Nestled in the beautiful rolling hills of Northern Lancaster County sits a beautiful, spacious house that was confronted with a very nasty problem. The homeowners were facing uncomfortable temperatures in both the heating and cooling seasons. The summers here can become hot and humid and the winters at times can be brutal with chilling winds and abusively cold temperatures. Thomas Soukup, Patriot Water Heater Co., Kirkwood, Pa., was contacted by the homeowner to come in and investigate these issues and come up with a custom solution to alleviate these pain points.
The Situation
Right off the bat, Soukup was presented with end-of-life, direct expansion, refrigerant-based heat pumps. With the tremendous amount of electric backup heat, the customer experienced bills exceeding one thousand dollars a month. The three-story house is 4500 sq. ft. of an open floor plan, contemporary design.
Anyone who has dealt with these types of homes before knows that when dealing with open staircases it creates a very efficient pathway for the conditioned air to go where it does not belong. All the hot air from the lower rooms chimneys upstairs when you do not need it to and vice versa with the cool air. This creates many challenges in creating a space that is comfortable. Also, to top it off, the house has many windows which creates tremendous solar gain and air infiltration.
Pinpoint zoning and control in the different living areas becomes a headache. In the winter months, homeowners could wear tropical clothing on the third floor but need a snow suit on when on the main floor. Obviously, the customer wanted this problem rectified.
The Design
First step was the math. Soukup provided a heat loss and heat gain calculation. The calculations were performed on a granular basis: doing the math on a per room basis. Measurements were taken of the available duct work and registers to figure out if they would be able to provide the correct amount of heating and cooling.
Soukup sat down with the customer and figured out how the house was originally zoned with three separate air handlers. Each handler was controlling multiple areas across different floors and the layout was scattered and improperly designed. It also was clearly not the most efficient way of zoning out the structure.
A kitchen and solarium remodel were in planning stage at the time of the calculations. Soukup learned that all the current ductwork on the registers were going to be covered by cabinetry. For the remodeled solarium and cabinet design, there would be no way to add additional ductwork to handle the load. Other solutions would need to be considered due to this.
The customer also brought to my attention in the planning phase of our project that their pool heater had failed, and swimming was a very important part of their daily regimen. While this slightly altered the design somewhat, it did cement the idea that a high-efficiency hydronic system was by far the best solution for both the heating and the cooling.
The Solution
Soukup chose a reverse cycle chiller for cooling and heating. Also installed was a mod-con boiler for the higher heating demands. One of the unique challenges was being able to run the chillers in cooling mode while running the mod-con boiler in heating mode to heat the pool and domestic hot water. A point of demarcation was created to separate the cooling system and the heating system. That was done with a buffer tank that the chillers were piped into and off that tank the circulator pumps were piped for the heating and cooling zones.
This also gave the advantage that when the chillers were used in heating mode and not able to keep up with demand, the boiler would provide that supplemental heat to the buffer tank. This was done with careful hydronic design and strategic placement of pumps.
In the solarium, due to the remodel, additional heating and cooling needed to be added to accommodate the new layout. A hydronic high-wall emitter was installed on the wall in an inconspicuous location where the kitchen met the solarium in a large opening. That gave that pinpoint cooling and heating needed and gave the customer the ability to control the level of comfort at will.
Additional air flow was needed to the bedroom side of the house as well as the master bedroom on the third floor. To make this a non-invasive install and to reuse as much of the previously installed ductwork, the decision was made to block off the vents in the lowest portion of that zone (an exercise room). Since that lowest room had the lowest requirements another hydronic high-wall emitter in that area. This opened the air flow to go to the critical rooms.
This was a perfect solution to go with ECM pumps and Soukup chose Grundfos Alpha2 ΔP. This created the opportunity to use less pumps and get the flow where it was needed, when it was needed.
Spacepak Chiller Control was installed to allow for the switch between heating and cooling based on thermostat demand. It also allowed to bring the boiler online to satisfy additional demand based on the outdoor temperature.
This is where the math is critical. Based on the loss calculations and the EDR (equivalent direction radiation) it allows it to know at what point additional water temperature was needed to satisfy the demand. This situation required 40-degree outdoor temperature for the boiler to come online and the chillers to go offline. Soukup arrived at this by looking at the temperature curves of the chillers based on the ambient outdoor temperature. The boiler was set up on an outdoor reset curve as well.
The Result
As a professional in the industry, when Soukup is presented with unique situations, he looks outside of the box to provide custom solutions. A large focus is put on looking at a problem analytically: marrying mathematics with proper products and equipment. Even if he’s used a product before and trust it, he always makes sure to study the manufacturer specs to know its strengths, weaknesses and what other auxiliary systems he needs to make it operate at peak efficiency.
The customer was satisfied and happy. Soukup walked away knowing he had taken the time to listen to their needs, see where the previous system had failed and give them something flexible and reliable, they could enjoy year after year. No matter how hot the summer, or how biting the winter they now have what everyone deserves. Comfort in their homes.
Information was provided by Thomas Soukup, Patriot Water Heater Co. Please visit www.patriotwaterheater.com.
