Air Conditioner working:

Air Conditioner (AC) work on Thermodynamics principles.

This article explains it in very layman language: https://aircondlounge.com/air-conditioner-working-principle-simple-explanation-with-diagram/

HVAC School: A channel on youtube devoted to HVAC workings. Very informative. Watching first few of them will give a very good idea: https://www.youtube.com/@HVACS

AC Service Tech: This guy has a youtube channel, with over 0.5M subscribers which has lots of details on AC. Even better is the website that he has that details a lot of basics that you won't find anywhere else.

A detailed doc on basics of refrigeration cycle is in this pdf by copeland: Fundamentals of refrigeration

Minisplits: These are slightly different than std AC that you see in homes. These are ductless, and can work to both heat and cool w/o using any gas or heating element. As such, they are very efficient in heating too.

Here's a video that shows very neatly the internals of a mini split: => https://www.youtube.com/watch?v=ATk1fx_N_qc

Refrigeration cycle of mini split in cooling mode => https://www.youtube.com/watch?v=Os2WMQxGSws

Refrigeration cycle of mini split in heatlng mode => https://www.youtube.com/watch?v=8gSmOxkbpBg

 

 


 

Vapor Pressure (VP):

This is the most important term to know before you learn AC. We learned about Vapor Pressure (VP) in "Phases of Matter". Basically, it's pressure of vapors that form above a liquid when liquid is completely enclosed in a jar, which is close to a vacuum (i.e no other gases inside). In such a case, a liquid won't remain 100% in liquid state. Some of it will vaporize and fill the space, so liquid will become partially vapor and partially liquid. How much of it will become vapor, depends on temperature. If temp is very high, 100% of it will become vapor. If temp is very low, almost all of it will be in liquid state (it will never be able to get to 100% liquid state).

The P-T chart is the most used chart in AC industry and it shows this vapor pressure at each temperature. Basically this is the pressure that the mixture of liquid + gas will have at that temp.

R410A refrigerant, the one that is most widely used, is approximately a 50/50 blend by weight of:

  • R‑32 (Difluoromethane, CH₂F₂) with a molar mass of about 52.02 g/mol

  • R‑125 (Pentafluoroethane, C₂HF₅) with a molar mass of about 120.02 g/mol

My minisplit takes about 35 oz (2 lbs 3 oz). So, R32 and R125 are both 1lb 1.5oz. However, mole wise, there are twice as much of lighter R32 molecules than those of R125 in this mixture.

The P-T chart exists separately for R32 and R125, but we don't need that. We are interested in the P-T chart of the mixture of the two. Turns out that P-T chart for each of the two refrigerants is pretty close to that of the mixture R410A. The P-T chart for R410A is here => https://www.igasusa.com/files/R410A-PT-Chart.pdf

 

Operating pressures in AC:

Non operating pressure in an AC are just the above pressure based on ambient Temp. However, when the AC is running, pressure in Vapor line (suction line) go lower (~120 psi) while pressure in Liquid line (discharge line) go higher (~350 psi). Below link talks about this

Link from AC Service Tech => https://www.acservicetech.com/post/r-22-and-r-410a-operating-pressures-charging-and-recovery-setup

 


 

Superheating and Subcooling:

Delta T => This is the temperature diff b/w the hot air from inside our house getting sucked into the blower vs cold air coming out of the blower and going back into our house to cool it. For a house sitting at 80F, and AC trying to cool it, the cold air coming out may be at 60F (assuming thermostat is set at 60F or that is what the homeowner's desired temp is). So, we get a Delta T of 20F in this case.

These are 2 other important terms to know since they are used so often. These 2 measurements determine the proper working of your system.

 

Superheating (SH): This is in the evaporator side of system. It is the temp difference between the temp of liquid refrigerant (LR) entering on one side of evaporator (after the EEV, see below diagram), and the temp of vapor refrigerant (VR)  before it goes to the compressor. It's the extra heat that VR has, so it's called SH. Ideally you want 100% LR to get converted to 100% VR at same temperature, so that you take out the most heat from the room which you are trying to cool. The SH is that extra heat in VR which allows for some margin. Usually, the liquid entering from EEV is 80% LR and 20% VR (not 100% LR). It gets converted into 100% VR when exiting on other side. On a system running properly, SH is between 8F to 15F (or 5C to 10C).

One of the best SH vid by Pioneer HVAC Control => https://www.youtube.com/watch?v=As44ldnUWh8

Assumption: One of the assumption that all these AC systems make is that the pressure of Refrigerant we measure inside the evaporator coil is actually the pressure in the middle of the evaporator coil. This vid from AC service Tech says that => https://www.youtube.com/watch?v=gsgC6mV4Ip0

This is true irrespective of whether the Refrigerant is all vapor or all liquid. Vapor Pressure (VP) inc from start of evaporator coil to end of evaporator coil, as the Temp inc (as per P-T charts). Once it's all vapor, then use PV=nRT to determine final pressure based on Temp rise (by knowing heat supplied, and specific heat of vapor). So, on a real system, Temp and Pressure vary continuously. Temp (and hence Pressure) at the end of evaporator coil (suction line) is higher than the one near the start of evaporator coil (after TXV). Pressure that we measure is avg pressure, that we call as VP and use that to get avg Temp (in the middle of the coil). We get PT chart to get this Temp (Call it T1). Temp that we measure towards the end of evaporator coil is the real Temp after absorbing the heal and we call it the Vapor temp (VT). The difference b/w VT and the one obtained from P-T chart (by measuring pressure) is called the SH = VT-T1. Even though, it's not exactly the SH in literal sense, but this is the best we can measure, and we call it SH.

