"Is this potentially something you would be interested in?"

Not just no, but hell no. My eyes glazed over immediately. I then skimmed down to see what exactly this overly complex bunch of wires and gadgets would actually DO, and it's a fancy thermostat. I can buy a $35 thermostat with 7 day programmable and it can do more than I actually need it to do.

I even read a few lines to my engineer husband and he begged me to stop. You're bringing coals to Newcastle here and the wheel doesn't need to be reinvented. There might be 4 people in the world who would get excited about this. Tops.

You are mostly correct in that it is a fancy thermostat. It is a multizone thermostat. That cannot be purchased for $35 that I have seen.

I guess that is 1 heartily in "Nay" column.

For a multizone thermostat, consider what ductless (minisplit) heatpump systems can do. For most homes, zonal application of an hvac system is impractical.

@Kirkhall

Why do you feel that they are impractical? (Genuinely curious, no condensation implied.)

Based on the research I have been doing, round duct dampers are around $70 - $100 per unit. While the costs do add up, they are one time costs.

Jason

I agree with above post. You are basically re-inventing the wheel when its already been done. At this point if home automation is what you are after, you need to narrow down your needs and wants versus your budget and how much you want to spend. Of course the more gadgets you want the more expensive it will be. You can start off in the budget/diy tier looking at systems like Elk M1 Gold or HAI. If you are willing to spend more money and want your system turn key, then you can look at more expensive systems such as Crestron, Control-4 or Savant. Once you narrow down your wants and needs vs budget if you are building it will be much easier to have a plan before the house is built and pre-wire all the wire you can. Will be a lot cheaper to run wires with walls open than having to retrofit. Link below will get you started on the possibilities that are available and makes for good reading.

Hope that helps!

Here is a link that might be useful: Wiring your new home 101

The impractical part of extensive small zones has to do with the design of basic HVAC systems. The cheapest option for a HVAC is a single stage fixed speed, and the costs from there skyrocket. You would not be able to use typical HVAC equipment - look at the amount of minisplits in new construction in the US - it is probably .01%. You would need that but they have a number of limitations most significantly they don't use NG - which is currently the cheapest way of heating a house in the US. They also aren't made to my knowledge with geothermal capabilities.

So you are immediately impractical by not being able to use the most efficient technologies. There are commercial systems that can ramp to do what you want but they aren't made in residential sizes and they are too expensive to be practical for home use.

The key to a comfortable home is balance. And then you still have to fiddle - like the space heater in my toddler's room.

Definitely look at Carrier Infinity as they have incorporated a lot of what you are looking for - although certainly not all. But you can be shocked at the internet interface cost for example.

There are $100 stats now at Lowe's that are wi-fi capable and smartphone app controllable. Even the Nest has some interesting features. What you are looking for is just too complicated for the majority of people to even think about which makes its commercial viability hard to fathom.

I like computers, but what I want from my HVAC system is simplicity, not 10,000 options. We figure out what temperature is comfortable and then what vents need to be opened or closed depending on whether we're heating or cooling (which is a twice a year thing) and then I don't mess with it. We might bump the heat up a little if we have a guest whose inclined to be chilly, but otherwise it requires no attention.

I could see someone with a large art collection wanting a system that gives them this kind of control so they can be sure their investment is kept in a stable environment, but most of us don't need to keep things quite so perfect.

NOTE: I've worked on complex electromechanical systems, installing, repairing and operating them.

It sounds expensive and difficult to install, a nightmare to program, and too complex to operate.

The hard-wired central controller approach is obsolete and would be more expensive than a combination of off the shelf systems.

I suggest you study the current state of industrial control systems and programming control systems, communication protocols, HVAC systems, microcrontroller chips and revise your design.

http://www.microchip.com/
OR
http://www.automationdirect.com/adc/Overview/Catalog/Programmable_Controllers/

Main Interface Panel (MIP): The MIP would contain multiple microcontrollers and act as the central wiring point and perform the actual sensing, control and monitoring of the home. It would be connected and/or interfaced to the computer, wall units, lighting control, HVAC, audio switch and other systems. The MIP would have some level of intelligence and be very expandable. The MIP would be able to provide basic level HVAC control in the event of the computer failing.

Why hard-wired? And why would it take multiple microcontrollers to handle something as slow-moving as household automation? Microcontrollers of today are smarter than the PC of the 1980s and 1990s.

