Contractors are a dime a dozen, but how do you know if yours is any good? If you didn’t do your homework, chances are you could wind up with an air conditioning contractor that just isn’t up to snuff.
Below, we list six signs that you picked the wrong air conditioning contractor. Do any of these apply to you?
1. Your contractor doesn’t take the time to accurately determine your air conditioner’s size.
Seems pretty basic, right? If your contractor doesn’t do this, he is definitely screwing up.
2. Your contractor doesn’t give you a written agreement.
You are entitled to know what’s going on with your air conditioning system. A good contractor will provide a written agreement detailing the desired outcomes of the job.
3. Your contractor doesn’t give you a service warranty.
This is a huge red flag. If your contractor doesn’t stand behind his work, your air conditioning system could very well start malfunctioning as soon as he gets his paycheck.
4. Your contractor isn’t NATE-certified.
The North American Technician Excellence (NATE) is an independent, non-profit national organization that ensures quality within the HVAC industry. If the technician servicing your air conditioning isn’t certified, he might not be using the most modern and safest techniques.
5. Your contractor doesn’t check out online.
You’re probably already great at Facebook stalking. Use those same skills to make sure your contractor isn’t going to make your air conditioning worse instead of better. Check their standing with the Better Business Bureau, as well as reading online reviews.
6. You called the cheapest contractor you could find.
You might get away with buying off-brand peanut butter at the supermarket, but don’t go calling the cheapest contractor you can find just because you’re trying to save a buck. Skimping on your air conditioning system may save you in the short term, but you’ll be wasting energy (read: money) in the long term – and, ultimately, you’ll probably need additional repairs sooner than if you had hired a good contractor in the first place.

It’s easy to install an air conditioning system and then forget about it. As long as the cool air keeps blowing, you’ve got nothing to worry about, right?
Wrong. When you only wait until the last possible moment to service you air conditioner, you’ll learn an important lesson: it’s much easier to deal with a few minor kinks in the system here and there than to have to worry about a major overhaul down the road.
Like any other piece of relatively complex mechanical equipment, an air conditioning system is only as good as the service that goes into maintaining it. That’s why we’ve put together this guide. Here, we list the crucial steps you need to take every six months to maintain the evaporator for your air-cooled condensing systems.
1. Check the electrical panel to make sure that all the connections are tight.
Just like a loose shoelace could put you at risk for tripping, electrical connections that aren’t tight can put your air conditioner at risk. Make sure to tighten spade connections if they’re loose, and also have a good look around for wear on terminals and the insulation of the wires.
2. Check the defrost heaters.
You can’t expect anything near ideal heat transfer when your heating system is out of whack. Make sure amp draw and voltage are at manufacturer-recommended levels and that the terminals are in good shape.
3. Examine the fan.
Put the “fan” in fantastic with proper maintainence. First things first: does the thing turn? If it doesn’t – or if it’s quite stiff – you’ll want to replace the motor. Wear and small cracks are also common problems. Replace the blades if this is the case. Even if everything is in tact physically, you’ll want to give it a good cleaning and lubricate the motor’s fittings.
4. Inspect your drain pain.
Drain pans should drain easily and smoothly. If they’re not, it’s probably because there’s something in the way that you need to remove, like gunk or debris. Get it out of there!
5. Wash your evaporator coil.
The surface of your evaporator coil needs the odd rinse, as dust and grime tend to get drawn in and collect over time. A cleaner, especially a foaming one, is great for this. Doesn’t need to be anything too fancy. A commercial-grade product will do.

