Showing posts with label 1. General Information. Show all posts
Showing posts with label 1. General Information. Show all posts
Heating Installation Stages and Scheduling for New Construction
To keep things running smoothly, I have created a project schedule as it would refer to your heating sub-contractor, hopefully me. Either way, this will help you to know what to expect and when to call for each stage.
1. Foundation Wall Knock-out, if needed.
- Scheduling: Just Call for Measurements
- This is the hole in your foundation that will be needed to get air from the garage to under your house. Call me for the measurement to give to your concrete sub.
- Scheduling: Call 1 Week Ahead
- Call 1 week before garage slab is poured (this will ensure we can get there before fill goes in, which means no digging).
- Scheduling: Call 1 Week Ahead
- Before final roofing material.
- Sheeting needs to be on trusses before layout so we can cut in our roof jacks.
- Framing needs to be complete, including fireplace (if needed).
- We would prefer to meet the plumber on-site if at all possible.
- Scheduling: Call 3 Weeks Ahead
- After Plumber and before Electrician
- Final roofing must be complete
- Drywall should be hung where equipment and exposed duct work will be installed
- On all 90%+ gas furnaces, air conditioners and heat pumps; a condensate drain source needs to be provided by your plumber at the furnace location.
- On all Rinnai water heaters that do not vent directly out the wall; a condensate drain source needs to be provided by your plumber at the heater location. As well, a Rinnai water heater needs an electrical outlet within 3 ft. of unit.
- Standing water in crawl space, if any, will need to be removed for safety.
- During or Shortly after Rough-In Installation.
- Framing must be in place or accurate location marked.
- During or shortly after Rough-In Installation.
- Meter or Regulator and all gas appliances (including BBQ or Hot Tub) need to be clearly marked prior to installation.
- During or shortly after Rough-In Installation.
- Location of air conditioner or heat pump needs to be clearly marked if concrete pad has not been poured yet.
- Scheduling: Call 3 Days-1 Week Ahead
- Once Electrician has installed fans. If you bought fans from us, we will do it during install.
- Scheduling: Call 3 Days-1 Week Ahead
- After Mechanical Inspection.
- If Propane, we need tank on site and full with regulator set.
- If Natural Gas, we will need service to the house and we will call for the meter set.
- Scheduling: Call 1 Week Ahead
- After Painting
- Before Plumbing Final so water heater is in place
- If flooring is not done, we will leave registers in box by the furnace.
- If you have an Air Conditioner or Heat Pump, we need the Electrician present for hook-up
- If you have a fireplace, we need to have full access to it. Meaning we will not be able to work around a Mason or Tile Guy who may be working on your mantle or chimney, etc.
Heating System Replacement Tips
Space heating is the largest energy expense in most homes, accounting for two-thirds of annual energy bills in cold climates.
Why Buy An Energy Efficient Furnace/Boiler?
Heating is the largest energy expense in most homes, accounting for almost two-thirds of annual energy bills in colder areas of the country. Heating systems in the United States emit a billion tons of carbon dioxide (CO2) and about 12% of the sulfur dioxide and nitrogen oxides emitted by the nation. Reducing energy use for heating is the single most effective way to reduce your home's contribution to global environmental problems.
Conservation efforts and a new high-efficiency heating system can often cut your pollution output and fuel bills in half. Upgrading your furnace or boiler from an AFUE (annual fuel utilization efficiency) of 56% to 90% in an average cold-climate house will save 1.5 tons of CO2 emissions if you heat with gas or 2.5 tons if you heat with oil and will cut your heating bill by almost 40%.
If your furnace or boiler is old, worn out, inefficient, or significantly oversized, the simplest solution is to replace it with a modern high-efficiency model. Old coal burners that were switched over to oil or gas are prime candidates for replacement, as well as gas furnaces without electronic (pilotless) ignition.
About Furnace/Boiler Efficiency
A central furnace or boiler's efficiency is measured by annual fuel utilization efficiency (AFUE). AFUE is a measure of how efficient the appliance is in using fossil fuel (gas or oil) or electricity (for an electric furnace) over a typical year of use.
An all-electric furnace or boiler has no flue loss through a chimney. The AFUE rating for an all-electric furnace or boiler is between 95% and 100%. The lower values are for units installed outdoors because they have greater jacket heat loss.
