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How It Works

The versatile Ground Heater® - solves cold weather construction problems! Ground Heaters®' dry, radiant, hydronic heat is economical and easy to use!
  • Thaw frozen ground for excavation and concrete placements
  • Thaw up to 1 foot deep per day!
  • Accurately quote winter construction jobs
  • Deliver projects on time
  • Keep crews and equipment working all winter
  • Protect exposed footings from frost heaving
  • No need to build temporary roads.. adjacent ground stays frozen
  • Cure concrete - achieve required strength gain sooner
  • Quote projects accurately
  • Keep projects on schedule
  • Keep crews and equipment working all winter
  • Avoid risk and expense of frozen concrete
  • No expensive enclosures to build
pdf thaw sheet pdf cure sheet

 

job studies

 

Go to the Thawing section

Go to the Curing section

 

 
 

THAWING

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Problem:
Ice in the soil!

Know Your Dirt! Ice Content of Frozen Soils

GRAVEL.gif (1520 bytes) SAND.gif (1475 bytes) CLAY.gif (1626 bytes) SILT.gif (1798 bytes)
Gravel
5 to 7 lbs.
in 1 cu. ft.		 Sand
14 to 18 lbs.
in 1 cu. ft.		 Clay
16 to 22 lbs.
in 1 cu. ft.		 Silt
15 to 52 lbs.
in 1 cu. ft.
Up to 1,001
Btu's required
to melt ice		 Up to 2,574
Btu's required
to melt ice		 Up to 3,146
Btu's required
to melt ice		 Up to 7,436
Btu's required
to melt ice
Melting ice requires 143 Btu's per pound!
 

Frost Facts

  • Soil does not freeze

  • Water in soil freezes

  • Ice binds soil

  • Melting ice requires 143 Btu's per pound!

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Best Solution:
 Ground Heater®

 
Ground Heater® System
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94% of the heat is conducted into frozen ground!
 

  • Thaws at a fast rate - typically 1 ft. deep per day

  • Achieves up to 10'  thaw depth per application

  • No temporary enclosure to build

  • Uses fuel efficiently; fuel costs per cu. ft. thawed:

    MINI_E3.gif (1264 bytes)= less than 2¢
    PROPHEAT.gif (879 bytes)= $1.10

  • Requires minimal supervision

  • Utilizes BTU's efficiently with minimal heat loss

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Old Solution:
 Hot Air

 

Hot Air System
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Only 15% of the heat is conducted into the frozen ground!

 

  • Limited thaw depth

  • Requires building costly temporary enclosures

  • Requires noisy propane heaters

  • Creates outrageous propane bills

  • Emits noxious fumes into enclosure

  • Requires constant supervision
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Thaw Cost Comparison		  
Thawing 6,000 sq. ft., 3 ft. deep

 

Hot Air PROPHEAT.gif (879 bytes)

Ground Heater

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Own Rent
Time 25 days 3 days 3 days
Equipment/labor/
materials cost		 $4,934 $913 $1,860
Fuel Cost $19,800 $390 $390
Total job cost $24,734 $662 $1,568
Cost/cu. ft. $1.37¢ 8.7¢ 16.7¢

NOTE: Figures above are based on average rates/costs. Actual rates/cost incurred may vary depending upon geographical location.

Ground Heater® MINI_E3.gif (1264 bytes)out-performs hot air!
Thawing 6,000 sq. ft., 3 ft. deep

Time

8:1

Fuel Cost

50:1

Overall Cost

14:1
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Ground Heater® System Setup

 
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1.

Prepare Site
Scrape snow and ice from thaw site.

2.

Position Heat Transfer Hose
Space hose 2 feet on center over thaw site area. A closed system, only heat goes into ground.

3.

Lay Poly Vapor Barrier
Place minimum 3 mil poly vapor barrier to contain water vapor.

Prevents loss of heat

Keeps soil moist for better heat conduction

Keeps hoses and blankets clean

4.

Place Insulation Blankets
Prevent heat loss and direct heat into ground. Requires 2 to 3 layers of high R value blankets.
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Benefits!
 

  • Thaw fast - typically 1 foot deep/ day!

  • Thaw cheap - as low as 9.7¢/cu. ft.

  • Thaw deep - up to 10 feet/application

  • Thaw easy - no enclosures to build; set up is simple

  • Thaw large areas - up to 18,000 sq. ft./application

  • Thaw safe - certified in the US and Canada

 

NOTE: Figures above are based on average rates/costs. Actual
rates/cost incurred may vary depending upon geographical location.

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copyright © 1998-2008 Ground Heaters

 

legal notice

 

CURING

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Problem:

 Cold temperatures slow speed of
concrete's cure, causing cost
increases and schedule delays.

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 Best Solution:

Use a Ground Heater®  MINI_E3.gif (1280 bytes) to accelerate the cure.

A Ground Heater® raises concrete to ideal curing
temperature (65°-75°F), greatly reducing costs and delays.

 
Fact #1:
Hydration 
Reaction		 Fact #2:
Temperature		 Fact #3:
Speed
Cement chemically reacts with water to produce calcium silicate hydrate... the chemical compound that makes concrete hard and strong. Temperature mainly determines the speed of this hydration reaction. The speed of the hydration reaction determines how long it takes for
concrete to set and develop strength.
The speed of the hydration reaction is mostly determined by the temperature of the concrete.
Concrete Curing Process:
Aggregate & Paste

Plastic Phase

Concrete is placed

Cold temperatures delay initial set and increase the risk of concrete freezing.

Temperature vs Time to Initial Set
Initial Set

Set Phase

Finishing operations are completed

Cold temperatures delay final set and increase the risk of concrete freezing.
Concrete must reach 500 psi before it can withstand a freezing cycle.

Temperature vs Time to Reach 500 psi
Final Set

 

Hard Rigid Concrete

 Hardened Phase

Curing measures are implemented and strength development begins

Cold temperatures delay strength gain.  Concrete must reach 75% design
 strength to strip forms & withstand load.

Temperature vs Time to Reach 75% Design Strength

 
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 Benefits:

 

  
  • Cure fast - achieve initial set in 2-6 hours
  • Cure all placements - flexible hose allows any configuration
  • Cure easy - no enclosures to build; set up is simple
  • Cure large areas - up to 45,000 sq. ft./application
  • Cure safe - certified in the U.S. and Canada

Slab on Grade


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1. Preheat ground 2. Remove insulation & hoses 3. Place concrete on warm ground 4. Maintains slab at  65°-75°F

Poured walls or Columns

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1. Preheat forms, cover with insulation 2. Pour 75° concrete into forms 3. Ground Heater® maintains 65°-75°F concrete for curing period


Elevated Slab

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Ground Heater® heating elevated slab Cross-section view Ground Heater® maintains 65°-75°F concrete for curing period


 

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copyright © 1998-2008 Ground Heaters

 

legal notice