AZ Garn project

[SteveGH]

I've made the choice and the Garn has been delivered. Why a Garn in AZ you might wonder? I live in Lakeside in the White Mountains about 180 miles NNE of Phoenix at about 7,000 ft. Our heating degree days don't match most of you guys but we still have our seasons. Currently I'm using LPG forced air system and will add the Garn to a separate system of radiators/wall panels. I've had a lot of help from everyone on this forum and look forward to suggestions/help as my project starts. I will install the Garn in a 10x20 shipping container and then have the container delivered to our home where we will finish the install (insulation and initial plumbing and electrical). I hope to post pics along the way and might even have my own web site for the project (JimK is my inspiration here..Thanks).

One of many questions I have is the basic plumbing philosophy. I'm a pharmacist so drugs are my life but I look forward to learning some plumbing with this experience. Kenny, who I purchased the Garn with has said a very simple one loop system will work for my situation. His thoughts are one pump taking water from the Garn to a manifold system that will go to two loops in the home, a spa, a DWH, and an extra loop for possible future use. The plan is to use 1" to and from the manifold and 1/2" from the manifold for the loops. I've been reading a lot of posts that refer to primary/secondary loop systems. I've ordered the books that have been mentioned here, "Pumping made easy" and the one on primary/secondary loops so I hope to get info from those. Simple is very attractive with less parts to install and repair but it seems to good to be true reading about so many other installs. I feel comfortable with Kenny's ideas but respect the opinions of members of this group.

sfg

 

[Eric Johnson]

I've always found simple to be best, even though my initial plans on these projects tend to be more complicated than necessary. Eventually, they wind up being dumbed down, mainly because things tend to work better that way. At least that's the way it goes for people like me who don't have any formal training or heating system education. So I'd say that Kenny is right. And you picked the right boiler--the Garn, as impressive as it is, is pretty easy to plumb.

Bear in mind that with a Garn you're dealing with an unpressurized system with lots of onboard storage. There are special considerations, such as corrosion protection, that you need to address. It's not more complicated--just different than a pressurized system, which is what most people with other indoor boilers have.

We have a number of members here who have bought and installed Garns, so I'll defer to their expertise and experience. But it sounds to me as though you and your friend are on the right track.

BTW, you can burn almost anything that's organic and dry in a Garn. Do me a favor, will you? Burn teddy bear chollo cactus so that I don't get attacked next time I go hiking in the AZ desert.

 

[jebatty]

As always highly recommended, do a heat load calc for each loop and size pipes and circs accordingly based on head and pump curves for your setup. The Garn should provide plenty of "supply." In general, a 1" supply at 8 gpm should be able to feed 5 1/2" loops at 1.5 gpm. Each 1/2" loop will supply about 15,000 btu's at delta-T=20F. One major error made by many is under-sizing the supply/return lines from the boiler. IMO 1" is problematical in just about every situation, especially with the Garn, as design Garn btu's are much higher than 80,000, which is the standard capacity of 1" pipe. If 80,000 btu's are all you need, you may be greatly over-sizing your boiler.

 

[Jim K in PA]

Congratulations! Definately keep us posted on the progress. The shipping container install is very interesting to me. Its metal construction could potentially be a liability, depending on how, and how well, you insulate the GARN. Be sure to have a thermal break between the GARN and the floor of the container.

 

[SteveGH]

Decided on the metal container for cost reasons. Even though the site will have to be worked on, clear some rocks, level and put some rail road ties down it will be much less expensive than a full foundation for a stick built building. Also the cost of the container including two doors cut in and delivery will be much less than that of a new building. Being steel we won't have to worry about the fire issue, and if we ever move, which is not in the plans right now, we'll be able to take our heating system with us. As for insulation, I'm definitely planning on researching that. I will have the Garn placed on the blue foam board as the install manual states. I'm looking for a source of vermiculite preferably or rock wool. I've heard, or read, and these two seem to be preferable. As a third choice unfaced bat will be considered but am concerned about "stuffing" that underneath and in corners. As I understand bats, the less they are stuffed the better the R value.

sfg

 

[Eric Johnson]

You can get bags of vermiculite at concrete supply places. I've bought it in bags, but you can probably find a place that will sell it by the yard.

 

[SteveGH]

You can get bags of vermiculite at concrete supply places. I've bought it in bags, but you can probably find a place that will sell it by the yard.

