Terra-Dome Earth Shelter Build

[carpolisher]

You should be OK. We have basically the same duct system as you with 20 - 12 x 4 registers. The dip switches are set for low speed cooling about 800 cfm and it works well for air circulation. Is the ac size based on a standard stick built home? I recall Jay from Terra Dome recommending a 1.5 ton unit with a ducted dehumidifier regardless of the sq ft. Our indoor temp stays a constant 73 when its in the 90s. Jay suggested covering the roof asap once the black waterproofing is applied. His concern was overheating the steel in the roof.

 

[SamWalton]

You should be OK. We have basically the same duct system as you with 20 - 12 x 4 registers. The dip switches are set for low speed cooling about 800 cfm and it works well for air circulation. Is the ac size based on a standard stick built home? I recall Jay from Terra Dome recommending a 1.5 ton unit with a ducted dehumidifier regardless of the sq ft. Our indoor temp stays a constant 73 when its in the 90s. Jay suggested covering the roof asap once the black waterproofing is applied. His concern was overheating the steel in the roof.

Our AC sizing is based on our roof and only two other walls are covered in the conditioned area. We have extreme heat in Oklahoma. We have 25 4肺12 vents and lots of windows. The five ton may be more than needed when we get the roof and outside walls completed but we can run some solar hydronic heat in conjunction with the cooling to aid in humidity removal. I have never lived where there is this kind of heat.

If you are running your blower at 800 CFM and you have 20 vents you are only providing 40 CFM per vent, doesn稚 this seem too little? Many systems are providing up to 200 CFM per vent.

I guess I need to talk to Jay. My concern was it you cover directly after applying the water proofing you have a lot of work when tiring to repair leaks.

 

[carpolisher]

The 40 cfm per register works well for ventilation. I would increase the cfm for ac or heat mode. Here is my take on waterproofing. Use the Econoline for damproofing (vapor barrier) then granulated bentonite in valleys / cold joints and parapet overhangs. Cover with 6 mil poly strips. Back fill the valleys and cover every thing with an inexpensive pond liner of some sort. Extend the liner a few feet beyond the walls. This keeps the dirt over and around the house dry. Turn on the sprinklers for a day and check for leaks. Lay down some insulation as you back fill. It rained about every day the past 2 months and a lot last fall and we have not had any leaks.

 

[SamWalton]

The 40 cfm per register works well for ventilation. I would increase the cfm for ac or heat mode. Here is my take on waterproofing. Use the Econoline for damproofing (vapor barrier) then granulated bentonite in valleys / cold joints and parapet overhangs. Cover with 6 mil poly strips. Back fill the valleys and cover every thing with an inexpensive pond liner of some sort. Extend the liner a few feet beyond the walls. This keeps the dirt over and around the house dry. Turn on the sprinklers for a day and check for leaks. Lay down some insulation as you back fill. It rained about every day the past 2 months and a lot last fall and we have not had any leaks.

Please elaborate with product links on the granulated bentonite, 6 mil poly strips and the pond liner.
Thanks

 

[carpolisher]

The liner is a 12 mil dura-scrim from Raven Industries Standard Product Line. Jay can order it at your specified size at a discount and have it drop shipped from Raven. They also have kits for sealing around penetrations but you could make your own. The laminated poly/bentonite sheets are way too expensive so I just made my own. You can get the bentonite in sacks from local well drillers. I Just sprinkled it in the cold joint valleys and parapet overhangs.
Then covered it with 6 mil poly sheeting from Lowes cut in 3- 4' strips. We also laid drain pipe on top of the poly but I dont think it was necessary as water should not get to it. At this point we just filled the valleys and overhangs and used sprinklers for a leak test.

 

[arkbound]

Hi Sam and everyone,
I saw you were looking for bentonite and here is a supplier in Oklahoma area.
BTW Happy Father's day to all you Dad's out there.

Seminole Mud Company: Providing Sodium Bentonite as a Pond Leak Sealer :thumbsup:

John L

ok TTYL

 

[patrick_g]

I got a good quote of $2772.10 on a Goodman R22 13 SEAR heat pump with a variable speed inside unit with heat strips and 50 feet of insulated copper lines. I think we will run with this.

About 5 years ago we got 2 each 19.2 SEER heat-pumps (air to air with propane backup). One is 3 ton and the other is 5. They are still running totally trouble free. The cost savings based on cost to operate (electricity) is rapidly amortizing the extra cost of the units.

