Comments for IWillTry.org

Comment on Seal Your Ducts by Gerard

Gerard — Wed, 01 Feb 2012 12:51:02 +0000

This information is great, I started sealing my ducts yesterday and thought I was almost done. After checking out this link, I see I have more work to do. The detailed pictures really help, thanks again.

Comment on Build a rocket stove for home heating by Len Jenson

Len Jenson — Mon, 30 Jan 2012 04:05:50 +0000

Rob, Are you the same fellow who wished to build a wood stove for an RV? Do you have a hard copy of plans for your creation and would you accept a donation for same if no rules of are violated? I attempted a download from Apostol Engineering and all I ever received was a message that a download was in progress. After making coffee and watching “Sink the Bismark!” on dvd with nothing coming in I gave up.

Comment on Build a rocket stove for home heating by omarswelding-omar

omarswelding-omar — Sun, 29 Jan 2012 16:41:34 +0000

rob like your rocket stove made my first yesterday it work buy i think the burn chamber is to big i just used what i had in my shop one pcs 6i n stove pipe one 55 gallon drum and a square steal drawer i put a steal plate over open top cut the 6 in hole left the front open to load wood put a steal grate 1 in off the bottom cut a 4in exhaust it was just a test my next well be out of a 100 lb propane tank

Comment on Build a rocket stove for home heating by Rob

Rob — Thu, 26 Jan 2012 07:59:07 +0000

Hi Delta,
Re insurance: I doubt any insurance company would consider a policy covering the use of a home built wood stove of any kind. So it’s either don’t ask don’t tell, or don’t insure in the first place. I believe it is a poor decision to insure anything you can afford to lose (on average it will cost you less if you just be careful and take your chances). I can afford to lose my home, and I’m willing to live with the risk. I also never leave my stove unattended.

Re heating a sauna: I think a stove this size would probably heat the sauna you described reasonably well, but it might take a long time to warm up. Perhaps increase all tubing by 25-50% (say 6″ in place of 4″ and 4″ in place of 3″) for faster heating.

Comment on Heat your home with a dehumidifier by Rob

Rob — Thu, 26 Jan 2012 07:24:05 +0000

@ JohnC, I appreciate your persistence. But compare the two scenarios:

1. Without dehumidifier: cool moist air enters the home and room temperature moist air exits the home.

2. With dehumidifier: cool moist air enters the home and room temperature dry air plus liquid water exits the home.

In both scenarios the air and water vapor coming into the home contain the same amount of energy (I think we agree on that). But in Scenario 2, the air and liquid water exiting the home contain less energy than the air and water vapor exiting the home in Scenario 1 (I’m not sure we agree on that… if not, look up “enthalpy of condensation” in wikipedia). Since Scenario 2 has less energy loss from the home, where do you suppose the “saved” energy goes? The first law of thermodynamics says energy must be conserved. The answer is that the energy (the enthalpy of condensation) is released inside the home in the form of heat.

Comment on Build a rocket stove for home heating by Delta

Delta — Mon, 23 Jan 2012 23:43:29 +0000

If you wanted to make one for a sauna say a 8x8x8 size room as and example.

Most Saunas you need at least 150F to 180F or 65c to 82c to get a good sweat going

To get ithis high of temp would you have to make size changes in the internal combustion chamber as well as the Feed Tube size or just change the size of the feed tube to handle more wood?

Thank You

Delta

Comment on Build a rocket stove for home heating by DELTA

DELTA — Mon, 23 Jan 2012 23:28:56 +0000

Hello Rob,

I’m curious. I dont know where everyone lives but what does your house insurance company say about having these in your house for heaitng? Do they consider them like woodstoves or it’s like dont ask to tell thing?

Comment on Build a Solar Attic by EK

EK — Mon, 23 Jan 2012 21:42:02 +0000

Great idea. I plan on doing something similar on my garage renovation this summer. It might help to have an additional layer of glazing, say a thin sheet of plastic sealed to the backside of the rafters. It would have to be baffled or have flow channels, but I imagine you could achieve additional heat gain from this insulated layer, as well as stop night-time convective losses back out of the glazing. As opposed to using corrugated polycarbonate, I want to use 4mm twinwall in two layers (4″ apart).