On a hot day, it sure feels good to get out of the sun, whether that’s under a tree or in the shadow of a tall building. The air in the shade is cooler, and you’re more comfortable for it.
Your air conditioner isn’t any different. Like most people, air conditioners prefer the shade, as well – they work better when the air they’re cooling isn’t as hot to begin with.
For this reason, trees and awnings can make a big difference in the unit’s efficiency. But there’s one thing that’s even better than either a tree or an awning when it comes to cooling the air around your air conditioning system: a storage compartment. By making this one simple change, you can greatly increase your air conditioning system’s maximum cooling output.
What do you need? Plywood and common lumber, mostly. You’ll need it to construct a storage compartment with a sloped roof that (most likely) attaches to your house.
There’s two reasons behind this shape. One is purely aesthetic. The angle is likely similar to the angles of your home’s roof. The second reason accessibility – it’s easier to service the unit with the extra clearance.
Now, you can build this storage compartment as big or small as you please. The main consideration is that there be airflow. After all, what’s the point in shading the unit if it can’t draw in any air?
Naturally, a bigger storage compartment allows for more airflow. An added benefit of a large storage compartment is that It can also double as a place to keep gardening equipment such as tools and fertilizer. If you’re going to the trouble of building this kind of structure, you might as well make it more versatile while you’re at it.
So, are you all ready to start building your storage compartment? Don’t get to hammering away just yet. Even if you’re sure the unit will get enough airflow with the design you have in mind, you might be dead wrong. Consult with you air conditioning service provider to determine whether you’ll be providing sufficient clearance before kicking off the project.

When it comes to keeping cool in your home, you’ve got options – four, actually. Whatever you choose (or happen to already have in your home), all air conditioning systems share these five common traits: a refrigerant, compressor, condenser, expansion valve and evaporator coil.
Below, we’ll discuss what defines each type of air conditioning system and how they work. Which type of air conditioning system do you have?
1. Window Air Conditioner
Window air conditioners are literally the total package. The unit contains all the air conditioning components, including the evaporator, cooling coil, compressor, condenser and expansion coil or valve. For a simple solution to your cooling problems, window air conditioners are it!
Window air conditioners have a pretty obvious drawback, and we’ll just go ahead and say it: they’re kind of ugly. But if anything is going to help you come to peace with the clunky aesthetics, it’s the cost-savings: because these units allow you to cool a single room – namely, the one you’re in at the time – you’ll spend less over the short and long term.
2. Split Air Conditioners
Divide and conquer. That’s the motto of the split air conditioner. The unit divvies up the work of cooling one or two rooms between its outdoor and indoor components. On the outdoor side of things, you’ve got the compressor, condenser and expansion valve, whereas indoors you’ll find the evaporator coil and cooling fan.
3. Packaged Air Conditioners
Say you’ve got a bigger cooling job than just a room or two, and a window air conditioner or split air conditioner just won’t do. In cases where you need to cool down multiple rooms or large, open spaces, a packaged air conditioner is definitely the better choice.
These units are arranged in one of two ways. First, a single box can contain the various components (a compressor, condenser, expansion valve and evaporator). Once air is cooled down in the packaged air conditioner, it is then sent to each room through the ductwork.
In the second case, it’s individual units, each with their own expansion valve and cooling coil, that do the cooling. These are located in the rooms you want to cool. The compressor and condenser are contained in one unit.
4. Central Air Conditioners
As air conditioning systems go, this is “the big one”. It’ll cool your offices, your hotels, your larger buildings, your homes in their entirety. A giant compressor does most of the work. Cool air from the air conditioning unit gets pumped throughout the structure through ducts and out of registers (openings in walls, ceilings and floors, often covered by a metal gate).