The efficiency of manufactured furnaces is governed by the National Appliance Energy Conservation Act of 1987 and regulated by the U.S. Department of Energy. The minimum allowed AFUE rating for a noncondensing, fossil-fueled, warm-air furnace is 78%; the rating for a fossil-fueled boiler is 80%; and the rating for a gas-fueled steam boiler is 75%. A condensing furnace or boiler condenses the water vapor produced in the combustion process and captures the heat released from this condensation. The AFUE rating for a condensing unit can be much higher (by more than 10 percentage points) than a noncondensing furnace. Although a condensing unit costs more than a noncondensing unit, the condensing unit can save you money in fuel costs over the 15 to 20-year life of the unit.
Tips for Buying a New Furnace/Boiler
- If you live in a cold climate, it usually makes sense to invest in the highest efficiency system available. In milder climates with lower annual heating costs, the extra investment required to go from 80% to 90%-95% efficiency may be hard to justify.
- When shopping for high-efficiency furnaces and boilers, look for dependability. Buy a system with a good warranty and a reputable company to back it up.
- When buying gas and oil systems, specify sealed combustion. Sealed-combustion appliances bring outside air directly into the burner and exhaust flue gases (combustion products) directly to the outside, without the need for a draft hood or damper. They generally burn more efficiently and pose no risk of introducing dangerous combustion gases into your house. With nonsealed-combustion appliances, back-drafting of combustion gases can be a big problem, especially in tightly-sealed modern homes.
- Set your thermostat as low as is comfortable.
- Keep the temperature fairly constant, as frequent changes will utilize more energy by causing unnecessary cycling on and off. Setting back the temperature at night, however, is recommended.
- Clean or replace furnace filters once a month or as needed.
- Oil-fired boilers should be professionally cleaned and tuned once a year. Gas-fired equipment needs to be checked every other year.
- Clean warm-air registers, baseboard heaters, and radiators as needed; make sure they are not blocked by furniture, carpeting, or drapes.
- Keep draperies and shades on south-facing windows open during the heating season to allow sunlight to enter your home; close them at night to reduce the chill you may feel from cold windows.
- Close the door to an unoccupied room or area that is isolated from the rest of the house and turn down the thermostat or turn off the heat for that room or area.
- Use kitchen, bath, and other ventilating fans wisely. Turn these fans off as soon as they are no longer needed. In about 1 hour, these fans can pull out a house-full of warmed or cooled air. They can also pull dangerous furnace combustion gasses into the house in some situations.
- Check your ducts for air leaks. First look for sections that should be joined but have separated and then look for obvious holes.
- Do not use duct tape to repair leaky ducts. Standard duct tape has been shown unreliable in sealing duct leaks. Various mastics or non-cloth-backed tapes are preferable.
How to Maintain Your Heating and Cooling Equipment
Just like your favorite car, your heating and cooling system needs a regular trip to the mechanic to keep it purring. Without regular servicing, heating and cooling systems burn more fuel and are more likely to break down. With the proper attention, they can keep you comfortable year-round.
Heat pumps and oil-fired furnaces and boilers need a yearly professional tune-up. Gas-fired equipment burns cleaner; it should be serviced every other year. A close inspection will uncover leaks, soot, rust, rot, corroded electrical contacts and frayed wires. In furnace (forced-air) and boiler (hot-water) systems, the inspection should also cover the chimney, ductwork or pipes, dampers or valves, blower or pump, registers or radiators, the fuel line and the gas meter or oil tank—as well as every part of the furnace or boiler itself.
Next, the system should be run through a full heating cycle to ensure that it has plenty of combustion air and chimney draft. Contractors can use specialty metersto check for sufficient draft and also test the air for carbon monoxide.
Finally, it's time for the down and dirty task of cleaning the burner and heat exchanger to remove soot and other gunk that can impede smooth operation. For the burner, efficiency hinges on adjusting the flame to the right size and color, adjusting the flow of gas or changing the fuel filter in an oil-fired system. A check of the heat pump should include an inspection of the compressor, fan, indoor and outdoor coils and refrigerant lines. Indoor and outdoor coils should be cleaned, and the refrigerant pressure should be checked. Low pressure indicates a leak; to locate it, contractors feed tinted refrigerant into the loop and go over it with an electronic detector.
The Low Blow
Tuning up the distribution side of a forced-air system starts with the blower. To do the job right, it must first be removed. The axle should be lubricated, blades cleaned and blower motor checked to insure the unit isn't being overloaded. The fan belt should be adjusted so it deflects no more than an inch when pressed. Every accessible joint in the ductwork should be sealed with mastic or a UL-approved duct tapes. Any ducts that run outside the heated space should be insulated. On a hot-water system, the expansion tank should be drained, the circulating pump cleaned and lubricated and air bled out of the radiators.
