september 27-30, 2012 denver co - phius · an earth tube. (1) is the building cooling load and (2)...
TRANSCRIPT
7th Annual North American Passive House Conference
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7 Annual North American Passive House ConferenceSeptember 27-30, 2012 Denver CO
Jason MoroskoCPHC
UltimateAir IncUltimateAir [email protected]
7th Annual North American Passive House Conference
Session Learning Objectives:
7 Annual North American Passive House ConferenceSeptember 27-30, 2012 Denver CO
Session Learning Objectives:
• Design factors for residential earth air tubesDesign factors for residential earth air tubes• Heating/cooling capacity for residential earth tubes• Cost economics and paybackp y• Data collection results and methods
EARTH TUBES:Heating/Cooling/DehumidificationHeating/Cooling/Dehumidification capacity, Design, and Experimental
D tData
Jason Morosko UltimateAir Inc Athens, [email protected]
About Me:
Jason Morosko, MSME, Certified Passive House Consultant
Manufacturer/Designer of energy recovery ventilation equipment
High performance home design consultant, specialty in envelop/mechanicals
PH project: www sustainablepath usPH project: www.sustainablepath.us
ABSTRACT
h ll f h d l h bThis presentation will focus on three residential earth tube designs as installed and operated in North America ‐ detailing their costs, design factors, climate, capacity to heat and cool as g p ymeasured‐ and extrapolating this to a calculation methodology for predicting overall viability of earth tubes in the North American MarketMarket.
Earth Air Tube: An ‘earth tube’ is a form of heat exchanger which harvests ‘heat’ (hot and cool) from the ground, direct to
the air. Also called a Ground Air Heat Exchanger.
Design Considerationsesign Considerations1. Conductive heat exchange
• Soil and pipe properties2 Water removal2. Water removal
• Gravity drain / sump / french drain and gravel bed3. Cleaning of the tubes4. End result design driven 5. High water table6. Radon
PROJECT 1.
Location: Athens, Ohio 6500 HDDTube type: 8” SDR 35 PVC
[standard sewer pipe][ p p ]Tube length: two runs‐ 100 foot eachTube Depth: 5 feet to daylight [nominal]
Description: Two pipes side by side with 8” separation, 6’ down. Entering the shell below the footer and up through the concrete slab. Pipes each have 1‐ 90 degree elbow and one 45 degree elbow. They l f th b ildi d t d t f b k h tslope away from the building and protrude out of a bank where water drainage occurs. Filter box to be installed at the outside air intake (not complete).
Measurements are on one pipe only. One pipe is currently in use.
www.sustainablepath.us
PROJECT 1.
PROJECT 1.
CONCEPT
PLAN VIEW
2’ Wide – 5’ Deep with pipes at edges of trench
PROJECT 1.
PROJECT 1.
PROJECT 1.
PROJECT 1. RESULTS
• From one 100’ tube‐ will second tube “double” capacity?From one 100 tube will second tube double capacity?• air/water tight‐ drained to daylight• relatively straight pipe
PROJECT 2.
Location: Philadelphia, PA 5000 HDDT b t 6” t d l th l iTube type: 6” corrugated polyethylene pipe
[standard drain pipe]Tube length: 780 feet at two elevationsTube Depth: 8 5‐10 feetTube Depth: 8.5‐10 feet
Description: Two levels of three pipes, all six inch in diameter. Placed in a serpentine manner around the footing excavation andPlaced in a serpentine manner around the footing excavation and under the garage slab. Backfill around pipes was 1B drainage aggregate, and a layer of landscape fabric between layers and above the upper layer. 130’ X 6. Designed in conjunction with Larry Larson‐http://www.earthairtubes.com/
Blog: passivehousepa.blogspot.comEmail: [email protected]
PROJECT 2.
PROJECT 2.
PROJECT 2.
PROJECT 2.
PROJECT 2.
PROJECT 2.
PROJECT 2.
PROJECT 2. RESULTS
PROJECT 2. RESULTS
• 203 ft/min air velocity (very low)• Increased surface area due to pipe corrugation• Increased turbulence (air bouncing off of pipe walls) due to serpentineIncreased turbulence (air bouncing off of pipe walls) due to serpentine installation• Installation in gravel bed
From Owner‐Project 2, Bob Rosania: The project is a 6600 TFA PH level shell. Current ACH50 of 0.22. Walls R58 – Under Slab R45 – Roof R92.
Currently‐ temperature stabilizes at 73 F without active cooling (summer hot/humid, PA) Need minor amount of dehumidification but expect this to dissipate as home ages and the materials inside acclimateto dissipate as home ages and the materials inside acclimate.
PROJECT 3.
Location: Ottawa, Canada 8050 HDDT b t 8” SDR 35 REHAU ECOAIR i ti i bi lTube type: 8” SDR 35 REHAU ECOAIR pipe – antimicrobialTube length: 180 feetTube Depth: Average of 5 feet
Description: Single 180’ run. Sloping toward the building with condensate pump inside. 8‐ 90 degree elbows.
PROJECT 3.
PROJECT 3.
PROJECT 3.
PROJECT 3.
PROJECT 3.
PROJECT 3. RESULTS
• low humidity outside resulting in little latent performance• 430 ft/min air velocity
RESULTS
COMMENTS and SUMMARYSUMMARY
This is a snapshot of data and analysis of three ground tube heat exchangers. Listed herein are peak capacities of relatively new systems. Peak capacity relates what we can expect on extreme days. The capacity is a calculation of the energy transfer between the ground and the air stream within the pipebetween the ground and the air stream within the pipe.From this data, we can surmise the capacity of these independent systems‐ against one another‐ and anticipate peak capacity. Each system is different in climate, soil type and tube design‐ so direct comparison of any single design aspect is not possible.
Further work needs to include yearly performance on an hourly basis to calculate yearly kWh benefits to the building. Differentiation between cooling/heating of the outside air‐ versus cooling and heating of the building need to be separated andoutside air versus cooling and heating of the building need to be separated and calculated.
COMMENTS and SUMMARYSUMMARY
There are at least two distinct loads to attempt to eliminate with the introduction of an earth tube. (1) is the building cooling load and (2) is the defrost requirement for an air to air heat exchanger (ventilation) system.
The design of the earth tube would be significantly different if choosing to eliminateThe design of the earth tube would be significantly different if choosing to eliminate just one of the above loads versus the other.
From the results documented‐ it should be completely viable for an earth tube to cover the defrost requirements in the continental US.
From the results documented‐ more study will need to be done to determine if a system can be designed for main stream cooling.system can be designed for main stream cooling.