Slashdot Mirror
DIY HVAC
An anonymous reader writes "I found this very interesting project called DIY Zoning. It allows one to add air flow balancing, temperature control, zoning, home automation, and more to an existing or new HVAC system. After getting a $200 electric bill, this sounds like a good solution for those who are getting screwed with outrageously high electric bills due to their HVAC unit especially since organizations like TVA have raised the electric rates."
DIY Zoning is just one in a family of projects.
Don't forget about Haywire, Jukebox, and ServoMaster, all of which are hosted at SourceForge and directly tie-in to the temperature zoning system featured in this Slashdot posting.
[Oh, and FWIW, Professor Tkachenko's son is a cutie (an old college friend of mine knew him)!]
Background: 28/M/Bi-Sexual; Owner of a Linux company; MBA Harvard 2003; B.S. Comp Sci MIT 2000
Im just waiting for someone to recycle toilet water for showers. When is the madness going to stop.
for non-eXtreme geeks like myself, HVAC stands for Heating, Ventilation, & Air Conditioning.
Not that it would matter to you if you are working on it by yourself, but without support for the technologies that the spec requires going forward, you face the unenviable position of being stuck with some out of date specs.
I have been pwned because my
Put the real thermostat somewhere hidden and place a dummy one in the hall for the wife and kids.
Putting a circuit in to turn off the AC when someone opens a window helps too.
Beep beep.
Is going on a lot here where I live. Berea College has completely rebuilt many of their buildings to make them more environmentally friendly, and to cut down on their "outrageous energy costs". Not to mention that Berea College owns all the utilities here anyways.
;).
I really don't get why this kind of project is really worthy of doing anyways. May save some money, but most people's houses dont use more than 1500 kWa of electricity a month... ~140$ of electricty around here (considering we pay the "Berea College Utilities" tax). Now a worthy project would be covering your house with solar panels and breaking even on your utility bills
"Victory means exit strategy, and it's important for the President to explain to us what the exit strategy is." G.W.Bush
This is why I only use solar energy!
Ack, gotta go, a cloud's coming!
A friend of mine is doing this himself using parts from a website (the name escapes me) and drivers that he is writing himself. I also ran into this a while back. It looks like a lot of work, but considering how much a system like this would cost, its probably a pretty fair bet for experienced hackers with some spare time.
Complaining about TVA rates? Haha... You are getting some of the cheapest, subsidized electricity in the country.
Read this:
http://www.nemw.org/tvareport.htm
Does anyone remember way back in the BBS days of the early 90s (when the net was new or undiscovered for so many) when HVAC meant "hacking, virii, anarchy, cracking"?
/.
What a weird yet fitting title to see on
As an ex plumber-pipefitter, zoning is a must for any eficient system.
,it is looks like a full blown commercial install, When I was out of town once the boiler went out (flooded expansion tank) so my wife called the company I worked for, my friend glen cam out and said , "uhhh youre gonna have to call in a commercial outfit were all residential and Ive never seen a system like this before Chris (me usually handles all our commercial stuff"
Take this house for example, 2000 sq ft 2 story farmhouse, 1950's anderson windows, still nice but not real tight, no in wall insulation, attic is aesbestos (but now sealed)
The house is set up into 3 zones, on an old , circa 1950 American Standard electro-mechanical zone system, it is hot water heat, about half baseboard, the other half cast radiators, the heat throught the hose is awesome, never too cold anywhere. Now, the fun part, we dont have gas, and electric was way too ineffecient to heat this house soooo, my grandfather a pipefitter as well installed the system back in the 50's
The wind up of all this , my heating bill for the entire year ? Under $600 Thats 350 gallons of oil, I only took 310 or so after 13 months last time I topped off. And I live near Cleveland Ohio (Akron), not exactly warm winters here ya know
It's quite simple, really.
:)
/. readership are bachelor males. Of course, a fantasy alternative would be to get a girlfriend with her own place and just crash over there.
Learn to do without.
I know it sounds contrite, but hear me out.