Few scenarios here:

  • Low heat going thru the evaporator coil (underloaded system): These are couple of cases where Low heat happens => Dirty filter or closed supply vents, bad blower indoor motor, Low return temp, etc. Heat going from the blower motor onto the evaporator coil is what boils the LR into VR. If there's not enough heat, then all LR will not boil, and we will have 0 SH. This is really bad, as LR will get into the compressor (known as flooded compressor). Low SH happens when when all LR has boiled, but didn't get enough heat to get rise in VR temp.
    • Low SH => not enough LR was able to boil
    • Low side pressure => low (It's similar to Overcharged system below, but here, the pressure is low in contrast to overcharged system, where low side pressure is high). So,if you see low pressure, it doesn't always mean it's an undercharged system (since undercharged system also shows low pressure), it may also be due to dirty filter. Not sure why? FIXME
    • High side pressure => high or low? Not sure? FIXME
  • High heat load (Overloaded system): This is in cases where house is just too hot, and AC needs to throw in a lot of LR to evaporator in order to cool it. EEV will keep opening more t allow more LR to flow thru.
    • High SH => since LR just keeps on boiling completely too soon.
    • Low side pressure => high
    • High side pressure => high
  • Restriction on refrigerant flow: This happens at the filter dryer or the EEV, where something may get into that hole and restrict the flow of refrigerant. So, evaporator will be starved of refrigerant, leading to low pressure in evaporator coil (anywhere in between the EEV valve and suction line, as the pressure is the same everywhere within this section). SH will be high (as very low amount of liquid is coming thru the EEV, so boils off quickly). Pressure will be low in evaporator (low side pressure line), but it will be higher than normal in compressor (high side of pressure line), as Refrigerant was backing up in compressor.
    • High SH => very little LR
    • Low side pressure => low
    • High side pressure => high
  • Low refrigerant (undercharged or starved): This is the most common case that you will see with most AC units, as refrigerant keep leaking over time (they are not supposed to leak, but most units develop some small leak somewhere). Here, the quantity of refrigerant is low to start with.  So, all pressures will be below normal in both sections of pipe. 
    • High SH => very little LR
    • Low side pressure => low
    • High side pressure => low (different than above case of restriction). In "restriction case" it was high, due to the refrigerant backing up in compressor, 
  • High refrigerant (overcharged or flooded): This will happen only if you put more refrigerant by mistake. Here, the quantity of refrigerant is high to start with. So, all pressure go high. 
    • Low SH => since LR is not able to boil completely, SH will very low (0 or close to 0). Delta T will be high at 30F or so, and you will see good cold air coming out and cooling the house rapidly.
    • Low side pressure => high
    • High side pressure => high
  • Correct amount of refrigerant (ideally charged): Here all pressure and SH will be within spec.  

Subcooling (SC): This is in the condensor side of system. It is the temp difference between the vapor refrigerant (VR) entering on one side of condensor (after the compressor), and the liquid refrigerant (LR)  before it goes to the EEV (see below diagram). It's the extra cooling that LR has, so it's called SC (sub cooling and NOT super cooling, as temp go further below). Ideally you want 100% VR to get converted to 100% LR at same temperature, so that you give out the most heat from the refrigerant to the outside air. The SC is that extra heat that we sucked out from LR which allows for some margin. Usually SC is between 10F to 15F (or 5C to 8C). SC has slightly tighter limit than SH, not sure why ?? FIXME?

One of the best SC vid by Pioneer HVAC Control => https://www.youtube.com/watch?v=5_qgIUFt6ls

How do these numbers look like with different amount sof refrigerants in AC. Let's look at 3 cases:

Properly charged:

Undercharged:

Overcharged.

Dirty filter or bad air flow:

Very hot outside air temp:

Very cold outside air temp:

 

Flash Gas: This refers to the LR that enters the evaporator coil. It's usually 80% Liquid and 20% gas. It's called Flash Gas.

My AC specs:

I've a 3.5Ton AC.

  • When turned on with inside temp set to 82F, while inside temp was already 84F and outside temp was 86F, these were the specs:
    • Suction Line (Thick line): P=155 PSIG, Temp of Line=68F (Felt beer cold). The P of 155PSIG corresponds to 55F. So, SH=68-55=13F
    • Discharge Line (Thin Line): P=340 PSIG,  Temp of Line=88F (Felt hot). The P of 340PSIG corresponds to 105F. 
    • Fan air discharge temp on outside unit = 100F

 

AC Fundamentals (Summarized):

Below I've tried to summarize the fundamentals in one page.

In a nutshell, this is what happens in an AC:

 

 

Here's an hand drawn diagram that summarizes it in 1 page:

AC Functions Diagram

 


 

AC Components:

Below are details of few imp components.

Thermostatic Expansion Valve (TXV): This is the component that regulate the amount of refrigerant that goes into the evaporator. If it's too hot inside the room, that more refrigerant needs to be sent to the Evaporator, so that there is more liquid to evaporate, taking in more heat and hence lowering the temp. In essence, it maintains the Superheat (SH) to a range of 8F-12F in general. TXV is used in duct AC systems that are used in central AC. Minisplits use Electronic Expansion Valve (EEV) which uses electronics to achieve the same result.

TXV working (AC service Tech) => https://www.youtube.com/watch?v=WkgshvMOx00

 

 

 

 

 

Physical Exercises:

Apart from a healthy and balanced diet, you also need to keep your body active. We are not looking for 6 abs, just enough activity to keep ourselves healthy. Below are some easy and effective exercises:

  • Running: Running is the best and the easiet exercise that can be done anytime, anywhere and doesn't require any equipment. We should tr to run at least 1km every day, which should take about 4-5 minutes. This gets you warmed up so that you may continue to do other exercises.

 

 

How much exercise is needed?

Thee link below suggests at least 30 min exercise everyday for 5 days/week. You should also do muscle strengthening exercise 2 days a week as without it, your muscles will start decaying every year after 40. After age 40, you start losing muscle mass at 3%-8% per decade. Within your lifetime, you lose > 30% of muscle mass (varies from person to person). Muscle strengthening exercises are needed to prevent this loss.

