Towards a better tinyhouse

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The tinyhouse wiki is up and running!

with one comment

After looking and searching and testing various wiki hosting sites, I settled on Wikia, because they seem to be the only ones with software that provides adequate function, and let you use an appropriate copyleft license. Surprise, surprise, it is based on the same software wikipedia uses, MediaWiki.

The runner-up was Wikispaces, but I abandoned them after I found that unregistered users cannot add new pages to the wiki, which I assume would slow growth.

MediaWiki is open source, and I think free, so I don’t know why other providers don’t use it, but whatever.

I have not added any articles to the wiki yet, but I try to add some when I get time. See some suggested ideas in one of the posts below, if you are looking for some inspiration.

If you would like to become an Admin, or a Beaurocrat, we need you, or we will, anyway, so do sign up for a wikia account, and email me, Gregor folouk at hotmail . You are not obligated to do anything at all. It just gives you various rights to revert pages and stuff. More info here :

Anyway, so here it is

The Tiny House Wiki

( also works)

I can change the name and URL of the wiki, too, all that stuff, if someone has a better idea for how it ought to be. I would be happy to pass the Benevolent Dictator For Life role (that’s the official term), to someone else, who has a good reputation. Basically the SuperAdmin role.

Oh, and of course, all the content is under a liberal copyleft license, in this case the Creative Commons CC-BY-SA license, more info here.

The remains of testing the runner up is It’s here : if you want a look at it.


Written by gregor

May 12, 2011 at 00:42

Posted in Uncategorized

Sort of signing off. Or maybe drifting off.

with 6 comments

Well, looks like no progress is going to happen on the political front in tinyhouses any time soon. I’m still interested in tinyhouses because ultimately I want to use one. It’s altogether possible I may use the concept in the future. In fact I see little else in terms of practical long term housing options, at least until I am making better money. And even then I would probably prefer a tinyhouse to save said hard earned money, at least until it’s time to sell it and move on to another phase of life.

But for now I have pretty much lost interest in them. I don’t really have much else to say left either, maybe a bit on politics, which is the only issue of relevance to me at this point, if I get the time. And this blog gets very few hits from readers these days – about 7 out of 10 hits is just people finding the posts through search engines.

So just thought I should let y’all know that I probably won’t be posting much in the future, anyway, rather than just drifting off.

Written by gregor

May 11, 2011 at 23:12

Posted in Uncategorized

inexpensive off grid air conditioning for a tinyhouse

with 2 comments

Okay, so I was wondering how to do this, and I put together a spreadsheet. I’m no spreadsheet ninja, and this is the first time I have used Calc, but you can put your own data in, and see for yourself how these things could apply to your own situation. I got my data from here . It would be interesting to look at a hotter climate, and see what sort of approach would work there, and I tried to find some data for California, but no dice. The data I use here is for July, the hottest month here. See the last graph for the actual temp. data plotted.


Scroll way to the right, there are the graphs and stuff, and the assumptions like the U value of the walls and stuff, that you can adjust. I’m assuming a third of the walls are getting pretty hot from the sun, 45 degrees, but it turns out it doesn’t have that much effect anyway.

There are a couple of ways of cooling without electricity, and you have no doubt heard of thermal mass storage, which I have been calling thermal closeting, though turns out that is not a very common term for it. Whoops. Also, evaporative cooling . The spreadsheet includes a basic simulation of both these approaches. Definitely basic. But it tells you more or less what you can expect. But first we need to know the cooling requirements:

The reason the graphs are so spiky, rather than having a smoother increase in the amount of cooling required as the ambient temperature goes up, is that it turns out, surprisingly, that by far the biggest load is the heat produced inside the house by electronics, cooking, all that stuff, plus solar gain from the windows. By far. I assumed it is 200W at night and 400w during the day for electronics, and a sort of arbitrary 100w for solar. If the temperature is below 23 degrees out, hypothetically, you can just dissipate the heat by dumping it outdoors. When the temperature is higher than that (or whatever you consider to be the maximum), all of a sudden, you need to produce that lower temperature, to remove the heat. The contribution to the cooling requirements that dehumidification and the need for ventilation imposes do change more smoothly.