Do you really need both of those monitors? If not, chuck one, or turn it off. Monitors draw quite a bit of power. Also, make sure you turn off your monitors when you're not using them, or make sure their power saving modes are on. Alternatively, you could go LCD to help reduce the costs, but I've always looked at that with some suspicion in that the prohibitive costs related to 19" and higher LCD's offset the potential savings.
How many computers are you running? If the answer is more than one, ask yourself if you really *need* to be running the others. Sure it's nice that you've gotten that old P233 up and running as your firewall, but frankly, a Linksys dedicated router/firewall is going to draw much less power, with fewer moving parts.
Air Conditioning: Learn to live a bit warmer. Learn to open windows instead of reaching for the thermostat. You'll find that your body can and will adjust to warmer temperatures if you let it. I live in the South with oppressive humidity and heat during the summer and my dad tells me stories of him growing up when they didn't have A/C. It can be done. And, if you follow the first 2 items above, you'll find your house isn't as hot. Computers + Monitors == lots of heat. Now, in my apartment, I don't have central A/C, only a couple window units, unfortunately. A trick I've learned is to shut the door to my bedroom, which happens to be decently sized, and only run the A/C in that room. It gets downright cold pretty fast. Now, it does make me somewhat of a prisoner in that room, only venturing out to use the can or to cook something in the kitchen, but I've learned to cope. Besides, I can grab my laptop and browse the web wirelessly from anywhere in my house. Also, at least here, the hottest part of the summers is only one or 2 months that you have to "suffer" through. Actually, if you work a lot, here's an excuse to work some OT.
My bill dropped from $150/month to less than $50/month once I adopted these measures.
If you're married with kids, feel free to ignore because I'm assuming most of the
If you were me, you'd be good lookin'. - six string samurai
The project was born out of a total and absolute frustration which in turn was a result of a fruitless search of information about existing temperature zoning solutions. The only information available on the zoning system manufacturer web sites was usually "call us for an estimate". The estimates were usually being performed by salespeople. Technical people were difficult to get. Read the complete story for details.
The author obviously didn't look in the right places. Here are a few links to get started:
SmartHome
HomeTech Solutions
Bass Burglar Alarms
I've done business with all three, and have retrofitted my home with a two-zone system powered by an RCS zone controller and electronic dampers. All three have been extremely helpful in providing technical advice.
One thing to remember: The HVAC business (as well as the burglar alarm business) are very protective of their turf. You stand little chance of finding an HVAC contractor willing to work with you on designing a custom HVAC system.
So this is essentially a programmable thermostat for your PC with some more advancded features like zones, right? Or am I missing something?
The HVAC community is definitely different from Open Source community, and whenever they get close, it gets quite hot
Doesn't seem that hot - fun reading I'd say! The idea is great though (not new, but great) - As open source branches in to more and more area, the people involved with open source software are more likely to adapt OSS principles to non-software aspects of their work.
"An open-source future is one in which we realize that reality itself is open source" to quote an unknown guy on the internet. Hope it happens this year!
I think the idea of open source energy solutions is a great idea. Right now, we have NO choice of who we buy our electricity from. The situation with electricity and fuel is 20X worse than Microsoft's control of the computer industry. What happens when petroleum gets too expensive and runs out?
Its time to do something about it.
What is the fate of a few third-world countries compared to the convenience of a heated driveway.
Throw that snow shovel away!
This site includes a number of ideas for reducing that energy bill, including zoned heating/cooling. There are several interesting real-time graphs of current energy use.
I found the site while searching for information on heat pump water heaters. One example graph they give shows the heat pump water heater using less than half the energy as resistive heating.
If installed properly, a heat pump water heater will also help air-condition your house. A good place to put ducts is in the kitchen, where the waste heat from cooking can be removed and used to heat water. Ideally, the returned cooled air can be directed at your refrigerator's condenser coils for increased efficiency.
While there's no good reason I can think of that retrofitted zoning would be a zoning problem, sometimes what's permissable and what's not isn't always self-evident.
