Staying

Comfortable:

Eco-Friendly

Heating

and Air

Conditioning

High-efficiency Furnaces

Hydronic Heating Systems

Heat Pumps

Window A/C Units & Unit/Space Heaters

Ductless Mini-Split Heat Pumps & -Air

Conditioners

Evaporative Coolers

Energy Recovery Ventilator (ERV)

Passive Ventilation

Programmable Thermostats

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CONDITIONING

HEATING and AIR

Heating and air-conditioning (HVAC) units are primarily responsible for controlling indoor temperature in any home. However, they do not work alone, because they need to be supplemented with proper ventilation, insulation, and properly installed and oriented ductwork. Ultimately, HVAC systems must conserve energy, maintain good air quality, and keep

the family comfortable.

Being environmentally responsible obviously means evaluating HVAC systems. According to the Department of Energy, over 50% of energy used in the home is for heating and cooling. Ensuring the system is energy efficient can have a major impact on utility bills and reduce environmental emissions from 20%to as much as 50%.

ENERGY STAR recommends replacing air conditioners older than 10 years and furnaces older than 15 years. When it’s time to replace the unit, consider energy efficient alternatives. The latest technology has produced remarkable systems, such as geothermal heat pumps, which use the heat stored in the earth, and energy recovery ventilators (ERVs), which use exhausted building air to condition incoming outdoor air.

But even if replacing an existing unit is not feasible for you right now, there are still steps you can take to reduce energy usage, such as installing programmable thermostats. Some utility companies are even providing these for free. This section reviews the types of energy efficient heating and cooling systems and related components available today.

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High

Efficiency

Furnaces

What is it?

A furnace’s efficiency is measured by the Annual Fuel Utilization Efficiency (AFUE), which is the ratio of the heat output of the furnace by the total annual amount of energy consumed by it. Older, inefficient furnaces have an AFUE of 56–70%, while more modern “mid- efficient” furnaces have an AFUE of 80–83%. High- efficiency furnaces can have an AFUE of up to 90–98.5%, converting almost all of the available fuel to heat in a home. High-efficiency furnaces typically have electronic ignitions instead of continuous pilot lights and use a sealed combustion unit rather than a natural draft. Most high-efficiency furnaces are “condensing gas furnaces” where heat is extracted from the exhaust gases in a second heat exchanger and used, which leaves behind cool exhaust gas and condensate water.

Why do it?

Pros:

Very energy-efficient

Environmentally friendly and burns the majority of the fuel it consumes

Sealed combustion unit contains all of the combustion products, providing better indoor air quality and improved fire safety

Quieter than older models

Few temperature fluctuations from thermostat set point

Cons:

Higher up-front costs

Payback in energy savings is not as great in mild climates

More efficient systems are inherently more complex, potentially requiring more repairs.

Maintenance:

Regular maintenance includes replacing the air filters at a recommended monthly interval, as well as inspecting the furnace for dirt or rust, and inspecting the vents for blockage. Inspect the condensation drain for blockage and clean, if necessary. Also, be sure to check the smoke and carbon monoxide sensors on a monthly basis to ensure they are working properly. A qualified technician should inspect the equipment at least once per year.

Timeline:

Professional installation takes 1 day.

Steps:

Contact a local HVAC contractor with experience installing furnaces to evaluate your existing system and, if necessary, install a high-efficiency furnace.

Cost Estimator:

If the new high-efficiency unit can be connected to existing ductwork and flue, it will cost $3,000-$4,500. The cost will be higher if ductwork or a new flue needs to be installed.

Quick Tips:

Make the home as energy-efficient as possible before installing a high-efficiency furnace. This includes duct-sealing and weatherization of windows and doors, as well as ensuring the house is properly insulated. This will help to properly size the furnace and make it more efficient.

Adding a variable-speed blower and adding a programmable thermostat to the high-efficiency furnace saves even more energy.

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Hydronic

Heating

Systems

What is it?

