty handling?

Rob,
I'll contact you directly via email when I'm ready.

Here's one technical update. I'm rethinking the auto thermostat switching. The problem I thought of was that if you're in bypass mode and you want to temper the AC output by adding in a bit of heat , you can't. You also couldn't run AC defrost and heat the car at the same time if the thermostat was tripped to switch the valve to bypass. So I think the final design is just going to be a 2-position switch that you set to bypass or not. The final design WILL incorporate the automatic return to the non-bypass mode when the ignition is turned off so the coolant pump circuit will operate as designed.
Tony

PS Sorry this is creeping along, I'm just spread thin with real work at the moment.

PPS I will create a very detailed set of instructions with pictures.

PPPS I may or may not build complete units for other people. It will probably take me an hour per valve once I get the process down plus $50-60 in parts. Maybe I could just do some of the mounting plates with an equipment list and wiring diagram and let the interested parties put the pieces together for themselves. Looking for feedback.

[DesignIt]

Originally Posted by Tonywa28

Here's one technical update. I'm rethinking the auto thermostat switching. The problem I thought of was that if you're in bypass mode and you want to temper the AC output by adding in a bit of heat , you can't. You also couldn't run AC defrost and heat the car at the same time if the thermostat was tripped to switch the valve to bypass. So I think the final design is just going to be a 2-position switch that you set to bypass or not. The final design WILL incorporate the automatic return to the non-bypass mode when the ignition is turned off so the coolant pump circuit will operate as designed.
Tony.

Sounds great Tony. I like the simplicity of simple switch.

Originally Posted by Tonywa28

PS Sorry this is creeping along, I'm just spread thin with real work at the moment.

PPS I will create a very detailed set of instructions with pictures.

PPPS I may or may not build complete units for other people. It will probably take me an hour per valve once I get the process down plus $50-60 in parts. Maybe I could just do some of the mounting plates with an equipment list and wiring diagram and let the interested parties put the pieces together for themselves. Looking for feedback.

No need for an apology. I think you're making great progress considering this is a spare time project. An equipment list and wiring diagram would be perfect since I enjoy fabricating brackets and such. When you're finished and happy with the outcome, I think you should set a price for your list and diagram and start accepting PayPal deposits. I'll be your first customer.

[jimthalheimer]

When it is working, it works well. The dealer had to fix mine twice so far, freon leak. Been good for about a month now.