Q. Air conditioning costs more but what exactly is the difference between the two systems? Is air recirculation effective at cooling or heating the vehicle interior on hot or cold days?

A. Air Recirculation and/or the Max A/C button do the same thing. They close off the vents that let fresh air into the car from the base of the windshield. Air Recirculation should be combined with A/C usage, which is why on some cars (older domestic US cars in particular) it's labled Max A/C. Air Recirc setting helps the air conditioner system by recirculating already cooler air through the system, rather then trying to take warmer outside air and cool it down. You can use it with heat, but on some cars (older Japanese and German cars in the US) they aren't set-up to run the A/C compressor in defrost mode. Any moisture at all will cause your windows to fog, ALL OF THEM, unless you also turn on the A/C button too. A/C doesn't really cost much more then 1 mpg on most cars. For me personally, I'll use A/C whenever I can. My comfort is worth more then 1 mpg.

Q. Ok so i am ddeciding whether to buy a porsche 944. i just need a list of what to look for. i dont plan on taking it to the track but just to drive 3 or 4 times a week to and from destinations. if i were to drive it casually would it still end up breaking down and repair costs skyrocketing? i just need to know what to look for when buying it and if many parts of the car will need repairing/replacing even if i do not abuse it on the race track Mileage: 136,000 Body Style: Coupe Exterior Color: Silver Interior Color: Burgundy Engine: 2.5L I4 Transmission: MANUAL 5SPD Drivetrain: N/A Doors: 2 Wheelbase: 94 Inches Options Included: Air Conditioning, Cruise Control