The interior of the house isn’t enough thermal mass to take full advantage of thermal mass storage, as you can see below. This graph is with a 1 ton of water, I would think more than the interior of a tinyhouse, and it still leaves some days unconditioned (the heat capacity of wood is about half of water’s). Even if you are willing to settle for 25 degrees, it doesn’t get you though day 5 or 6, because the temperature the previous night was too high. Plus, if you are using the interior of the house, that ignores the fact that you are cooling the thermal mass to an uncomfortably low temperature sometimes, and need to blow a lot of air through the house to recharge the mass. Also, I did not include anything to take into account the possibility of it helping with the latent heat needs, because it would have no effect anyway in this climate. It would have to go below about 14 degrees during the previous night. Maybe in the desert, though.

Strictly speaking, there should be some factoring in of the thermal resistance between the thermal reservoir and the house, but I ignored that for now. In effect, that would slow the rate at which the reservoir absorbs heat, a couple degrees before it was full. You could use phase change material, and that could make it a bit more practical than a ton of water, but to make a good decision about what types and how much you’d have to look at more data, I think, but 20 kg of phase change material would really help with those times when the night temperature is really close to the max. permissible indoor temperature.

Oh, by the way, I got some bad news about the heat exchangers. Turns out the manufacturer’s lie through their teeth about the efficiencies Looks like 60% for sensible heat, and 40% for water vapor is more reasonable. It does go up, though, if the airflow is lower, and in this calculation the airflow is 8 CFM (223 LPM), rather than the 120 or so that the exchangers are usually tested at, so you can change the heat exchanger efficiency in the sheet if you want.

One thing is, though, that it might turn out that they are pretty expensive, though. In that case you would go for the smallest one around, I guess.

Another, kind of unfortunate effect of the fact that it is the heat produced inside that is the main problem, is that you can’t easily distribute the cooling power through the ventilation system as is done in a forced air system. The 8 CFM of air would have to be pretty cold to transfer the necessary amount of energy, especially during the daytime. Which would pretty much require electrical cooling.

Instead you would have to either put cooling coils in the wall or something, or, I think probably more practical, is to use a fan blowing over an air-water heat exchanger. I remember seeing a tinyhouse with a ceiling fan once. That could work fine, just put the exchanger above it. Or, I noticed there are fairly cheap “evaporative air conditioners” out there, which by all accounts don’t work for jack, but they have the air-water heat exchanger and a fan in them. Maybe that or some other consumer product could be used.

They might work as an evaporative cooler, too, but you have to put the evaporator outside…. The problem with their design is that the evaporator is indoors, so it increases the humidity in exchange for reducing the sensible heat (eg decreasing the temperature of the air), which is exactly the opposite of what you want.

It’s pretty amazing how much cooling power you can get from water, though, the system below uses about 10-15 liters per hot day. I plotted it in 100s of ml so it would show up on the graph. You can see it’s far from perfect, though, it’s no good on the days humidity is high. This device is made to cool the water, not the air, then you pipe the water around wherever and use it to absorb heat. Unlike a swamp cooler, it does not add water to the indoor air.

The system in the spreadsheet, uses a regenerator to improve it’s efficiency. To see what would happen without it, set the efficiency to zero. Basically something like the Ultra cheap ERV I just posted, but you don’t have to worry about the smell of the regenerator media, so you could use polyester quilt filler material, or sewn together sweatshirts or something. But it can’t ever cool below the outdoor dew point – or rather an outdoor dew point.

An idea occurred to me, that if you did a whole bunch of evaporative cooling during the night, when the dew point is lower, using it to cool down a thermal reservoir to the ambient dew point during the night, then it could be cold enough to be used to do some dehumidification during the day (when the dew point rises). Unfortunately it looks like that wouldn’t do much good in this climate. What you really want to do is to remove water from the indoor air, as it comes out of the heat exchanger (heading to the interior of the house). The dew point during the previous night has to go below the dew point of the indoor air the next day before it even starts working. Well, I guess you could dehumidify the air going into the exchanger from the outside, and that could help just a bit on some days. Hm, sounds like worth looking into, if it helps enough to open up other options elsewhere….

