At the time of visit, the Energy Specialist must find out the number of hours of air sealing required in the home to get cost-effective energy savings. Most of the homes could have some air sealing work. Spray foam, metal flashing, caulking, door sweeps, and weather stripping can be used to block the home. Air sealing should be done before insulation work starts if attic insulation is recommended. Attic air sealing must be recommended because that is where air loss and convective heat loss are the strongest. Attic air sealing may also bring a huge impact on energy savings and decreasing the attic moisture concerns. Some of the important air sealing features are:
- open chimney chases
- open wall cavities such as found in balloon framing
- attic knee walls
- ducts in the attic
- open duct chase
- multiple hatches that must be weather-stripped
- multiple attic spaces or unheated basements
- recessed lights
- floored attic areas and transition areas where dense-pack cellulose is not to be installed
- plumbing and electrical penetrations
- rim joist/wall plate seams
NOTE: For air sealing to be cost-effective, 60% of the attic area must be air sealed along with all chimney and plumbing by-passes.
Insulation of vertical surfaces with no air seal or ventilation requirement:
The following attic sites may be insulated without air sealing or ventilation, only if the insulation will have negligible impact on attic temperatures.
- Skylights
- Walk-up walls
- Level changes