It would royally suck to need something inspected later on, such as when selling a house, only to be told it wasn't code and had to come out or be expensively upgraded to meet code. I've done a ton of electrical work (some in conjunction with remodeling which was heavily inspected) and nobody said boo, but it was all code-compliant.
And speaking of resale, even though a zoned hvac system would be nice, one that's more complicated than your grandma can operate will actually lower your resale value to most people since it will be seen as a maintenance liability. I put in a Honeywell 7 day programmable thermostat and my wife hated me for a couple of months until she figured out how to work it. I can only imagine what she would do with something that made one room cold and another warm without being totally obvious (like a 15" LCD touch screen with a floor plan of the house and car-type heat controls).
But my swamp cooler keeps the house cool and saves me a lot of money over my A/C cooled neighbors.
Evaporative coolers use electricity only to spin the fan vs. compressing freon or whatnot, which takes a lot more energy.
Treatment, not tyranny. End the drug war and free our American POWs.
See my user info for links.
go to home depot, buy a $30 digital thermostat. install it yourself (its 3 wires for the heat/AC and a AA battery for the thermostat). program it so in the summer your AC is at 78 when you are home, 85 when you are at work, and in the winter, 68 when you are asleep and 72 when you are home). the digital thermostat will easily pay for itself in 1 month in the summer.
Does the name Pavlov ring a bell?
Actually I think you do have choice.
Here you can buy from the government regulated electrical power grid. Or you can generate your own electricity. Solar cells, gas generators, waterfalls or whatever you want.
But there is a reason most people don't do this, the utility price is easy, cost competative and reliable.
I think rates aren't all that high, most people waste huge amounts of electricity. I read somewhere the average household in my area uses 750kWh/month, I just just over 300 kWh.
Insulate your house. Insulate your attic, insulate the walls, insulate the pipes and add secondary glazing. It's the cheapest and most effective thing you can do.
Government of the people, by corporate executives, for corporate profits.
Not as good as using dampers, but much simpler. I put a copy of the webpage for this system on my website:
System_Hvac
My father owns an HVAC company, and he uses a program called RHVAC to run loads of new and replacement installs, and gives the full report to the customer before they purchase. So not all companies are that bad. :)
Xbox reviews.. We think they're funny.
Sounds like a pretty cool idea, and cheap. From reading the site, its definetely cheap. Somewhere around $20/room for tempature controls/etc. I just don't like the idea of it being computer-controlled, in areas like where I live, it would suck if the controller crashed, and it was -40 out. Frozen pipes/kitty cats.
Bored? Why not join a decent mess
Just do what I do. Gorge and eat as much as you can in the summer, turn the thermostat to 60 in the winter and sleep for 6 months.
Works for bears, works for me.
From looking at their site, I would say if it subtracts value or decreases resale value, you can likely undo all your hardware changes in a couple of hours at no cost (servos on the actual vents, wiring in the duct system, no extra cutting, drilling, or equipment in inconvenient places.) While the solution is suboptimal (as they say, vent-placed equipment is not perfect), it is cheap and easily reversible in case you worry about that.
;)
Now as to the usability, it appears there is a current problem there with respect to the common user. However, once invested in the hardware and if you have a decent head for development, the system seems that it has a great potential for being amazingly simple (I have not looked at the code myself) to tack on a custom designed GUI with your touchscreen in mind. Of course, embedding a significant flat panel in the wall is not so reversible as the cheap approach
XML is like violence. If it doesn't solve the problem, use more.
And that's for a business? Now you understand what the whole ruckus was about in CA, back in 2001.
My home electric bill is roughly $200 (The water is also about $200). And that's LA DWP, which was a damn sight better than the poor fools who got 10x rate increases during the crunch.
The only reason we have the rights we have is that people just like us died to gain those rights. -- Cheerio Boy
The sensible heat load is the outside temperature seeping through the walls, but it is also the sum beating down on the roof and walls and pouring through windows. The latent heat load is largely the result of air infiltration with some contribution from showers and cooking: running a dryer contributes to latent heat because it pulls 150 CFM of inside air through the dryer vent that gets made up by air seeping in.