Another, more useful idea (for me) is to use an electrical heat pump like a compressor cooler to handle the dehumidification. If you are off grid, chances are you will have a solar panel somewhere, which means you’ll have extra power available in the summer. Might as well put it to use. The compressor in a cooler might not be powerful enough, though, but it could be worth checking. You’d need to have a way to get it to do just the dehumidifying, without the need to release the cold air (since it has to cool the air down first before it starts to extract water). You could use a… I know, I know, not another one, but, a counterflow heat exchanger. The air goes through it, into the cold chamber where water condenses out, then back through the exchanger again, and out. This one would be a cheap one, because you only need it to exchange sensible heat. You can make such an exhanger with Al tape and Al foil and some cardboard, just fold it like an accordion, and one fluid flow goes on one side, and the other on the other side.

Heck, if you had a big enough solar collector, after thermal mass storage, you might be able to use an electrical air conditioner, I remember seeing a 5000 BTU one somewhere, and you can get really small 12v ones for truck cabs, as a low cost replacement for a broken main AC system. 4000 BTU/hr is about 1000 watts, IIRC, so that’s just about right, and it should take 300 watts or so to run.

Another way would be to use a solar powered desiccant system . Liquid, or the desiccant wheel thing if you can swing it, they don’t seem to say so on that web site but with heat input, the desiccant wheel can be used to actually pump water vapor, too. You heat the air that is on it’s way out of the system directly before it passes through the wheel. Apparently they have an efficiency of 10% or something, but you don’t need much power here anyway. With the wheel system you can use a lower temperature, so you can use a flat panel collector, whereas I think the liquid ones need vacuum tube collectors. Might be hard to get a hold of a suitable one, or the carbon stuff, though. It doesn’t have to be a wheel, you can use 2 or 4 stationary beds of adsorbent material, and use an air switch to switch the direction of airflow between them. I wonder if you could make you own adsorbent by dousing some activated carbon with calcium chloride.

For the liquid system, take some tangled fish netting, or something similar, and by dripping water on it, that can form an evaporator (or absorber), just as a way to present a large surface area of water to the air. Then the water goes off to be heated by the sun, driving the water out, and back to absorb some more.

The last cool possibility that I was thinking of is a personal cooling device of some sort. As long as you can keep your body temperature down, you stay comfortable. I don’t know if you’ve ever walked out of an over conditioned theater into a really hot day, but it’s actually pretty pleasant at first. Until your body temperature rises because you can’t dissipate enough heat (or, if it is above 37 degrees, because heat is even being conducted into you, too).

“Personal cooling system” finds plenty of examples. I wasn’t impressed with any of the ones I saw, though. Not very efficient, so you have to lug around a big cooling reservoir. Also, I wonder if having the cold tubing against your skin would be very comfortable.

It seems like the best way from a comfort standpoint would be to only have air in contact with the skin. Basically, to shrink the air conditioned room down to the size of a vest. It would have comfortable elastic cuffs around the arms and waist, and a turtleneck around the neck to seal it. There is no need for any ventilation, though, because you are not breathing the air. You can just have a fan or something blow air around, through a tube on the back of the garmet to the right side, then into the vest, across your torso, gets sucked in the other side, to the cooling coils or whatever, then back for another run. Or maybe use tubing made of a water vapor permeable material (the tubing does not contact your skin), and flow cold water or a desiccant material through them. Water vapor then diffuses into the tubes, and the heat, and flows away, keeping everything comfy. It can then be cooled with evaporation if a desiccant, or ice for water – the advantage of using a desiccant is that it does not have to be at a low temperature to absorb water, so it can be cooled purely by evaporation. Evaporation gets you about 10 times as much cooling power for the same weight, and you don’t need a fridge to keep producing ice. Mind you, if you are indoors, that would raise the humidity…

