location of hotel and air conditioning questions...

I would say air conditioning in a private dwelling would be very exceptional. This is Europe north of the Alps, just open the window if you are too hot.
Near the Eiffel tower and near Nôtre Dame are equally good. No one place is near everything. Getting around is easy, métro and buses. Your decider should be distance to nearest métro, everywhere in the city of Paris is walking distance from a métro station.

As far as AC goes, you're going to get many opinions. True that few Paris apartments have AC because it isn't called for often. But if you're here when AC is called for and you have a busy sight-seeing schedule, you're going to be miserable without. It stays light with lots of sun in July so cooling off an apartment is difficult. Then, I've also nearly frozen to death in July. Toss up.

Maybe you can ask the airbnb host how much sun the room gets - if it's inward facing towards a courtyard, it may be that it doesn't get too much sun and would stay cooler. Keeping the curtains closed (or window shutters if their are some) can help if it's full on in the afternoon sun. A desk or floor fan can really help (our bedroom gets quite warm in the summer and we have a ceiling fan and floor fan going which helps a lot).

Does the airbnb have lots of reviews? Check thru and see if there are any mentions about how warm the room gets. We've stayed about a 10 min walk to the Eiffel Tower once and are staying in the same airbnb next month. She's technically in the 15th arr, but right on the edge of the 7th with a metro stop just a minute away. It's fine for walking to the ET and Invalides, but by Notre Dame may be a little more central for you.

I was in a hotel in Paris with no a/c in July and I almost died. It was excruciating. My one window faced a courtyard with very noisy neighbors, so I had to keep the window open for air. Take the a/c, even if it will not be as "chill" as you may be used to having.

Don't worry about which location is more convenient; once you get your bearings, and once you learn how to navigate the Metro system, Paris is very easy to get around in.

A/C is highly subjective. I just checked the Paris page of the tour section of this website, and the average high in July is in the upper 70s - to me that's sweater weather!. That doesn't mean it never gets hot - of course it does. The suggestion to "open a window" is a good one, and will stand you in good stead in all but extraordinary weather. How important are the washer and dryer to you? If your family is large, with children, that might be more of a deal breaker for you.

Frankly, I'd say don't sweat it (pun intended.) Find something that has several features you like, in your price range, in an interesting (markets, parks, churches) neighborhood. There is no perfect choice; relax and know there will be a few bumps along the way.

Have a great trip.

You never know when a heat wave will hit Paris.
If you are used to living with central air conditioning or window units almost all year long, you will probably be miserable without it.

If it's hot, and the owner offers fans, they just won't cut it.
Even if there are lots of windows in the apartment, you probably won't be able to open them, for noise reasons.

You can always find "laveries" - coin-operated laundromats that do a much more efficient job than apartment washers and dryers do. It takes an average of 2 hours to do one small load in an apartment washer, then you have to hang your clothes to dry completely. It is rare to find a separate dryer in apartments - the "amenities" section on websites doesn't normally have a space for a separate dryer, so it might be a combo unit, which just spins dry.
In addition, "house rules" normally prohibit renters from using machines past 10 PM at night. You might get a knock on the door from an irate neighbor.
Just Google "laveries" in the neighborhood where you plan to stay. There are machines that sell soap and softener specially made for the hard water in Paris - about 1 euro each.

I'd choose to book a hotel with air-conditioning and do laundry if needed in the neighborhood.

I wouldn't choose the neighborhood around the Eiffel Tower, because there really isn't much to do there, except the Rodin museum and the Eiffel Tower, and it's difficult to walk to other attractions, though the Metro is easy.
Many cafes and restaurants close early - and will close on Sunday and Monday because they can't get deliveries - because they rely on students and businessmen. There are also very long stretches without anywhere to go to the toilet.

I agree with chexbres about AC and location. For me, AC in July is more important than a washer. True it may not be super hot, but if it is, you will need it.

Nôtre Dame is the most central location in Paris and where you can walk to lots of places you'll want to go. The ET area is not central at all and you'll be very dependent on the mêtro. I like the mêtro, but I prefer to stay where I can walk outside and already be in the heart of things. And if it is hot, the mêtro is miserable. The area around ND is especially beautiful with the river surrounding you.

One thing I might advise is to ask about what kind of AC is provided. It would be very rare to have central air in the way people in the US are used to. I stayed in an apartment that advertised "air conditioning" and it really was a sort of window unit that worked within the tall narrow windows most places have. It didn't do much cooling!

