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No. These shutters are usually made of aluminum or plastic and may have some weatherstripping, but are not designed to seal off air leakage in the winter.
"Additional sealing and insulation are necessary to reduce this potential heat loss," said Bruce Snead, extension specialist in residential energy at Kansas State University.
The air seal can be provided by a reusable plastic film or heat-shrink film which is mounted to the trim around the louvers.
"This approach should be coupled with insulating batts draped over the fan in the attic, or with an insulated box which fits over the fan," Snead said.
These batts or the box can be left in the attic year round and remounted in the fall.
"Another idea is to make an insulating panel with weather-stripped edges that fits over the louvers from below," Snead said. "This panel will need to be attached to the ceiling with screws or hooks and, thus, will be visible from inside the house."
Regardless of which method you choose, be sure to turn off the power to the fan before you work around it. Ideally, whenever the fan is covered, the circuit the fan is on should be shut off.
The most common causes of this problem are either air trapped in the radiator or failed steam traps," said Dennis Matteson, extension specialist in small business energy at Kansas State University.
"Air trapped in the radiator is sometimes referred to as air locking," Matteson said.
This trapped air prevents steam from entering part of the radiator.
This problem is most common in single-pipe steam systems, radiators with only one pipe to them.
"These air vents are located on the opposite end of the radiator from the steam inlet," Matteson said.
These vents are designed to vent the air from the radiator until the radiator fills with steam. These vents have small openings, which are prone to plugging.
"If this vent is plugged, it should be replaced with a vent that has the proper pressure range," Matteson said.
Steam traps are used to hold the steam in the radiator until it condenses. The trap then allows the condensate to return to the boiler. If the trap fails while shut or is obstructed, the condensate cannot be removed, or is removed too slowly, resulting in insufficient steam entering the radiator.
"Have your steam traps checked by a professional if you suspect trap failure," Matteson said.
Traps that have failed in the closed position will reduce heating capacity, and traps that have failed in the open position will decrease the energy efficiency of the steam system.
Many boilers have limits on the minimum water temperature to prevent condensation within the boiler.
"Cast iron boilers are among the most tolerant of low water temperature," said Gene Meyer, extension mechanical engineer at Kansas State University.
While lower water temperatures will improve heat transfer from the flue gases to the water, these gases may become cooled sufficiently to allow moisture to begin to condense. When this moisture combines with the sulfur dioxide in the flue gases, it forms sulfuric acid.
"This causes extensive corrosion in some boilers and the boiler stacks, which are not constructed to withstand this corrosive environment," Meyer said.
In order to circulate water below the minimum water temperature of the boiler, use a three-way mixing valve on the exterior. The water from the boiler will be blended with return water to maintain the desired circulating water temperature.
"With this situation, you must be careful to maintain minimum circulation rates within the boiler to avoid hot spots and possible tube failure," Meyer said. "Often a pumped boiler configuration will be required."
"Hydronic heating systems can get air trapped at the highest locations in the system," said Dennis Matteson, extension specialist in small business energy at Kansas State University.
Water systems may have automatic air bleed valves at the highest point of the distribution system to purge the system of air. If there are no bleed valves, the velocity of the water is designed to remove the air.
"In some cases, radiators located higher than the distribution system may have bleed valves ," Matteson said. "Check these valves. If they are operated manually, they may need to be bled as problems arise."
Another problem may be the loss of water in the system. This is typically caused by an automatic water make-up valve, or pressure-reducing valve stuck in the closed position.
"This will decrease the pressure of the system, and it could cause air leakage into the system," Matteson said. "Air leakage will increase the potential for air locking."
Unless you have technical training in these systems, contact your heating service personnel to determine the source of the problem.
A ground-source heat pump is a heating system that uses the earth as a heat source in the wintertime and as a heat sink to eject the heat in the summertime.
"Ground-source heat pumps may be either open-loop or closed-loop," said Dennis Matteson, extension specialist in small business energy at Kansas State University.
A closed-loop system circulates the same water through the loop for the heat source and heat rejection process.
The closed-loop heat source or sink may be a vertical hole or horizontal trench.
"The advantage of the closed-loop system is that the water in the loop, because it is recirculating, can be treated and the system can be used in areas where the water in the water may be contaminated or hard," Matteson said.
An open-loop system would be used where the water quality is good, and soft water. The advantage of the open-loop system is the initial cost is usually lower and the efficiency is usually higher.
"These products are primarily designed for use in new construction as a method of reducing air infiltration," said Bruce Snead, extension specialist in residential energy at K-State. "They are rolled sheet goods usually installed with staples or tape over the exterior sheathing."
Some brand names are Tyvek, Rufco-wrap, Barricade and Airtight-wrap. Their intent is to minimize the passage of air while still allowing water vapor through the exterior skin of the building.
Three basic types currently are available. The first house wrap was Tyvek. It is a spun-bonded polyethylene. This is a mat of polyethylene fibers "spun-bonded" in a patented process. The second type is perforated polyethylene film. The third type is spun-bonded polypropylene, a different type of plastic.
"Each of these can be effective air barriers if installed according to its manufacturer's recommendations," Snead said.
"Condensation which forms overnight on windows may not be damaging if it evaporates as the glass warms during the day," said Richard B. Hayter, director of Engineering Extension at Kansas State University.
"Unfortunately, much of the damage from extended condensation may be in places where it cannot be observed. Therefore, the potential for, or level of, damage may not be readily apparent. Condensation can occur within a wall in a crawl space, or above a ceiling beneath an attic," Hayter said.
The dew point is the temperature at which water vapor in the air will condense on surfaces.
"Two factors influence condensation," Hayter said.
First, as the humidity or moisture level in your home increases, the dew point temperature also will increase. Secondly, as temperatures drop outside, the temperature of the window or other surfaces also will drop. Hayter said.
The moisture which condenses comes from the water vapor in the air within the home. Homes with a high moisture level may have more humidity than desired. This can be caused by excessive humidifying or by water vapor produced through showering or other household activities.
Secondly, the temperature of a surface may fall below the dew point causing condensation to form. This may be apparent on window glass or where it is difficult to observe such as inside wall cavities.
"Condensation on your windows and on other cold surfaces in your home is evidence that the temperature of those surfaces has dropped below the dew point temperature," Hayter said.
"The easiest and most effective way to control condensation is to control humidity," Hayter said.
Typically it is not necessary for health or comfort reasons to have humidities greater than 30 percent. Humidity is controlled by decreasing or eliminating moisture sources and by venting moisture directly to the outside. Consider connecting your bathroom exhaust fan to a moisture sensing switch. Also, make sure your clothes dryer is vented to the outside.