Lastly, personally, I noticed something this summer, which struck me as pretty handy and useful – I, for reasons I won’t go into, had a bunch of wet clothes laid out on my bed. It was really uncomfortably hot and humid. The air conditioning is intermittent here, and it was not turned on, though I don’t remember the exact temperatures, checking the weather records wouldn’t have meant much, because I’m pretty sure it was hotter inside than outside (I didn’t want to open the windows because the noise is really bad here). I was resigned to spend a night sweating. So, anyway, I went to go to bed, and they were still wet, and, being pretty tired, I was faced with a dilemma: Put clothes away or no? At first I assumed I better put them away, because I fuzzily recalled sleeping on wet clothes is uncomfortable (yes, this had happened before). But then I realized that was only because it was so cold. So I tried it, and it was actually really comfortable all night. I slept better than usual, even. It’s amazing how they seem to stay wet and cold all night long (previously very annoying). I think this could be really useful in Ottawa here, where there are usually only a relatively few nights a year where it is really too hot, or for tinyhouses with no AC at all.

They weren’t fully wet, they had been in the dryer, but the “automatic dry” feature screwed up, and they were not dried fully. They were definitely heavier, just to give you an idea of the water content. Wetter clothes would work fine, I guess, just from after the spin cycle. You would think mildew would grow, but it didn’t. Having just been washed inhibited it enough, I think, and maybe because there was still some detergent on them.

Essentially this is a bit like a wet bulb thermometer. You are the thermometer, and of course the clothes are the wet cloth.

Written by gregor

May 11, 2011 at 00:42

Posted in Uncategorized

Chest freezer as a fridge.

with 2 comments

They are much more energy efficient than a normal fridge or bar fridge. They can also be quieter than most bar fridges.

All you need is an external thermostat widget, plug the freezer into the widget, then put its temp sensor in the freezer, set it to the desired temp and you are all set. Apparently they make these widgets for home brewing purposes. They are about $60-$80.

However, I would point out that compressor coolers probably consume less energy still. If you needed more space, though, this is an economical option.

I think I would want a shelf. For shelving I suggest a small upside down cardboard box, and cut away one side, and the freezer already comes with a basket. That seems like it would be about right for my danby 2.7 cu ft freezer.

Some links for your convenience:

(note that this guy: notes that in a solar power scenario you have to take into account the power consumption of the inverter, if the thermostat itself consumes power, that could prevent the inverter from turning off during periods during in which there is no other power draw. Mind you there is probably always going to be some anyway in a normal house from the microwave or whatever, and the inverters I have seen, at least according to the documentation provided by the mfgrs are highly efficient right down to 0 draw, though there is a good chance they are lying, and that normal inverter technology just can’t really do that.)

It would be nice if mfgrs of chest freezers would tweak their thermostats a smidget so new freezers could do this right off the bat. From what I know of the way they operate, this would be trivial. Heck, you might be able to just reach in there, or maybe it would take some dismantling, and bend the right thing.

They are based on the pressure of the coolant lines, there is a hollow box with a flexible metal side, and when that flexes due to a higher temperature inside the freezer (leading to a higher pressure in the coolant lines), it moves one contact of a switch closer to the other contact. Adjusting the thermostat dial moves the position of the second contact. When they are too close, there is a mechanism (like a magnet) that snaps them together. So by changing the position of the dial, the switch will close when the temperature inside the freezer reaches a certain level, and open again at a different level. Bend something so that second contact is a little farther away than it usually is, and the freezer will operate at a lower temp, for a given dial setting.

Written by gregor

May 10, 2011 at 00:27

Posted in Uncategorized

The laundry pod, and other stuff about laundry

with 3 comments

Sigh. I want it to be good, don’t get me wrong. But I think the options in the laundry options post are more interesting.

I mean no agitation at all? Unless they have a special detergent or something, I’m not impressed. It says on the website there is some sort of agitation, but from the video (which was on the tinyhouseblog but taken down) there appears to be none. If you have electricity you might as well soak it in a bucket and get a spin dryer. Even if you don’t, see further below. And absent any special detergent soaking does not work very well without agitation based on all the reading I have done but recently and previously (and it was discussed in some places, people in rvs often try it but are disappointed).

