Saturday, January 16, 2010

How much are your windows costing you in Heating Expenses?

The historic buildings in Hoboken tend to be older and have heat problems due to their age. A variety of factors affect how well the buildings retain heat during the cold seasons, but one of the major ones in the windows. The windows in modern buildings tend to be built into a wall with insulation surrounding it. The few inches of insulation in the wall provides better heat retention in apartments and homes alike. When a window is surrounded by glass block or lacks heat, which is the case in many Hoboken Apartments, heat is not retained very well.

John Estees from Regional Home Inspection was hired by the Hoboken Plaza Condominium Association to make an assessment of all of the windows the associations buildings to determine if there replacement would stop heat loss and reduce heating costs. The Association pays for heat and hot water so by reducing heat loss, the association is holding down heating costs and by extension monthly condo dues. Replacing the windows is an option and may be essential in some buildings. John was hired to inspect apartments to see if the windows are the true cause of the problem. With his crew, John analyzed a variety of factors to see if the windows were efficient or to see if they needed replacement. The assessments needed to be conducted during the evening as temperatures tend to vary more during daytime hours.

The first factor looked at was insulation in the walls. Using infrared cameras to measure the temperature of the window and surroundings areas, John was able to see if there was insulation in the walls around the window. Insulation in walls is essential to keep heat in apartments. Older buildings tend to lack insulation which causes apartments to be cooler. With the device, John was able to see if there was a consistency in wall temperatures, which shows that the wall is properly insulated, or an inconsistency, which shows a lack of insulation. The areas measured were the wall space above, below, and to the sides of the windows.

The window seal, which was the second factor looked at, was an important factor as well because minor drafts allow cold air to come in and heat to flow out. A smoke pen was used to see how well the window was sealed in the wall. The smoke pen, which is a device that is pen like device that is lit with a match, shows where drafts come in around the edges of the window and in the window were the pains touch. John explained that when the smoke drafts off the window fairly quickly for six to eight inches, there is a poor seal. Some people may not notice that they have drafts in their apartment because they just up the thermostat and heating system output, but the smoke pen shows how air is coming in from outside and how people are unaware of it.

The combination of these two factors allowed John to make an accurate assessment of how the well an apartment would retain heat. With a lack of insulation and in the walls and poor seals, heat is able to leak in fairly easy. If a wall does have a proper seal and insulation in the walls, an apartment will stay fairly warm. Windows with a temperature that is around 6 degrees cooler than the wall is average and appropriate. Window temperatures that are more than 8 degrees cooler than the surrounding wall show that apartments lack insulation and proper heat retention.

Many art deco and even modern buildings in Hoboken use glass blocks as an accent surrounding a window which does offer better lighting but it may be at a high cost. Often, the glass does not provide enough insulation and do not retain heat in apartments well. Glass blocks tend to be 10-12 degrees cooler than the window pain, causing apartments to be colder during the winter. Glass blocks are not thermal effective. John can see this by looking at the R value of the product surrounding a window. A normal wall with insulation has an Rvalue of around 16-24. In some of the old buildings in Hoboken, walls that lack insulation have an R value of 10-12. Glass blocks have an R value of around 2-4, which is very low and demonstrates that there isn’t proper heat insulation. As a result the Association will be looking for an efficient replacement.

Many of these buildings are considered historic so simply eliminating the block may not be allowed by the Historic Preservation Board. There are many efficient products on the market that look very similar to the historic glass block but have a much better Rvalue.

At the time of the assessment John could not determine if the windows in a whole building needed to be replaced. Some apartments have been renovated, while windows have been replaced and insulation has been added. He did come to the conclusion that it may be possible to change some factors in the apartment without replacing the glass blocks and the windows. Making sure radiators are working properly, sealing windows, and adding insulation to walls may be most cost effective that replacing windows, which runs about $400 per window.

My having a study done by an outside party, it will be easier to convince condo owners to change their windows. In this building, the condo owner is responsible for their windows which explains why some apartments had new windows than others. Being able to quantify the impact of old windows makes the argument for investment easier.

The Associations gas broker determined that it cost the Association on average $150 a month over the winter months for every unit that left an air conditioner in a window. Window air conditioners sit in an open window and never fit perfectly in the window leaving gaps for air to come in just as when a window has a poor seal (likely worse).

Using this information from both the engineering firm and their gas broker, the Association can plan for remediation.

Do you have drafty windows? How much have you spent on heat loss? When looking at buying use your inspector to figure out the general condition of the windows. Use your realtor to find out if the unit owner or Association is responsible for window repair or replacement. If the unit owner is responsible, use that information to negotiate on price.


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