One of the points made was that in fall in Florida, the air conditioner runs less so the indoor humidity climbs to the sticky range. They are recommending a variable speed air handler so that a low flow setting, the air gets chilled more so more of the AC goes into humidity removal. Heat pipes have been recommended as well -- to pre-chill the air handler input and pre-warm the output to trade less cooling for more condensing.
Other approaches include not running your fan in continuous mode because that just evaporates the moisture film on the coils every time the AC cycles off to better draining cooling coil pans.
But a fundamental problem is that the latent heat load is pretty much constant across the day while the sensible load varies with the sun and contributes to the big electrical peak. One idea is to paint the roof with titanium white to cut down on the sensible heat load.
The idea I have is to try to smooth out the electrical peak load by letting the AC run more at night and run a little less during the day, and to let the sensible-heat temperature cycle up and down during the day, but to have some combined measure of heat and humidity remain constant. Instead of maintaining a constant temperature to try to maintain a constant indoor dewpoint.
This system would 1) have it cooler at night to make sleeping easier -- I can stand it warmer during the day, 2) smooth out electrical peak demand, 3) more efficiently remove humidity averaged on a 24 hour basis because humidity removal efficiency goes down if the AC duty cycle goes up during the day and you are pulling the indoor humidity below 50 percent.
Carrier makes a rather expensive ($200 plus) Humidistat product that controls the AC to both temperature and humidity targets. A cheaper solution for me is to use a setback thermometer which lets the temps go down at night and go up during the day, and to only start lowering temps at sleep time. A typical setback unit has night, wake, day, and return times -- I may go for 75 night, 74 wake, 77 day, and 78 return (the thermal pulse from the sun shining all day makes it through the house by evening, and at 78 the AC will be cycling to lower the humidity anyway). I also use an electronic humidity gauge and dial all those temps up or down a degree or two to get about 50 percent RH).
> for non-eXtreme geeks like myself, HVAC stands for Heating, Ventilation, & Air Conditioning.
And for the rest of us, it stands for High Voltage AC. Though that's usually fairly darwinistic as a DIY-project.
That is a cheap solution that will for for some. However your temperature settings are wrong.
When you are at home in summer, set the thermostat to 85, or 2 degrees below the outdoor temperature. You do not need it any colder, you body can handle high temperatures just fine. (There are exceptions, but those folks are under doctors care often anyway) When humidity gets to you, lower the thermostat just enough to get some of it out of the air.
In winter your pipes need heat more than you do. Invest in a few sweaters. When you have guests raise the temperature to 68. When you are sick set the thermostat above 68 if it makes you more comfortable. Set it to 62 when you are sleeping, invest in some blankets if this seems cold. I keep my thermostat at 60 in winter, no matter what, and I'd go colder but the thermostat is upstairs, and I don't want to chance my pipes freezing.
Check with your utility before doing anything though. Mine offers a discounted energy rate (off-peak) if I let them control the AC. I need to leave the AC on my at home temperature all day, because when I get home they normally hit peak loads, and so are most likely to turn my unit off. (This sounds bad, but in practice you never notice it, other than lower utility bills despite having a cool house all the time). They have a similar program for heat, but I have gas heat so I don't pay attention
I have a fairly paltry income, I was willing to do anything to cut back on expenses to make my daily life a little easier to live.
Started with the electric bill, did the obvious things, knocked the thermostat in a direction that'd keep the costs down. Replaced all the bulbs in the house with florecents. Switched to more energy effecient devices and appliances. It helped, but didn't make a real dent. My problem was heating and cooling. I live in a location with all the seasons. Very hot, very cold.
Then a co-worker inspired an idea. He faught in Viet Nam, told me bout how the guys rotated back to the world and stopped in Hawaii for refueling. All the guys in combat were so used to the hot humid jungle that the 88F weather of Hawaii was just too cold for them, they all had on leather jackets trying to beat the chill.
It was then I realized, that to a degree, my battles with TVA were more easily won by conditioning. All these years I had been spoiled by AC and electric heat. So I did a little experiment this Winter.