I actually was recently looking for just this sort of thing again since I live in an apartment now but the landlords won’t let me use a “washing machine”. So I did some reading. I did find this interesting page which has some truly innovative ideas, unlike the laundry pod. They also cost a fortune, I’m sure, but some could be done more cheaply, and some like the individual drum one could of course be cut down to a smaller size. Plus, there are already a lot of small washing machines out there, including ones that look a lot like and are the size of a blender (reviews on the wonder wash on btw iirc indicate it doesn’t work because it does not actually agitate the clothes). There are also similarly sized spin dryers out there.

As ideas I also came across the “biclavadora”, pedal powered washing machine, and a very interesting option that is hand powered. Also, an inflatable washing machine, though it seems to be out of production and was probably too small, the idea could be used and extended. I also found that ultrasonic vegetable washing machines can purportedly wash laundry, but they are >$200 each amazon has some and the “xcube” mfgrd by “Pollex” is another bigger one I saw.

There are also small front loading machines that would be perfect for me at least, except it’s Not Allowed. And I totally understand the concerns about not bothering the neighbors with the vibration but that is a trivial problem to solve with an anti vibration mount. But try explaining that to someone who is already set against the idea. I was also much annoyed to find that they have poor spin dry RPMs, but if you use a spin dryer anyway….

Secondly, how fast will the laundry pod spin? I seriously wonder how well this will dry compared with wringing. The electric spin dry machines go 3000 rpm or so, and centrifugal force is mass*(r*pi*rpm/60)^2/r so you spin it at a tenth the speed (though the drum radius r is wider) you have to spin it for a lot longer time. I apparently stores energy as compressed air, so ;t be much energy, and sounds pretty useless.

In other words, we can do a lot better than this, people.

First of all you have to decide what you want, are we making someone for a villager in Peru or not? Sure if you could have it all that would be nice, but what good is something that works like crap for everyone (or worse only works for some hypothetical person that doesn’t actually exist anywhere or we can’t find or who already has something else or better) – we want something that works well and costs little for whoever is actually buying and using it…

However frankly saying this would be useful for someone in a remote are with little money smells a lot like marketing to me. First of all it is a mistake to assume they do not already have certain methods that have been developed and refined over a long time. I have read about how laundry is done in India and they have ways – one is to rub the detergent directly on the damp clothes, giving you a very high concentration of detergent where it needs to be while using very little total, agitate, then rinse, squeeze (not wring that’s too much work), rinse, in 3 successive buckets, giving you 3 divide by operations with very efficient water use, and the final bucket water is clean enough to reuse. Pretty smart really.

Secondly this looks like it uses the same sort of manufacturing approach as a salad spinner or something. I.e. it will break and there will be no replacement parts available. And it will cost >>$100. Which, I don’t know for sure but sounds to me like an awful lot to someone who cannot afford electricity. Also, check out that thing I linked to on lifehacker, which is based on actual on the ground research so it stays in touch with these sort of realities, unlike the laundry pod.

I did my laundry just the other day in the bathtub so was naturally thinking about this sort of thing the whole time (would have done it the Indian way if I had some friggin buckets), and for tinyhouses, I wonder about a folding (or inflatable I guess) drum. First, the high speed water extracting spin is done separately from the agitator drum, in a centrifugal dryer. Should be pretty easy, perhaps triangular, made out of silicone sheet and stainless steel rods. It could be just the drum with bearings, a stand, crank, the relevant holes for adding and removing water and clothes, and the small motor. Would be pretty cheap.

Normal front loaders have of course a circular drum but with paddles sticking into the drum, to cause the laundry to be lifted up, then fall. I though at first if yo uhad say just a metal drum sans paddles, the clothes would just slide along the side so you don’t get any tumbling. But I noticed the description of how the drum is made for the biciclavadora does not mention paddles. Also, maybe using a triangular drum would get you the tumbling. If that wasn’t enough, since the walls are made of silicone, they could be molded such that they have small fingers sticking into the drum, gripping the clothes. Or you could just add paddles to the drum, be pretty easy I guess.

I also came across a top loading washing machine that doubled as a laundry bin, I forget where now ( It automatically started when it was full, and notified you by email when done too). We could certainly do that but front loading (so less water and det) and in conjunction with a folding drum, the drum could still have stuff put in it while it was folded. In case it’s not obvious, you eliminate the outer part of a normal washing machine, the boxy part that houses the drum. So you can touch the turning drum, but there is no safety concern because we are not doing the high speed spin (the counterweight and shock absorbers and powerful motor is also thereby eliminated, reducing cost size and weight).