We know, we know. You’re probably thinking that high-velocity air conditioning sounds kind of intense.
Well, we’re here to tell you that it’s nothing like sticking your head out the window while driving down the highway. Or a hurricane. Or a tornado.
It’s called high-velocity because of the size of the ducts: at a size of just two inches, they’re quite small! This increases the velocity of the airflow (think of it like water through a pinched hose). To cope with the extra noise this makes, the system uses materials to muffle the sound, so you can relax in perfect comfort.
Starting to sound pretty good? To know if it’s perfect for your home, check out our list of five things to consider before installing high-velocity air conditioning.
1. Do you own an older home?
You won’t be able to enjoy your cute, old home if you spend summers sweating because you’ve got no air conditioning. In homes like these, though, it can be difficult to install a bulky, standard air conditioning system – you might even have to remodel your home to accommodate it. With a high-velocity system, you can work around existing design quirks and tight spaces thanks to the system’s small ducts.
2. Do you hate waiting around for your room to cool?
We’ve all been there: you want your room cool now, but your dated air conditioning system is taking its sweet time. Not so with high-velocity air conditioning. Using only half the airflow, high-velocity air conditioning can take your room from sweating-sitting-down to couldn’t-be-more-comfortable faster than you can say, well, high-velocity air conditioning system.
3. Do you live in a humid environment?
You’ll appreciate your high-velocity air conditioning most on muggy days – it’s 30 percent more effective than a traditional system at removing moisture.
4. Do you hate it when parts of a room are hotter than others?
You know when you heat up food in the microwave and the outside is burning hot, but it’s still cold inside? Rooms can get that way, too. If you hate it when some parts of a room are hotter than others, high-velocity air conditioning could be right for you. The circulation system ensures even temperatures.
5. Do you mind a bit of a breeze?
As we discussed earlier, high-velocity air conditioning blows air faster than standard systems. That means when the air is blowing out of the register and into the room, you’ll definitely feel it. This does bother some people. A good contractor will keep this in mind and position the registers so as to be the least bothersome to the homeowner.

We’re going to put it plainly: air cleaners aren’t perfect. That is to say, an air cleaner could be performing at its very best and still not remove every last pollutant from the air.
Some might say you’re better of with an air cleaner than without one, but is that necessarily true? In the following article, we’ll talk about what you can expect from an air cleaner and what it is (and is not) protecting you against.
Like we said before, if you’re looking for an air cleaner that will remove all the gas and impurities from the air, you’re not going to find it. What an air cleaner is going to do is potentially lower the risks associated with some contaminants.
For example, let’s say you’re smoking indoors. This fills the air with smoke and particulates. Your air cleaner may be able to mitigate some of the particulates, but it’s going to have a lot harder time with all of that smoke.
The real kicker is that your air cleaner can actually undermine itself in a situation like this. How? Particulates from the smoke can get hung up in the cleaner. What happens next is a bit ironic: these contaminants can then be spat back out into the room.
That’s not fantastic, is it? Well, if you thought tobacco smoke was bad, you don’t want to know how your average air cleaner handles radon. Answer: it doesn’t, really. And with all the side effects associated with exposure to radon, you’d be smart not to put too much trust in your air cleaner.
Allergies affect a wide range of people. For some, it’s cats that set them off. For others, it’s mold. And for others, it’s pollen.
Whatever your trigger, an air cleaner won’t be much help. Studies have shown that it’s difficult to combat allergens with air cleaners, so keep that box of tissues close.
In fact, you’re almost better off with a properly functioning air-conditioning system alone, especially on muggy summer days. It’s biggest strengths lie in forcing out air from outdoors and reducing damp – two big causes of the sniffles.
For those sensitive to pollutants and allergens in the air (and anyone who cares about clean breathing), a logical first step is to make sure your air-conditioning system is running smoothly. Only if contaminants in the air pose a serious risk should you consider using an air cleaner.