Muscle loss => https://www.health.harvard.edu/staying-healthy/preserve-your-muscle-mass

Exercise duration => https://lifehacker.com/how-much-exercise-do-you-really-need

 

Yoga:

You probably already know what Yoga is. You have seen those esoteric poses and breathing and concentrating. Yoga aims to integrate mind, body and spirit. Yoga is a sort of mental and physical exercise. What I'm going to discuss below are some poses or asanas that are very powerful and very good for your physical and mental well being. These are also exercises, but are lower activity.

Asanas: Asanas are postures that

 

 

Getting Internet connection

 

What are the different types of Internet connections?

There are primarily 5 different types of Internet connections available in the market:

  • Dial up Internet connection - OBSELETE - This is how internet connection used to happen in early 2000 and before. This has been phased out since mid 2000s as wired phone lines are mostly gone. To get a dial up internet connection, one needs only a dial up. phone connection without any hassle of an external modem. This is the slowest (download speed up to 28 or 56 kbps) of all the available internet options but it used to be the cheapest option (as low as $10 per month). Another disadvantage of having a dial up internet connection is that your phone line will be busy during web surfing. Moreover only one person can access internet at one time. If there are two or more people trying to access internet in the same home with one phone line, that was an issue. Popular names in business were: NetZero, AOL, EarthLink, MSN, PeoplePC.
  • DSL Internet Connection - OBSELETE - DSL is "Digital Subscriber Line" internet. This is also mostly gone as of 2020, and is only offered for remote areas. DSL uses same copper lines of phone to transmit/receive internet data, but it uses digital signals over the phone line. That means it doesn't tie up the phone while using internet, as phone uses analog signals, so the two types of signals can coexist. To get a DSL connection, the bare minimum requirement is to have a phone connection at home and the self installation kit including a modem from the ISP. DSL internet speed (which varies from 1.5 mbps to 6 mbps) is generally 70 times faster than the traditional dial ups and moreover home networking where in more than one computer can access the same internet connection at one time is possible via wireless network. Some of the big companies in business were: AT&T, EarthLink, Verizon, Qwest
  • Cable High Speed internet connection - This is the most popular option for most of the geographic locations in USA as well as in poorer countries. There are no more hassles of being hooked to a telephone line. Cable internet comes through a coaxial cable to a modem, much like the coaxial cable brings a cable TV connection to your cable box.  To get a cable high speed internet connection, you need to have cable lines coming to your house or close to your house. Most of the areas in USA are served by one or more cable companies, as they have put elaborate network of cable lines under the ground. Installation of cable modem and needed wirings is done by a installer provided by the Cable company or ISP and it may be free or charged depending on the specific plan or vendor you choose to go with. This is the fastest way to access web and the speed (varies from 5 mbps to 8 mbps) is almost 100 times than the traditional dial ups. It costs about $50/month. But now a days, you can get faster Fiber or satellite internet (see below) for same price, so go with cable internet, only if you don't have the below 2 options, or price is a lot lower. Some big names in business are: Comcast, Road Runner (affiliated with Time Warner)
  • Fiber High Speed Internet connection - This is the latest and most popular internet connection. Fiber broadband (sometimes called Fiber internet) is an internet service delivered over fiber optic cable. This is different from traditional cable internet, which transmits information by sending data over copper wires. Fiber has the potential to transmit data at faster speeds than DSL or cable-based internet, but it may not be available everywhere, as it requires it's own fiber lines, which are costly to lay. It has speeds over 5 Gbps and is the fastest internet connection available as of 2022.Big players in this market are AT&T, Spectrum.
    • INDIA: In India,Fiber internet plans go for about $10/month with speeds of 100Mbps+. Reliance, Airtel etc have their fiber wires and boxes coming to nearly every neighborhood. so, it's very likely, that they will be able to pull their fiber cable to your home with a router provided for free. There's no setup charge, but they bill you for 3 months upfront, and then the plan rolls over on a monthly basis. So, the first time you setup, you have to pay about $30 for first 3 months, and then $10/month thereafter.
  • High Speed Satellite internet connection - This comes in handy at locations where neither DSL, Cable or Fiber exists. As the name implies, satellite internet gets its connectivity capability from satellites in space, just like satellite TV does. Satellite internet is typically available in more locations than either cable or DSL internet because a connection can be accessed anywhere that is not obstructed by trees or large buildings (by putting an antenna on roof or unobstructed place). Satellite internet works by using a satellite dish that receives a signal and then carries this internet signal into the home via cable to a modem or router. Satellite internet is high speed but not fast as cable or Fiber. However it's lot more expensive than all other options. Big players are Starlink, HughesNet.
    • This link has more details: https://www.satelliteinternet.com/
    • As can be seen, the speed is low at < 100Mbps and prices are > $100 a month. Data is also capped to a low limit.
    • ex: HughesNet, provides one of it's its 'recommended' plan including 20GB of monthly data and 25Mbps download speeds for $70/month. It's very expensive for the speeds you get.
  • 4G/5G Cellular Home Internet: This is a brand new internet service that reaches to you via the cell phone towers. Companies like AT&T, T-mobile, Verizon etc provide cell phone service using these towers. Now they provide internet service using the same towers to your home over the air. In the past, it was difficult since over the air data speed was low with 4G. Now with advent of 5G, speeds have gotten much faster. This service is available anywhere you can get a cell phone signal. Tmobile is a leader in this area. Only the big 3 carriers provide this Internet service as of 2024 (since it's their leased towers).
  • Cell phone "Hotspot" mode: This is your cheapest option if you don't want to pay for internet services. Most likely, you already have a cell phone service, along with a smartphone. All smartphones have a "hotspot" mode, where you turn your phone into a wifi modem/router. Once you turn "hotspot" mode on, give your wifi hotspot a network name and assign a password, it starts appearing as a "wifi" network router. Now you can open your laptop, and connect using wifi to this "hotspot" network, and browse internet on your laptop. Of course, internet speeds are dependent on what speeds your data plan supports. Speeds are at least 25Mbps with any big cell phone provider in USA.
    • INDIA: In India, with companies like Airtel and Jio, you can buy phone plans for $5/month which gives 75 GB data for a month with speeds of 25Mbps+. This is good enough speed to do your office work. You can also buy additional 50 GB data chunks for about $2-$3. When traveling to India, I buy a SIM card with unlimited talk, text and 150 GB of data for about $10/month. Plan rolls over from month to month and you pay for a month at a time, so you can cancel it anytime. Once you are done, just discard the SIM card. Even though plans say 2GB/day for 30 days, there's no daily limit. You are allowed to use 2GB*30=60GB within a month anyway you wish. Once you run over your 60GB limit, you have to recharge an extra 50GB or 100GB depending on your need. Don't go for wired internet connections in India, as they cost more, and don't provide much benefit for 99% of the consumers, especially if you there temporarily for a few months only.
    • USA: Most carrier companies in USA limit their usage of hotspot to a max number (i.e hotspot limited to 10GB/month) exactly for this reason, so that people don't using it as a home internet replacement. 

