avancerichs: Gear up for a cooler summer: save money and reduce your carbon footprint

Hot weather is around the corner, and you can make your home more comfortable while saving money through long-term energy conservation savings.

First Step to Comfort and Energy Savings: Conservation Measures

Energy conservation measures leading into summer can make for a much more comfortable, cheaper summer and put you in a position to half your winter heating bills. A typical payback for a few thousand dollars spent on building envelope sealing and insulating will be well within five years, for an effective return on investment better than an aggressive mutual fund, even in bull market years we’ve not seen for a while.

Several organizations stand ready to help:

Energy Coordinating Agency offers energy audits and help connecting you to financing, if needed, to implement their recommendations. Qualifying low-income home owners can get free or low-cost energy audits.
EnergyWorks provides financing for building energy efficiency projects, and can help connect you to contractors to assess needs and opportunities, and do the actual work to get ease you into summer and take the edge off winter — both financial and temperature-wise.
Mark Group is a major international contracting company that has become a big player in weatherization work throughout the greater Philadelphia region. Whichever contractor(s) you select, the Mark Group website provides good introductory information to the audit and energy improvements process. Like ECA (above), Mark Group won a major contract to work with Philadelphia Gas Works (PGW) on its energy saving retrofits for low-income customers.

Prepare your home’s electric system for weatherization and insulation

Insulation around wires reduces their ability to dissipate heat, and weather sealing may be a waste of time and money if you may be opening walls or drilling holes to run new wiring a year later. These new penetrations could drain blow-in cellulose insulation out of insulated cavities, or create new paths for unwanted air circulation that your weatherization contractor will have worked diligently to eliminate. In most cases, weatherization contractors will refuse to apply insulation where there is knob-and-tube wiring (typically, an attic), due to concern for its age, condition, and the potential for runaway overheating when the wiring can no longer dissipate heat as it did before insulation.

Regardless of the presence of knob-and-tube wiring in spaces to be insulated, many Philadelphia-area homes’ electrical systems could use updates and upgrades. Homes with extensive remaining knob-and-tube wiring should be completely re-wired in cases where the original knob-and-tube installation has been modified by subsequent contractors who didn’t understand the original system and wiring methods. Where the knob-and-tube has been left alone or treated properly, it may remain in fine condition and pose minimal fire risk, comparing favorably to more modern wiring systems. Still, home insurers increasingly demand knob-and-tube remediation, and this work will be cheaper prior to installing insulation and weather-sealing the building envelope — not to mention less disruptive of these weatherizing measures if the electrical work comes first!

Even if your home is wired with modern cabling throughout, you should consider carefully whether any electrical improvements are on the horizon, before burying your attic floor in cellulose or filling or sealing other cavities with spray foam type insulation. Do you want a recessed receptacle for your entertainment center behind a flat panel display? New recessed lighting in one of the rooms on your top floor (beneath the attic/roof)?

Robert Monk Electric has replaced and upgraded knob-and-tube wiring ahead of several attic insulation projects by Mark Group and other area weatherization contractors.

Step Two for Summer Comfort: Air Conditioning (incl. ceiling fans)

Circulating/ceiling fans, window units, mini-split systems, and central air may all be a part of your solution

Your approach to comfort during Philadelphia area’s torrid summertime will depend on such factors as your own heat and humidity tolerance, the natural and retrofit characteristics of your home (see Step One, above), how many people may reside there, their vulnerability to extreme heat (infants and the elderly; others with medical conditions), and everyone’s consideration for the energy costs of cooling equipment, both in term of your home economics and in terms of the earth’s ecology and climate system.

Ceiling fans and other circulating fans

This time-tested indoor climate-control method should be a part of every home’s strategy for summertime comfort control (reversing the fan direction upward can improve heating system efficiency in winter, too).

Whether you supplement the cooling effects of moving air with active AC cooling equipment or not, the circulation from a ceiling fan, box fan, window fan, or HVAC system blower fan can improve your comfort through the effects of wind chill and by circulating otherwise stagnant warm air away from living areas. If you do use central AC, mini-split systems or window units, circulating/ceiling fans can help extend the ‘reach’ of this equipment, and even out its effects — especially for window units and mini-split blowers that have enough capacity to cool beyond a relatively small room where they may be located. If you don’t have central AC, you can still use your forced-air heating system as a circulating fan system by getting a thermostat (or having one installed) that allows you to turn on the furnace’s blower fan without turning on the heat. This may be a good economy approach on less-than-hellish days, even when you do have the option of central air.

Note that energy efficient lamp types have complicated the process of matching ceiling fans with ceiling fan/light controls.

Robert Monk Electric can install ceiling fans for about $150 for the first and $65 each additional.

Window AC units provide cooling where you need it, cheaply

If you don’t occupy your whole home, or really need cooling only at night to get you to sleep, a window-mounted AC unit may be a good economical approach for both equipment and installation cost and energy consumption.

Beware of Overloading: install a dedicated circuit to avoid circuit overload and fire hazard

Keep in mind, however, that many Philadelphia-area homes have original or older wiring intended for the smaller appliances such lamps and small circulating fans that were available to consumers at the time the wiring was installed. An original/older receptacle (typically installed in baseboard and non-grounded — whether or not the receptacle itself appears to have a ground pin receptacle) will have a maximum capacity of 15A (times 120V = 1800 Watts — and that’s pushing limits), and it will be shared with other receptacles and/or lighting throughout the house, not just the same room. The entire circuit capacity is the same 1800 Watts (truly, 1440 Watts with a proper margin of safety), so most any window AC unit (they typically consume at least 1200W) will result in overloading of an original/older circuit. The concerns for overload, and the possible remedies, are similar for both window AC units in summer and plug-in space heaters in winter.

Robert Monk Electric can install new dedicated circuits suitable for window AC units (and plug-in space heaters).
Mini-split AC systems provide flexible, semi-central AC installations (and supplemental heating capability)

With this approach, a central compressor provides heat-pump power to chill (or heat) a fluid circulation medium, and individual radiator/blowers blow air over radiators to distribute cooled or heated air locally. A typical central compressor requires from 30A to 60A at 240V, and distributes 120V power to up to four individual blowers, along with the fluid circulation lines that are run on the exterior of the building.

Robert Monk Electric can install the feeder circuit for mini-split central compressor units.

Central Air Conditioning (AC) systems may require electric service upgrades for adequate capacity

If your existing service disconnect/main breaker is 100A or less, you will likely need a service upgrade in order to run central AC for your home. An exception could be a small, 2-story row home with no 240V electric appliances. A 150A electric service will be sufficient to run central air in most homes under 2500 square feet and with up to 30A of existing 240V appliances. 200A or more may be required for larger homes and/or where there are several 240V electric appliances.

HVAC contractors typically install their own equipment and even feeder circuits, but my observations suggest that less than half of them know (or care) how to do it right. I suspect that far fewer than that obtain the proper permits for the electrical portion of their installations.

Whether your central AC system will require a 200A service upgrade, or a distribution subpanel for major equipment remote from the main panel, contact Robert Monk Electric for a quote on the work.

avancerichs

Thursday, April 11, 2013

Gear up for a cooler summer: save money and reduce your carbon footprint