FWIW, in the 1990s my brother automated large freighters engines, boilers, and water-chilled HVAC with ONE off-the-shelf generic 16-bit PC and a couple of custom interface boards. There was enough computing power left over to log the ship's movements. Today he could do it with one $25 "Raspberry Pi" and the custom I/O boards.

Computer: The computer would be either a completely separate unit or housed in the same unit as the MIP. Pros and cons exist for both methods, however its role would be same regardless. The computer would contain all of the advanced logic that controls the system. It would also provide for remote interfacing capabilities (i.e. web, tablet, smart phone, etc.) This is where the true brains of the system would reside.

Uh ... the whole point of a microcontroller is to get rid of the computer.

Wall Panels: Wall panels would be analogous to current thermostats and audio control panels. These could range from very simple (a few buttons and basic display) to very complex (full touch screen) and would connect to the MIP. Additionally the wall panel could house additional sensors.

The cost of the display and buttons is not trivial, and the touchscreen is even more expensive.

Also, I think there's an app for that for your smartphone or tablet. No dedicated wall panels needed.

http://www.gottabemobile.com/2011/08/03/cheaply-control-your-thermostat-with-a-smartphone/

http://news.cnet.com/8301-11386_3-57361886-76/need-a-better-thermostat-look-to-your-smartphone/

-Audio control via IP or serial. Why? I already have it via wireless. From every computer in my house, via the wireless router.

-Multiple sensors (temp, humidity, inside, outside, doors, windows, etc. Essentially, anything that one would want to monitor, could be monitored.)

And what if you decide you need to monitor something else? With your setup, there goes another wire ... which will fit where? This idea lacks flexibility.

And how do you get the information to the user? If I have to walk to a wall panel to find out, it's not convenient.

I want it to IM me :)

-Multiple control outputs via relays. With a relay, anything that has an on/off state could be controlled.
And how will you handle the stuff that needs 5VDC, 12VDC, 24VDC, 120VAC, 220VAC, etc. Another relay on the far end of the wire? That's a boatload of relays.

-Variable speed control (variable speed fans in air handlers, for example.)
Best handled by the thermostat and the air handler and HVAC unit's existing controls - the makers have well-paid design engineers for that.

-All inputs and outputs are assignable. (No forced groupings of ports to zones.) Already possible without your large number of relays and wires and stuff - it's called MAC address, NAT address and for wired things, the "CAN BUS" code that tells the listening devices who is being given orders.

Intelligent Heating/Cooling: Assume all zones are set to 70F and the dead band is 2F. (Heat comes on below 68F and goes off at 72F.) Zone 1 crosses to 67F. Instead of just turning on Zone 1 heat and waiting for another zone to cross the threshold, All the other zones are checked. If Zone 2 is at 69, it will also be supplied with heat.

Why? You just eliminated the purpose of the gap. Maybe that room was going to start drifting up without any extra heat.

Complex Conditions: Instead of just taking the temp from the wall unit, various other sensors and data could be used. An average (weighted or not) of floor, wall and ceiling temps could be used. Humidity (internal or external) could be used. Outside temp and/or humidity could be used. Various and complex if/then conditions could be checked.

Why? Will these complex measurement algorithms improve the comfort level of the home by enough to warrant the expense of installing the sensors and developing the software?

Intelligent Pre-Heat/Cool: As the system would be monitoring the internal temp/humidity/etc, it could also monitor external values as well. Based on historical information of inside temp, outside conditions and defined arrival/wake-up time the system would know that is takes X minutes to bring the space to the desired temp. The system would then turn on the heating/cooling at T-X, where T equals the arrival home or wake-up time.
Already on the market for $300 or less, web enabled to use the local weather data from the net or from your backyard wireless thermometer/humidity gauge. If the outside temperature starts changing quickly, the thermostat compensates for it.

Outside Air: (Note, I do not know if there are any code issues surrounding this.) With the use of dampers and outside supply and exhaust, the system could be used to bring in fresh air. This could be done continuously at a low level (particularly spring/fall) or as a defined time to clear out a stuffy room.
It's already on the market, and it's called an air exchanger. It has a heat exchanger in it to bring the incoming air to equilibrium with the inside air, and a HEPA filter. Many units also have a dehumidifier built in.

Required by some codes.

