Solar homes -- Solar additions -- Solar Repair --Solar hot water systems -- Solar radiant heating systems -- Solar electric systems -- Wind tubine electric systems
Tax credits are finally here for your solar projects. Look at the links below to find out how you may apply for them.
For additional information of the Federal Solar Tax Credits please use the following
A properly sized System can provide 65-80% of your home Hot Water needs. A Solar System can save hundreds of dollars a year in heating costs, and thousands of dollars over the lifetime of the system.
- A Solar System can pay for itself in as little as 3-5 years (and even lower when Federal & State Incentives and Credits are accounted for).
- Federal & State Incentives and Credits for the purchase and installation of Solar Water Heaters have increased in the last few years, and are expected to continue to increase over the foreseeable future. Solar Systems can be used to provide domestic hot water for showers, laundry and washing dishes, as well radiant heating for floor and baseboard heating systems for you home or office.
There are several different types of solar water heating systems, each designed for different climates and different types of operation to perfectly meet the needs of your budget, location, and application. These systems may be identical to each other except for inclusion or removal of one part, while they may also be completely different except for the inclusion of solar collectors and heat transfer elements.
There are two major concepts to understand when comparing the different types of Solar Water Heating Systems:
1. The difference between open-loop and closed-loop systems
2. The difference between passive an active systems
Open-Loop Systems
A System in which the domestic hot water, which comes directly out of the shower heads and sink faucets, is itself directly heated in the solar collector.
Closed-Loop Systems
A system in which a heat transfer fluid is heated by the collector, and the heat is passed to the domestic water through a heat exchanger.
Passive System
Uses no mechanical parts to circulate the water through the heating system.
Active System
Uses moving parts such as pumps, valves or controls to circulate water through the heating system.
1. Solar Batch Heater – Easy installation, passive operation
2. Thermosyphon System – Easy installation, passive operation
3. Open-Loop Direct – Lightweight, installation, nice aesthetics
There are two main types of Solar Water Heater Collectors available on the market today; Evacuated Tube Solar Collectors and Flat Plate Solar Collectors. Each of these have their own specific set of strengths and weaknesses when compared to each other, and to traditional water heating sources. It is important that you understand these benefits, and the situations, locations and applications that the collectors are meant to be used in before deciding which collector is right for you, and your budget.
Flat Plate Solar Collectors
Flat Plate Collectors are a highly efficient, low cost Solar Collector for water heating in domestic, commercial and municipal applications..
The Benefits
- Typically lower cost than Evacuated Tube Collectors
- High efficiency in warm, sunny climates
- Can be installed in a variety of system types
- Very cost effective, with high return on investment
The Downside
- Limited freeze protection available
- Needs direct (overhead) sunlight to operate efficiently
- Not designed for cold, northern climates
- Entire collector must be removed/replaced if damaged
Evacuated Tube Solar Collectors
While evacuated tube solar collectors typically cost more than flat plate collectors, they offer a much higher efficiency and protection in colder northern climates than other collectors. Great for residential, commercial, industrial, and municipal applications.
The Benefits
- High efficiency in all climates, including freeze conditions
- Easily replaced and serviced
- Continue to operate even after a tube is damaged or removed
- Can be installed in a number of system types
- Very cost effective, with high returns on investment
- Operates efficiently with sun at most angles (increased morning and evening operation)
The Downside
- Typically more expensive to purchase and install
Call us for your Free Solar Estimate Today! 603-494-7538
Selecting Energy Efficient Windows in New Hampshire
Look for Efficient Window Properties on the NFRC Label
Solar Heat Gain Coefficient (SHGC)
The SHGC is the fraction of incident solar radiation admitted through a window. SHGC is expressed as a number between 0 and 1. The lower a window’s solar heat gain coefficient, the less solar heat it transmits. Use a computer program such as RESFEN to understand heating and cooling trade-offs. SHGC=Solar Heat Gain Coefficient in fraction of incident solar angle.
U-Factor
The rate of heat loss is indicated in terms of the U-factor (U-value) of a window assembly. The insulating value is indicated by the R-value which is the inverse of the U-value. The lower the U-factor, the greater a window’s resistance to heat flow and the better its insulating value. U=U-factor in Btu/hr-sf-°F.
Air Leakage (AL)
Heat loss and gain occur by infiltration through cracks in the window assembly. Air leakage is expressed in cubic feet of air passing through a square foot of window area. The lower the AL, the less air will pass through cracks in the assembly. While many think that AL is extremely important, it is not as important as U-factor and SHGC. AL=Air Leakage in cfm/sf.