The only heating-cooling problems we have had on these systems is a failed actuator for a damper and stuck dampers (zoned system.) On the other hand our geothermal unit had water treatment problems but now that we know more about that we expect no problems.

We don't usually try to cool all of the spaces at any given time although we have the capacity to do so with the exception of the zones cooled by the 3 ton unit. It is sized to do any two of the three zones at the same time but that is no problem as I can't be in three places at the same time (I can just barely do two.)

Our great room ceiling peak (12:12 pitch) is about 28 ft above the floor and there is a loft above about 1/2 of the floor. In most situations I can heat and cool the loft by using the two ceiling fans in the great room to push conditioned air up there. In extreme weather such as with triple or single digit temps You can turn on the zone stat for the loft and get any reasonable temp you want as it is serviced by the 5 ton unit.

Our master suite is ICF construction and the small amount of "leakage" air that gets past the closed zone control damper that controls flow to the master suite admits sufficient cool air to drive the temp below the set point of the room stat. So, when the main floor (great room etc) is calling for cool the bedroom gets a little cool air but since the ICF effective R-value is so high the room is always cooled below the stat's set point.

There is the theoretical and your plans and then there is reality. These are not always in agreement but I was lucky and our reality is acceptable.

Pat

 

[patrick_g]

Hi Sam and everyone,
I saw you were looking for bentonite and here is a supplier in Oklahoma area.
BTW Happy Father's day to all you Dad's out there.

Seminole Mud Company: Providing Sodium Bentonite as a Pond Leak Sealer :thumbsup:

John L

ok TTYL

John, thanks so much for posting the Bentonite link. I called and got pricing and other info from the Seminole, OK operation. I am in dire need of some Bentonite for pond sealing. I may have to use the 50 lb bags as the 3000 lb pallets (big bulk bag - one cubic yard) is too heavy for my tractor to lift with FEL pallet forks. Their material is granulated and not so prone to wind problems as the powdered material. My dump trailer is only rated for a little over 6000 lbs but luckily it is only about 30 miles (40 min) away so multiple trips are not a big deal.

Pat

 

[arkbound]

Hey Pat,
Glad to be of assistance. I have learned so much from this blog. You guys that are doing it, really impressed me. I have 5 acres over near Mountain Home, AR, and I just had an excavator guy with a forest mulcher attachment to a Bobcat skid steer clear the lane in and about an acre of it. The pictures came a little grainy but now I can see the trees from the forest. LOL :laughing:
I will be going up and spend the month of October there at a "resort" fishing cabin with my wife to see if we indeed want to move there. I will be looking into putting a arched steel building on a concrete slab as a vacation cabin and future guest house. I am restricked by a deed to "No manufactured or mobile homes" and "No hunting allowed". So what ever I have to "live" in must be stick built and I think this will be allowed. I can bolt stuff easier than being a carpenter. lol
I will be contacting that crystalline additive company "Krypton" about costs and that will be in the contract for my Terra Dome home when I can get that working. Got to wait for the real estate economy to pick up down here in Florida. It is still going down. I will try to attach a picture or two to this here blog for your information and edification. lol

John L
Arkbound

 

[patrick_g]

OOPS!!! I misstyped. The Seminole Mud Co. (Talk to Mark to arrange for loading) has granular Bentonite in 50 lb bags and in 2000 lb bags, not 3000lb as I previously posted.

Yesterday I bought 3 of the 2000 lb bags on pallets. It costs 10 cents per lb.
The 50 lb bags are $8.50 each

Of course right after we loaded the three big bags/pallets I noticed one of the tires on my dump trailer was separating as evidenced by one of the rows of tread lugs being misshapen. So, I drove while on "pins and needles" about 20 careful slow (50 MPH) miles to a tire store where I trade and arrived just about closing time but got 2 new tires to replace 2 original tires (including the one with the problem.) A couple days earlier I had replaced the other two after one blew out with the trailer just sitting still almost an hour after I had finished unloading a load of gravel. Apparently the original equipment tires were not the highest quality as 2 out of 4 went bad with over 90% of the tread left.

I saved $360 by buying the bentonite in 2000 lb bags instead of 50 lb ones, more than enough to buy the new tires.

Now if only my 3PH mounted PTO driven fertilizer/seed broadcaster with the conical hopper will do OK with the granular bentonite...

Note for Sam W. If you go to get bentonite you have to call first because the bentonite storage location is not manned full time during business hours. Mark will meet you there and take care of business. The building is on the north side of state highway 9 at 4.1 miles east of the stoplight at Walmart in Seminole.

Patrick