High Performance House

The Challenge:

We set out to see if we could use the sun to cost-effectively do four key things:

• Heat the House (In the Winter)
• Heat the Water (Year round for all Showers, Sinks, Washing Machine, and Dishwasher )
• Cool the House (In the Summer)
• Power the House (Year round for all Lights, TVs, Appliances, and Mechanical Systems)

The Solution:
We developed an innovative system: SSI (Szoradi Solar Integration)
Here is how our integrated high performance system works.

1) Solar - Heating the House (In the Winter)
To heat the house in the winter, the Solar Integration system uses rooftop Solar Hot Water Panels to heat water that is then used for radiant floor coils via a 350 gallon insulated tank in the basement.  All of the electrical needs for the pumps are met by a companion rooftop Photovoltaic system that generates the power for the whole house. To put the water tank size in perspective, a typical home hot water tank is 50 or 80 Gallons. On even overcast winter days, the sun heats the water in the panels up to over 100°F and in the summer the temperature can exceed 180°F.  The hot water is then piped from the basement tank through radiant floor coils that are encased in 1.25” of Gyp Crete that has an additional half inch of stone tile on the upper walking surface. This radiant ‘Thermal Mass’ warms your feet and then rises through the rooms. One of the advantages of radiant over forced air heat is that the heat stays around your body rather than blowing up towards the ceiling. Szoradi Solar Integration also includes Multi-zone in-floor thermostats and Energy Star Programmable Thermostats that you can set for maximum comfort and energy savings.
 
One of the advantages of the combined Gyp Crete and stone tile is that ‘Thermal Mass’   holds the heat longer than wood or other materials and then releases it back into the room. So, you benefit well after the sun goes down. As well, with the proper southern orientation and the Low-E energy efficient windows the sun actually heats up the floor when the light comes through the windows. Solar Integration involves calculating the proper overhang so that the sun is well shaded during the summer from heating the house and welcomed in over the winter to warm it. As an example, at the latitude of Philadelphia, PA the angle of the sun is about 85% off of the horizon at noon in the summer but it drops down to an angle that is only about 25% off the horizon over the winter. So in this area, overhangs of 18” can effectively shade all of the direct sunlight over the summer peak hours and let all of it in over the winter peak hours. As well, super insulated walls help hold the heat inside the house. The combination of the double insulated walls and low-tech Passive Solar overhang calculations is key to Solar Integration and it is often overlooked by home builders and even many architects. An additional feature is a fan system that draws filtered warm air from the walk-out lower level ‘basement’ up into the living spaces. Since the ‘geo-thermal’ ground temperature is typically about 50-60°F, it is often warmer than the outside air in the winter and cooler in the summer. Solar Integration involves building basements and if possible walk-out systems for increased natural light and access to the back or side yard.

On very cold winter nights, the sun alone cannot heat the whole house through the radiant floors without some support. So, Szoradi Solar Integration includes Solar Photovoltaic Panels (PV) for generating electricity. The electricity not only powers the pumps for moving the water through the radiant floors, but also powers the motors in Multi-Speed Reversible Ceiling Fans that are used on slow speed in the winter to gently circulate the warm air that rises to the ceiling back down in to the rooms. As well, the electricity powers a back-up electric hot water heater for the radiant floor system if there is a particularly overcast or snowy winter day. If the radiant is not enough, then the electricity generated from the PV Panels powers dual Multi-zoned High-Efficiency Heat Pumps that works like a furnace to blow warm air throughout the multi-zoned duct work in the house. Basically, a heat pump works like an air conditioner in reverse, blowing warm air in and cold air out.  By using a heat pump you are also possibly eligible in your region for reduced rates on the cost of electricity from your local electric company. As an example, with PECO in the Philadelphia area we pay HALF of the regular market rate for electricity between October and May, just because we use heat pumps. If the sun does not generate enough electricity to power the heat pumps, the Solar Integration works with a Dual Electric Meter system. Basically, you sell the power that you create when it is sunny to the local electric company, and you buy it back when you need it. This avoids the additional cost of a battery to store up the electricity and it creates an efficient billing system with a debit and credit record each month. As a back-up to the back-up system, Szoradi Solar Integration ensures comfort by including a High-Efficiency Gas Furnace.

2) Solar - Heating the Water (Year round for Showers, Sinks, Washing Machine, and Dishwasher )
To heat the domestic hot water for the house all year round the Solar Integration system uses rooftop Solar Hot Water Panels to heat water that is then stored in a 350 gallon insulated tank in the basement  that has a separate coil from the radiant floor system. On even overcast winter days, the sun heats the water in the panels up to over 100°F and in the summer the temperature can exceed 180°F. Hot shower water temperate is typically about 110°F,  and when you ‘buy’ the water from the Water Company is comes in underground at about 55°F. So, most American households have a tank that works pretty hard to raise the water temperature and then keeps the water at about 140°F all day even when it is not being used. This is basically a waste of energy to keep the water hot, and it would be like leaving your oven on hot all day every day, just because you like to occasionally heat up food. Solar Integration pre-heats the water and if it needs a ‘boost’ on an overcast day, the Szoradi Solar Integration system includes a back-up Tankless Water Heater also referred to as an On-Demand or Flash Hot Water Heater. The hardware basically works rapid fast to flash heat the water only when the pressure is released from any of the shower, sink, washer, dishwasher, etc. So, you typically end up saving 50% on hot water utility bills. The European and Asian markets have successfully used these systems for years, and they are only recently gaining traction in America. Solar Integration takes the tankless system to a higher level by feeding pre-heated water through it. If the water going in is over 110°F, the temperature sensor does not fire up the system, and there is no additional power needed.

