Thursday, February 25, 2010

PETER & SHELLY, June 2009 completion, February 2010 (customer projection), "36% reduction"

Pete and Shelly have a home built in 1998.  They had some temperature control issues and rodent/insect issues that were frustrating them, but because of the home's age they initially had reservations that solutions were justifiable.   

Their master suite comprises the East side of the second floor, so it gets some pretty good solar load in the morning.  Keeping the master suite comfortable so Shelly could get ready for work without feeling like she was just back from a morning jog was a challenge.  Pete found himself programming the dining room thermostat to drop to 62 at around 5:30 am to make the master suite comfortable in the morning.

Eventually, exasperated, they hired us to perform a comprehensive home assessment.  We uncovered some significant but all to common deficiencies that were contributing dramatically to their comfort and control challenges.

From the assessment I was able to build a list of recommendations with varying degrees of comfort, control, and energy reward.  Working with Peter we developed a plan that fit their needs.  Before going into the plan, let me share an e-mail Peter sent me February 24th, 2010:

Just doing some crappy calculations going from actual to actual reads (July to January)...
08/09 energy costs $1435 vs 09/10 $910. I used the same pricing for each period. Last read was 1/25/10. Next actual will be around 3/25/10 for a full Winter picture.
08/09 July-Jan 809.1 therms, 6616 kwh
09/10 July-Jan 461.6 therms, 5385 kwh
36% decrease with a warmer/cooler house. I know it's not been as cold perhaps this year but still. That's huge. We could see $1,000 drop in a year. Maybe not quite.


Pete
The NY Home Performance with Energy Star Comprehensive Home Assessment report projected annual savings was $526 per year.  This indicates to me that this system is conservative in it's projections.  It's nice to under-promise and over-deliver!


Here is the work scope/list of improvements:
Insulation:





Baffle Repair in main attic – Home is in a windy area and common practice of using batt insulation between vent and wall top plate is not a durable solution.  Remove any remaining batting used as soffit wind blocking material.  Pull insulation between joists 1 – 3 feet away from end wall area.  Install Vent Baffle to block area between wall top plate and rafter vents in main attic.  Spray flash coat of urethane foam to affix at bottom, sides and top and to air/weather seal.  Spray liberally to bottom (areas adjacent to conditioned space in this typically weak thermal perimeter area) and fold fiberglass back into place.  Use spray foam to air seal other attic penetrations, any IC rated can lights, and around abandoned chimney chase.  INSTALL HOMEOWNER PROVIDED DRYER VENT.  BRING 6” PIECE OF 6” ALUMINUM PIPE.

Attic Hatch/Corral package – install proper attic hatch.  Corral, air seal and insulate. 

Add 8” Cellulose to Main Attic Area up to the point white loose fill fiberglass ends (above hall leading to bonus room). 

Spray Foam Basement – Additional air sealing is needed in the basement.  Penetrations for ducts, plumbing and electrical need to be flash coated.  Penetrations through joists bays that are panned as returns need to be hit as well.  There is an extended cavity area at the West end of the basement that has joist runs extending beyond the sill plate that represents an air sealing challenge.  The surface drops beyond the sill plate, making spraying difficult.  There is significant connection here between the garage and basement.  Addressing this is somewhat at spray gun operators’ discretion and experience.  I propose filling this area with rigid foam to a level the operator can flash coat for air sealing.  Also, the blocks extend into basement beyond the plate.  If spray operator can seal these openings as well that would be great.  Seal abandoned chimney and chimney chase.
There is also an area under a bay window that should be inspected and improved if possible.

Air seal bottom edge of garage east wall drywall with caulk and/or minimal expanding foam.  Again – deferring to installation crew expertise for best practice.

Attach Foam and Wood Weather stripping and door sweeps to 2 front doors and garage door.  Inspect rear French doors, determine if weather sealing measures can be performed and attempt improvements. 
Parts List:
Navien:

Install Navien 240a ng on board and stand.  No condensate pump or pre-piping on board.  Include whole house water filter and fittings un-mounted.  Pre-pipe gas pipe, electric conduit, electrical box; emergency switch ok – left side preferred for electric.

Infinity Furnace:
Install 60mbtu MVC 060 with Infinity Zone Control and Infinity System Access Module, Media Air Filter and 3.5 ton Puron N coil. Install turning vanes in retn drop.  No condensate pump.

Infinity Heat Pump:

Install 3 ton 2 stage Infinity Heat Pump pre-attached to legs and pad with pre-brazed stubs, puron vapor & liquid lines both insulated.  Use existing electrical whip & disconnect (?)

Infinity Zoning & Duct Modifications

There are notes on ductwork indicating repairs & modifications necessary for zoning.  Controls: Infinity 4 zone control, 3 infinity “smart sensors”, 5 round dampers, 4 rectangular dampers (sizes to be determined at site visit with Clinton).  Main Infinity Zone Control to be installed either in Master Suite or current t-stat location in Dining Room.  Smart Sensors to be installed in Master (or dining room), either north guest room or west guest room (NOT EAST GUEST ROOM!) and bonus room.  East guest room has significant solar loading.  Zone damper may need to be attached to Master or Guest zone depending upon which performs better.  Inspect and repair returns.  Between 4 & 8 hours to be spent sealing accessible ductwork with mastic.  Supply & return ducts nearest furnace, and supplies before zone dampers receiving highest priority

Peter absolutely loves the zone control.  Being able to get his master or the bonus room to comfortable temperatures without boiling or freezing the rest of the house has made him fall in love with his house again. 

Rapid temperature drop was a comfort issue, now he marvels at how it seems to "stay" in mild weather.  In other words, when it is not too hot or cold outside the equipment shuts off and doesn't come on for a long time.

This hasn't been without challenges.  The on demand water heater needed some upgrades, but overall the job has been a gratifying success.

2 comments:

tedkidd said...

On July 23, 2010 Pete sent me his energy history. From one year to the next here are his results:

2008-2009 his gas use was 1428 Therms and electric use was 8567 Kilowatts.
2009-2010 his gas use was 892 Therms and 8849 Kilowatts.

Gas use was down 37.5% and electric was up 3.2%

This represents a gas savings of $644, and an electric increase of $31.

His audit projected savings of $526.

Strat said...

Hey Ted- RG&E just revised our monthly budget from $245 to $170 per month! Pete, 9/1/10.