I vowed never to turn on the heat unless there was a chance that the pipes might freeze. Went and bought a coleman sleeping bag and a bunkbed at a thriftstore, kept myself closer to the cieling and snuggly in my sleeping bag. Kept very warm at night, during the day I'd burn a few candles just to take the chill out of the room, wore long sleaves.
My electric bill went from 270$ a month to around 30$.
Success through suffering. But the experiment worked, now I can run around in shorts when it's 38F out and it's not big deal to me.
How will I fair during the Summer tho? Many people die in the South from heat stroke, so I'm a little concerned about that. I really don't wanna die or get sick to save a dollar. So I think I'm going to do some zone cooling, reasonable AC set on 80 and lots of fans.
The methods illustrated in the story would have been tempting, but I'm a renter. Not a whole like I can apply to the living structure without violating my lease and being homeless where it's gonna be really cold out.
This whole submission is a sensationalist troll. "this sounds like a good solution for those who are getting screwed with outrageously high electric bills due to their HVAC unit". According to the article rates went up 7.4%, hardly a 'screwing'. Thus, if your bill was $200, that means it was $186.74 before, which means your "HVAC unit" (the definition left as an exercise to the reader) is pretty much shit anyway.
How does this stuff make the front page, is the editorial staff of Slashdot the Socialist Worker's Party or something?
I want to delete my account but Slashdot doesn't allow it.
UPnP is absolutely the wrong direction to go. If it's DIY in the first place, you are ideally suited to maintain it yourself, and UPnP is insecure (as in, it makes no attempt at security) and unnecessarily complicated for such a simple task as this. It requires a web server and parsing XML, not to mention TCP/IP... It might make sense for a commercial product but it will be expensive, adding probably a good fifty bucks to each device. (You could use Lantronix XJack or XPort or wtfever it is for example.)
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
Now i just need some soil moisture conent probes, and some light meter things, and i can finally have my computer controlled, uber-efficient closet marijuana garden!!
ah, technology.
Look out honey cause I'm usin' technology
Ain't got time to make no apologies
Actually, the single most worthy project would be simply buying a new refrigerator. They are the #1 electricity consumers in almost every household, because they run 24x7x365, and are never thrown out until they completely fail(after years of working below the already mediocre factory performance). Newer refrigerators are MUCH more efficient than those made 5, 10 years ago. There are even models that are so efficient, they can be run entirely off solar power.
Wanna reduce your electric bill, but can't replace your fridge? Leave enough space behind it for airflow, and vacuum/dust the coils, especially those under the unit. Oh, and properly set the controls; buy a thermometer and adjust until both compartments are cold -enough-. The freezer control, by the way, doesn't control the freezer compartment temperature- it controls the RATIO of cooling between refrigerator and freezer compartments.
All in all, even if you buy a new fridge, it could end up paying for itself in a year or two in saved electric costs. Oh, and slowly switch your lights over to fluorescent bulbs, wrap hot water pipes in foam insulation, put sealing inserts behind outlet plates+switchplates, etc. In the winter, cover windows in rooms you don't use with the window insulation you can buy at the hardware store. Find out the R-rating on the insulation in your walls, attic, etc; old insulation can be horrible compared to the latest new stuff(which can often be "blown" into place, install is a cinch). Got an old furnace? Get a new one; they're also a thousand times better these days. My folk's new gas furnace is so efficient, its exhaust is a 2" PVC pipe that is barely warm to the touch when it's going full blast...
Last but not least, turn off the damn computer when you're not using it, get an ISP account with webspace instead of running your own webserver, etc. I worked it out once...100-200W over 24x7x365 equals a LOT of money per year!
Please help metamoderate.
The main unit in this case can be a PC which uses devices not unlike the control units (except without servo control) and which have a power supply for the other devices, as an interface to the system. And, there are no big expensive components which are difficult to interface to because they are either on or off. Heating devices have a thermocouple which will provide a few mA of current to let you know when they are ready, you can pull that signal and then you just connect it through to another wire to turn on the heater. (I assume that AC is similar, though obviously not identical.) A thermostat is an amazingly simple device, especially electrically. Those devices will (at least internally but also externally) work like this basically forever because there is no reason for them not to.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
When I bult my house I used Wirsbo(tm) tubing under the hardwood flooring upstairs, and in the concrete slab downstairs. It is set up with zones, digital, 7 day thermostats, etc. The floors are always warm, any backup heat is from a pellet stove. All DIY. It is very comfortable.