Hydronic heating systems use water or other liquid substances as a medium to heat the home. Water or steam runs through plastic pipes in the floor in slab or floor joists, a baseboard wall heater, a radiator, or even the ceiling. Water has the ability to transport more energy than air, so it is a more efficient way to heat a home. Instead of heating the home through a conventional forced air system to maintain a comfortable room temperature, heat radiates from the water running through the pipes. Adding a high efficiency boiler to the system increases energy savings. Hydronic systems may also circulate the heated water through a fan coil located in a forced air furnace where the heated air is distributed through ductwork in the home.

Why do it?

Pros:

Can provide 20–40 percent more energy efficiency than traditional furnace or heat pump system

Allows better thermal comfort because there is less temperature fluctuation from the thermostat set point

Temperature can be set simultaneously for different points in the house

Warmer floors and tiles

Improves humidity on cold days where forced air heat tends to dry out the air

Improves indoor air quality without molds and allergens

Leaves more space available because there is no need for ductwork

Cons:

There are higher initial installation costs for hydronic heating systems installed in the slab (not a good fit for a retrofit or renovation idea)

Hydronic heating systems will not provide ventilation or air filtration

Most homes receive a proper amount of ventilation through infiltration, but not if the building envelope is tightly sealed and weatherized

These systems can raise potential for water leaks

Temperature changes can be slowed due to the use of thermal mass

Some areas may not have experienced contractors to install a hydronic heating system.

Maintenance:

Baseboard panels and radiators need routine cleaning to ensure the convective fins are free from dirt and lint.

Radiantfloorandceilingsystemshavenoneedformaintenance except for the routine upkeep of the boiler or water heater.

Boilers and water heaters require routine maintenance as recommended by the manufacturer. It is also important to regularly inspect the water pressures in the circulation loops to ensure there is the proper amount of pressure in the loop. A pressure drop could indicate a leak in the piping.

Timeline:

Radiant floor heating installed in-slab has to be done when the home is being designed and constructed. On the other hand, hydronic baseboard panels or radiators can be retrofitted into a home within several days.

Steps:

Contact a local HVAC contractor with experience installing these systems to evaluate your home and, if necessary, install a hydronic heating system.

Cost Estimator:

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Quick Tips:

✓✓Traditionally, hot water-radiant floor systems have been installed in the concrete slab of a home, but advanced designs and installation techniques now make it possible to install hydronic tubing in floor joist systems and below hardwood floors, carpet, laminates, and vinyl flooring.. However, ceramic tile is the most effective floor covering for radiant floor heating, because it conducts heat well and adds thermal storage.

✓✓The hydronic system and flooring installers must be aware of each other’s work, so they can make any necessary adjustments to the materials, and protect the hot water tubing when the flooring is installed. Speak with the hydronic heating system manufacturer and installer for advice on flooring materials that will ensure the system will function at its best.

✓✓If the radiant tubing is set into wet concrete, it will use the thermal mass of the concrete itself to radiate heat into the home. For this to work properly, insulation must be placed below the slab to prevent heat from going down into the soil, instead of up into the home.

✓✓For carpeting, use a thin carpet with dense padding and install as little of it as possible. If some rooms, but not all, will have a floor covering, those rooms should have a separate tubing loop to make the system heat these spaces more efficiently. Wood flooring should be laminated to reduce the possibility of the wood shrinking and cracking from the drying effects of the heat.

✓✓Radiators and baseboard hydronic heaters are simple to install because there is less piping to utilize overall. They are also easier to maintain because of simpler access.

Installation of a hydronic radiant floor system for a typical 1,500-square-foot home costs $10,000–$20,000.

Hydronic baseboard heaters for a similar-sized home can cost $6,000–$8,000.

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Heat

Pumps

What is it?

An air-source heat pump is a type of HVAC system that uses the outside ambient air to exchange heat in order to cool or heat a home. Instead of generating heat through a fossil fuel furnace or boiler, the heat pump extracts heat from the air through a process called the vapor compression cycle, where the refrigerant is pumped through coils in units both indoors and outdoors to transfer the heat. For residences, this type of system is usually split, with a compressor (fan unit) outside the home connected by the refrigerant piping to an evaporator inside the home, which is inside the air handler. The hot or cold air is then distributed through the associated ductwork.

Why do it?