A. Gabe, I understand this will be a "Long winded answer" but try to take it in, after having a 924 and 944, and doing the maintenance on both, there is a lot to learn about these cars. So I enjoy helping anyone when I can. No matter how you drive a car, parts will eventually break down, and need replaced. The thing about the 944 is that parts can be costly, they are FAR more difficult to work on comparatively to their 924 little brothers and have different maintenance intervals. At 136,000 miles, you are approaching the wear for the mainshaft bearings if they haven't already been replaced. As well as the clutch if that isn't already replaced. On top of this you'll need to change the timing belt every 3 years or 40,000 miles. To buy the tools alone, just to do these things alone, yourself, the clutch kit will be about $400-600, the tools for the timing belt are $150-200, and the bearings will be about $100 + the tools to do those. If you have the time to do it you're looking at about 4 hours for the timing belt, 6 hours for the mainshaft rebuild, and a lot more for the clutch. This doesn't include the actual timing belt cost, which will be around $100 to get the belt and countershaft belt. If you've never done a timing belt, it may be a bad idea to start with a 944 as the first one as they are an interference engine, and if you get the timing belt off by a tooth or two and start it up, you'll bend all the valves in the engine and then get to learn how to install new valves and guides as well. The other things to keep in mind is that these cars are horrendously neglected by the previous owners on a common basis as there are very few shops that know these cars extremely well since they are so old. To keep the car from "Breaking down" you'll need to keep on top of the maintenance. That means ensuring to stay up on what Porsche recommends. Brake flush every other season, keep on top of inspecting the fluids, make sure to check the belts from time to time, make sure to inspect under the shield for the clutch and flywheel from time to time as they have rubber centers on the disc that can tend to wear out, inspect and repack wheelbearings at intervals replacing if necessary, flushing tranny at the right intervals with GOOD fluid. And most importantly using GOOD OIL on the changes as the 944 has hydraulic lifters in the engine that will go out over time if they are starved and lose the seals in them and seep oil which is costly to replace. As others have recommended, it is extremely important to have the car personally inspected. Make sure if you do have it inspected that you take it to someone who specializes in these unique cars, as said before there are not a lot of dealers or shops that specialize in them and it's harder to find knowledgeable people on them on the things to look for. If you are by any means new to these cars do not buy one without having it looked at FIRST. Here are some major things you can look for as a buyer that you should be able to tell: - Hydraulic lifter noise - will sound like a very aggressive TICKING coming from the car. Will sound worse when the engine is revved. If the lifters are going bad, or having a hard time, or have crap oil in the car, the sound will sound slightly better as the car warms up but WILL NOT go away. Normal lifters will be noisy for a minute or two, and the sound will almost entirely dissipate once the car is warmed up. Sort of a "clackityclackityclackity" almost like a slight "diesel motor" type clicking at startup. Again, normal operation this will go away within a minute or two of the car warming up. - Wheel bearings - if the user/seller of the car is willing to let you inspect it in the garage, have the car jacked up, wiggle the wheels by grabbing the top and bottom of the tire and trying to wiggle it. If there is play and it can be wiggled the bearings are loose, need repacked, or could be bad. There also should be no audible "clunk clunk clunk" when you spin the wheel freely. - Wiring - Look at the fuse box. It should look CLEAN. If there is any white corrosion, you're going to face some serious wiring issues in the near future. Stay away. Also check the engine bay and wires for any similar issues. - Tail lights - as the seals wear out in the 924/944 tail lights they can attract water, and corrosion. Pull carpet back, check wiring for corrosion, and lights for corrosion. - Clutch pedal - Common for some years to have the master cylinder seep if it sits too long due to bad seals. The clutch should feel STRONG, and be STRONG when let out. If you feel it STRONG in, and then PARTIAL out and then snap back, or slowly retract, you may be facing seal issues, this can be inspected by laying on your back, looking up PAST the fuse box, at the top of the pedal where it attaches to a rubber boot, if it looks WET or dirty from fluid, it is is leaking. This is a big PITA to fix. Again, inspect this. - Timing belts - can't really check them without pulling the covers off. So your best bet is to ask for CLEAR records. Again, interference engines, if they are not changed at the interval, and snap, you get to buy new valves and guides, yeehaw. Make sure the car has good records. These are all things you can check if you look for them, and all of which are fairly common on the 944 to need replacing. More so on used cars being sold as many people find out they need fixed, get a quite, and don't feel like dealing with it. Get it inspected, check these things out yourself, and make a good decision. The last time I got a quote on a timing belt replacement at a Porsche dealership it was $2000, i've heard others at $800, and $1500. Either way you cut it, when the materials cost $100, that says something about how much fun these cars are to work on. If you're mechanically savvy and aren't afraid to tackle it, they're a ton of fun, but can be draining sometimes to work on. Again, I'm in no way deterring you from buying one, simply being realistic. They are a deceivingly maintenance involved car. A lot of people will say "Poor man's Porsche." but while some would say it's because they are entry level, others would say it's because they'll nickel and dime you till you get tired of paying for it. Do the maintenance yourself if you want to keep the cost down. It'll cost you mostly just your time, rather than the cost of the parts. Otherwise if you take it to a dealer, you'll end up paying the cost of the car in labor easily in a short period of time. Great cars though. They're fun, handle well, quite reliable when running strong (long as you keep them that way), and have decent power. I'm actually driving a 944 as my daily, and the 924 is my play car, and project track car. The 944 is getting around 30-33mpg on the highway for me so I won't complain, that's impressive coming from a 2.5L engine, given the displacement. If you do get it, do a tuneup on it right away, people leave the cap and rotor and wires to rot on them all the time. A good tuneup and they run like a champ. Make sure to check the do it yourself check items above, inspect the car, and if they give you green light, enjoy it. Wonderful cars. If you're looking for an easy entry level porsche with LESS maintenance and similar design, the 924 has superb handling, a smaller engine, a different injection system, and is far easier to work on. They don't have all the power features like power steering, nor are they as "Civilized" and "Grown up" as the 944, but for a driver's experience I actually have MORE fun in my 924 than my 944. But the 944 just feels more comfortable for daily driving, that and you just don't see them a lot.

Q. I think my AC unit is shot. I suspect the repair to be major, so cost is pretty important to me. Can anyone recommend a dependable repairman or repair service that won't gouge me? Thanks!!

A. Independent HVAC steve baser 214-724-1862

A. American Home Shield They have an excellent plan for under $500/yr. Service calls are $55 each to repair or replace. Some items have a 30 day waiting period for new customers. They cover not only appliances, but electrical, and plumbing as well. I have used them for years. In one year they replaced my 38 year old (orig. to the house) hot water heater, 38 year old (orig. to the house) dishwasher, and 38 year old (org. to the house) paper duct work. Each time it only cost me the service call. All work is guaranteed by the contractor for 90 days. We recently moved, and they warranty my new house as well.