The heat for the infloor system is from standard water heaters. Since the water heaters are downstairs, I don't need to turn on the thermostats for pump control - simple thermosiphon will cause the hot water to flow thru the system in the upper two stories.
The system is simple and convenient. If power goes out I still have heat from thermosiphoning.
It is possible top retrofit homes with this system, either with baseboard radiators or running the tubing between the joists (plus some drilling to get to each joist bay) as long as the crawl space is available.
There are other companies besides Wirsbo that produce this type of heating system/product.
When you are ready to build/buy your own house I recommend comparing HVAC and infloor heating. Look at "Fine Homebuilding" magazine for ads and articles, they are at the obvious web site.
To make my heating system more viable I used foam insulation for R-50 in the walls and R-60 in the roof. Double paned windows and a 5 foot overhang to reduce summer heat gain (my outside walls are 11 feet high). If the are more than 8 people in the house at a time I need to turn all the heating off, as the heat thrown off by the bodies raises the inside temp.
All in all a rather pleasant solution to the heating/cooling system.
Since I live on the northern California coast I don't need cooling. Average year round temp is 55 degrees F.
If you need cooling the system could be adapted for that. To cool the house you only need to cool the circulating water, a heat pump would the best solution.
A few months ago, I bailed on a seven-year stint as an active HVAC contractor in Florida; I love this project.
But I am glad I don't have to answer the radio shout for help from the poor on-call technician who gets a look at this equipment for the first time at 0200 on a Sunday morning. If something breaks on a system like this, and the geek that built it is gone, then things will likely progress as you describe: The hardware changes will be undone in a few hours, returning the system to a state understood by the servicer, even if the problem is as simple as a mechanically broken servo link. Many of the HVAC techs working have trouble using their VOMs efficiently on the high voltage sections of the system. For these guys, controls are mysterious scary voodoo magic. For such a cool system to survive its inventor it'll need killer documentation, easy to find and comprehend, and hard to lose.
The article mentions the Trane XV1500. We had a bunch under our care; they were wicked good air conditioners. They stopped making them because the average service tech was helpless to make them go when they broke, so they tore them apart and tried to make them work in a more simple way...which was not possible with those systems, as the compressor was a frequency-controlled DC motor. Much unhappiness for tech, for homeowner, for service company, for Trane. So now they make a condensing unit with two old fashioned compressors, and stage those. They still get butchered, but at least coldness can happen on an emergency call on the 4th of July weekend.
According to my schedule the episode of This Old House on PBS this week will show how in Bermuda it is standard practice to collect rainwater for all a house's water needs - in fact if a family uses too much water, they're forced to buy water from the government. Show info here shows up to last week's episode: This Old House
directly tie-in to the temperature zoning system featured in this Slashdot posting.
The temperature controller is an *excellent* idea, I think I'll take a look at incorporating it into my house.
Here's my little (non-computerized) ecological project: a gray water toilet which recycles water from my washing machine.
Fire and Meat. Yummy.
Come on, a cheap mini-itx with a decent processor can be put together for less than the cost of a simple digital thermostat, let alone one as complex as a multizone controller.
There are 4 boxes to use in the defense of liberty: soap, ballot, jury, ammo. Use in that order. Starting now.
Would there be anything wrong with using your shower water as toilet water? I honestly can't see anything wrong with that and it'd certainly cut down on somebody's water bill from month to month.
I meant to reply here rather than my post in the previous parent, I clicked on the link and brainfarted about the subject.
My toilet costs me about $200/year to flush (based on number of flushes per day counted for a typical week, and the size of the toilet's tank). So I built a system to refill it using water from my washing machine.