3) Solar - Cooling the House (In the Summer)
To keep the house cool in the summer Szoradi Solar Integration system uses a combination systems including rooftop Solar Photovoltaic Panels (PV) for generating electricity that powers the air conditioning.  The air conditioning units are Multi-zoned High-Efficient Heat Pumps with Energy Star Programmable Thermostats that you can set for maximum comfort. By using a heat pump you may also be eligible for reduced rates on the cost of electricity from your local electric company.

As well, the ‘Thermal Mass’ floors hold the cooler temperatures because they are made of 1.25” of Gyp Crete that has an additional half inch of stone tile on the walking surface. One of the advantages of the combined Gyp Crete and stone tile is that ‘Thermal Mass’ holds the coolth longer than wood or other materials and then releases it back into the room. Since Solar Integration involves calculating the proper overhang so that the sun is well shaded during the summer from heating the house overhangs of 18” can effectively shade all of the direct sunlight over the summer peak hours when it is very high in the sky. As well, super insulated walls help hold the cool air inside the house. The combination of the double insulated walls and low-tech Passive Solar overhang calculations is key to Solar Integration and it is often overlooked by home builders and even many architects. An additional feature is a fan system that draws filtered cool air from the basement up into the living spaces. Since the ‘geothermal’ ground temperature is typically about 50-60°F, it is often cooler than the outside air in the summer. Solar Integration involves building basements and if possible walk-out systems for increased natural light and access the back or side yard.
 
The electricity generated from the sun powers the motors in Multi-Speed Reversible Ceiling Fans that are used on moderate speed in the summer to create gentle breezes and lift warm air up in reverse mode. If AC is needed and the sun does not generate enough electricity to power the heat pump and the fans, the Solar Integration works with a Dual Electric Meter system. Basically, you sell the power that you create when it is sunny to the local electric company, and you buy it back when you need it. This avoids the additional cost of a battery to store up the electricity and it creates an efficient billing system with a debit and credit record each month.

One of the key components of the Solar Integration cooling system is natural and cross ventilation with windows located to capture ‘cross-breezes’ on days that are not extremely hot or humid. Casement windows allow you to open the full size of the windows vs. double hungs which only let you open 50% of the viewable area. Since the evening temperature typically drops below the daytime temperature, you can typically ‘draft’ the house after the sun goes down to bring the cooler outside air in to replace the inside air that has built up during the day. As a boost to the cross ventilation, Solar Integration includes a High-Efficiency Quad Motor Whole House Fan. You may have seen the large propeller of a whole house fan in the second floor ceiling of your grand parent’s house, because before central air conditioning, these fans were used to literally suck the hot air up and out of the house via the attic. The concept is very valid, but the old fans used a lot of electricity and were very noisy.  The new fans use less than half of the electricity, draw twice the air, and make much less noise in part because multiple motors do the work instead of one giant blade. They also take up much less space in the ceiling, often just a single 16” joins bay. The best thing about a whole house fan is that you can open just one or two windows when you come back from work in the evening, flip the whole house fan on for about an hour and let it literally flush the hot air out of all the rooms due to the pressure differential. The whole house fan that we recommend also has a high and low speed to give you the most flexibility. So, instead of running around opening all the windows, you save time and effort. Then you can decide to either use the A/C or not given the day. This ‘pre-conditioning’ saves the A/C from doing a lot of work to bring the house down in temperate even just a few degrees. Basically, this move is like being on a sailboat rather than a powerboat. On a sailboat, you need to be aware of the conditions and engage with the elements more directly, while on a powerboat you basically just expect it to run. The environmental savings, fuel savings, and the satisfaction of connecting with the elements is part of the Szoradi Solar Integration experience, but the system is also well equipped to go on autopilot at any given moment.

4) Solar - Powering the House (Year round for Lights, TVs, Appliances, and Mechanical Systems)
Solar Integration includes Solar Photovoltaic Panels (PV) for generating electricity. The sun generates more power on the surface of the earth in one day than all of the fossil fuels underground. The size of the appropriate solar panel array for a home is directly related to the amount of roof area that has access to the sun and also the amount of energy needed to supply the house. In some cases the available roof does not cover the total needs, but a portion of the utility bills is better than nothing. In addition to generating power Solar Integration involves creating efficiencies to actually reduce the power that is used. This all works toward the goal of creating a ‘sustainable’ residence. To help reduce electricity demand, Solar Integration incorporates Compact Fluorescent Lights (CFL) that use 66% less energy and last up to ten times as long as incandescent bulbs. The latest generation CFLs provide homeowners with choices of different types of light: Soft white, Bright White, or Daylight. As well the new ‘dome’ casing evens the glow and makes them look more like regular bulbs than the original ‘spiral’ in a fixture such as a recessed light. Other energy reducing aspect of the home include Energy Star Appliances, Sun Tubes, Sky Lights,  Standby Power Reduction, Translucent interior doors, switches on timers, and switches with motion detectors.

Collectively the Solar Integration system reduces energy consumption and cost to save money and the environment.