Smithfield Construction Portsmouth, NH... Custom Homes... Energy Star Partner... Geothermal Energy... Solar Energy... Serving New Hampshire, Massachusetts & Maine

Smithfield Construction Portsmouth NH An Energy Star Partner
Smithfield Construction - PO Box 370 Portsmouth, NH 03802 - 603-674-5204
Ask Joe Thermal


Energy Star Homes

Q: What are ENERGY STAR qualified new homes?
A: Homes that are at least 30% more energy efficient than required by the 2006 International Residential Code (IRC). Our homes are more than 50% more energy efficient than required by code.

Q: Are all energy efficient homes ENERGY STAR homes?
No. A home can be very energy-efficient, but unless it is independently modeled and tested by a qualified third party, it can't carry the Energy Star label.

Q: What are the benefits of purchasing an ENERGY STAR Home?
1. Better Performance
2. Lower Cost of Ownership
3. A Smart Investment, Better Resale Value
4. Protection for the Environment
5. Peace of Mind

Q: Are Energy Star homes good for the environment?
Yes. Home energy use accounts for 15% of all energy used U.S and 17% of all greenhouse gas emissions.  Since 1995, Energy Star homes have eliminated four million pounds of carbon emissions nationwide and the U.S. Government has set a goal of reducing greenhouse gases by 9 million metric tons through Energy Star qualified homes by the year 2012.

Q: Are Energy Star homes healthier to live in?
Yes. Energy Star homes are built with tight construction standards and have had the joints, holes and seams created in construction air sealed. This air sealing greatly reduces the penetration of outside air pollution, pollen, car exhaust, dust, radon and pest infestation. A constant flow of fresh air is provided by mechanical equipment. The amount of ventilation can be accurately controlled by the homeowner.

Q: Are Energy Star homes more comfortable?
Yes.  Because the homes are air sealed and tightly constructed, cold drafts are virtually eliminated, temperatures are more even, and the homes are much quieter.

Q: How does a home acquire the ENERGY STAR label?
It is a 3 step process:

1. Preconstruction-Each home plan is reviewed by an accredited independent Energy Star Ratings Partner. The Ratings Partner creates a computer model that estimates the energy consumption of the home.

2. Construction-Prior to drywall installation the Ratings Partner performs an on-site inspection. They use an EPA designed "Thermal Bypass Checklist ". Any findings are noted and corrected prior to drywall being installed.

3. Post Construction-The Ratings Partner performs a final inspection including a blower door test and a ductwork pressure test, then generates a report for the home.

Q: What is a Blower Door Test?
The blower door test is an air leakage test for your home. It measures how leaky or tight the home is. A calibrated instrument with a fan on it is attached to the front door of the home. Air is sucked out of the house until a pressure is reached that is equivalent to having a 25 mile per hour wind blowing on all 4 walls and the roof at one time. An airflow number is captured at the test pressure.

Q: How is ductwork tested?
This test is very similar to blower door test. We measure the leakage to the outside of the home. This ensures energy is not lost to the outside air. This is important as 10% of fuel used in a typical home can be lost through the ductwork.

Q: How is fresh air provided?
A: We use heat recovery ventilators or pressure compensating exhaust fans by Panasonic.

Q: What about mold and mildew?
Our Warm Wall™ system includes exterior insulation that eliminates any possibility of condensation in the wall cavity, so mold and mildew can not occur.

Q: What is EPACT?
EPACT is the Energy Policy Act of 2005, since renewed and still in effect. EPACT includes a $2,000 tax credit for building a new home that uses less than 50% of the energy of a new home built to current codes.

Q: How will I know if a new home is Energy Star compliant?
The Energy Star label should be prominently displayed near the circuit breaker box or your new home.  Also, ask for the Energy Report and Certificate.

Q: What percentage of new homes qualifies for an Energy Star label?
A: Less than 12% of the new homes built in the US earn this label.