Another function that I see as a benefit to the kitchen would be an "Evac" mode, where only the kitchen dampers are opened and the fan runs at full speed bringing in outside air to clear out smoke from a something burning in the oven. (This would not be to fight a fire, but would be when there is too much smoke for the range hood.)
That's called the range hood and the "make-up air" that is already required by most building codes.

Huge level of physical expandability would be available. There could be a over 250 wired wall panels and a total of over 2000 sensors/inputs/outputs.
Why would any household need that much expansion ability? What would you be measuring that would need 2000+ sensors?

My eyes are bleeding just reading this. Soon to be followed by a brain aneurysm.

All over HVAC controls? Sheesh. Get a better hobby.

@David

I think I failed to adequately articulate my ideas on the infrastucture of the system. Please allow me to clarify and address your comments.

The idea, and my research of what is out there bears this out, is to use conventional HVAC equipment. Be it a boiler, furnace/air handler, heat pump or other. The control unit would turn on the appropriate unit and close the dampers/valves for the zones that do not have demand for heating/cooling. This could a simple single stage unit or more complex multistage, variable fan, etc unit. Multiple units (such as one each for upper and lower floors would be easy to accomodate. Where there would be a seperate system for each zone (mini-splits and the like) are not taken in to consideration. NG would certainly be able to be used.

You are correct regarding the cost/sizes for commercial HVAC equipment. yes, it has a great deal more features/functionality than the standard residential, but there are some advances in residentail capbilities. I have seem a few furnaces/air handlers that have variable speed fans and such. It is not as common, but they are starting to appear.

You comment on blanace, is what I am trying to achiev. Without the constant fiddling. Yes, there would be some fine tuning to get to your partularly level of comfort, but them the system just runs.

The Infinity looks interesting, but very tightly coupled to Carrier's products. My intention is something that uses more common, off the shelf components and integrates with various products. Yes, the "brains" would largely be tigtly coupled with each other, but it would be able to talk to most any system. It would not matter what your heating/cooling source is, or who made it. Same for the valves/dampers an other components. The system would interface with all of them. (At least in theory.)

As for the complexity, sure it could be very complex. At a base level, however, it could be very simple. Connections from the wall units to the controller could be standard thermostate wire or Cat5. The connection from the controller to the furnace would be no different that from a regluar thermostat to the furnace. Granted there is also the wiring of the dampers, but that is a very simple 2 wire connection per damper. However, if/when the owner desired, they could use the more advanced functionality of the system. Also, I see this as product similar to whole home audio. There are a number of system out there where you have to go through a distributer. Residential HVAC companies could easily accomplish the more advanced functionality but it would still be available to DIY minded consumer.

Essentially, what I am looking at is a conventional heating/cooling arrangement with dampers/control valves.

I hope that clarifies that aspect a bit. If not, please let me know and I will provide further detail. (My appologies if I rambled a bit.)

Jason

You are going to spend a lot of money up front and in maintenance for very little practical benefit.

One way to increase the failure rate of almost anything is to make it more complicated.

There are real reasons large commercial buildings have full time 'standing engineers' to keep things running.

I think it's a good idea for a hobby but as the mainly negative replies show it doesn't have broad appeal in the USA.
I'd like to have an automated HVAC system that can selectively heat or cool different rooms. My parents have that and I liked to be able to heat my room to 75 at night while they preferred 68 for their bedroom.
It's standard in my former home country but people in the USA are't used to this standard and apparently don't miss it. You could not sell a new house without room by room HVAC control where I grew up.

I'm not interested in this kind of thing. What I hear is, Expensive to install, Probably going to break down, The monthly fees will cost a fortune.

Similarly, when I see those TV commercials about turning on your alarm system from work, locking your doors from an airplane, etc., I just think, "Who wants this product?"

I hear that you're excited about it. Good for you, but I wouldn't take this product if it were free.

Mrs. Pete-- our local cable company is pushing a service where they set up cameras in your home so that you can monitor your house remotely. Whenever I see the ad, I think about who within the cable company might have access to the feed, and why anyone would so need to see their house when they are not there that they'd be willing to give up their privacy like that.