Pros:

One system used for both heating and cooling

30–40 percent more energy efficient than separate air conditioning and furnace system

Safer and more environmentally friendly because there is no combustion

Better thermal comfort because less temperature fluctuation from the thermostat set point

Better dehumidification than conventional air conditioning and better humidification than a typical furnace

Cons:

Colder climates may require supplemental heat, typically electric

Performance is affected by low airflow or an insufficient amount of refrigerant

Maintenance:

Regular maintenance of a heat pump system includes replacing the air filters on a recommended monthly basis, cleaning the registers, and having your air handler inspected by a qualified technician once a year. This inspection may include cleaning one or both sets of coils if needed. The technician should also check

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for refrigerant and duct leakage, verify adequate airflow, inspect the belts, and lubricate the motor. Also, be sure to clean the condensate pan and drain line once a year. Lastly, keep the area around the outdoor unit clear from any vegetation or debris.

Timeline:

A heat pump system can be installed by a qualified contractor within a day or so, depending on if they are installing a brand new system where there was no previous HVAC system (including ductwork), or if they are replacing an inefficient air conditioning and furnace or boiler system.

Steps:

1.Contact a local HVAC contractor with experience installing these systems to evaluate your existing system and, if necessary, install a heat pump.

2.Before installing a new heat pump, you should make your home as energy efficient as possible . This includes duct sealing and weatherization of windows and doors to begin, as well as ensuring the home is properly insulated. This will help to properly size the heat pump to the house, making it more efficient.

Cost Estimator:

A heat pump can range in cost from $1,500 to $7,500, depending on efficiency, size, brand, and home layout and orientation. It also depends on whether the heat pump is being installed where there was no previous central HVAC system , or if the heat pump is simply replacing an existing air conditioning and furnace system.

Quick Tips:

Manufacturers rate the efficiency of heat pumps in two ways: SEER and HSFP ratings. The most efficient heat pumps have a SEER between 14 and 18 and an HSPF between 8 and 10. The higher the SEER and HSPF, the more energy efficient the heat pump. ENERGY STAR- rated heat pumps must have a SEER greater than 14.5 and an HSPF greater than 8.2 for split systems. In warmer climates, the SEER is more important than HSPF, and in colder climates the HSPF is more important.

Other features to look for in a heat pump include a desuperheater, which can be used to heat your domestic water by harvesting the waste heat rejected from the heat pump. Also look for dual mode compressors and variable speed blowers.

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Geothermal

Heat Pump

What is it?

The major benefit of a geothermal, or ground source heat pump, is that it uses the near constant 50–60 °F temperature of the earth as a medium to exchange heat, versus the highly variable temperature of the outside ambient air, which the majority of residential heat pumps use. In the winter, the geothermal heat pump extracts heat from the ground to warm a home. In the summer, the device extracts heat from the home and transfers it to the ground to make the home cooler. This makes the geothermal heat pump much more efficient than conventional A/C systems, using 25–50% less energy.

Why do it?

Pros:

25–50% more energy efficient than conventional heat pumps

Better thermal comfort because lower temperature variations can be set from thermostat set point

Quieter than conventional heat pump compressor fan unit

Requires less maintenance (with 1/3 the cost) than conventional systems

Has a longer lifespan than conventional systems

Can be used to heat water

Cons:

Higher initial installation costs than conventional systems

An alternate, backup heating source may be required in colder climates

Potential limitation of available land for horizontal loops, or

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high costs of drilling and trenching in rocky soils

May be difficult to locate a reputable installer.

Maintenance:

Routine maintenance includes replacing air filters regularly and regular cleaning and of the air handler unit. However, there is no outdoor unit or furnace to maintain and the underground loop requires no maintenance.

Timeline:

While installation time depends on soil conditions, length of pipe, and equipment required, it usually takes 1-2 days.

Steps:

Find an installer accredited by the International Ground Source Heat Pump Association (IGSHPA) to begin the process.

Cost Estimator:

The average geothermal heat pump system costs about $2,500 per ton of capacity. For a typical 2,000-square-foot home with a 3-ton unit, the cost could be $7,500, plus installation and drilling. A comparable conventional heat pump costs about $4,000. The average total installation cost for a home is around $20,000, but can fluctuate depending on the home size, climate, type of underground system, and drilling costs .