 

What are the different available options of ISPs?

These are the biggest players in market for providing internet services:

  1. AT&T => The mos expensive of all providers. They will have deals from time to time where you get $200-$300 in gift cards. They provide wired fiber internet.
  2. Tmobile => Tmobile is providing the cheapest internet plans starting at $50/month (as of Aug 2024, it's $30/month). This is cellular internet (not cable or wired internet), so it's available anywhere in the country, with just a small antenna. Tmobile hasn't rolled it out yet to all the zipcodes, so search for your zipcode to see if it's available. It's expanding fast, and is the cheapest option widely available.
    1. Link => https://www.t-mobile.com/home-internet
    2. UPDATE Aug, 29025: Tmoble is allowing custom
  3. Verizon: Just like Tmobile, Verizon also provides internet plans thru cellular, with prices starting at $35/month. They have promo from time to time to have internet for $25/month for life. The prices are slightly higher for people with no Verizon cellular service, but stil cheaper than AT&T.
    1. Link => https://www.verizon.com/home/internet
  4. Spectrum => This is another alternative to AT&T, as they too provide wired fiber internet. Spectrum's parent Co is Charter Communications. Usually Spectrum is little cheaper than AT&T (sometimes even half the price of AT&T), but Customer service is worse than AT&T.
    1. Link => https://www.spectrum.com/internet
  5. Time Warner Cable (TWC): They used to offer internet services as "RoadRunner". However, they were bought by Charter (parent company of spectrum) in 2016, so they don't exist anymore.
  6. Xfinity: They also provide cheap plans starting at $20/month, but you need to be their mobile (i.e cell phone plan) user.
    1. Link => https://www.xfinity.com/learn/internet-service
  7. Google Fiber: This was rebranded as GFiber in 2023. Google entered Fiber Internet business in 2010, and has been expanding since then in big metropolitan areas with speeds of 1Gbps-8Gbps. They are expensive at plans starting at $70/month. Even though they may be providing service in your city, they may not be having fiber lines all the way to your neighborhood. Check on their site:
    1. Wiki Link => https://en.wikipedia.org/wiki/Google_Fiber

 

Some companies provide both Cable and High Speed Internet in which case it makes sense to sign up for basic cable and Internet separately to get the lowest price. With Comcast one may get both Cable and Internet for around $55-60 per month. There are some companies like Road Runner who provide just the High Speed Internet for around $30-$45 per month depending upon promotional price or location. In order to avail the High Speed Internet Service alone (without signing up for Cable) you need to reside in Time Warner network. Generally starting few months one might get discounts but the above mentioned prices are representative of long term charges.

 


 

Getting the fastest/cheapest Internet connection:

RoadRunner by Time Warner Cable used to be the cheapest option in 2010 (Time warner cable is the parent company of RoadRunner),. They provided >7mbps speed which was considered blazing fast in 2010. The only catch is that Time warner Cable/box needs to be there in your apartment complex, or home. As of 2024, optic fiber or cellular internet is available at most of the places with speeds > 100Mbps with prices of > $30/month. So, no need to stick with cable anymore. Usually new customers get the promotional rate. Existing customers are charged a higher rate, and that's the way business is done in USA. In order to save money, you have to keep switching internet providers. If you are not sure, who are the internet providers in your area, ask your neighbors. If you have more than one provider, you are in the driver's seat.

As of 2024, most of the internet providers have optic fiber lines coming to your or near your house. Usually rates are $50/month for > 300Mbps speed. Speeds of > 100Mbps are adequate for any office work, streaming, games, etc. Go for the cheapest plan with the longest duration. The only problem with landline internet is that usually you have only 1 provider, or if you are lucky you may 2 providers. Availability of 2 providers with landline internet allows you to switch b/w the 2 of them every year to keep getting promotional rates.

Largest Internet providers:

  • AT&T => As of 2024, cheapest plan is $55/month. However, they give away rewards cards worth $100-$300 for new customers from time to time. That can bring your effective cost to $30/month.
  • Tmobile => As of 2024, Tmobile has 2 internet plans available. See deal section below for the links.
    • Tmobile's cellular internet (not cable or wired internet) is available at most of the places in USA and costs only $50/month with lots of promotions from time to time. You should be able to get one for < $30/month.
    • Tmobile also has a mobile dataplan with 30GB limit per month that doesn't require a phone line or any prior service with Tmobile. It will cost $10-$15 per month and is one of the cheapest options:
  • Spectrum => As of 2024, spectrum provides the cheapest plan. Their cheapest plan is $30/month for 100Mbps, and comes with a free cellular phone service for a year. See deal section below for the link. Only 1 cellular line is free, and only for a year. They don't extend the free offer after a year.
  • Google Fiber/GFiber => This is a competitive option to get if Gfiber serves your address. It's expensive at $70/month, but much more reliable.