Regardless of some of the more negative views here, our houses will become more and more automated, and even we in the US will adapt. I read an article about a Japanese urinal that had a built in sensor that sent data to the user's doctor, and thereby monitored his values. :) Funny example perhaps, but in this day of iPads and mobile devices our homes are really the remaining dinosaur. So much more can be done, and indoor air quality and comfort, not to mention energy savings, should have high priority. There will always be people like MrsPete who objects to new technology, but companies like Control-4 are taking off for a reason. The Nest thermostat is produced by former executives of Apple. (Wouldn't a control unit from Apple be cool? Controlling whatever you want via apps.)

My personal opinion is that this seems to make most sense in new construction, as it should be hard wired for reliability (I have a wifi based security system and all I can say is never again). I think you biggest problem is to package this so that the general technofob doesn't get scared, and then reach a price point that competes with Control4 and the likes. I think Control4 seems very promising, but their dealer installation requirement may scare off many custom builders, which I assume is a primary target market for them. LazyGardens also had some very good observations that you may need to consider.

And no, I wouldn't want Comcast to have access to my camera feeds either.

I'm not opposed to new technology -- I love my ipad, I use the newest and best digital cameras in my classes, and I have plenty of other new technology. I just don't see any real benefit to the items in this particular discussion.

I think the home automation that takes off will be devices that make things simpler, not ones that add complexity. And it will have to work in a way that doesn't mean that you can't turn on the light next to you until you find your phone (or worse, have to sit in the dark because your phone's battery is dead).

I'm not a technophobe by any stretch, but that doesn't mean I want to make my home more complicated, especially when the current solution works quite well for my purposes. Also, I've seen a fair number of homes that had the state of the art technological gizmo built in 20 or 30 years ago, and it hasn't been used in ages, and is more in the way than anything else. I don't want to spend a ton of money building in a system that is out of date immediately.

Fair enough, but capability doesn't have to imply complexity. I see nothing in the OP description that couldn't be completely automated for the user once installed. The systems I see (like Control4) are usually complemented with light switches and analog thermostats for redundancy. No need to sit in the dark.

The real issue is when you close dampers you upset the airflow dynamics of a conventional HVAC system. They are designed with just enough duct size to keep things running. Close a damper and you raise pressure in the system. Close multiple dampers and you can cause really big problems. You can't expect an average residential furnace to heat one room at a time - it creates big problems.

As far as other countries with room by room HVAC, they are using minisplits which make no sense in a country like the US with super cheap NG. In Europe, they pay 5 times as much as us for NG - so minisplits make more sense.

I looked into a lot of home automation and wired my house to the nines but I haven't used much of it. Sure homes my gradually get more automated but the tech is there - really no one wants it. The tech has been mature for years now but the market penetration is tiny. It is mostly a gee whiz kind of thing - it is really hard to come up with truly practical things to do that don't cost so much to set up to have value.

Sure I'd like my lights to turn on in rooms before I get there but it isn't worth the money to do it. Now whole house audio and video is a totally different thing and people are doing that in significant numbers.

I'm a computer scientist. Used to design real-time systems for NASA, Navy, and DoD.

I would NEVER have a home automation system.

There have been, and are many home automation systems. None of them have ever captured any market share. You may find someone to install, but after a few years, and not enough sales, you will be stranded with a system that has no support or growth.

What you're talking about is something they have in submarines - but not in residential homes.

"So much more can be done, and indoor air quality and comfort, not to mention energy savings, should have high priority. "

At what cost?

We have already devolved to most major consumer electronics being essentially 'disposable' (non-repairable) with limited lifespan based on components used in them (like aluminum electrolytic capacitors that only last around 10 years).

Systems that will not provide cost savings in the expected life of the system commensurate with the initial cost are failures.

Spending $100 today to save $50 over a ten year system life is a failure.

Some good points here, and it seems most here object due to high cost at doubtful value. However, Joe consumer has shown over and over again that cost of utility is much more sensitive than cost of convenience. As David points out, once it involves sound and video things come into a different light (no pun intended). David contradicts himself a bit here "The tech has been mature for years now but the market penetration is tiny. It is mostly a gee whiz kind of thing - it is really hard to come up with truly practical things to do that don't cost so much to set up to have value." Hardly sound like a mature market to me. Surely it would be convenient to orchestrate lighting with moods or setups rather than walking around and switching things on and off? Some may get regulated. In California all toilets space must have motion sensors to save electricity. A large portion of new homes have security systems and many complement that with cameras for the main entrance, etc. Houses with many window shades could benefit if the price was right. And I still think many would like to control temperature in zones if they could afford it or it was simpler. What if it indeed did become simpler and was offered by someone like Apple? (I'm just using Apple because it's a name people can relate to, and I quite frankly wouldn't be too surprised if it were to happen sometime in the future after they've had success with a TV).