Radiant floor heating is a popular choice for a reason – it’s been used for centuries! With hundreds of years of great results, it’s no surprise that most folks choose radiant floor heating.
With radiant floor heating, there’s no huddling around a single heat source like a fire or a stove (not to mention the general mess associated with these heat sources). The heat radiates up through the floor – hence the name!
This works for a pretty simple reason. Think about it. Where are you coldest? Your toes! Radiant heating starts from the floor up, warming your feet and then on up to the rest of your body. It’s as convenient as it is soothing.
And it’s almost like magic. No noise. No bulky radiators wrecking your living room arrangement. With radiant floor heating, your body temperature and room temperature are ideal.
Compare this to a forced hot air system. With this system, you get air coming in from the outside, you get higher boiler temperatures that decrease the lifespan of your system, and – to put it simply – you simply get less out of your system.
Imagine a pizza stone warming up in an oven. That’s similar to how radiant floor heating works (and what makes it so efficient). A hot concrete slab beneath your floor sends warmth up through the floor boards. It is warmed by either a boiler or a geothermal pump. Now, the catch is that if it cools off considerably, then it will be a bit slow getting hot again. This is why you need to regulate the system properly.
That said, you wouldn’t want a wall thermostat judging temperatures on the floor, would you? Enter the floor thermostat. These vary as to what you’re able to control, but some smarter, fuel-saving systems allow for checking the outside, ground and room temperatures, which can give you that little extra boost toward a cozy home.

How to Set Up an HVAC System

HVAC systems are crucial to keeping us comfortable. They circulate air and provide temperature control. What makes a great system, though? As HVAC experts, we know that it’s all in the details. Here, we lay everything out, from planning the system to putting it together to checking its ultimate performance.
Requirements for an HVAC System 
If you’re looking for quality, you’ll want to be sure of the following things.

Check each room for heating and cooling loads. The size of a room is a big consideration when determining proper air flow.
Get a duct that will bring air into the room. You’ll also need a return system that will ensure proper circulation.
You’ll want to be able to satisfy those computed loads from step one. For that, you’ll need a handler that monitors the air pressure so that it stays within the requirements that it was designed for.
You need to make the return and supply systems work in harmony. Balance is key to keeping pressure neutral in each room and throughout the home.
Make sure you’re not losing (or gaining) any heat around your handler and register.
A funky odor can ruin your hard work. Check that no car exhaust or stale attic air is getting into the air conditioning. A good seal on your ducts can help with this.
Pressure gauges will help you know if your refrigerant is charged. You’ll also want to double check your burner.

Putting it Together: Your HVAC System
Grab your ACCA manuals and handbooks (or whatever guides you prefer; we’ll reference ACCA literature here) – you’ll need them for putting together and maintaining your air-conditioning system.

Determine the loads and airflow in each room that you are servicing (refer to Manual J).
Handbook D will be your friend when it comes to sizing up your potential duct system.
You’ll want to consult Handbook S to get your practical load just right.
You may run into construction jams when putting together your HVAC. By laying your duct system out, you can properly anticipate potential issues given the various limitations of the space.
Manufacturer’s specifications will come in handy when installing everything. As you’re going about it, make sure there’s nowhere that might leak air.
Before you really turn up the heat, see to it that your furnace burner and firebox are operating correctly.
Refrigerant charge comes down to properly tuning your superheat and subcooling. Measure them with care.
To keep your HVAC system humming, do one last look around for leaks, as well as spacing and air flow return. Finish up with a static pressure check.

Have you ever wondered how your air conditioner works? In this article, we explain what’s going on inside an air conditioner that allows it to cool your room and elevate your comfort.
Let’s start from the moment you switch your air conditioner on. When you flip that switch, the thermostat control inside your air conditioner springs into action, sending 120 volts of alternating current to two different components: the compressor and the fan motor.
The compressor is basically a pump that compresses refrigerant into the condenser coils at the rear end of the unit. It’s a gas at first, but the condenser coils actually condense it into a hot liquid. The resulting heat is then dispersed as the liquid passes from the condenser coils and the capillary tube on into the evaporator coils.
The evaporator coils can be found at the front end of the air conditioner. This is the part of the cycle where the refrigerant liquid becomes a gas once again. If you’ve been following along closely, you’ll be able to guess exactly how this takes place: the refrigerant cools! The coils then cool as a result.
The final part of the cycle takes place when the gas passes through a suction line attached to the compressor, where it’s changed back into a liquid.
While all this is happening, your room wouldn’t see much benefit if not for the fan motor. This is because for your room to be cooled, your air conditioner needs to suck in air from the room, cooling it as it passes over the evaporator coils. And just like that, you’ve got cool air!
The unit keeps itself cool with the condenser fan. As you might imagine, the condenser fan’s job is to blow air from outdoors over the condenser’s coils to cool them.
To get the temperature just right in your room, you probably know that you use either the thermostat switch or an electronic control board. But how does the air conditioner know when it’s cooled the room to your liking?
This is accomplished with the sensing bulb or electronic sensor, which measures the temperature of the air in the room as it passes into the evaporator coils. Once the temperature in the room reaches desired levels, the thermostat shuts down the compressor.
One more thing to note: water tends to collect inside air conditioning units. This isn’t a sign your unit is malfunctioning – it’s a normal part of the process. To keep this water from running into your room, tip the unit back slightly when you’re setting it up in your window. The water will drip outside (and hopefully not onto someone’s head below).

