Energy efficiency upgrades for houses

Energy costs are a consideration these days but most houses in the New York metropolitan region were built during a time when energy costs were not a concern. Thus, they were not built with energy efficiency and conservation in mind. Following are some common energy upgrades that you may consider.

Attic insulation
All exterior surfaces of a building lose heat to the outside, even the basement floor, but warm air rises and so the most heat is lost through the top ceiling. Adding insulation above the top ceiling is a relatively inexpensive measure that has a good return on investment, as well as improved comfort. Most houses we see average around 5 – 6 inches of fiberglass (R19), whereas the newly released New York State building codes require 16 inches (R49) for new construction. Use caution, however, as insulating the top ceiling makes the roof deck colder and more prone to condensation of moist air that makes its way into the attic. If you have insulation added, the top ceiling should be air-sealed as well to minimize air movement from the conditioned space to the attic.

Wall insulation
Insulating walls from the interior is invasive and has a limited return on investment. It is best done during a gut renovation, when walls will be open anyway. You can use spray foam, which is more expensive, but it does a superior job of air sealing the building shell. If you are replacing exterior siding on a wood-framed house, wall insulation can be applied from the outside in two ways – by blowing insulation into wall cavities from outside and/or applying foam insulation boards to the exterior walls behind the siding. Use of foam boards is a good approach, because it provides some measure of air sealing and also prevents thermal bridging through walls studs, which readily causes heat loss though the walls to the outside.

Simple Air Sealing
This is a simple DIY measure that anyone with a caulking gun can do. Common construction techniques leave gaps around trimmed areas in exterior walls where air can blow through. Seal all window / door trim pieces together and to the wall and seal base trim to the wall and floor. This can be done with latex caulking, which is paintable. Air tends to blow through outlet and switch boxes. There are gaskets available to go under the cover plates that can cut back on the air flow.

 

 

New Windows
Replacing old windows does not have a good return on investment with regard to energy savings, given their cost. Windows should only be replaced if you are unhappy with how they perform — are they drafty, broken, difficult to operate? It’s hard to put a price on family comfort!

 

 

 

Air conditioning
If you would like to make the jump from window and wall A/C units to a central cooling system, you can either go ducted or ductless.

Installing ducts in a house is very invasive and often results in ducts and cooling equipment located in the hottest place in the house — the attic. Sound counterintuitive? It is, and usually results in severe energy losses. Someday this practice will be prohibited by building codes, but now it’s standard procedure. It is best to avoid using the attic for cooling equipment, tempting though it may be.

If you want to avoid the hassles of ducts, you could go ductless. Ductless equipment, also known as mini-splits, is hitting its stride in the HVAC market and has many advantages. Mini-split equipment is quieter and has a less invasive installation. Also, it is far more energy efficient than common ducted systems, mainly because it avoids altogether the transmission losses that occur through ductwork in unconditioned spaces like attics and inside walls, etc. Moreover, the equipment itself better utilizes the energy input through variable refrigerant flow and variable fan speeds. The wall units don’t need to be on outside walls like wall A/Cs do and a few strategically placed units can cool down an entire floor in short order. The outside condensers can drive up to 8 or more wall units. This equipment has computer controls and is quite complex, so you need to have an installer who is well-versed in installation and servicing. Mini-splits can also come with optional heating mode, which can serve as a supplemental heat source or even a backup in the event of heating equipment failure.

In terms of costs, there are probably similarities between ductless and ducted systems, though one could go higher than the other in consideration of the specifics of a given house.

Heating upgrades
The highest return on investment is switching from an old oil-fired boiler to a high-efficiency condensing gas boiler. The typical payback period can be 5 – 8 years in heating savings. The return is two-fold: Oil right now costs more than gas and the increase in equipment efficiency means that more of the energy in the fuel is utilized, rather than going up the chimney as waste heat. Two other savings that can occur in such an upgrade is the lack of need to restore an old chimney and rebates that are offered by the utility (contact them for details). Even though installation of high-efficiency equipment is more expensive than an in-kind replacement of your existing boiler, the long-term investment makes good sense. Even if you already have gas heat, but your boiler or furnace is nearing the end of its life, switching to condensing equipment makes sense. Condensing units rip so much energy out of the gas, that the exhaust is much cooler and gets vented through a plastic pipe. Brick chimneys are used for conventional heating equipment because the exhaust gases are so hot. This is known as waste heat! Again, condensing equipment is complex, so be sure to work with an installer who understands proper installation of this equipment and is capable of providing future service.

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