I did also consider using the water from the shower, but in practice, the water from the washing machine provides enough water to keep the storage barrel full.
Whether you have one or several toilets, the number of flushes per day is probably proportional to the number of people in the house. Since the laundry usage is also proportional to the number of people in the house, the water barrel is likely to remain full, but I'm sure there'd be no harm in dropping a pipe off the clean-out port at the bottom of the bathtub/shower U-trap, putting in another U-trap to serve as a vapor barrier, and draining that into the barrel. A couple of barrels should probably also be paralleled for a high-volume multiple toilet installation, but if you store too much water, it will start to grow (stinky) algae.
I tried paralleling barrels, but in practice, I didn't need to - just two people in my house. It'd be very easy to do, just a hose connecting fittings near the bottoms of each barrel, and they'll reach an equilibrium even if it's several minutes after the washing machine has finished a drain cycle.
As for what's wrong with gray water toilets, I don't know. I know it's against building codes here, but I don't know why. My system, not being a permanent installation or requiring any modification to the existing plumbing, skirts the rules about building codes.
I have yet to find a single disadvantage to my gray water system.
Fire and Meat. Yummy.
Over the past few years, we've had to replace our 20 year old central heating system (as our old one died) and recently, we've had cooling installed in the house.
Originally, we investigated the possibility of going for an HVAC reverse-cycle capable system but the running costs, along with the prohibitive installation costs were from Mars, or something. They wanted "only" AU$3000 for install of the three phase, plus it was about ten grand for the system and installation.
Installing split-system wall units was also an idea, however, cold air doesn't easily move throughout the house due to airflow being restricted so you'd realistically want units in every room. All of a sudden, Carrier's centrally airconditioned system doesn't look too bad.
In the end, we went with two evaporative coolers from a company called Brivis (Australian). These units are self-cleaning and self-maintained, too, so we don't have to dash up on the roof every six months. Our heating system is also from the same company and was the most efficient on the market when we had it installed.
Now, the nifty thing is that our wall controllers have backlight LCD displays and use RS232 (or 422 - I can't remember but I know that it was standard) for communication, so it should be easy to, say, hook one up to a PC if I really wanted to, although these AU$200 wall controllers have been installed in factory environments with 12 coolers in them. On one controller.
And because the installers of the cooling were slack (we should be able to have both coolers AND the heater on the ONE controller) and didn't want to run cables under the house, they installed seperate controllers for each cooler. So I've got one to play with if I felt like running some cables.
So how is it? Cheap to run, but be warned that evaporative coolers are better when you start them in the morning before it gets hot - the ideas is to cool the air by moving a lot of it. Windows need to be kept open to allow the airflow to occur or else things get very humid. And on a reasonable day, I've had the coolers bring the temperature from 38C down to a comfortable 21C.
But as other people have observed, these coolers become ineffective on humid days - we had a day with 80% relative humidity where the temp came down from 40C to about 32C - still a change, but it was still hellishly humid inside.
I'd love real HVAC cooling. It's dry, quiet and I can keep all the doors and windows closed, however it costs a fortune to install and a fortune to run.
Also, most HVAC systems had zoning as a feature. Heck, my heating has zoning built-in. I don't see what all the fuss is about.
Begining to change - a number of these industries are moving into SOAP, with such niche languages as CSML (Control System ML) and legacy-extenders such as Bacnet/XML and LON/XML creeping into the market
Check out the Continental Automated Building Association (CABA) a consortium of companies now working on OBIX, (Open Building Information eXchange) whose mission is to expose the API's or Building Automation Systems (HVAC, Access Control, Security, even X10 is on board) under a common XML schema.
Somewhere out there is a White Box ML, for interfaces to Refrigerators, Washing Machines, Dryers, etc. This effort is an extension of the earlier UPNP (Universal Plug and Play) work done earlier than SOAP was around for interfaces to consumer electronics, computing, home automation, home security, appliances, printing, photography, computer networking, and mobile products.