Q: What are Energy Efficient Mortgages (EEMs)?
Energy efficient mortgages (EEMs) are mortgages for Energy Star homes with special underwriting guidelines. All or part of the energy savings can be used to increase the appraisal for the home or to increase the monthly payment limit for the borrower.

Q: Who underwrites Energy Efficient Mortgages?
Fannie Mae, Freddie Mac each offer energy efficient mortgages.

Q: What is the difference between Energy Star and LEED
Energy Star homes are rated based on their use of energy. LEED ( Leadership in Energy and Environmental Design) homes are rated based on broader environmental concerns including energy use but also including areas such as the recycled material content of the home, green building materials, landscaping selection, and site characteristics such as driving distance from shopping, schools, etc.

Conservation and Geothermal Energy

Q: Why is conservation so important?
Both the initial cost and the operating cost of the geothermal system vary by its size and capacity. The most cost-effective installations include conservation measures to reduce the heating load of the home in conjunction with adding the geothermal system.

Q: What thermal envelope improvements are typically recommended?
A thorough approach and attention to detail are the keys. In an existing home, we will provide you with an inventory of the existing components, recommended improvements and their costs. Frequently included are items such as basement insulation, wall insulation, attic insulation, window and door improvements, infiltration reduction and ventilation.

Q: How large is the savings that can be obtained through conservation improvements?
In an older home, a reduction by 50% is frequently possible.

Q: Are tax incentives available for geothermal energy?
A: Yes, a federal tax credit equal to 30% of the installed cost is available. Congress recently removed the previous $2000 limit.

Q: One well and two well systems, what is the difference?
A: In a one well system, water is drawn from near the bottom of the well and returned to near the top. In a two well system, water is drawn from one well and returned to a separate well.

Q: What are the requirements for the well(s)?
In a one well system, the rule of thumb is that 100-120 feet of water column is required per ton (12,000 BTU's) of heating/cooling capacity. The water production of the well is not affected because the water that is drawn is returned.

In a two well system, the rule of thumb is that 3 gallons per minute is required per ton of capacity. If the supply well is used for potable water as well, the well needs to produce enough water for both the potable and heating requirements.

Q: Can I use my existing well?
Yes, although it will probably need to be drilled deeper so that there is sufficient water column for the size of the geothermal system.

Q: Can I use my existing well pump?
A: The well pump needs to have the capacity to pump the amount of water required by the geothermal system. Most residential well pumps are smaller, so a larger capacity pumps is usually required. Also, the newer constant-pressure pumps provide better water pressure.

Q: What problems can be caused by hard water?
We will test your water for hardness, acidity and iron content before the heat pump is installed. High mineral content can cause mineral deposit build up in the heat pump. The solution is to tune your heat pump accordingly or to add a heat exchanger.

Q: Do geothermal wells cause environmental damage?
No, the heat pump only moves heat from one source to another, therefore no pollution is generated. The only change in the water after it is used by the heat pump is a slight increase or decrease in temperature. However, as with most everything, systems that are incorrectly designed or installed can cause problems.

Q: Are there any laws that apply to open-loop installation?

Not currently in New England . Some areas, the State of Maine , being one, are considering adopting a system of regulation.

Q: Why do power companies favor Geothermal Energy?
Power companies own and operate expensive power generation and distribution systems that are sized for peak demand. Peak demand is typically a few afternoons in the summer. The rest of the time, the fixed cost infrastructure is underutilized. Higher utilization during low demand periods without increasing peak demand will result in a reduction in the cost per kilowatt.

Q: How efficient is Geothermal Energy?
A: Our systems, using wells as a water source, have Coefficient of Performance (COP) for heating of 3.5 to 4.0, meaning they produce 3.5 to 4.0 times as much energy as they consume. They are also more efficient for cooling, using 20% to 40% less electricity than conventional central air conditioning.