Turn It Up
While thermostats rarely fail outright, they can degrade over time as mechanical parts stick or lose their calibration. Older units will send faulty signals if they've been knocked out of level or have dirty switches. To recalibrate an older unit, use a wrench to adjust the nut on the back of the mercury switch until it turns the system on and, using a room thermometer, set it to the correct temperature. Modern electronic thermostats, sealed at the factory to keep out dust and grime, rarely need adjusting. However, whether your thermostat is old or young, the hole where the thermostat wire comes through the wall needs to be caulked or a draft could trick it into thinking the room is warmer or colder than it really is.
Humidifers
A neglected in-duct humidifier can breed mildew and bacteria, not to mention add too much moisture to a house. A common mistake with humidifiers is leaving them on after the heating season ends. Don't forget to pull the plug, shut the water valve and drain the unit. A unit with a water reservoir should be drained and cleaned with white vinegar, a mix of one part chlorine bleach to eight parts water or muriatic acid. Mist-type humidifiers also require regular cleaning to remove mineral deposits.
Filters
Most houses with forced-air furnaces have a standard furnace filter made from loosely woven spun-glass fibers designed to keep it and its ductwork clean. Unfortunately, they don't improve indoor air quality. That takes a media filter, which sits in between the main return duct and the blower cabinet. Made of a deeply-pleated, paper-like material, media filters are at least seven times better than a standard filter at removing dust and other particles. An upgrade to a pleated media filter will cleanse the air of everything from insecticide dust to flu viruses.
Compressed, media filters are usually no wider than six inches, but the pleated material can cover up to 75 square feet when stretched out. This increased area of filtration accounts for the filter's long life, which can exceed two years. The only drawback to a media filter is its tight weave, which can restrict a furnace's ability to blow air through the house. To ensure a steady, strong air-flow through house, choose a filter that matches your blower's capacity.
Duct cleaning
Inside the walls and floors of 80 percent of American homes run a maze of heating and air conditioning ducts that connect the each room to the furnace. As the supply ducts blow air into rooms, return ducts inhale airborne dust and suck it back into the blower. Add moisture to this mixture and you've got a breeding ground for allergy-inducing molds, mites and bacteria. Many filters commonly used today can't keep dust and debris from streaming into the air and overtime sizable accumulations can form—think dust bunnies, but bigger.
To find out if your ducts need cleaning, pull off some supply and return registers and take a look. If a new furnace is being installed, you should probably invest in a duct cleaning at the same time, because chances are the new blower will be more powerful than the old one and will stir up a lot of dust.
Professional duct cleaners tout such benefits as cleaner indoor air, longer equipment life and lower energy costs. Clean HVAC systems can also perform more efficiently, which may decrease energy costs, and last longer, reducing the need for costly replacement or repairs. Cleaning has little effect on air quality, primarily because most indoor dust drifts in from the outdoors. But it does get rid of the stuff that mold and bacteria grow on, and that means less of it gets airborne, a boon to allergy sufferers.
How BTUs and EERs Work
Most air conditioners have their capacity rated in BTUs, or British Thermal Units. A BTU is, generally, the amount of heat required to raise the temperature of one pound of water one degree F. Specifically, a BTU is 1,055 joules, but the first definition is easier to understand in real-life terms. One "ton", in heating and cooling terms, is 12,000 BTUs. A typical window air conditioner that you find at K-mart might be rated at 10,000 BTUs. What that means is that the air conditioner has the ability to cool 10,000 pounds of water (about 1,200 gallons) one degree in one hour. Or it could cool 5,000 pounds 2 degrees in one hour. Or 2,500 pounds 4 degrees in one hour, and so on.
Not many of us live in aquariums, so knowing how much water an air conditioner can cool is not much use. To get a very rough idea of how much air can be cooled, take the fact that a cubic foot of water weighs about 63 pounds. Water is about 6,300 times denser than air. So 100 cubic feet of air weighs about a pound. A typical bedroom contains about 1,000 cubic feet of air, or 10 pounds of air. That means (ignoring differences in heat capacity) that a 10,000 BTU air conditioner can lower the temperature of a bedroom, if it is perfectly insulated, by 10 degrees in just a couple of minutes. It is not the case that the room is perfectly insulated (in fact many rooms have little or no insulation) but what that tells you is that you probably do not need a 10,000 BTU air conditioner for a typical 10' x 12' bedroom. For comparison, you can happily cool an insulated 2,000 square foot house with a 5 ton (60,000 BTU) or so system, implying that you might need perhaps 30 BTU per square foot. Keep in mind that these are all rough estimates and you should not rely on any of this information to size your home's air conditioner - ask a HVAC contractor.