Points to note:

  • First time, you sign up with any internet provider, look for all the promotions. There should be no installation fees, all cable/modem equipment is provided at no cost and you get free wireless wifi modem/router. AT&T provides free installation, while some other companies ask you to do it yourself if you don't want to pay for installation (If .
  • After 12 months you can cancel, and sign up for the service in your spouse name (or if you don't have spouse than you have to wait 2 months, before you can sign up again for the promotional offer). then 12 months later, rinse wash and repeat the process as long as you want. You don't have to cancel the service before transferring it to your spouse's name. Once the new service is activated, the old one is automatically disconnected.
  • Remember that you have to call them before expiration of 12 months, as they will continue your service at higher price after expiry of 12 month promotional offer. If they tell you that they don't have any offers for existing customers, just tell them that you want to cancel, and then you will be transferred to the cancellation/Retention department. Tell them you want to cancel. They will offer you a deal, probably 12 month contract at $35/month or 2 year contract at $30/month. Choose whichever you prefer. Do NOT cancel the service w/o talking to the folks at Retention Dept.
  • Note that most internet providers will move your service at no penalty if you move before your contract expires provided there is service in the new area.
  • Remember, you should never have to pay more than $30/month if you search for att/spectrum/tmobile/time warner cable/roadrunner offers on internet. Not all offers are available on their own website, so look around. You won't get best offers on their website directly.
  • You can buy wireless router (you always get them for free at various stores after mail in rebate) and then you can have wireless internet around the house. You can have as many computers connected to wireless internet as you want. Never pay for a buying a router from the ISP provider as they charge you a monthly fee for using that. Newer modems have integrated wireless routers, and those don't carry a monthly charge. But ask to confirm all the charges. Sometimes, internet companies will try to charge you if you use your own wireless router, but don't fall into that. There is absolutely nothing that you should pay for this. As of 2024, fastest wireless routers are available for $30-$50 on amazon and walmart. Look for refurbished (used, like new)

 

 


 

DEALS:

 

 

2025:

 

 


 

08/25/2025: TMobile Home Internet plan for $50/month (Unlimited data)  => expiry unknown

Link => https://slickdeals.net/f/18478927-t-mobile-up-to-300-virtual-prepaid-mastercard-w-new-5g-home-internet-line

This is home internet plan, not tied to your phone. No existing Tmobile phone lines are required to get this data plan. You will create an a/c with just this data line.They provide a router. Download speeds of >100Mbs and upload > 10Mbps, which should suffice for most people.

You get $200 GC from Tmobile with their cheapest $50/month plan. TCB is offering additional $202 CB (as of Aug, 2025).

TCB => https://www.topcashback.com/t-mobile-home-internet/

You'll pay $600/yr + $35 activation fee - $200 GC - $200 CB = $235/yr + taxes, which nets to $20/month. It's a good deal, as long as you can switch and repeat after a year. Else, on a yearly basis, it's expensive. 

 


 

 

2024:

 

 


 

11/25/2024: TMobile Mobile Internet plan for $10/month (30Gb limit)  => expiry unknown

Link => https://slickdeals.net/f/17923848-30gb-t-mobile-internet-byod-hotspot-10-mo-after-autopay

No existing Tmobile lines are required to get this data plan. You will create an a/c with just this data line.You can bring any device that takes a sim card, and insert the sim card from Tmobile into that device. It will act as hotspot, but speed is good. So, it's an easy and cheap replacement for Internet lines you get from AT&T etc. If your regular internet provider is charging too much, get this as a backup while you are still shopping for a deal.

This plan has been on tmobile site for over a year, but is not advertised at all.

 


 

02/01/2024: Spectrum Mobile + Internet plans for $50/month (300Mbps) for 1 year with $50-$100 in Visa Gift cards => expiry unknown

This is an older thread from 2022, but different deal is still available: https://slickdeals.net/f/16011433-spectrum-charter-internet-300-mbps-20-or-500-mbps-30-or-1gbps-40-mo-no-bundle-contract-price-huge-ymmv

Once you enter your exact address, you will see $50/month 300Mbps plan + $100 Free Visa card + 1 Free mobile phone line for 12 months. You will also qualify for 2 phone lines for $30/month for 12 months, as an existing Spectrum Customer (Confirmed with CS that only free line per account is allowed. So, once you get a free line with the plan, you can't get Buy one, get one free anymore). For 12 months, internet price comes out to $35/month, assuming phone line is valued $15/month. You will have to pay activation fee for both the internet and the phone ine which is around $30+$20=$50. This may be negated by Free $100 Visa GC. $100 Free Visa card may or may not show up depending on how you get to the Spectrum website. I would suggest trying it from different sources as slickdeals, banners, google search, etc. Mine showed up after going thru some search link on google. Confirm with CS that $100 Visa Gift card offer is there on your service. As per Spectrum CS "There is a redemption period of 8-12 weeks. you must be I good standing with the account and enrolled in autopay. after the 12 weeks you will receive an email to redeem the gift card".

UPDATE Mar 2025: I wasn't given the $100 GC even after talking to multiple reps. They all said that there was no such offer in my area. So, even though the screenshot was there from initial order that showed the GC and I confirmed via chat that I'm going to get it, I never did. Just wasted bunch of hours with them, so don't count on that $100.

UPDATE June, 2024: There's also a cheaper $30/month plan with 100Mbps speed, which is more than enough for any household. You get free phone line with this too. This is lot cheaper than 300Mbps plan above. May not be available at all locations though. Your price is locked in for 2 years, which is even better.

 


 

 

2023:

 

 


 

11/21/2023: AT&T Fiber Internet plans with $350 in Visa Gift cards

https://slickdeals.net/f/17073514-new-at-t-fiber-internet-residential-customers-order-fiber-internet-get-up-to-350-in-rewards-cards-more

This AT&T offer is inferior to offers from Spectrum, Tmobile and Verizon. AT&T cheapest plan is 300 Mbps starting at $55/month. With $350 in rewards cards, and canceling after a year, you will end up paying $25/month + taxes and other fees. Not sure, if you can get full $350 in reward cards with the cheapest plan. There is $20 dollar monthly discount for ATT Fiber if you have ATT wireless and $5 if you have "auto payments", so that will make it a lot cheaper. It's not worth sticking with AT&T beyond a year or 2 as all bonus and promo rates expire.