Q. I had a Heating and Air company come out last December to check on my furnance. They said I needed a new one and we agreed to purchase one. They butchered the install badly and have now installed it three more times and it still has too high of a temp rise and it's noisy. We had another company in to look at it and they said that our duct work is too small for the furnance they installed. Now they want to put holes in our floor hoping that will fix it. We have regsiters in the walls now. I'm tired of dealing with them. The other companies said they would have told me I had to replace my ducting before they would have sold me a new furnace. If I had been told that initially, I would have chosen to repair my old furnace. It's been almost 90 days. I just don't know what type of attorney to contact. Thanks,

A. You were defrauded by a company and you should have by now all the information as well as documentation to prove it. Call the city inspector in your community and find out what recourse you have toward a lawsuit also if you live in a city most cities have a department for this problem in the case of contractors doing this. Also contact the attorney general of your state, the reason is you want all these entities on your side when and if you need to contact a attorney because they can inspect and help present your claim as well as maybe you can find out the name of the contractor owner have have a "lien" against his home until he pays damages to your home caused by his companies bad workmanship. You have your work cutout but you sound tough so get going, and good luck to you.

Q. Looking for a reputable HVAC company to service on central A/C in a 15,000 square foot home. (Hopefully, someone who does not see dollar signs when they see the home...)

A. Listen Michelle you need to specify more, ok. Are you looking for a reputable company to do work on your home system. Or are you talking about HVAC as in for a company, hospital, school, commercial bldg, manufacturing bldg etc. Another tip; all industrial companies should and will be SMACNA professionals ( Sheet Metal and Air Conditioning Contractors National Association Inc. The reason I'm asking for more info is this is my field, and I can best advise when I know what type of client we are talking about. My credentials are as a degreed engineer who has twelve years in contruction and more as an engineer. I build hospitals, schools, and universities. I would suggest the name brand companys you airhandler is; such as York or Carrier because they have the most outlets regionally. A call to one of their company offices and they will give you the name of a repair / installer in your area. I am assuming you want the system checked out, serviced and a initial start-up running. So that during the season there are no problems. Here are a few other companies, cannot honetly tell you their cost; IMI (IndependentMechanical Industries,Inc- 773-282-2046 they are in Chicago on Montrose Ave. C&W Sheetmetal Inc. -773-622-8757 on North ave. Even if you don't use these people, try and get three estimates to choose from. ask them if the estimate is free. Also remember you can and should ask neighbors who they use too. You want an overall cost not time and materials because thats the most expensive. There will be a lobor charge but should your system need parts it should be standard with parts and assemblies right off the shelf. Good luck

Q. Just looking for ideas to check for when a service technician comes out to look at my air conditioning. I know these guys are very busy this time of year and just want to be careful that I am not being taken for a ride as they tell me a whole lot of this that may not even be the problem so they could just charge more. Basically, my problem is if you feel the skinny high pressure line from my condenser unit outside it is colder than the insulated line and I don't think that is the way it should be. My neighbors high pressure line is hot, why is mine not? The cooling inside is doing okay but it feels as if it should be cooler. Also any advise on what else I could check for myself before I call the service tech would be greatly appreciated.

A. Its hard to say what your system is doing unless we had system pressures, superheat and subcooling readings. Does the air off the top of the condensor feel warm? it should be at least warm. Now your liquid line( skinny line) shouldnt be hot but it shouldnt be cold either, the heat is pulled from the refrigerant at the condensor and is cooled down back to a liquid state from a gas state, the temperature of the liquid will drop as it makes its way back to the indoor coil. You can check your temps in the house, you should have about an 18-22 degree split between the air returning to your unit and the supply air coming from the air registers.

Q. I went to school for hvac got out and started at a company but they started me out as an installer and im not sure if thats the start i wanted to this career i mean if i need it ill do it but what else can i do apartment maintanence or look for a helper position or should i just stay and try to become a lead install and how long would it take to become a service tech from an install?

A. School can teach you the fundamentals, but you NEED hands on experience to learn the things they don't teach you, the tricks of the trade if you will. Besides, isn't installing an AC part of being a tech? There are very few occupations where you can just take what you learned in school and jump into the real world. Most occupations have some form of apprenticeship. Did they teach you how to deal with customers that overlook your shoulder? Code violations you find? Dealing with building inspectors? Getting paid? Dealing with suppliers? Writing up estimates? Did they teach you EVERY cause of every problem in an AC? Have you been taught on every make and model there is, old and new? (I had to read and interpret the wiring diagram on my air handler to the ac tech working on my system that couldn't figure it out). If you're as independent as you think you are, the company will soon recognize your talents, and let you go on to other responsibilities. And just remember, with the economy the way it is, there are plenty of unemployed craftsmen that would be willing to start at the bottom again. Be humbled.