Quick Tips:

When selecting a contractor, be sure to look for documented experience in geothermal heat pump installation and certification from a reputable source such as the IGSHA.

There is currently a 30% federal tax credit with no upper limit for geothermal heat pumps installed in new or existing homes before Dec. 31, 2016. Some states and utilities may also offer an additional credit. Search for available credits in the area at http://www.dsireusa.org/

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Window A/C Units and Unit/space Heaters

What is it?

A window air conditioning unit or unit/space heater is a type of HVAC system that heats or cools a specific area or room. You can purchase one at a hardware store install it yourself. These types of units aren’t particularly efficient when compared to central heating and cooling systems, but they use less energy. Instead of heating or cooling the entire house, they regulate the temperature of only specific areas of the house. Window A/C units plug into an electrical outlet, while unit heaters can be either electric or gas-powered (propane, natural gas, kerosene etc.) Most gas-powered unit heaters are for outdoor use or for use in a well-ventilated area such as a garage.

Why do it?

Pros:

Low initial cost

Easy to install and maintain

Uses less overall energy than a central heating and cooling system when sized and controlled properly

No energy is lost from ducts

Portable; can be moved from room to room (easier with heaters than window units)

Cons:

Noisy

Blocks windows where installed

Can use more energy than it saves if not properly sized or left to continuously run in unoccupied rooms

Safety is a top consideration when using space heaters.

Maintenance:

Clean and/or replace the air filters on a monthly basis. Remove and store window units during winter months and follow manufacturer’s instructions for proper removal and storage. Vented space heaters should be professionally inspected

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annually. If the heater is not vented properly, or if the vent is blocked, separated, rusted, or corroded, dangerous levels of carbon monoxide (CO) can enter the home, causing sickness and death. Carbon monoxide can also be produced if the heater is not properly set up and adjusted for the type of gas used and the altitude at which it is installed.

Timeline:

A window A/C unit can be installed in less than an hour. An electric unit/space heater is simply plugged into a wall outlet, whereas a gas powered heater needs proper ventilation.

Steps:

1.Calculate the square footage of the room that needs to be temperature-controlled. This number is necessary when picking out a window unit or unit heater.

2.Measure the inside window dimensions of where the unit will be installed.

3.When choosing a size for a window A/C unit, a good rule of thumb to use is 20 BTU/hr per square foot of living space. For example, a 300-square-foot room would require a 6,000 BTU/hr (1/2 ton) unit.

4.For the highest energy efficiency, the unit should have an ENERGY STAR label.

Quick Tips:

The required cooling capacity for a room air conditioner depends on the size of the room being cooled. Proper sizing is very important for efficient air conditioning. A bigger unit is not necessarily better because a unit that is too large will not cool an area uniformly. A small unit running for an extended period operates more efficiently and is more effective at dehumidifying a room than a large unit that cycles on and off too frequently. Based on size alone, an air conditioner generally needs 20 BTU for each square foot of living space.

Other features to look for include:

A filter that slides out easily for regular cleaning

Logically arranged controls

A digital readout for the thermostat setting

A built-in timer

Don’t place lamps or televisions near the A/C thermostat. The thermostat senses heat from these appliances, which can cause the air conditioner to run longer than necessary.

SettheA/C’sthermostatashighasiscomfortablypossible in the summer. The smaller the difference between the indoor and outdoor temperatures, the lower the overall cooling bill will be. Don’t set the thermostat at a colder setting than normal when the air conditioner is on; it will not cool the home any faster and could result in excessive cooling and unnecessary expense.

Set the fan speed on high, except on very humid days. When humidity is high, set the fan speed on low for more comfort. The low speed on humid days will cool the home more effectively and remove more moisture from the air because of slower air movement through the cooling equipment.

Consider using an interior fan in conjunction with a window air conditioner to spread the cooled air through the home without greatly increasing electricity use.

A window A/C unit’s efficiency is rated by the Energy Efficiency Ratio (EER). The most efficient units (ENERGY STAR- rated) typically have an EER above 10.

Some portable air conditioners can be used to provide heat in colder weather, providing a versatile unit that fulfills multiple needs.