 


 

 

2022:

 

 


 

12/11/2022: Verizon FIOS Internet plan for $25/month for 10 years

https://slickdeals.net/f/16290709-fios-internet-10-yr-guarantee-rate-as-low-as-24-99-w-select-5g-service-req-d-and-autopay-when-switching-from-cable-25

This Verizon offer is to counteract Tmobile offer. This requires Verizon phone service. However, you can get this for $30/month even if you don't have Verizon cell phone service.

 


 

12/06/2022: Tmobile Internet plan for $25/month for life

https://slickdeals.net/f/16285891-t-mobile-internet-for-25-a-month-for-life-25

Won't get better offer than this. However many zipcodes that were previously eligible for Tmobile Internet are no longer eligible, so you might have to wait a while before your zipcode is eligible again. However, if your zipcode is eligible sign up for this right now.

 


 

08/02/2022: Tmobile Internet offer for $30/month

https://slickdeals.net/f/15779185-t-mobile-home-internet-30-month-with-autopay-on-magenta-max-and-get-up-to-50-prepaid-card

You need to have magenta max cell phone plan to get $30/month offer. Also $50 prepaid card is free with this.

 


 

 

Social Security + Medicare benefits:

If you have worked in USA, you know it hurts to pay Social Security (SS) + medicare taxes, that average about 7.5% of your wages. It's 6.2% (upto a certain threshold) for your SS taxes and 1.45% for medicare taxes (with no threshold, i.e you are taxed on your whole salary).

For Social security + medicare taxes that you pay during your working career, it's good news if you make it past 62. You start getting some of the SS taxes back as monthly paycheck. If you live long enough and your wages weren't high to start with, then you would get a lot more than what you paid into SS taxes.Same goes for Medicare taxes, where a major portion of your medical bills are paid by medicare, with a minimal amount coming out of your pocket.

It's not only the retirement benefit that SS office pays, but it also pays out disability benefits. This is particularly helpful, if you get disabled or pass away. You or your family can collect disability benefits so that they can at least survive, even if you or your spouse can't do a paying job. It also pays medicare benefits, and usually both SS + Medicare are clubbed together as SS benefits.

The link to official SS govt site is: https://www.ssa.gov/

Here you can open an account and track your SS benefits that would get in retirement or on getting disabled. Make sure everything over here is accurate wrt SS taxes and earnings reported. If you find a discrepancy, contact the SS office. They also send you a yearly statement, though I haven't been receiving them for a while (maybe they stopped sending)?

SSA Trust:

All money that we pay in as SS taxes get put into a fund, and then money is paid out of it as benefits. In the past, more money was collected as taxes, and less money was paid out, resulting in accumulation of money in this trust fund. This Trust fund is divided into following sections:

  1. OASDI (Old-Age and Survivors and Disablity Insurance) Trust fund for Retirement + Disability benefits. Total of 12.4% (10.6%+1.8%) of payroll taxes are deducted for this. It's separated into 2 parts:
    1. OASI (Old-Age and Survivors Insurance) Trust Fund: This is what pays monthly retirement (old age) checks to millions of Americans. 10.6% of pyaroll taxes are deducted for this.
    2. DI (Disability Insurance) Trust Fund: This is what pays disability benefits when you become disabled. 1.8% of pyaroll taxes are deducted for this.
  2. Medicare Trust Fund for paying medical benefits. Total of 2.9% of payroll taxes are deducted for this. It's separated into 2 parts: 
    1. HI (Hospital Insurance) Trust Fund: This is what pays for primary medicare. Payroll taxes of 2.9% are deducted for this.
    2. SMI (Supplementary Medical Insurance) Trust Fund: This is what pays for any additional medicare benefits (Part B and Part D). The funds for this doesn't come from payroll taxes but instead from govt funding and premiums paid by members who enroll in this.

2023 Report of SS Funds (published in 2024) => https://www.ssa.gov/OACT/TRSUM/tr24summary.pdf

As seen in this report, OASDI collected payroll taxes of $1T (OASI) and $0.2T (DI). Medicare collected $0.4T (HI) and $0.6T (SMI, where govt contribution=0.45T and premiums=$0.15T). Looking at payroll taxes collected for HI, we get a ballpark of $10T of total payroll income taxed. About 180M people in US pay into this fund as payroll taxes. All in all, $2.35T were collected as tax/interest to be put into the SS trust

OASDI/Medicare benefits paid out almost same as what was collected as payroll taxes + tax/interest collected. Benefits paid out for OASDI were $1.2T (OASI) and $0.2T(DI). Benefits paid out for Medicare were $0.4T (HI) and $0.6T(SMI). However after accounted for other administrative expenses, the total money going out is projected to be about $0.2T more for OASDI fund, and $0.05T more for HI fund. 58M people received OASI benefits and 8M received DI benefits, amounting to 67M people receiving OASDI benefits. In addition, 67M people received Medicare benefits (mostly the same people who received OASDI benefits). All in all, $2.5T were paid out as benefits/expenses out of the SS trust

At end of 2023, OASI reserves were $2.6T, DI were $0.2T, HI and SMI were each $0.2T. Since money paid out is more than what is coming in, reserves started getting depleted from 2021 onwards. OASDI funds are getting depleted by $0.1T/yr and will get completely depleted by 2034.  Same with HI funds which will deplete in 2035. After that, money coming in will only be able to pay 80-90% of benefits, unless there's  change in law or more money starts coming in via higher SS taxes on payroll.

