A/C for Wet Heads

On April 4, 1999, a historical Victorian row house in Georgetown was seriously damaged by fire. All of the home's original windows, a three-story staircase and the central air-conditioning system were destroyed. The kitchen, dining room, upstairs bedrooms and other parts of the house were ruined. In short, the house needed some work.

On the bright side, this provided a unique and unexpected opportunity to upgrade the three-story, 3,300-sq. ft. home.

This unique opportunity also faced some unique challenges. All of the renovations had to be approved by the Commission on Fine Arts for Washington, D.C., and the Historic Preservation Review Board of the District of Columbia, due to the home's historic status.

The last time the home had been retrofitted was in 1973 with a central air conditioning system installation. When this happened, a lot of the home's original living space and interior dimensions were compromised to make room for the ductwork.

The renovation after the fire included the installation of a radiant floor heating system along with a high-velocity, or Hi-V, air conditioning system by SpacePak. This combination allowed the homeowner to regain living space and restore the original dimensions of the home - not to mention have a very effective and efficient comfort system. The owners never knew of the possibility of having such an unobtrusive system that would perform just as well as their old, space-consuming system. It was up to Kevin Reed of Reed Heating and Air Conditioning to set them straight.

In the house, there was not one single bulkhead added to accommodate the new air conditioning system. One of the parameters outlined by the Historic Preservation Review Board was that there could not be an unsightly air conditioning unit on the ground next to the house. This requirement was met by placing the main cooling and blower unit in the attic.

In addition to the high-velocity air conditioning system, Reed installed a radiant floor heating system - eliminating the house's radiators and opening even more space. "The idea was to maximize the floor space of the house - using as little space for equipment as possible," said Reed. Following this idea, Reed opted to have the radiant system's boiler installed on the roof of the house. The former boiler room has been opened up and is now a part of the finished basement with a kitchen and fireplace.

Another challenge was finding a system that would heat and cool the space surrounding the three-story staircase. As you could imagine, controlling the temperature in a three-story open space can be tricky - especially with a duct system. However, when using a radiant system to heat and the high-velocity system to cool, this problem disappears. With a radiant heating system, the heat is produced from the floor and is allowed to naturally and evenly migrate upwards.

One of the principle advantages of high-velocity air conditioning systems is the ease of zoned climate control. Though more applicable in office and other commercial buildings, it proved extremely useful in the Georgetown house when deciding how to cool the wide variety of rooms - the three-story staircase had drastically different requirements than a small room in the basement.

Hi-V In Action

With a high-velocity air conditioning system, the vents are small holes, usually placed in the ceiling of a low-traffic area. The system works upon a principle called "aspiration," which refers to the dissemination of the treated air into the room.

The air is both cooled and compressed in the main unit. Then the cool compressed air is shot through the tubing. When the air reaches the room through the small hole in the ceiling, it expands rapidly - creating a low pressure zone around it. This low pressure draws air that was in the room into the stream of cool air.

The result is a great deal of air movement within a room. Although there is this increased air movement, it is not "drafty." The air coming from the hole in the ceiling does not shoot across the room and blow candles out - it expands immediately upon exiting the vent. The only area in which a breeze can be felt is within an 8-inch cone extended from the vent. This causes air to circulate around the entire space being treated by the air conditioner.

In the instance of a three-story staircase, the entire room will be cooled more evenly and efficiently than if there was a vent just blowing air towards the opposite wall.

One of the effects of all this air circulating is people feel more comfortable in a higher actual temperature. The three main influences upon a person's thermal comfort are air temperature, direct air velocity and humidity. If a person is comfortable at, for instance, 70 degrees F, he can also be comfortable at 74 degrees F - if some of the humidity is taken out of the air.

The SpacePak system is capable of producing air with 30 percent less humidity than a conventional central air system. This means the high-velocity system is more energy efficient, since the actual temperature of the air can be higher without people experiencing discomfort.

Hi-V In The Old Home

The lower humidity level is another advantage high-velocity systems offer antique homes. The last thing older homes and antique furnishings need is high humidity levels warping ancient wood.

The installation of the high-velocity system in the Georgetown home eliminated all modifications that were added to the house to support ductwork. This is made possible by the system's narrow, flexible tubing that replaces conventional ductwork. The roughly 4-inch diameter tubing easily can be concealed within walls - making it suited for older houses whose owners desire the modern convenience of central air conditioning without compromising the historic details of the house.

The tubing is made of flexible material coated on the inside to prevent the material from deteriorating and being introduced to the building's air supply.

The exterior of the tubing is sealed with sound dampening material, which makes the system more quiet than a conventional duct system.

The SpacePak system's tubing has "kwik-connectors," which make joining lengths of tubing very easy. They literally snap into place, quickly creating a seal and decreasing labor.

A high-velocity air conditioning system is an excellent partner for a radiant heating system. In fact, a heating coil can be added to the blower unit to convert the system into a heater that specializes in raising the air temperature quickly while the radiant system warms up.

In older homes that need retrofitting, systems like SpacePak are actually less expensive to install than conventional duct systems because the contractor doesn't have to spend as much in time or materials concealing the ductwork.

Hi-V In The Market

Reed and his five-truck company have been installing SpacePak systems for three years. He attended a course to learn how to install the systems because proper training is important to him. He learned the engineering principles behind the system, such as the minimum and maximum lengths of tubing, and the range of static pressure.

The market for Hi-V air conditioning systems is growing rapidly - last year was a record year for sales of SpacePak systems, according to SpacePak product manager Ted Doyle, who thinks SpacePak's acclaim is growing alongside that of radiant heat. "This product has become very popular with the radiant crowd," says Doyle.

According to Reed, "the market is wide open" for renovating older homes with high-velocity air conditioning. "Not many people are even aware that a system like SpacePak exists," says Reed. Offering such an efficient and comfortable system of Hi-V air conditioning as an alternative to bulky ductwork is a good marketing tool to tap into the niche of restoring old homes.