Your building is fighting the cold. But how prepared is it? Is it winning? Or is it losing at your expense? Can every building be treated the same? What is the best way to resist the cold with reasonable effort and cost? The concept is simple, but the application can be complicated, even detrimental.
The idea of people wearing the same outfit in all conditions is absurd, but your house has to.
New England houses need to fight the heat and the cold, the wet and the dry, and everything in between. The best way to determine a building’s health and the opportunity for upgrades is to complete the right inspection.
An energy audit determines where a building is an energy hog. Energy Audits may be completed by National Grid for a reduced cost or for free, but
many houses need more than a basic run through. Energy Audits start with visual building inspections, looking at insulation, holes, water and moisture, doors and windows, and other building components. They can review the energy efficiency of appliances like furnaces and boilers, hot water heaters, refrigerators, and others. The most essential part is a blower door test, which is the most effective way to determine where air is coming from. In the colder months, infrared scanning can see into walls, finding out where insulation is lacking.
The final auditor’s report will review the findings, and provide suggestions where to best upgrade the building.
Moisture and Water
Moisture and water are buildings biggest threats. Direct water causes wood elements to rot, allows building parts to get way, stay wet, or just wallow in moisture. Direct water can come from poor flashing and trim, gutters, chimneys, overhangs, and roofs. Direct water absorbs into wood, fiberglass and blown in insulation, and transfers cold much quicker than dry parts. Moisture comes in the form of condensation, airflow, wet basements and other indirect ways that can have the same effect as direct water. Water and moisture causes wood rot, mold, lichen, and other unfavorable conditions that can be destructive to
buildings and unhealthy for occupants. A qualified building contractor can assess a building’s conditions.
Drafts are by far the biggest culprits of heat loss. An eighth inch gap around a door is the equivalent of a three inch hole in a wall. A modern Passive house (German: Passivhaus) requires little energy for space heating or cooling using aggressive insulation and thermal bridging techniques, but relies on very little airflow. A recent Passive House built in Wakefield has an air flow equivalent of the size of a smart phone. My 1908 house has the size of a garage door. When drafts are not managed, the air exchanges quite often, which is healthy, but not very good for trapping heat. Loose blown in or fiberglass insulation only filters drafts and holds moisture.
A hat and socks
Having a properly insulated attic space is key. There are two ways to properly insulate an attic. The first “cold roof system” allows air to move from the overhang to the top, with the insulation below the airflow. Typically soffit vents bring air in, and ridge vents bring air out. The key is no
t to block the airflow, and to be well insulated below it. The second method is a “hot roof system”, which makes the roof framing and insulation one mass, with no airflow. The hot roof system can be complicated but effective. Hot roof systems use spray foam or rigid foam insulation, and rarely use fiberglass, blown in, or other open cell insulations since they can trap moisture.
The final analysis is not every building is the same. There is not one treatment that fits all. The best approach is to complete upgrades in increments, using sound scientific and observational methods to determine a retrofit’s effectiveness.