SOAP is also creeping onto electric meters (see Power Measurement's ION line, some of the GE product lines) although these are still priced more for the industrial solution. Eaton Electric's Cutler-Hammer is even selling a SOAP-enabled Power Panel (you know, the grey box with circuit breakers in your back room)
The IAI, the engineering standards group, is working the issue from the other end, developping top-down standards drilling down to meet OBIX coming up, most notably in Green Building XML (GBXML) which has a lovely schema. Major CADD companies such as Autodesk, Bentley, and Intergraph have committed to support GBXML in their tools when modelling is used for design.
There is going to be a lot more of this in the future, and SOAP is going to be the ticket.
I'm not a professor, for better or worse :) That's a different guy you're thinking about.
Time, time, time. DIY Zoning is modular, and in the very beginning I hoped that TINI (that runs native Java) will be able to host one of the modules. Alas, never had time nor chance to get my hands on it. Still, thinking about rewriting the project in C++, after all the architectural things are done.
Java can be compiled to native code. Why would you rewrite something just to change the language!?
My other car is first.
I've considered that, but you are ignoring the most expensive part of all that: my personal time in setting that up and getting it balanced out to where my family and I find it usable. It is the difference between a TiVo and MythTV: where I am concerned I would choose the latter, but because my family gets put into the equation I go with the former. Could I have gone with a Radio Shack learning remote? Sure, but throw my then-6-year-old into the mix and I went for the Pronto so that they don't have to remember "AUX1 is for this, but you have to hit AUX2 anbd power after that." I don't want the family to have to reboot the system because they're friggin freezing and some stupid patch hasn't been put up on a site yet. Besides, a lot of the digital thermostats from sites like SmartHome integrate into MisterHouse which runs on Perl and doesn't bog my server down. Best of both worlds.
"Beware of he who would deny you access to information, for in his heart, he dreams himself your master."
Con Ed in New York is about 3 times that. The little tables on energy efficient bulbs doesn't even go as high as our electric rates.
Energy efficiency is very important here and would have a great payback period, except that unless you do it entirely yourself the contractors will make you pay through the nose. The state makes various "barriers to entry" such as several layers of licensing so tradespeople's hourly rates for jobs of that kind of size are comparable to lawyers and doctors (I am not kidding).
When it gets hot here it is frequently very humid and this takes even more energy to cool. My worst computer failure was one summer when I was out, the air conditioner tripped off, and the room where I had my system got to 130 degrees. The complete failure and subsequent head crash of the disk was made serious by the failure of the backup system to make usable tapes for the past month.
For heating, zoning works well, since your heating costs are proportional to the difference between inside and outside. For cooling, it's a little different, since the equipment size and air volumes need to be reasonably matched to get a working system. If the airflow is decreased because a zone is closed off, the equipment is less efficient. How much less, compared to the savings of not cooling a room is up to you. Also, having zones shut off can cause floodback conditions, causing wear on the compressor, which can cost alot more than you can save. Heating is less critical, although you can have heat exchanger problems in a furnace if there isn't adequate airflow, ie. half the zones are closed.
IOW, be careful. I sell my expertise. If someone wants to design a system, then they are welcome to, but I'm not interested in getting involved. This isn't unscrupulous. Guess who you'll call if it doesn't work? Or something burns out? And my time is expensive. I could fiddle with something for days, but will I be payed for it?
Another issue is the high efficiency cooling equipment, or heat pumps. In humid areas, if you install as per manufacturer's specs for the most efficient, the unit will not dry the air out, and can contribute to mould and high humidity issues. So you may save a couple hundred over a year, then need to spend multiple thousands replacing windows, saturated insulation, etc. Again be careful.
Swamp coolers work well in very dry areas. In moderate to humid areas, don't even think of them. They will rot your house, and possibly make you sick.
The best way to save on cooling costs are to shut it off. To save on heating costs, have the house cooler and even cold at night.
Derek
Actually, I work for a HVAC wholesale distributor and I can get a Honeywell Chronotherm IV Single Stage Heatpump for 63.62 USD. The guy in the article 'vt' was using a Honeywell Chronotherm III. I don't know anyone who could build a micro tower for less than that.
peace,
-Grokent