Visible Transmittance (VT)
The visible transmittance (VT) is an optical property that indicates the amount of visible light transmitted. The NFRC’s VT is a whole window rating and includes the impact of the frame which does not transmit any visible light. While VT theoretically varies between 0 and 1, most values are between 0.3 and 0.8. The higher the VT, the more light is transmitted. A high VT is desirable to maximize daylight. VT=Visible Transmittance in fraction of incident visible radiation.
U-Factor
The rate of heat loss is indicated in terms of the U-factor (U-value) of a window assembly. The insulating value is indicated by the R-value which is the inverse of the U-value. The lower the U-factor, the greater a window’s resistance to heat flow and the better its insulating value. U=U-factor in Btu/hr-sf-°F.
Solar Heat Gain Coefficient (SHGC)
The SHGC is the fraction of incident solar radiation admitted through a window. SHGC is expressed as a number between 0 and 1. The lower a window’s solar heat gain coefficient, the less solar heat it transmits. Use a computer program such as RESFEN to understand heating and cooling trade-offs. SHGC=Solar Heat Gain Coefficient in fraction of incident solar angle.
Visible Transmittance (VT)
The visible transmittance (VT) is an optical property that indicates the amount of visible light transmitted. The NFRC’s VT is a whole window rating and includes the impact of the frame which does not transmit any visible light. While VT theoretically varies between 0 and 1, most values are between 0.3 and 0.8. The higher the VT, the more light is transmitted. A high VT is desirable to maximize daylight. VT=Visible Transmittance in fraction of incident visible radiation.
Air Leakage (AL)
Heat loss and gain occur by infiltration through cracks in the window assembly. Air leakage is expressed in cubic feet of air passing through a square foot of window area. The lower the AL, the less air will pass through cracks in the assembly. While many think that AL is extremely important, it is not as important as U-factor and SHGC. AL=Air Leakage in cfm/sf.
Recommended Properties in the Northern Zone (mostly heating)
U-factor
Solar Heat Gain Coefficient (SHGC)
Visible Transmittance (VT)
Air Leakage (AL)
Windows: U≤0.35
Skylights: U≤0.60*
Note: If air conditioning loads are minimal, windows with U-factors as high as 0.40 are also energy-efficient if the Solar Heat Gain Coefficient is 0.50 or higher.
No requirement.
Note: To reduce heating, select the highest SHGC you can find (usually 0.30-0.60 for the U-factor ranges required in colder climates) so that winter solar gains can offset a portion of the heating energy need. If cooling is a significant concern, select windows with a SHGC less than 0.55. Select skylights with a SHGC of 0.55 or less.
No requirement.
Note: Select windows with a higher VT to maximize daylight and view.
No requirement.
Note: Select windows with an AL of 0.30 or less.
Low-E coatings, gas-fills, and insulating spacers and frames can significantly reduce winter heat loss and summer heat gain.
Improved Daylight and View
New glazings with low-solar-gain low-E coatings can reduce solar heat gain significantly with a minimal loss of visible light (compared to older tints and films).
Improved Comfort
In summer and winter occupant comfort is increased; window temperatures are more moderate and there are fewer cold drafts. Discomfort from strong summer sunlight is reduced.
Reduced Condensation
Frame and glazing materials that resist heat conduction do not become cold and this results in less condensation.
Reduced Fading
Coatings on glass or plastic films within the window assembly can significantly reduce the ultraviolet (UV) and other solar radiation which causes fading of fabrics and furnishings.
Lower Mechanical Equipment Costs
Using windows that significantly reduce solar heat gain means that cooling equipment costs may be reduced.
Window Technologies: Low-E Coatings
Low-emittance (Low-E) coating are microscopically thin, virtually invisible, metal or metallic oxide layers deposited on a window or skylight glazing surface primarily to reduce the U-factor by suppressing radiative heat flow. The principal mechanism of heat transfer in multilayer glazing is thermal radiation from a warm pane of glass to a cooler pane. Coating a glass surface with a low-emittance material and facing that coating into the gap between the glass layers blocks a significant amount of this radiant heat transfer, thus lowering the total heat flow through the window. Low-E coatings are transparent to visible light. Different types of Low-E coatings have been designed to allow for high solar gain, moderate solar gain, or low solar gain.
Double-Glazed with High-Solar-Gain Low-E Glass
This figure illustrates the characteristics of a typical double-glazed window with a high-transmission, Low-E glass and argon gas fill. These Low-E glass products are often referred to as pyrolitic or hard coat Low-E glass, due to the glass coating process. The properties presented here are typical of a Low-E glass product designed to reduce heat loss but admit solar gain. High solar gain Low-E glass products are best suited for buildings located in heating-dominated climates. This Low-E glass type is also the product of choice for passive solar design projects due to the performance attributes relative to other Low-E glass products which have been developed to reduce solar gain.