Space heaters are classified as vented and unvented or “vent-free.” Unvented combustion units are not recommended for use inside the home, because they introduce unwanted combustion products into the living space—including nitrogen oxides, carbon monoxide, and water vapor—and deplete air in the space.Look for sealed combustion or “100 percent outdoor air” units, which have a duct to bring outside into the combustion chamber. Sealed combustion heaters are much safer to operate than other types of space heaters, and they operate more efficiently because they do not draw in the heated air from the room and exhaust it to the outdoors. They are also less likely to backdraft and adversely affect indoor air quality.

GBRIonline.org/ROOTS 1. Smaller-room air conditioners (i.e. those drawing less than 7.5

amps of electricity) can be plugged into any 15- or 20-amp, 115- volt household circuit that is not shared with any other major appliances. Larger-room air conditioners (i.e. those drawing more than 7.5 amps) need their own dedicated 115-volt circuit. The largest models require a dedicated 230-volt circuit. Ensure that there is an adequate outlet in reach of the power cord from the unit.

2. Models can be installed in most single- or double-hung windows, and typically come with accordion panels that allow for a secure fit. Some models can fit in sliding windows. They do require a support of some kind, such as a wooden plank or a specially designed shelf that can be attached to the exterior of the home for dedicated reinforcement.

3. Once installed, the unit should be level so that the inside drainage system and other mechanisms operate efficiently.

4. Install foam weather stripping around window units to keep cool air inside.

5. Set the unit’s programmable timer, if it has one, to 78 degrees. The timer should be set to only run at times when people are home. If the unit does not have a programmable timer, you may be able to purchase a mechanical timer and plug the unit into it.

Cost Estimator:

A window A/C unit can range from $100 for a 5,000 BTU unit to more than $1,000 for a 20,000 BTU unit. Space heaters are priced similarly.

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Ductless

MiniSplit

Heat Pumps

and Air

Conditioners

What is it?

A ductless mini-split heat pump and/or air conditioner is a type of HVAC system that has a compressor and condensing unit outside the home, connected through refrigerant pipes to multiple evaporators (blowers) inside the home. This design differs from traditional heat pump and air conditioning systems in that there is no ductwork. The blowers are located directly in the areas, or zones, of the home that need the heating/cooling. This is more efficient because ductwork can contribute as much as 30– 40% of energy loss in a normal HVAC system. Instead of heating or cooling the entire house, ductless mini- split systems focus only on the areas in use. They also tend to have a higher Seasonal Energy Efficiency Ratio (SEER) than traditional heat pumps/air conditioners, with a SEER of up to 26. These systems are perfect for retrofitting homes that don’t have existing ductwork in place for air- conditioning systems.

Why do it?

Pros:

Extremely energy efficient with a SEER of up to 26; most traditional heat pumps have a SEER of 14– 18

Allows for“zone control”in the home because the temperature can be controlled via one thermostat for the entire home

Quieter than other HVAC units

Improves indoor air quality by eliminating ductwork, which often contains dust and mold allergens

Easy installation and maintenance; only a 3-inch conduit needs to be installed through the wall to the outside unit

Blowers can be free-standing, or mounted in ceiling or on the wall

Cons:

Initial cost can be high

May be hard to find a contractor near you with experience installing mini-split systems

Newer technology may make it difficult to find a qualified technician to install/maintain.

Blowers are not as small as regular duct registers and could be considered unattractive

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A home located in a cold climate may need a backup heating system

When there are long runs of refrigerant piping, there is the potential for refrigerant leakage

Maintenance:

Regular maintenance of a ductless mini-split system includes cleaning and/or replacing the air filters on a recommended monthly basis and having the system inspected by a qualified technician once a year. This inspection may include cleaning one or both sets of coils if needed. The technician should also check for refrigerant leakage, inspect the belts and lubricate the motor. Lastly, be sure to keep the area around the outdoor unit clear of any vegetation or debris.

Timeline:

A mini-split system can generally be installed by a qualified contractor within a day (4 – 8 hours).

Steps:

Contact a local HVAC contractor with experience installing these systems to evaluate your existing system and, if necessary, install a mini-split system.