# Sovereignty Module: Build the Heater

## Complete Masonry Heater and Tile Stove Construction: From Brick to Warmth

A masonry heater burns a small, hot fire and stores heat in massive brick or stone, radiating warmth for 12-24 hours from a single firing. This campaign covers design, construction, flue routing, and operation.

### Chapter 1: Masonry Heater Types

| Type | Origin | Mass (lbs) | Efficiency | Heat Duration | Difficulty |
|---|---|---|---|---|---|
| Russian stove (pechka) | Russia | 3,000-8,000 | 80-90% | 12-24 hours | High |
| Finnish contraflow | Finland | 2,000-4,000 | 85-90% | 12-18 hours | High |
| Kachelofen (tile stove) | Germany/Austria | 2,000-6,000 | 80-90% | 12-24 hours | Very high |
| Rocket mass heater | Modern | 1,000-3,000 | 80-90% | 8-16 hours | Moderate |
| Grundofen (base stove) | Austria | 3,000-6,000 | 85-92% | 18-24 hours | Very high |

### Chapter 2: Operating Principles

| Principle | Explanation | Benefit |
|---|---|---|
| Hot, fast fire | Burn a full load of wood quickly (1-2 hours) | Complete combustion, minimal pollution |
| Long flue path | Exhaust gases travel through channels in the mass | Heat transfers from gas to masonry |
| Thermal mass | Heavy brick/stone absorbs and stores heat | Radiates warmth for 12-24 hours |
| Radiant heat | Heat radiates from warm surfaces | Comfortable, even warmth |
| High efficiency | 80-90% of heat captured | Very little heat lost up chimney |

How it works: 1) Load firebox with dry wood. 2) Light fire and burn hot and fast (1-2 hours). 3) Hot exhaust gases (1500-2000°F) enter flue channels. 4) Gases travel through channels in the masonry mass. 5) Heat transfers from gases to brick (gases cool from 2000°F to 300°F). 6) Cooled gases exit through chimney. 7) Heated masonry radiates warmth into room. 8) Surface temperature: 150-200°F (warm to touch, not burning). 9) One firing heats for 12-24 hours. 10) Fire once or twice per day in cold weather.

### Chapter 3: Basic Construction

| Component | Material | Purpose | Specification |
|---|---|---|---|
| Foundation | Concrete or stone | Support mass (2-4 tons) | Sized for full heater footprint |
| Firebox | Firebrick (refractory) | Withstand flame | 2,600°F rated firebrick |
| Flue channels | Firebrick or common brick | Route exhaust, absorb heat | 6-8 inch square channels |
| Outer shell | Common brick, stone, or tile | Radiate heat, appearance | 4 inch minimum thickness |
| Chimney connection | Firebrick to metal flue | Exhaust to outdoors | 6-8 inch diameter |
| Cleanout doors | Cast iron | Access for cleaning soot | At each channel turn |
| Bypass damper | Cast iron | Direct exhaust to chimney (startup) | At firebox exit |

Finnish contraflow (simplest effective design): 1) Build firebox (firebrick, 12x18x24 inches minimum). 2) Exhaust exits top of firebox, rises through center channel. 3) At top of heater, gases split and descend through side channels. 4) At bottom of side channels, gases enter chimney connection. 5) This up-center, down-sides path is the contraflow pattern. 6) Total flue path: 8-12 feet (within a 4-foot tall heater). 7) Outer shell: common brick, 4 inches thick around channels. 8) Total mass: 2,000-4,000 pounds.

### Chapter 4: Flue Channel Routing

| Pattern | Path | Efficiency | Complexity | Best For |
|---|---|---|---|---|
| Contraflow (up-down) | Up center, down sides | Very high | Moderate | Most applications |
| Bell (free gas movement) | Open chamber, gas stratifies | High | Low | Simple construction |
| Horizontal channels | Side to side, multiple passes | High | Moderate | Wide, low heaters |
| Vertical channels | Up and down, multiple passes | Very high | High | Tall, narrow heaters |

### Chapter 5: Operation and Maintenance

| Task | Frequency | Method | Purpose |
|---|---|---|---|
| Fire (cold weather) | 1-2 times per day | Full load, burn hot and fast | Heat the mass |
| Fire (mild weather) | Once per day or less | Smaller load | Maintain comfort |
| Clean flue channels | Annually | Open cleanout doors, brush soot | Maintain efficiency |
| Inspect firebox | Annually | Check for cracked firebrick | Prevent gas leaks |
| Check chimney | Annually | Inspect for creosote, damage | Fire safety |
| Replace firebrick | Every 10-20 years | Remove and replace cracked bricks | Maintain firebox integrity |

### Reference Card

1. Burn hot and fast (a masonry heater works by burning a full load of wood quickly at high temperature; this produces complete combustion, minimal smoke, and maximum heat transfer to the masonry). 2. The mass stores the heat (2,000-4,000 pounds of brick absorbs heat during the 1-2 hour fire and radiates it back into the room for 12-24 hours; this is the fundamental advantage over a metal stove). 3. One firing per day in most climates (a single hot fire in the morning heats the home all day; in very cold weather, a second evening fire may be needed). 4. The flue path is the key (exhaust gases must travel 8-12 feet through channels in the masonry; this long path allows the brick to absorb most of the heat before gases reach the chimney). 5. Surface temperature is safe (the outer surface of a masonry heater reaches 150-200°F, which is warm to the touch but will not burn skin or ignite nearby materials). 6. Use only dry wood (wet wood produces steam, creosote, and incomplete combustion; the firebox temperature drops, efficiency falls, and flue channels clog with soot). 7. The foundation must support the weight (a masonry heater weighs 2-4 tons; the floor and foundation must be designed for this concentrated load). 8. A masonry heater is the most efficient wood heating system (at 80-90% efficiency, a masonry heater extracts more heat from wood than any other wood-burning device; it uses less wood and produces less pollution than a conventional wood stove).