In heating-dominated climates with a modest amount of cooling or climates where both heating and cooling are required, Low-E coatings with high, moderate or low solar gains may result in similar annual energy costs depending on the house design and operation. While the high solar gain glazing performs better in winter, the low solar gain performs better in summer. Low solar gain Low-E glazings are ideal for buildings located in cooling-dominated climates. Look at the energy use comparisons under Window Selection to see how different glazings perform in particular locations.
Double-Glazed with Moderate-Solar-Gain Low-E Glass
This figure illustrates the characteristics of a typical double-glazed window with a moderate solar gain Low-E glass and argon gas fill. These Low-E glass products are often referred to as sputtered (or soft-coat products) due to the glass coating process. (Note: Low solar gain Low-E products are also called sputtered coatings.) Such coatings reduce heat loss and let in a reasonable amount of solar gain and are suitable for climates with both heating and cooling concerns. In heating-dominated climates with a modest amount of cooling or climates where both heating and cooling are required, Low-E coatings with high, moderate or low solar gains may result in similar annual energy costs depending on the house design and operation. Look at the energy use comparisons under Window Selection to see how different glazings perform in particular locations.
Double-Glazed with Low-Solar-Gain Low-E Glass (Spectrally Selective)
This figure illustrates the characteristics of a typical double-glazed window with a low solar gain Low-E glass and argon gas fill. These Low-E products are often referred to as sputtered (or soft-coat) due to the glass coating process. (Note: Moderate solar gain Low-E products are also called sputtered coatings.) This type of Low-E product, sometimes called spectrally selective Low-E glass, reduces heat loss in winter but also reduces heat gain in summer. Compared to most tinted and reflective glazings, this Low-E glass provides a higher level of visible light transmission for a given amount of solar heat reduction.
Low solar gain Low-E glazings are ideal for buildings located in cooling-dominated climates. In heating-dominated climates with a modest amount of cooling or climates where both heating and cooling are required, Low-E coatings with high, moderate or low solar gains may result in similar annual energy costs depending on the house design. While the high solar gain glazing performs better in winter, the low solar gain performs better in summer. Look at the energy use comparisons under Window Selection to see how different glazings perform in particular locations.
Variants on low solar gain Low-E coatings have also been developed which lower solar gains even further. However this further decrease in solar gains is achieved by reducing the visible transmittance as well - such coatings, which may appear slightly tinted, are best suited for applications where cooling is the dominant factor and where a slightly tinted effect is desired.
Major Principles
Good passive design for thermal comfort is based on the following six major principles:
Orientation of frequently used areas towards the equator (north in the southern hemisphere, south in the the northern hemisphere), to allow maximum sunshine when it is needed for warmth, and to more easily exclude the sun's heat when it is not.
Glazing used to trap the sun's warmth inside a space when it is needed, with adequate shading and protection of the building from unwanted heat gain or heat loss.
Thermal mass to store the heat from the sun when required, and provide a heat sink when the need is for cooling.
Insulation to reduce unwanted heat losses or heat gains through the roof, walls, doors, windows and floors.
Ventilation to provide fresh air and capture cooling breezes.
Zoning of internal spaces to allow different thermal requirements to be compartmentalised when required.
Orientation
Buildings should be planned in such a way that benefit is obtained from shaded indoor and outdoor living areas when the weather is hot and sunny indoor and outdoor areas with wind protection when the weather is cold.
Well designed buildings should be oriented, and the spaces arranged in such a way, that the majority of rooms face towards the equator. In this way the eastern and western sides are exposed to the low-angle summer sun in the morning and afternoon. The high angle of the sun in the sky in summer makes it easy to shade windows using only a generous roof overhang or horizontal shade. The longer north/south sides of the building benefits from the low angle sun in winter. The roof overhang or shading on the equator side should allow the Sun to shine into the building when its warmth is required in winter, and provide adequate protection from high-angle Sun in summer.
If the majority of windows are designed into the equator-facing wall, sun penetration into the building will be maximised. Living areas should be sited to gain maximum benefit from cooling breezes in hot weather and shelter from undesirable winds in winter. This does not mean that the orientation of the building should be varied from north towards prevailing breezes as it does not have to face directly into the breeze to achieve good cross-ventilation.
Within the internal planning, rooms such as dining and recreation area that require more heat during the winter months should be placed on the equator side. Rooms that are used for short periods of time during the day can be placed towards the rear, or more effectively, as buffer zones on the west side to protect living areas from the hot afternoon Sun (for example bathrooms, laundry, ensuite, entry corridors, stairs, bedrooms, bars).
Roofing building and roof repair in New Hampshire Amherst, Milford, Wilton, Mont Vernon, Bedford, Nashua, Manchester, New Boston, Brookline, Southern New Hampshire,NH