Q: Can one system provide both space heating and cooling for my home? And what about heating hot water?
A: Yes. A Geothermal Heat Pump can be a combination heating/cooling and hot water heating system. You can change from one mode to another with a simple flick on your indoor thermostat. Using a desuperheater, our geothermal heat pumps can save you up to 50% on your water-heating bill by preheating tank water.

Q: How do Geothermal Heat Pumps heat water for my home?
A: Using what is called a desuperheater, Geothermal Heat Pumps turn waste heat to the task of heating hot water. During the summer, when the system is in cooling mode, your hot water is produced free as a byproduct of the air conditioning. In winter, with the heating mode, the desuperheater heats a portion of your hot water. Stand-alone systems that will heat water all year around are also available, but are generally not cost effective.

Q: How much space does a Geothermal Heat Pump require?
A: Most of a Geothermal Heat Pump installation is underground. Inside the house, the heat pump units are about the same size as a traditional furnace or boiler

Q: How long will my Geothermal Heat Pump system last?
Geothermal heat pumps are durable and highly reliable. The technology is proven and is similar to central air conditioning. Well Pumps are durable as well.

Q: How noisy is the Geothermal Heat Pump?
Geothermal Heat pumps are very quiet. Inside, the sound is similar to a furnace in ducted installations, and quieter than a boiler in hot water installations. Air Conditioning requires no noisy outside condenser.

Q: How safe are Geothermal Heat Pumps?
Geothermal Heat Pump systems are safe and protected. With no exposed equipment outdoors, children or pets cannot injure themselves or damage exterior units. Geothermal heat pumps have no open flame, flammable fuel or potentially dangerous fuel storage tanks.

Q: Is the Heating and Cooling Even and Comfortable?
: A Geothermal heat pump moves warm air (90-105(F) throughout your home or business via standard ductwork or hot water through standard baseboard heaters. An even comfort level is a function of the characteristics of the thermal envelope more than it is a function of the source of heating and cooling.

Q: How long is the Warranty?
: Our FHP GT Series ground source heat pumps are warranted for 5 or 10 years. This is equivalent to the warranties for conventional heating and cooling systems. Manufacturers of plastic pipe used for ground loops warrant their products for 50 years.

Q: Can these systems be used for commercial, industrial, or apartment requirements?
Yes! Many Geothermal Heat Pump systems are being installed using a multitude of systems hooked up to an array of buried vertical or horizontal loops. We offer systems for these applications.

Q: How much does a GSHP cost?
The initial investment for a Geothermal Heat Pump system varies according to the size of the system and how much related work is undertaken. We recommend that conservation measures be undertaken along with the system installation. This minimizes both the initial installation cost and the operating cost of the system. Related work that varies includes items such as adding a ductwork system for air conditioning if there is hot water heat.

Q: What is the cost of the electricity to operate the well pump?
The COPs of our systems have ranged from 3.0 to 4.0 including the well pumps.

Q. How does a geothermal heat pump work?
A. You already have a heat pump in your home - your refrigerator. If you put your hand behind it, you'll feel the heat that's being pumped from the inside.

Click Here To View Video.

It's the same principle that a geothermal heat pump uses to warm your home. Instead of producing heat like a conventional furnace, a geothermal heat pump moves heat from one place to another - from the ground into your home.

The diagram above illustrates the summer cooling process:

  • The cool, liquid refrigerant enters the indoor coil during cooling. As it enters the coil, the temperature of the refrigerant is between 40 and 50 degrees.
  • As warm, moist room air passes over the cool coil, the refrigerant inside absorbs the heat.
  • The new cooler, drier air is circulated back into the room with a blower fan.
  • The refrigerant moves into the compressor, which is a pump that raises the pressure so it will move through the system. The increased pressure from the compressor causes the refrigerant to heat to roughly 120 to 140 degrees.
  • The hot vapor now moves into contact with the condenser (the underground loops), where the refrigerant gives up its heat to the cooler ground loop, then condenses back into a liquid.
  • As the refrigerant leaves the compressor, it's still under high pressure. It reaches the expansion valve, where the pressure is reduced.
  • The cycle is complete as the cool, liquid refrigerant re-enters the evaporator to pick up room heat.