Another way to agitate that occurred to me was to, after the clothes have been soaked with wash liquor (water+det) put it in a cloth bag, very full, with the laundry positively packed in, then sort of flatten it, then try to roll it in some way. I.e. the mass of laundry is continually being distorted, causing the clothes to rub past each other. The drum would consume almost no more volume than the packed laundry does. Rinsing would be a problem though, while with a tumble drum rinsing is pretty easy.

Probably I would be using these things in the bathroom, in the shower area, or maybe over the kitchen sink so that makes it a bit easier to fill and empty with water.

Obviously these are only ideas, any one out there with more ideas? Because I am not impressed with the solutions currently available, or the laundry pod, too expensive and/or too sucky or bulky for tinyhouse use.

Written by gregor

May 9, 2011 at 00:21

Posted in Uncategorized

Year round greenhouse with soap bubbles for transient insulation

with one comment

I just came across this accidentally, a way to grow food year round in a northerly climate without any heating, relatively inexpensively :

For living off the grid in a cold climate, this looks very interesting to grow your own food. I was trying, incidentally, to find out the price of greenhouse plastic for use with the gellified water idea… gellified water might be another option, but disappointingly I’m finding it might not be that practical because of the sheer weight of it.

BTW, if you want to read more in the vein of growing food all year in a relatively small area, nasa has this thing called CELSS, Controlled ecological life support system, which is really interesting reading.

Written by gregor

May 8, 2011 at 00:32

Posted in Uncategorized

Santa Cruz’s Accessory dwelling unit “promotion” program

with one comment

There are many tinyhouse-like things that have been around for a long time. There may be many other cities doing this sort of thing (seattle cottage housing and vancouver laneway housing are 2 I just happen to know).

An accessory dwelling unit in this case is roughly 500 sq ft. of habitable space, they can be detached from the main house, in which case it is essentially a stationary tinyhouse, but the term also covers attached dwellings.

The program’s main site. The program’s manual for people considering building one on their lot. Of course you have to remember it is probably written by a committee, so while some parts just give you a glimpse into the deeply biased half formed pseudo-thought processes some bureaucrats use to decide on the rules to impose on the rest of us, other parts look like practical information. Including about zoning and permitting and for those of us that are interested in seeing exactly what it *would* take make the zoning bureaucrats happy in a city, and a sympathetic one too.

Promotion in scare quotes because this is apparently these people’s idea of promoting something, they still include absurd rules like the owner of the property has to live in the main house, 5000 sq ft minimum lot size etc. Of 18,000 single family lots in the city 1,800 are “eligible” to have an ADU. As of 2005 they were managing to get a whopping 45 units built per year. Hoo boy, we’re really rollin’ now, that’ll sure get them housing markets straightened out in no time.

And is it any surprise? Actually it’s surprisingly many to me. These people and their regulations have jacked up the price of these things to what looks like roughly $100,000 judging from the figures in that doc, and even at roughly $1033 a month for a 1 bdrm apt and 6% mortgage that’s going to take forever before seeing a return on investment. And you have a stranger living in your backyard all the while.

If you’d get rid of the nonsense rules and the renter can just bring their own $20k house and feel free to leave anytime they choose with very little effort, things are so much better for everyone.

You can totally do the sensible things they mention, like talking to the neighbors, ensuring their sun rights and views are respected, all that stuff. It’s inexpensive and makes a good deal of sense. Requiring that the owner reside on the property, or that it be a hard and fast 5000 sq ft. minimum does not.

There is an order of magnitude of difference in the cost/benefit ratio of these rules, and some of them are just plain nonsense. There are good rules, and there are counterproductive rules that should be done away with. You dig?

If producing affordable rental housing was their homework assignment, they would get an F for effort and overall G for ghastly. And that’s when the government *wants* (purportedly, these people say all sorts of things) to promote this sort of thing.

Written by gregor

May 6, 2011 at 17:32

Posted in Uncategorized