Also another vote for the Notre Dame area (either side if the river, I like St Germain personally) - it's the most central and everything is easily reached on foot or by public transport. I don't love the ET area - less to do.

That "North of the Alps" thing didn't work for us last summer when there was a bad heat wave in Europe. And the AC we did find provided only small comfort. Of course, it's luck what kind of weather you get.

Wow, wide variety of opinions. Here's mine:
Take the washer/dryer and buy a rotating desk fan if it gets warm. Heck, buy 2. They're not very expensive. I don't agree that they don't cut it. Our experience has been the opposite. Plus, A/C in Paris apartments probably isn't what you're used to in the U.S. The ones we've come across are portable units that don't do a very good job of cooling the room they're in, let along the entire apartment.
You don't give ages or number of people in your group and I also don't know how you pack, or how fluent your French is but I'd think you're more likely to need to wash clothes than to need relief from the heat. I'd rather "waste" time in my apartment doing laundry than do so in a laverie. I don't like hanging around self-operated laundries in the U.S. and imagine it being even less enjoyable when I can't speak French very well. If your French is good enough that you can actually converse with the locals, that would be a plus in the laverie column.
There's more to do in the vicinity of Notre Dame than the Eiffel Tower for sure. We were sadly disappointed with the Eiffel Tower scene last year. It used to be this wonderful monument rising at the end of a wide-open grassy space. Now (or last year anyway) the security requirements ruin that scene. Rather than see the Eiffel Tower rising you see barriers, gates, lots of armed patrols. The commotion and confusion around the base of the Tower were a real distraction for us. I'm all for protecting it, I'm just saying it doesn't look like it used to. I hope we get to a time when it resembles its old self.

Yeah, north of the Alps meant nothing during the summer of 2015, either. No relief except at altitude in the Dolomites and for a few days up near Hamburg, Germany. If I had to commit to Paris lodgings in advance for July (without benefit of a close-in weather forecast) I would absolutely insist on a/c.

Paris's record high in July is 104.7 F. Even the average high (77.4 F) indicates pretty clearly that there are likely to be some quite hot days well into the 80s. Window screens are extraordinarily unusual in Europe, which is another reason (aside from noise) that depending on open windows for ventilation probably won't work well.

AC is rare in apartments and often if is one of those useless moldy portable AC units that vents out the window. We have found them worse than useless as they are always musty and trigger allergies for us. In July I would never visit Paris without AC and that would mean a hotel -- this is why we don't go to Paris in July. The one year we took leaves from work and spent 3 mos in Europe, we were in Paris for the heat wave where it was 105 by day and not much cooler at night -- it was a nightmare even though our apartment had good cross draft.

THANK YOU so much everyone for your great insights. As always, you bring up such good points to consider and help make our final decision.
Have a great day!
Jen

Though the "geographical center of Paris" is a brass plate set on the parvis of Notre Dame, this isn't necessarily where you need to be.
It's very crowded with tourists, noisy and there aren't many apartments or hotels nearby.

Most people would prefer a little more room, and easier access to the Metro and wandering around from attraction to attraction. The Latin Quarter is full of nice hotels to suit all budgets. Look for Postal Codes 75005 and 75006.

If you want a legal apart'hotel, have a look at this one - it has a kitchen and air-conditioning, but no laundry facilities:
http://www.residencehenri4.com/en/

Just one more thought...your decision will also depend on where you live and how well you tolerate heat. Me? Moved from FL to N. ID many years ago because I could not tolerate the heat. I thought I would croak last August/ early Sept in Paris, Germany, Austria and UK. Some of the days it was 95. Nope, AC is a must have for me. YMMV.

Actually, plans are to contain the Eiffel Tower within 8 foot walls of bulletproof glass. This is being done for security reasons, to protect individuals working at the Tower and to streamline ticket lines. People can still walk up the stairs, though.
www.thelocal.fr/20170209/eiffel-tower-to-be-enclosed-by-bullet-proof-wall-of-glass

Nobody has brought up the difference between French and American home washing machines, as well as French and American home dryers. You aren't getting what you think.

