Tropical Atrium Temperature and Humidity Control

This page is the open source project-launch blueprinting page specific to the free-sharing and global collaboration regarding the One Community Tropical Atrium heating, cooling, and humidity control details. The Tropical Atrium will provide an aesthetically pleasing and multi-functional center for the earthbag village (Pod 1). The internal environment will be maintained between 60-90 degrees Fahrenheit and 40-70% humidity. It is designed to grow food, capture and use rainwater, and recycle heat from the earthbag village showers, and provide a beautiful passive recreation space. This page contains the following sections:

• Initial Temperature and Humidity Control
• Temperature and Humidity Adaptation Options
• Summary
  
• FAQ

RELATED PAGES

TROPICAL ATRIUM OVERVIEW  ●  EARTHBAG VILLAGE HUB  ●  OUR OPEN SOURCE PURPOSE

INITIAL TEMPERATURE AND HUMIDITY CONTROL

Maintenance of the Tropical Atrium’s internal temperature of 60-90 degrees Fahrenheit and 40-70% humidity will be accomplished with the following diversity of methods:

HEATING AND SUNLIGHT

• Completely glazed South-facing roof and walls
• Round structure for maximum sunlight year-round
• Sloped South floor for maximum sunlight to the back wall in the winter
• Pond and stone walkways and walls for additional thermal-mass heat storage
• Pod 1 South, East, and West showers will provide additional heat via piping the water through the internal structure
• Building orientation will be slightly to the east and northeast by 10-15 degrees F to catch earlier sun and avoid the hotter late afternoon sun. Glazing is also being selected for maximum solar gain:

Solar Heat Gain with Respect to Azimuth Direction for 90 Deg Windows – Click to Enlarge

• Used shower water from the adjacent communal showers will be piped into the structure so the heat can be extracted/recycled.

SHOWER WATER HEAT-RECYLCING FEASIBILITY EXPERIMENT

Normal shower temperatures can range as high as 107 degrees F. Average shower length for people in the United States is 10 minutes. To test the feasibility of recycling shower water heat, we ran a conservative experiment to see how warm the water would be after a person took a luke-warm shower for only 7 minutes. In our experiment the room temperature was 81 degrees, the water temperature was 98/99 degrees F coming out of the shower head, and we plugged the drain. After the shower was done the shower water in the bottom of the shower was 93 degrees F. We consider this a good sign and are continuing our thermal assessment and design process.

COOLING, MOISTURE, AND AIRFLOW

• Primary venting via North and South doors and roof vents
• Secondary venting provided with East and West slider windows
• Pod 1 North greywater will be used underground to water trees and increase humidity
• Semi-subterranean design (10 ft depth at North wall) is to assist with temperature control
• Southwest exterior cold hardy plantings will be utilized to reduce excessive summer sun if deemed necessary

TEMPERATURE AND HUMIDITY ADAPTATION OPTIONS

We have planned additional strategies for controlling heat, cooling, moisture, and light so this structure is maximally adaptable for our open source research and development process and the predictably diverse duplication needs of others. We will additionally be building this structure entirely with screws, nuts, and bolts so it can modified easily as needed. Adaptation for the Tropical Atrium’s internal temperature needs of 60-90 degrees Fahrenheit and 40-70% humidity will be accomplished with the following diversity of methods:

ADDITIONAL THOUGHTS ON CREATING MORE HEAT

Vacillating winter temperatures between day and night are a major concern and could affect fruit production if not maintained above 55 degrees Fahrenheit. We will experiment and address this issue by building this structure with the ability for retrofitting of the following strategies, in the following order, if needed:

1. Thermal mass in the form of dark colored stone floors/pads and a few groupings of scattered boulders
2. Possible interior light colored stone walls that will both absorb and reflect heat to nearby thermal mass
3. Compost heating
4. Low-E glass, especially on the south side
5. Other insulation throughout (shutters, traditional, horticultural bubble wrap, etc.)
6. Dark barrels filled with water for heat retention and evening dispersion
7. Rocket heaters as a backup to the passive solar
8. Solar voltaic heating as a backup to rocket heaters
9. Other more significant structural modifications

ADDITIONAL THOUGHTS ON REDUCING HEAT

Too much heat could be a problem in the summer. Higher end temperatures in the 80’s – 90’s would be ok but we want to avoid going above 95. We will experiment and address this issue by building this structure with the ability for retrofitting of the following strategies, in the following order, if needed:

1. Additional roof  venting and/or other venting
2. Plantings for shade (vines and deciduous trees)
3. Addition of waterfalls and other cool-running water features
4. North side roof insulation – And no light permeation to begin with
5. Roof overhangs for shading and thereby reducing direct sun at the wrong time of year
6. Shade cloth or lath that reduces sun penetration

ADDITIONAL THOUGHTS ON HUMIDITY AND AIRFLOW

The hotter the temperature, the more essential to have adequate airflow, especially when atmospheric conditions suppress air movement. Mold is also a concern. Humidity levels will probably vary from 40% and up to a possible projected 70%+, depending on the time of year. Our objective is to define the plant needs relative to fruit production and comfort of the structure as a recreation space and then maintain the humidity at that ideal level. We will experiment and address these issues by building this structure with the ability for retrofitting of the following strategies, in the following order, if needed:

1. Additional roof venting and/or other venting
2. Creating convection currents with lower cool air intake rising to push out higher warmer humid air
3. Solar powered fans that will move night air by pushing down the warm air and providing circulation to decrease humidity levels and limit mold/fungus.

If lack of humidity is a problem, increasing plant proximity will create microclimates to enhance the humidity.

ADDITIONAL THOUGHTS ON LIGHTING

We project sufficient light but if we need more we could experiment and address these issues by building this structure with the ability for retrofitting of the following strategies, in the following order, if needed:

1. Addition of mirrors or North-facing windows
2. Sun Tubes/Pipes

SUMMARY

The Tropical Atrium is designed to be adaptable to almost any environment. It will be maintained between 60-90 degrees Fahrenheit and 40-70% humidity. To accomplish our adaptability, temperature, and humidity goals we have designed this structure with a diversity of heating, cooling, and humidity control options and possible modifications. Our entire research and development process will be open source so others can duplicated and further evolve everything we do with their own Tropical Atrium structures.

FREQUENTLY ANSWERED QUESTIONS

 Q: What is the purpose of the Tropical Atrium?

Please see the Tropical Atrium Overview and Open Source Hub page.

Q: What will you be growing in the Tropical Atrium?

Please read the Tropical Atrium Planting and Harvesting Page for complete plant and tree details.

Q: What if you can’t stabilize the temperature and humidity levels within this structure?

We feel the diversity of built-in temperature and humidity control elements combined with the even larger diversity of possible modifications for added temperature and humidity control make stabilization of this environment at our goal between 60-90 degrees Fahrenheit and 40-70% humidity almost guaranteed. That said, if we are unable to maintain this we will either modify the internal planting plan or, in a worst-case scenario, disassemble and remove the roof and turn this into a very beautiful and functional in-ground outdoor structure.