Among the charming features of the United States’ older homes are their hot water heating systems. The prevalence of this rather antiquated system in older homes is a big reason why most are located in the Northeast.
For folks there, it’s almost hard to imagine it any other way. They’ve gotten used to life without the drafts so often associated with forced-air systems – not to mention the odd noises, like clanking and gurgling, that go along with theirs.
Hot water heating systems work like this: a central boiler, warmed by either gas or oil, heats the water. The water then makes its way throughout the house via pipes that are much smaller in diameter than your average duct.
It’s sounds a bit like a water park in your walls, doesn’t it? It really would be if one of your pipes burst! Though this is a pretty scary thought, it’s unlikely to happen. One of the main reasons is the expansion tank, which accommodates extra water in the system as it expands and recedes.
When it comes to maintaining your hot water heating system, you can’t necessarily do it all. There are some jobs that only a professional can handle, like a furnace tune-up.
But don’t go thinking that this lets you off the hook. You are more than capable of getting your hot water heating system ready for the winter chill with a couple maintenance musts. Here are the three problem areas you need to maintain.
1. The Boiler
If you don’t brush your teeth for a week, it’ll start to show in your smile. In the same way, hot water heating systems can get bogged down by sludge, which results from the build up of minerals and rust. Fortunately, de-sludging your system is easier than you might think. All you need to do is drain water from the boiler.
Before you start, make sure to turn off the burner and close the water inlet valve. The water will still be piping hot at this point, so go occupy yourself for two hours or so while it cools. Once enough time has passed, it’s time to get draining.
The objective here is to drain the water into a metal bucket (the bigger, the better) until it’s clear. This is accomplished by opening the drain valve and letting the water run until you get the desired result. That done, you’ll need to close up the drain valve, open the supply valve and turn the furnace on.
You can usually get away with doing this about once a year. However, if you have an older system, you might need to be more vigilant. But that wasn’t so hard, was it?
2. The Tank
Guess what? You need to drain this, too.
Well, maybe. If you have a newer system, that is, one with a diaphragm tank, skip to number three, because there’s no draining your diaphragm tank. If you’ve got a more elderly system (read: a tank with a drain valve and a shutoff valve), you should be draining it every year.
Let’s talk about how this works for a moment. First, you’re going to want to close the shutoff valve. Next, open the drain valve and let the water run into a metal bucket. Once the tank is drained, close the drain valve and open the shutoff valve.
One thing to note: if no water comes out when you open the drain valve, try opening the drain valve’s vacuum-breaker plug, if it’s got one. That will generally get the water flowing. Do make sure to close it again right after you close the drain valve.
3. The Radiators
Air can get stuck inside your radiators and do awful, annoying things like stopping hot water from getting in. To fix this, you’ll need to bleed your radiators every year. Don’t worry: it’s not as gruesome as it sounds. It’s basically a process of letting out that hot air.
For this, you’ll need a pan. Stick it under the bleed valve and then open the valve with either a screwdriver or radiator key (you can pick these up at most hardware stores). Keep the valve open until water starts to flow out. This is a sign that you have bled all the trapped air.