GREEN HOME DESIGN/
Cape Cod
ENERGY ANALYSIS

Heating and Air Systems
Bigger Isn’t Better

Does your house have cold and hot spots? Is a basement bedroom always cold or damp feeling? Is an upstairs bedroom always hotter than the rest of your home? According to recent studies, 95% of new air-conditioning installations fail in regard to operating efficiency, with more than 70% of systems improperly sized or installed.

Heat Flows Downhill

Just like water, you can say that heat ALWAYS flows downhill, or from high energy (warm) to lower energy (cool). You see, heat will build up until it can find a cooler place to go. When you open your front door in the summer, heat rushes in. The cold air doesn’t rush out. Open your door in the winter, the heated air rushes out. Heat builds up in your home due to sunlight, people, appliances, etc. In the summer we want to get this heat out and replace it with nice conditioned air.

Residential air-conditioning systems are made up of indoor and outdoor systems connected by pipes that circulate a refrigerant such as Freon or Puron. Without getting into technical details, the compressor in the system compresses the liquid refrigerant. By manipulating pressure and temperature, the indoor unit can absorb heat out of the house or extract heat into the house depending on the season.

In addition to conditioning the air, air conditioners serve another important function. They dehumidify the air. In the same way moisture condenses on the side of a cold glass of water sitting outside on a hot day, air conditioners extract moisture from warm, humid air and deliver it outside the house through a evaporator coil.

Oversize units waste money and will not
dehumidify your home.

Oversized systems satisfy the temperature at the thermostat so quickly that very little moisture is removed from your home. This is known as short cycling. Short cycling is more of a problem in the southern US in humid climates. Short cycling also causes large peak demands on electrical supply systems.

Air conditioning units are least efficient when they first start up. It takes 15-20 minutes for a system to reach peak operating efficiency. Oversized units run shorter cycles so more time is spent running in the least efficient part of the cycle.

Shorter cycling and high humidity in your home equals an uncomfortable home and HIGH electric bills! At a cost of around $2000 per ton, oversized units cost considerably more. Why pay for a 5 ton system when 3 tons will do? That’s at least a $4000 savings!

Rye Home Energy Consultants Wants To Save
You Money! Lots Of It!!

So how do we determine the correct and guaranteed size of heating and cooling system you need? On new construction we take your home plans and run them through our computer using ACCA’s (Air Conditioning Contractors Of America) Manual J Residential Load Calculations. This is how we arrive at room-by-room totals for heating and cooling needs for your home. Manual J calculations are VERY IMPORTANT because you cannot design a duct system properly without these calculations. Duct systems installed without Manual J calculations are what we call “the Bubba method”. Bubba the contractor looks at your 3000 sq. ft. home and says, “Yep, you need 6 tons”. Some of you are smiling right now and thinking, that’s exactly what he said.

Now you tell me. How does he know this? HE DOESN’T! You may need 9 tons, or 6 tons, or even 3 tons. Do not let someone guess at the size system you need.

Manual J calculations takes into account solar-heat gains, direction the house is facing and orientation to the sun and shading, which can greatly affect the loads needed. We also take into account window sizes, ceiling heights, wall insulation, floor insulation, foundation type, ceiling insulation, and everything else that can affect the heat generated in your home.

Why do electric cooperatives all over the
country love what we teach?

Here is one reason why electric cooperatives all across the country love what we teach. Build your house energy efficient, let us size the heating and cooling system for your home, and you will enjoy a comfortable home with low utility bills.

So how does this help electric companies you may ask? See, when an electric company builds a power generating plant it must be designed for the maximum peak loads even if it only happens once a year. Right from the start they are already spending hundreds of thousands, if not millions of dollars more than they should have to.

Ever wonder why places like California have brown-outs during a hot summer? It’s because the power generating plants cannot keep up with the demand for electricity. Almost every single building in the state is calling for maximum cooling at the same time. Now remember, this may only happen once a year, BUT they have to build the plant large enough to handle this one peak.

When you build your home like we teach those peak demands are kept to a minimum, and when there is a peak it’s much lower because the amount of electricity needed is less. Which takes more electricity? 500,000 homes with 5 ton systems or 3 ton systems? You get the point?

Oh, and one other thing! Now we don’t have to import nearly as much coal from other countries to power the plants and now we can reduce the amount of emissions coming from the power plants.