Maximum taxable Wages for SS:

OASDI Taxes:

As long as you are in the workforce, you pay SS taxes. If you are employed by someone else, you pay 6.2% of SS taxes, and your employer pays 6.2% of SS taxes on your W2 wages. However, if you are self employed, you pay full 12.4% of SS taxes. This 6.2% or 12.4% only applies to first $100K-$200K or so of your wages, any wages after that aren't hit with the SS tax. Every year, a threshold is set for max wages that will be subject to SS taxes. It's adjusted every year by wage inflation rate. 

The history of max taxable wages is here: https://www.ssa.gov/policy/docs/policybriefs/pb2011-02.html#:~:text=Social%20Security%27s%20tax%20max%20has%20evolved%20throughout%20the,future%20benefit%20adequacy%20for%20middle%20and%20higher%20earners.

For year 1970, max wages subject to SS taxes was about $8K, while for 2000, it was $78K, implying a raise of about 8%/year. From 2000 to 2022, it went from $78K to $147K, which is lot slower rise of 3%/year. The chart in the link above also shows that only 6% of the people pay the max SS tax, as their wages go over the SS max wage limit. This 6% number has remained constant over last 15 years or so. So, it looks like wage inflation being priced in the formula for max SS wages is working as it ought to be. So, if you are paying the max SS tax every year, you can take console in the fact that you are in the top 6% of income earners (based solely on wages, and NOT on other income as dividend, capital gain, etc, as SS taxes don't apply to those). With a workforce of 160M people in USA, this works out to about 10M people who have wages over > $150K for year 2022. The number of people having income of over  $150K in 2022 may be lot more than 10M, as a large number of employed or unemployed people may have passive income as renting, dividends, capital gains, etc. People in top 1% have most of their income from assets and NOT wages. So, they may not be even in this 6% of people.

Medicare taxes:

You do have to pay medicare taxes too on all of your W2 wages. It has no max threshold. If you are employed by someone else, you pay 1.45% of Medicare taxes, and your employer pays 1.45% of SS taxes on your W2 wages. However, if you are self employed, you pay full 2.9% of SS taxes. If your wages are above a certain threshold, you pay an additional tax on top of this tax. So, you get penalized for Medicare (as opposed to OASDI taxes, where you had a max cap on taxes)

SS payout:

Now the important part - how much do you get in SS benefits once you retire or get disabled. Let's look at the retirement benefits.

SS benefits are calculated based on your 35 highest-earning years in the workforce, and are adjusted for inflation. If you don't have 35 years of earnings, zeros are averaged in for the years you didn't work at a job in which you paid into Social Security. The proportion of your income that is replaced by Social Security varies based on how much you earn. Consider a worker who turns 62 in 2011. To calculate his benefit, the first $749 of his average monthly earnings is multiplied by 90 percent, the next $3,768 by 32 percent, and the remainder by 15 percent. The sum of these three amounts equals his initial monthly payment amount. Workers also have cost-of-living increases added to their benefit beginning at age 62, even if they don't begin to receive benefits until a later year.

If you have worked for at least 10 years in USA with earning of > $5K/year, you will have accumulated 40 points (4 points per year is earned for taxable wages of $4K/yr). Having 40 points entitles you as well as your spouse/kids to get SS benefits. You don't have to work consecutively. As long as it's 10 years of wages, you will be eligible, no matter what your citizenship or visa status is. As an ex, if an Indian worked in USA for 10 years on H1B visa, and then goes back to India and settles in India thereafter, he would still be eligible for monthly paycheck once he reaches age 62. SS tax is your money, which you are eligible to get back in retirement. Since the money from SS fund is distributed in a social way to help poor people more than rich people, rich people get paid less than what they paid in, while poor people get paid more than what they paid in.

In June 2011, the average Social Security benefit was $1,180.80 per month. The maximum possible benefit for a worker retiring at age 66 in 2011 is $2,366. But to get this amount, the worker would need to earn the maximum taxable amount, currently $106,800, each year after age 21 for at least 35 years (as of 2011).

Here's the calculator on SS.gov website to show your retirement benefits, customized to your earnings: https://www.ssa.gov/benefits/retirement/planner/AnypiaApplet.html

Other quick calculator to give you a ballpark is here: https://www.ssa.gov/OACT/quickcalc/

As per above calculator, if you were born in 1960, and are retiring in 2022, and paid max SS tax for 35 years of your life, you would get $2K/month (in 2022 dollars). Your spouse will get the same amount if she also has same credentials as yours. Even if the spouse never worked, he/she would still be eligible for half of the SS benefits of her working partner. So, in this case, if the working partner got $2K/month in retirement, then non working partner would collect $1K/month if retiring in 2022 (i.e over 62 yrs of age). That would net a SS income of $3K/month.

However, if you earned only $5K/yr for your entire working life, you would get only $170/month. If you earned $50K/year (which is median wages), you would get about $1K/month in SS paycheck.

You may see that the SS paycheck is not enough to cover rent, not to mention food, utilities, transportation, etc. In states like Texas, it may not be enough to even cover the property tax on your house (even though you owe no mortagage and it's paid off). That's why you need other source of income such as 401K or your personal savings to survive in retirement. SS paycheck is just going to be enough so that you don't starve, though you might still be homeless.

Taxes on SS benefits:

Here comes the nail in the coffin - you would have to again pay federal income taxes on any SS paychecks that you receive in retirement or during your disability. It depends on your other income during retirement that eventually decides how much of your SS benefits would be taxed and at what rate.

Taxes on SS benefits are on this link: https://www.ssa.gov/benefits/retirement/planner/taxes.html

Most likely, 85% of SS paycheck is taxable assuming total income of > $50K in retirement.