It is a horrible thing that a laptop or an iPad doesn't last more than maybe 4-5 years for most people, and that it can easily cost $500-1,000. No doubt about it. But it is also another type of problem for another type of solution. I have an iPad and really love it, it has made my life easier, and if there is something that really moves the needle within the next 5 years I will upgrade to that instead. It doesn't matter if the technology inside only lasts 10 years, because our quest for convenience has already made it obsolete. One could of course wait ten years until tech has caught up with our visions, but why not benefit in the meanwhile? None of us are getting any younger. A convenient and efficient lifestyle has that value to me, and I think many will argue the same if someone comes up with a cost effective, easy to use home automation system from a company big enough to create some form of standard. I kind of like Control4 as a concept, they are relatively cost effective, seems to gather a fair number of manufacturer support and have an iPad driven interface with their own app store. However, they are not big enough nor have the awareness of someone like Apple. And a too big portion of the investment relies on the quality and honesty of the installer.

One of my close friends, he actually worked for NASA as well although not as an engineer, told me a couple of years ago that the trend with combining your music player and camera with your phone was ridiculous, who on earth would want that?

We are looking into home automation for a future (The plan-killer is the lack of standards for interoperability and connectivity - there is nothing like the USB standard, the RS-232 standard or the CAN BUS ... it's a mess of competing and proprietary standards. And vendor lock-in sucks!

So we're going to go with what is feasible and let the rest go unless/until the various industries get their heads out of their nether regions and get some standards set so we can mix and match from various manufacturers.

@lordnelson: "told me a couple of years ago that the trend with combining your music player and camera with your phone was ridiculous, who on earth would want that?"

The answer is children and people without a life.

Lol. Listening to music or taking pictures makes you either a child or someone who lacks a life? The world you live in must be grim.

In 2013 the market for smartphones is expected to be 875 million units.

Waste, and it will never work properly.

Too little air over the coil and it will freeze, too much will not perform properly. DOE has a project to hvac more efficient and separate humidity and cooling. As for now it is still in research.

I have commercial multi-zoning panel with up to 4 stage heating 3 stages cooling network humidistats, supports external air sens. Not sure I want it. Will be selling on ebay.

Vs I could set proper flow with real manual dampers, install R60 in the attic, add foam on exterior and still be cheaper than one of those and more reliable.

Schwefel,

Your meta concept is something that�s been kicked around before, lots of great ideas, but because its "not" a mature market there has not been the type of true integration of technology that would be required to really get people excited.

First, to everyone who says it�s a horrible idea, that no one needs/wants and is to complex� why do we need cell phones� land lines are just fine for phone calls, or why need a laptop or tablet� desktop computers do the same thing for less. It�s all about convenience, simplicity, and price! Much of the technology we use today existed 15 years ago in a complicated, inconvenient, and expensive form. As the march of progress continued, technology has become cheaper, more reliable, and simple to use. The idea of "smart" homes have been around since what� the 50/60�s (Disney had examples in their theme parks) � but there has never been a true integration of all our household items, working together, to create a simple, easy to use system.

Now back to the topic�
I understand you started your system off with the HVAC system, and as a component of a "Smart House" is great, but there are true scale limitations you would have to contend with to make it cost effective. I�m not an expert in thermo-dynamics, but understand there are limitations to current HVAC system design, both in their mechanical ability and their thermo-dynamic ability. To do what you want, it might require the new engineering of a system to enable it to change airflow speeds/temp/humidity based on what each room/zone requires and what is the most efficient way to get their based on constantly changing variables. I understand that this is done on industrial/commercial scale now, it might take 10+ (random number) years to cost effectively design a residential scale system to handle what you want to do.