The EER (Energy Efficiency Rating) of an air conditioner is its BTU rating over its wattage. For example, if a 10,000 BTU air conditioner consumes 1,200 watts, its EER is 10,000/1,200 = 8.3. Obviously you would like the EER to be as high as possible, but normally a higher EER is accompanied by a higher price. How do you decide if the higher EER is worth it?
Let's say that you have a choice between two 10,000 BTU units. One has an EER of 8.3 and consumes 1,200 watts and the other has an EER of 10 and consumes 1,000 watts. Let's also say the price difference is $100. To understand what the payback period is on the more expensive unit you need to know:
- Approximately how many hours per year you will be operating the unit
- How much a kilowatt-hour (KWH) costs in your neighborhood
Heating and Cooling Conservation Tips
Heating and cooling your home uses more energy and drains more energy dollars than any other system in your home. Typically, 44% of your utility bill goes for heating and cooling. No matter what kind of heating, ventilation and air-conditioning system you have in your house, you can save money and increase comfort by properly maintaining and upgrading your equipment. Remember, though, an energy efficient furnace or air-conditioner alone will not have as great an impact on your energy bills as using the whole house approach. By combining proper equipment maintenance and upgrades with appropriate insulation, weatherization and thermostat setting, you can cut your energy bills in half.
All major appliances including gas furnaces, boilers, air conditioners and heat pumps sold in California meet the Title-24 energy efficiency "standards." If you are thinking about purchasing a new central furnace, please check out our Appliance Database that lists the most energy-efficient models. This database will eventually be interactive allowing you to compare models.
- Set your thermostat as low as it is comfortable.
- Clean or replace filters on furnaces once a month.
- Clean warm-air registers, baseboard heaters and radiators as needed; make sure they're not blocked by furniture, carpeting or drapes.
- Use kitchen, bath and other ventilating fans wisely; in just one hour, these fans can pull out a houseful of warmed or cooled air. Turn fans off as soon as they have done the job.
- Keep draperies and shades open on south-facing windows during the heating season to allow sunlight to enter your home; close them at night to reduce the chill you may feel from >cold windows.
- Close an unoccupied room that is isolated from the rest of the house such as in a corner and turn down the thermostat or turn off the heating for that room or zone. Do not, however, turn the heating off if it adversely affects the rest of your system.
If you use electricity to heat your home, consider installing an energy efficient heat pump system. Heat pumps are the most efficient form of electric heating in moderate climates, providing three times more heating than the equivalent amount of energy they consume in electricity. There are three types of heat pumps: air-to-air, water source and ground source. They collect heat from the air, water or ground outside your home and concentrate it for use inside. Heat pumps do double duty as a central air conditioner. They can also cool your home by collecting the heat inside your house and effectively pumping it outside. A heat pump can trim the amount of electricity you use for heating as much as 30% to 40%.
- Do not set back the heat pump's thermostat manually if it causes the electric resistance heating to come on. This type of heating, which is often used as a backup to the heat pump, is more expensive.
- Clean or change filters once a month or as needed and maintain the system according to manufacturer's instructions.
Gas furnaces are rated for efficiency with an Annual Fuel Utilization Efficiency number, or an AFUE. According to the state's Energy Efficiency Standards, Title 24, the minimum AFUE for central furnace systems now sold in California is 0.78, which means that 78 percent of the fuel used by the furnace actually reaches your home's duct work as heat.
The higher the AFUE, the more efficient the furnace. AFUE numbers in today's furnaces range from 0.78 to around 0.90. If you are thinking about purchasing a new central furnace, please check out our Appliance Database that lists the most energy-efficient models.
Gas Furnace Tips
- Don't block registers, vents or heating units with furniture or drapes. That makes your furnace work harder and uses more energy.
- Consider installing a programmable thermostat. You can save as much as 10% a year on your heating and cooling bills by simply turning your thermostat back 10% to 15% for 8 hours with an automatic setback or programmable thermostat.
- Using a programmable thermostat you can adjust the times you turn on the heating or air-conditioning according to a pre-set schedule. As a result, you don't operate the equipment as much when you are asleep or when the house or part of the house is not occupied. Programmable thermostats can store and repeat multiple daily setting (six or more temperature setting a day) that you can manually override without affecting the rest of the daily or weekly program. When purchasing a new thermostat, look for the ENERGY STAR label (www.energystar.gov) and one that allows you to easily use two separate programs; an "advanced recovery" feature that can be programmed to reach the desired temperature at a specific time; and a hold feature that temporarily overrides the setting without deleting preset programs.