 

 

 

USA Visa:

If you want to enter USA and are not a citizen of this country, you will need to apply for a Visa in order to enter the country. USA Visa fall under 2 broad categories:

  • Non immigrant Visa: This is the category of visa for people who are coming to USA on temporary basis and don't intend to settle in USA. Usually when you are applying for a Visa for a job, education, visit for your parents, it's usually non-immigrant Visa. The maximum amount of time you can stay in the U.S. per year is 6 months, depending on why you entered the U.S., to begin with. These are 3 most popular Visa:
    • Work Visa: This Visa is needed if you want to work in USA. You can't directly apply for this Visa. It's your US employer who must file a petition for you with the USCIS, asking to grant you a Visa.  Usually when you complete your education in USA, you would need to apply for a work Visa to start working for an employer. Or your US emplyer can apply on your behalf to hire you directly from other country. Once the Visa is approved, you may start working. The criteria for this Visa is pretty restrictive. There are 2 most widely used Visa within Work Visa:
      • H1B/H1B1: H1B is the most widely used Visa to allow you to work in USA. Your non working spouse may get a dependent Visa based on your H1B Visa.
      • L1A/L1B: L1A and L1B visas are meant for individuals who transfer within a multinational company. So, for ex you are working for TCS in India, and company wants to transfer you to USA, they may apply for either H1B Visa or a L1 Visa. In the past, H1B Visa were used in such situations, but increasing L1 Visa are being used.
    • Student Visa: Student visas are made for individuals who want to study in the U.S. These are issued by the US embassy in your country when you apply to a USA university and get accepted. Then you appear for an interview in US consulate.
      • The F-1 visa is meant for full-time students going to an accredited educational institution. People with this visa type can only get a job on-campus. F-2 visas are available for children or spouses of F-1 visa holders.
    • Visitor Visa: Someone who wishes to enter the U.S. for tourism reasons or temporary business will need a visitor visa. Unless your home country is covered by the Visa Waiver program, you will have to get a B-1 or B-2 visa. Your documents for the application must be sent to the DHS. These documents should explain your travel reasons and your trip itinerary. The validity of the visa is usually between 3 months and 10 years, depending on where you live. Usually, people can stay in the U.S. for 6 months annually.
      • B1/B2 Visa: B1 Visa is for Business travellers while B2 Visa is for tourists. Generally, both of these Visa are issued under category "B1/B2" Visa (that is what gets stamped on your Visa)
  • Immigrant Visa: This category of Visa is for people who want to settle in USA permanently. An example of Immigrant Visa is "Geen Card". We'll talk about these in a separate section.

Getting Immigrant Visa:

Typical route for people from India to get an Immigrant Visa (aka Green card) is outlined below. Usually these are the 2 paths people choose:

  1. Apply to a US University. On acceptance, get a F-1 Visa, then come to USA, study for few years for MS/Ph.D. Then apply to a US Company for a job. On getting the job, they apply for H1B Visa on your behalf. As soon as you join the company, ask the company to file an application for "Green Card" for you. There's a long waiting line for Green Card processing. There are 3 categories of applying: EB-1 is high priority and you get a green card within a year. EB-2 and EB-3 are low priority and takes over 10 years to get a green card.
  2. Work for a company in India. That company send you to USA either on a H1B Visa or a L1 Visa. As soon as you land in USA, you ask your company to file an application for "Green Card" for you. If you came on L1 Visa, you file under EB-1, while if you came on H!B Visa, you file under EB-2 or E-3 category. If you want to get your green card soon, you should try to come on L1 Visa.

Once you get your Green card, you have to wait for 5 years before you can apply for citizenship. Once you get your citizenship, apply for a USA Passport. There is a separate section that deals with applying for USA passport.

 

Applying for Visitor Visa for your parents or relatives:

This is a link for US Embassy in India that issues USA Visa for Indian nationals: https://in.usembassy.gov/visas/

This pdf file on above link explains the steps: https://in.usembassy.gov/wp-content/uploads/sites/71/1.

Here are the steps (as of April, 2022):

  1. Fill out the application form at: https://ceac.state.gov/ceac
    • For Visitor Visa, fill out the DS-160 form: DS-160, Online Nonimmigrant Visa Application
    • It's a lengthy form, and needs to be filled for each applicant separately. Some of the entries to be filled may not be readily available to you, so use your best guess for those.
    • If you are planning for both of your parents to visit you, you should fill the form 2 times, and save a pdf copy of the final submitted form
  2. Now, go to usa travel docs website, create a user account (only one user account needed for both your parents). www.ustraveldocs.com
    • choose "India" as your country.
    • choose "non immigrant visa", and then on next screen, make your user account (if you don't have one already)
    • Once you log into your account, on left side menu, it will show "New application / schedule appointment". Click that and start filling in information for onw of your parents. At the end of the form, it will ask, if you want to add any more family members. Go ahead and add your parents with pertaining details.
    • You have to enter "confirmation number" from DS-160 form for both of your parents or other applicants. This is how this account gets linked to proper applicants.
  3. Once step 2 is almost complete, you will see instructions on how to deposit the application fee. As of 2022, it's $160 per applicant. You have to pay it in INR, and may only use Indian banks for this. So, either you need to have an online bank account with a bank in India (it may be anyone's account, not necessarily belonging to you or your relatives), or you need to pay in cash at one of the bank locations mentioned (Axis or Citi bank)
  4. Once the payment has been made , you have to finish step 2. You may return to http://portal.ustraveldocs.com/ and enter the bank reference number provided in your bank receipt (not the advice slip).
  5. On the same link, you will see option for Visa interview scheduling. Schedule two separate appointments online.
    • One for a visa interview at the U.S. Embassy or Consulate.
    • Another for biometrics collection at an Visa Application Center (VAC)
    • For people who are renewing their Visa, you may qualify for "Interview waiver" which waives the requirement to appear in person for the interview. You have to still submit your passport, and other forms to consulate. You will still get your appointment date and time. On that date and time, someone will need to go and submit your documents (it can be anyone, doesn't need to be applicant). Consulate will accept these documents and process it in the next few days. Renewed Visa + passport may be returned back you by mail, or you may pick up in person at the consulate (whichever you selected at time of filling the application). Mail is easier, otherwise you will again need to send someone to Consulate to collect the passport + Visa.

A this point, you are done with "visitor visa" for your parents or other relatives. Congrats !!