In my useless opnion, you need to start with "KISS" Keep It Simple Stupid. Every idea you have, needs to be distilled down to "if a 5 year old and a 90 year old can learn it and use it, people will buy it". For true mass market potential you should think about the ability to truly retro fit a home that is 100 years old at some type of cost effective pricing. That means designing a system that uses wireless signals (wi-fi, mesh wireless, Bluetooth, Near Field Communication (NFC), Ect�). Since these technologies already exist, you could retrofit an electrical socket with one that works on (for example) a mesh network, and is assigned a NAT or IP address to that every socket can be wirelessly connected. This would in turn be tied a home network that works with a smart phone/tablet app so that once it�s up and running, it�s simple and easy to use (I hate to say it but if Apple makes it� they will buy it).

I�m goanna stop now since I�m getting long winded and rambling but good ideas (I know I only hit a few). As the technology comes along and becomes simpler to install and use you�ll see a market with true scale develop that will make it cost effective to actually implement.

@lordnelson: "In 2013 the market for smartphones is expected to be 875 million units."

There is no end to low information voters. I expect the non-thinkers to far surpass us logical thinkers.

You are free to occupy your mind with any kind of drivel, it just doesn't help with the real problems facing our countries.

Just think about the fiscal problems in Greece, Spain, Ireland, the US. But all is good cause you can listen to tunes, send pictures, etc, it really numbs you to your pointless life.

I could only live in a high-tech house if my son was here to program/reprogram the thing. We used a 'smart house' device to operate our front light. It was incredibly complicated to program, and then it died after about a year. We just turn the light on and off with the switch now. I really don't care for anything with 'programmable' in the name. I don't have a smart phone, iPad, GPS, or any other gadgets. It's pretty remarkable that I can operate this lap-top. I'm an old timer, and set in my ways, but you young kids have fun with your toys.

To think that I just occupied my mind with Doug's drivel instead of worrying about the fiscal cliffs of the world. Oh my!

Hi,

I am building a 4K sqft home and have done all the automation in my last house (by myself). During that time I worked for a company that owned a division that sold home and industrial automation and I could get anything for 50% below cost.

Having said that we just broke ground on our second home and I am doing all the design install and automation for this home and here is what I am putting in from what I have learned in the past.

#1 - Lighting System. It was my favorite thing in the last house (a Leviton system). This time I am using Insteon for many reasons but it can be programed by a small box you instruct - plug into an outlet and let it do it's thing. Custom printed buttons, complex scenes - timers whatever. It is the most flexible system out there and goes from standard configuration to super complex and everything in between. It is also cost effective.

#2. You can get Insteon Thermostats that do a lot of goofy stuff - but I am going with 2 Nest units for each zone. Easy Simple.

#3. A Cat6 Camera system from Samsung (16 cameras - only putting in 8 to start). I really like the fact that I can see the house and the sump pump etc. when I am out of state.

#4. An ELK alarm system. This is the "brain" of the house and it talks to the lighting system and Insteon thermostats. You can hit the "Vacation" button and it will set the HVAC and even turn on and off random lights at night if you want.

#5. I am wiring for Somfy drapes and shades. Simply putting in the 16/2 DC wires in locations for now. The bedroom will be all blackout shades. Roll over and hit a switch and you are in a 1000 a night hotel.

I am not putting in any music systems. Never used them. I had a fancy Russsound AV distribution system as well and won't be doing that either. Simply doing Cat 6 everywhere, DirecTv, and will use wireless Apple products for music at patries.

You will NEVER use a computer to control these devices. You will never get up and use a wall touch screen. That being said this is a hobby and should be treated as such. You won't get your money out of it. Your friends won't understand it. Friends at parties won't understand it. But if it is something you like then go for it. It takes 10,000 times more effort, time, frustration, and money to do these things with an automation system than it is to get up and hit the light switch or pull the drape cord. But to me it is something I can't seem to live without.

Wife hates it - can't seem to understand how it all works - or the need for any of it. Even with custom labeled buttons that say "party" or "clean up" on the lights she still uses the switch instead of the scene button. It is nice to turn off every light in the house from your bedside - and then to have the alarm to arm automatically at 11:00 at night with no need to do anything. To have the lights come on and light the house when it detects motion etc.

That being said it is a very slippery slope. Don't listen to the salesmen - they want to sell you what they want to sell. Best advice is to do as much as you can and bring in a pro for the things you don't understand (alarm for me)...

Good luck!

Also - I think they make a multi room system like you describe. Link below. From what I hear it eats forced air central air units for lunch by choking the life out of the thing...

Here is a link that might be useful: HVAC