Comment on Heat your home with a dehumidifier by JohnC

JohnC — Mon, 23 Jan 2012 21:32:16 +0000

Hi Rob, Sounds like a great way to cool a house and keep it dry, but as far as gaining heat from cool moist air that enters the house through cracks and the like, your just bringing in cool moist air then heating it to room temperature removing the moisture and releasing it back out of the building along with the heat gain that was added from the building. Also you will be dumping a percentage of that heat down the drain.

Comment on Build a rocket stove for home heating by Rob

Rob — Fri, 20 Jan 2012 04:56:56 +0000

Hi Nathan,
I’m still here… but not sure I entirely understand your question/idea. In any case I don’t think I would have any particular advice. It’s always difficult to predict how geometry changes may affect fluid flow. Experimentation trumps theory. I can say that “prolonging the burn time” and “keeping more heat” (ie increasing efficiency) do not go hand in hand. A given pile of wood (with a certain surface area expose to air) has an optimum burn rate. If you decrease the rate, by reducing the draft, your wood may last longer but you’ll be running an inefficient rich mixture and your exhaust will contain unburned fuel (ash and wood gas). It’s analogous to adjusting air/fuel mixture for an engine or oxy/accetylene mix for a torch except you only have control over the air… the amount and surface area of fuel is fixed. It’s generally much more efficient to burn hot and fast for short periods than to burn cold and slow for long periods. It is possible to have too much draft as well, decreasing efficiency by expelling more air from your home than necessary to support combustion. While that’s common for open fireplaces, it’s rare for a wood stove.

Comment on Build a rocket stove for home heating by Nathan

Nathan — Thu, 19 Jan 2012 15:40:39 +0000

Hey Rob You still alive? I hope the tank didn’t blow!

Comment on Comparing natural gas vs electric heating by Rob

Rob — Mon, 16 Jan 2012 01:15:37 +0000

Bruce,
If you want to do annualized energy storage with a 15 m^3 storage tank you had better be starting with a very well insulated and sealed home. You cannot expect to achieve this just by spending $15000 to add a storage tank and collectors to an existing home. Some simple high school physics shows why:

Water has a specific heat capacity of about 4 kJ per litre per degree C. 15 m^3 is 15000 litres. Thus the heat capacity of a 15 m^3 storage tank is 4*15000 = 60000 kJ per degree C, or in more useful units, about 17 kWh per degree C. Lets be optimistic and assume you are able to heat this tank up to 90 degrees C during the summer. Let’s also assume the tank is perfectly insulated so no heat escapes until you want to release it into your home. Thus you have about 70 degrees C of useful temperature drop with which to heat your home (after that the water drops to room temperature of about 20 degrees C it cannot be used to heat your home). So the total energy available is 70 degrees C * 17 kWh per degree C = about 1190 kWh. My heating requirement for December and January alone is about 4,600 kWh. Thus a 15 m^3 storage tank might heat my home for a few weeks at best. This is assuming no additional solar input during those weeks but that is what “annualized” storage is all about. It’s also the stark reality in Vancouver where a sunny day in winter is a rare exception.

Incidentally, even if your home were insulated and sealed well enough that 1190 kWh of annualized heat storage could get you through the winter, that is only about $85 worth of electricity at current BC hydro rates. A savings of $85/year is not much pay back for a $15,000 investment. You’d be much better off putting your money in the bank and using the interest to pay your electric bill.

I’m not disputing that there may be a positive return on investment in solar heating solutions, but where there is, it most likely does not result from “annualized storage” but from continual collection, storage and release of solar energy, year round.

Comment on Build a rocket stove for home heating by Dale

Dale — Sun, 15 Jan 2012 23:34:54 +0000

Rob thought you and your readers may be interested in this rocket stove hot water heater design, it uses the rocket stove heater principle, simply amazing water heater, I am convinced I can use this hot water heater design to heat our water for our RV.

http://youtu.be/cy9Zlg4B0xQ

Comment on Comparing natural gas vs electric heating by Rob

Rob — Sun, 15 Jan 2012 21:08:42 +0000

I’m still quite happy with the results. Even at today’s prices, there is a cost savings for me to heat with electric space heaters instead of my old natural gas furnace. My utility bills reflect that. They may be higher than when I first switched to electric but they are still lower than before I switched to electric. Furthermore, I have estimated the capital cost and likely annual savings from alternatives like high efficiency gas or electric heat pumps and based on my energy needs, the time till payback for such systems would exceed the likely lifetime of the systems. I’ll re-evaluate from time to time, but for now I’m confident that sticking with electric space heating is the most cost effective solution for me. Other people’s energy needs and opportunity cost may vary so these results don’t necessarily hold true for everyone.