During the winter, the reversing valve switches the indoor coil to function as the condenser, and the underground piping to act as the evaporator.

In short, the indoor coil and underground piping cause the refrigerant to change state, absorbing and releasing heat through boiling and condensing. The compressor and expansion valve move the refrigerant through the system by changing the pressure.

It's the same principle that a geothermal heat pump uses to warm your home. Instead of producing heat like a conventional furnace, a geothermal heat pump moves heat from one place to another - from the ground into your home.


Solar Energy

Q: Is Solar Energy Cost Effective New England?
The practicality and cost effectiveness of solar energy collection systems for New England can be calculated based on the amount of energy contained in the solar radiation that is available at this latitude and in this climate. This establishes the theoretical limit for any possible solar system.

The average daily solar radiation falling on a collector placed at the ideal angle and orientation during the month of December in Concord , NH is 3.09 kilowatt hours per square meter per day.

First some conversion factors:

1 kilowatt hour (kw) = 3,412 BTU
1 sq meter (m)= 10.76 sq ft


Passive Solar Heating

Passive solar heating can be as simple as orienting most of the windows to the south. The cost varies by home but is limited to the costs of re-arranging or custom designing a plan and the cost of any extra windows. For Energy Star homes with most of their windows oriented due south, the sun can provide most of the heat required during daylight hours.


Solar Electricity

Assuming an average household use of 500 KW/month:

  • Collector area at 100% efficiency (impossible): 5.40 m = 58 sq ft
  • Collector area at 25% efficiency currently achieved by hard silicon PV: 21.50 m = 231 sq ft
  • Collector area at 12% efficiency currently achieved by Thin Film PV: 45 m = 484 sq ft

Conclusions: The collector sizes are in reasonable relation to the size of an average roof . Thin Film PV could be competitive if it could achieve an installed price in the range of 10,000-15,000 for the entire system.


Potable Water Heating

Potable water heating is spread through out the year, so it is reasonable to calculate an average contribution from solar hot water heating.

Here is a link to an informative chart:

The analysis assumes a 4 person household using 500 liters (132 gallons) of hot water per day, which is quite a lot. The following summarizes the chart.

Assuming an array of three quality 4' x 8' collectors with an average efficiency of 70%,
and 120 gallons of storage:

  • Annual potable water heating load in Concord , NH : 32.14 million BTU
  • Annual energy provided by the solar system: Flat Plate: 19.14 million BTU, Evacuated Tube:19.86 million BTU
  • Percentage of Water heating provided by the solar system: Flat plate: 60%, Evacuated Tube: 62%.
  • Savings per year: $200-$800 per year (depending on hot water use).
  • Cost of System: $10,000 to $20,000

Conclusions : The collector sizes are reasonable. The costs and savings will vary from reasonable to unreasonable depending on the particular installation and the alternative fuel.

Here is a link re energy used for water heating:


Solar Collectors for Space Heating

Space heating requirements are concentrated in the winter. Design heat loads are calculated on the basis of peak heating requirements.

Assuming a design heat load of 40,000 BTU for a well insulated older home the calculation is as follows:

  • Design Heat Load: 40,000 BTU/hour 960,000 BTU/day (281 kw/day)
  • Solar Radiation falling on a collector in December in Concord NH : 3.09 kw/m/day
  • Collector area at 100% efficiency (impossible): 91 m = 979 sq ft = Thirty 4 x 8 panels
  • Collector area at 70% efficiency 130 m = 1398 sq ft = Forty four 4 x 8 panels

Conclusions: The design heat load requires an excessive area of solar panels. If significant storage capacity were added, the design heat load could be reduced based on an average rather than a lowest design temperature, but these systems would remain excessively expensive.


This is an informative site:

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