Thanks for the info Eric. Just curious if you know anything about the danger of working with vermiculite. Someone just told me that it is one of the major causes of Mesothelioma, that cancer I see lots of adds from those ambulance chasing lawyers.

Also, not to many of the teddy bear chollo cactus up here but I know what you mean. It's amazing how those seek out and attack.

sfg

 

[Eric Johnson]

There are different types of vermiculite, apparently, and the stuff you can buy these days doesn't carry the same risk as the stuff they had 20 or 30 years ago. There was a popular insulation product called Zonolite, which contained bad news asbestos. You still want to wear protective gear when working with any of that stuff. Another thing that works, I hear, is perlite, which is used to improve drainage in greenhouse gardening soil and in commercial potting soils. It costs more than vermiculite (which is also sold for soil amendment purposes), but contains no asbestos. You still want to wear a respirator and eye protection when working with it, however.

 

[pybyr]

I think I recall that vermiculite is pretty ho-hum on the R-value per inch, as compared to most other forms of insulation. You'd get more insulation, per unit/ volume of material, with other things such as rock wool or cellulose:

http://www.sizes.com/units/rvalue.htm

 

[SteveGH]

Thanks for the link. very informative. Does anyone have experience with Rockwool?

sfg

 

[pybyr]

Thanks for the link. very informative. Does anyone have experience with Rockwool?

sfg

I have no experience with it (rockwool), but have gotten the impression that it's pretty obnoxiously irritating stuff to come in contact with, and has fallen into dis-use-- but I am not certain of this.

I do have experience with dense pack cellulose, and am very pleased with how well it insulates (and at least in this region, you can DIY-it, as long as you wear a filter mask and don't mind ending up looking like a grey version of the Abominable Snowman as the small fibers cling to your perspiration if you work with it on a warm day). If you look into this (cellulose), do: (a) check with Garn to see that they're OK with it; (b) make sure you are getting stuff that's treated with borate, not sulfur compounds, for vermin repellency (some cheap stuff apparently comes with sulfur compounds in the mix, which creates a corrosion factor); and (c) learn about dense-pack, which avoids the settling that is inherent with loose fill.

 

[SteveGH]

I have no experience with it (rockwool), but have gotten the impression that it's pretty obnoxiously irritating stuff to come in contact with, and has fallen into dis-use-- but I am not certain of this.

I do have experience with dense pack cellulose, and am very pleased with how well it insulates (and at least in this region, you can DIY-it, as long as you wear a filter mask and don't mind ending up looking like a grey version of the Abominable Snowman as the small fibers cling to your perspiration if you work with it on a warm day). If you look into this (cellulose), do: (a) check with Garn to see that they're OK with it; (b) make sure you are getting stuff that's treated with borate, not sulfur compounds, for vermin repellency (some cheap stuff apparently comes with sulfur compounds in the mix, which creates a corrosion factor); and (c) learn about dense-pack, which avoids the settling that is inherent with loose fill.

This part or the project sounds really a blast. I did see a post on a Garn forum that talked about an insulating product called Roxul. Has anyone heard of this? Any experience?

As always your info is so appreciated.

 

[Gooserider]

My understanding is that rockwool is not that popular mostly because it is more expensive than fiberglass, and doesn't have any real advantages for most applications - the only exception, which MIGHT be important in this case is that it has a higher temperature rating tolerance, and lower flammability... It is one of the prefered materials if insulating around a chimney or other such hot item... Given that a Garn basically only exposes the outside of the hot water storage tank, I don't know how critical they consider the insulation material - it is quite possible that cellulose or other low temp rating material would be acceptable.

Gooserider

 

[pybyr]

My understanding is that rockwool is not that popular mostly because it is more expensive than fiberglass, and doesn't have any real advantages for most applications - the only exception, which MIGHT be important in this case is that it has a higher temperature rating tolerance, and lower flammability... It is one of the prefered materials if insulating around a chimney or other such hot item... Given that a Garn basically only exposes the outside of the hot water storage tank, I don't know how critical they consider the insulation material - it is quite possible that cellulose or other low temp rating material would be acceptable.

Gooserider

Densepack cellulose borate treated blown- in insulation really does work really well for purposes of insulation and air sealing -- but I really did come out of my attic looking like a grey Aboninable Snowman after putting it in on a warm day...

Good borate-treated cellulose cannot be lit on fire even with a blowtorch...