It might surprise you to know that buying a bigger room air-conditioning unit won't necessarily make you feel more comfortable during the hot summer months. In fact, a room air conditioner that's too big for the area it is supposed to cool will perform less efficiently and less effectively than a smaller, properly sized unit. This is because room units work better if they run for relatively long periods of time than if they are continually, switching off and on. Longer run times allow air conditioners to maintain a more constant room temperature. Running longer also allows them to remove a larger amount of moisture from the air, which lowers humidity and, more importantly, makes you feel more comfortable.
SEER is the Seasonal Energy Efficiency Rating. SEER rates the efficiency during the cooling season. Look for a SEER rating of 13 or above.
- Whole house fans help cool your home by pulling cool air through the house and exhausting warm air through the attic. They are effective when operated at night and when the outside air temperature is cooler than the inside.
- Set your thermostat as high as comfortably possible in the summer. The less difference between the indoor and outdoor temperatures, the lower your overall cooling bill will be.
- Don't set your thermostat at a colder temperature setting than normal when you turn on your air conditioner. It will not cool your home any faster and could result in excessive cooling and therefor unnecessary expense.
- Set the fan speed on high except in very humid weather. When it's humid set the fan speed on low. You'll get better cooling.
- Consider ceiling fans to spread the cooled air more effectively through your home without greatly increasing your power use.
- Don't place lamps or TV sets near your air conditioning thermostat.
- Plant trees or shrubs to shade air-conditioning units but not to block the airflow. A unit operating in the shade uses as much as 10% less electricity than the same one operating in the sun.
Selecting Heating Fuel and System Types
Selecting the fuel and heating system best suited for your needs depends on the following factors:
- The cost and availability of the fuel or energy source
- The type of appliance used to convert that fuel to heat and how the heat is distributed in your house
- The cost to purchase, install, and maintain the heating appliance
- The heating appliance's and heat delivery system's efficiency
- The environmental impacts associated with the heating fuel.
Fuel Costs
One somewhat simple way to evaluate heating options is to compare the cost of the fuel. To do that, you have to know the energy content of the fuel and the efficiency by which it is converted to useful heat.
Fuels are measured in physical units, such as gallons of oil or propane, cubic feet of natural gas, or kilowatt hours of electricity (kWh). They are also measured by heat content. In the United States, the most commonly used value for expressing the energy value or heat content of a fuel is the British thermal unit (Btu). One Btu is the amount of energy needed to raise the temperature of one pound of water 1°F, when water is at about 39°F. One "therm" is 100,000 Btu.
The chart below provides a list of typical heating fuels and the Btu content in the units that they are typically sold in the United States.
| Fuel Type | No. of Btu/Unit |
|---|---|
| Fuel Oil (No. 2) | 140,000/gallon |
| Electricity | 3,412/kWh |
| Natural Gas | 1,025,000/thousand cubic feet |
| Propane | 91,330/gallon |
| Wood (air dried)* | 20,000,000/cord or 8,000/pound |
| Pellets (for pellet stoves; premium) | 16,500,000/ton |
| Kerosene | 135,000/gallon |
| Coal | 28,000,000/ton |
The efficiency of the heating appliance is an important factor when determining the cost of a given amount of heat. In general, the efficiency is determined by measuring how well an appliance turns fuel into useful heat. (The condition of the heat distribution or delivery system also affects the overall system efficiency.) Many types of space heating appliances must meet minimum standards for efficiency developed by the U.S. Department of Energy. This next chart provides average efficiencies for common heating appliances.
In addition to cost, you might consider the environmental impact of your heating fuel. You probably generate more greenhouse gases by heating and cooling your home than by any other activity, including driving.
Burning natural gas, oil, propane, wood, or pellets in your home with a high-efficiency furnace or boiler can be a very efficient way to deliver heat to your home. Of all these choices, natural gas burns cleanest.
In the NW, due to hydro power, using a heat pump is one of the most cost effective and clean ways to heat your home.Of course, the cleanest fuel for heating your home is solar energy, which produces no pollution at all. In most homes, solar energy will merely supplement the main heating and cooling source, although many are building homes that aim to consume net zero energy over the course of a year.
Choosing a Heating and Cooling System
When choosing a heating and cooling system, there is no one answer; it's largely a personal choice. For existing systems, your choices are pretty much set by the limitations of replacing the system with something significantly different. But for a new home, if your building contractor doesn't impose limitations, the choices are wide open.
Choosing between systems depends in part on your fuel options, but also on your preferences. Here are some questions you might consider:
- Do you want a central air conditioning system? If so, are any heat pump options—particularly geothermal heat pumps—practical for your home?
- If you don't want central air conditioning, could a baseboard hot water system or a radiant heating system meet your needs?
- If you need to cool your home but don't want a central air conditioning system, could a room air conditioner, or a ductless mini-split system meet your needs?
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