Comment on Heat your home with a dehumidifier by Rob

Rob — Sun, 15 Jan 2012 20:35:42 +0000

Hi JohnC. I agree that a house can be treated as a closed system. Standard practice in thermodynamic problem solving is to identify the closed system and identify mass and energy transfer mechanisms into and out of the system. It may be true that the transmission line is the only direct energy transfer into the home (excluding solar radiation), but there is mass transfer into and out of the closed system in the form or air infiltration. If that were not the case you would quickly exhaust all the oxygen in your home and suffocate. The amount of air infiltration is much more significant than you might imagine (typical minimum recommendation is 3 to 4 air changes per hour and houses that are sealed well still need to provide that using ventilation fans). If the temperature of the outgoing air is higher than the temperature of the incoming air, then I’m sure you would agree that represents a form of heat loss from the home. Likewise, if you condense water from the incoming air resulting in drier outgoing air plus outgoing liquid water (poured down the drain), then that represents a form of heat gain within the home. The amount of heat gained is simply the heat of vaporization of the water.

Comment on Heat your home with a dehumidifier by JohnC

JohnC — Sun, 15 Jan 2012 19:27:47 +0000

you cant gain heat from a closed system and your house is just that. the only heat gain is coming from the transmission line that is outside of the system and it is powering your dehumidifier. the humid air is already inside the house.

Comment on Build a rocket stove for home heating by Nathan Rimes

Nathan Rimes — Sat, 14 Jan 2012 21:00:07 +0000

Hello Rob,

I am a Welder Fab guy and when I saw this I was hooked. I wanted a wood stove and didn’t want to pay for all the pipe and drilling the hole in the wall etc… I have my old hot water tank and I am about to begin! I had a few thoughts and wanted to pass them by you. I am not an expert on the mechanics of gas flow but know some on air flow restriction. So my question / Idea if I can explain it is the bottom of the tank has a dome pressed plate. My thought was if I cut a 3″ hole in the center and weld it to the top of the exhaust pipe leaving a 2″ gap all the way around the top between the top edge of the upside down dome and the top inside of the tank, would it help keep more heat and longer combustion burn? My thought would be it would kill the draft you need. I was just thinking of how to keep the top of the tank hot longer for more efficiency. Nice job Sir!
If you could email me your thoughts I would thank you much!

Nathan

Comment on Comparing natural gas vs electric heating by بهراد

بهراد — Fri, 13 Jan 2012 04:56:12 +0000

Hi, are you still happy with the project result considering that Elec price has gone up and Gas down compared to 2 years ago?

Comment on About Me by Antor Paul

Antor Paul — Thu, 12 Jan 2012 01:41:31 +0000

Hey Rob!
For a science fair experiment I want to use (and change around a little bit) the data tables from:

“http://www.iwilltry.org/b/how-to-measure-the-drag-coefficient-of-your-car/”

I’ll put your name in my acknowledgments section and give a reason why.

-Thank you very much, Antor

Comment on Comparing natural gas vs electric heating by Bruce

Bruce — Wed, 11 Jan 2012 00:06:54 +0000

Solar water heating systems have been proven in Passivhaus, but recently become on par with comparable BC residential heating systems, especially in high efficiency new construction. It works by utilizing the surplus summer heat and storing it in an insulated container below the slab floor, then circulating that heat through radiant floor pipes.

The capital cost of 12 solar collectors (24m2) and a seasonal solar storage underground tank (15m3) is under $15,000. in Vancouver – to provide nearly all the domestic hot water for showers and cleaning, plus the radiant floor space heating. Once installed, the system is maintenance free for decades, plus the solar heat is clean and renewable.

I think once people know that the asymetrical solar supply/heat demand problem has been solved with annualized storage, and that it is reasonably cheap, it should become very popular in Canada, like it is in Austria.