First, you won't find a fast cycle on a home washer--count two hours. Every washer I have ever had over forty years (on and off) of housekeeping in France was 2 or 3 hours for the fastest cycle. Then the spin is super efficient, but it means you have to iron your clothes. An old Bretonne lady who beat the clothes sparkling white at the riverside was the spokeswoman for one brand of washer back in the day--we still talk about her, La Mère Denis. She was the symbol of ultra-clean, a goal of French washing machines. These machines beat the dickens out of our US wash and wear fabrics-- twist our cotton shirts, whew!

Second, if you think the dryer will take care of the wrinkles, you've never seen a French home dryer. Many are just the front load small washer that convert to a dryer afterwards. It takes hours and leaves the clothes bunched and wrinkled. I never had a dryer when I lived in France, nor does anyone in my family, so everyone hangs the clothes. Typically, they take three days to dry north of the Loire and one day south of the Loire, unless it's raining.

So when in Paris visiting, we hand wash undies, maybe a shirt or two, but send the heavy stuff to a laundry or do it ourselves at a self-service laundry with commercial washers and large, jumbo US-size dryers. When living in Paris, we wash overnight, hang to dry for several days on racks wherever we can find room in the apartment and iron it all. Voila! The washer and dryer wouldn't be an advantage on a short trip if you didn't want to iron.

Oh yeah, what Bets said. European washers and dryers. My sister moved to the UK a decade ago. We visited and asked to use her machine. Oh lord, I don't know how she did it with 4 kids. Compared to our top loader, it would holder about 1/3 of what we usually wash. And it was a washer/dryer combo...she didn't even bother trying to dry stuff...would put it on those wooden clothes dryers. So, depending on how modern or big the apartment, if you have a lot of laundry, I'd probably go to a laundromat just for speed.

I am a person who is always cold but after the summer of 2015, there is no way that in July I would rent an apartment or stay in a hotel in Paris in that lacked AC. And, I can't stress enough how much I am usually the last person to complain about heat. I've heard people say that Paris traps the heat. I don't know if it does but if it does so did Prague, Dubrovnik and Budapest that summer. It could be that while on vacation, one is more active than usual trying to get to all the sites that lured you to the vacation spot. It could be that there are fewer cool places to stop for a few minutes because stores etc. are not as air conditioned as they are in the US. But whatever it is, when it gets hot, especially if you are in an apartment on a higher floor with a southern on western exposure -- oh my. I'd risk not having AC in June but once it gets to mid July, I would not. And if you are from someplace like Houston where it gets crazy hot in the summer but the interiors are cooled to within an inch of freezing IMO, do not expect (thank goodness) that kind of cooling in Europe.

As to the washers and dryers, I know many people wash their clothes in the sink and line dry in the hotel or prefer apartments for the appliances, but for me I don't do the first option and the appliances in the apartment are often frustrating. Even when I used to rent apartments, we pretty much ignored the in-unit appliances and just spent 45 minutes one morning doing laundry at a laverie libre and getting everything clean and dry. I don't want to break anyone's washer or dryer machine because I misunderstand the directions and generally speaking the dryers are extractors and not "true" dryers anyway. The only time that I ever had a real washer and dryer was in an apartment owned by American expats who did a home switch and stayed in my home in New York City while I stayed in their place in Paris.

The combo washers are what we call 'clothes wrinklers' although newer models are a LOT better than those we used 20 years ago. However many apartments we have used in the last decade have American style heated dryers and we have not had problems with washers only and then hanging clothes to dry. Apartments with such appliances provide drying racks. the washers are slow. If the separate dryers are slow, it is because they have 't been maintained and their condensers are clogged with lint. Once cleaned they work as well as US dryers.

Commercial laundromats are faster and one option is to run the washer in the apartment and then carry the wet clothes to a commercial laundromat to dry. The large air dry dryers are fast and large.

The first time I visited Paris, I stayed with a friend who was lucky to have a small washing machine. All I remember is that she had all her clothes drying on every available radiator, had 2 drying racks, and it took days for anything to dry.

The machines in the laveries hold from 6 to 8 kilograms - that's a whole lot of laundry that you can do in one load. The dryers hold even more - 8 to 10 kilograms.

I don't see why anyone would waste time hauling dripping wet laundry to a coin-operated laverie unless it was an emergency involving someone who threw up on a duvet and you wanted to get your security deposit back.

AC? Only you can decide but here's something to think about. What if it's hot during your stay? Hot enough that it's uncomfortable, you can't sleep at night. That type of scenario would make my trip semi miserable. Better to have AC and not need it.

I have rented apts in Paris with washer/ dryer and a/c. Keep looking.