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Gives fresh air for life!

Helps furnaces function properly: All gas and wood heating appliances need combustion air to operate.  Furnaces need a minimum of 5 cu ft. of space for every 1,000 BTU/HR they produce. That means that for a 100,000 BTU furnace-- it needs to be located in a space that has a minimum volume (with the doors closed) of 5,000 cubic feet, or it is considered to be in confined space and needs an outside air source.  Unfortunately, not all houses are built correctly with this in mind.  I've seen large furnaces in 800 cubic foot rooms. If your furnace is in a small room it may not function without the addition of an outside air source. 

Some facts about the air you breathe:

  1. Indoor air pollution is the #1 public health hazard. (Environmental Protection Agency)
  2. 50% of all illnesses are either caused or aggravated by polluted indoor air. (American College Of Allergists)
  3. Children, the elderly, and those suffering with breathing problems or allergies are especially sensitive to indoor air pollutants. (Dept. Of Consumer Affairs)

US Plusaire
« supplies fresh air to a house, correcting indoor air quality, excessive condensation and negative air pressure. Tight houses could display any or all of these symptoms causing health problems for the occupants. A US Plusaire« whole house ventilator will provide warmed fresh air at the rate your house is exhausting or using it in the most cost effective manner.


Expressed simply, US Plusaire« supplies warmed fresh air to your house at a rate equal to or greater than the rate at which your house is using it.

Mechanical ventilation is when a fan is used to draw air into the house. Passive ventilation is the same as opening a window. Air is free to enter as its required. US Plusaire« uses both methods to bring air into the house.

Firstly air is mechanically drawn into the house by the furnace fan during the heat cycle, this is the time when more oxygen is burnt and exhausted up the chimney than at any other time. Air is also mechanically exhausted by the various fans such as in the bathroom, clothes dryer, central vacuum, and kitchen causing outside air to be drawn into the house through US Plusaire«. Without an entry point for the replacement air it would have to find it's way in through holes in the house structure, or depressurize the house.

Secondly, when the furnace fan is off, fresh air is drawn into the house through US Plusaire« by the combusting appliances such as a wood stove or fire place. The air that is being combusted must be replaced and US Plusaire« does this in the most economical way.

Remember for every cubic foot of air that leaves a house a cubic foot must be brought in to replace it. The diagram shows the method of installation and the air flows.

Other problems that can be corrected with US Plusaire«:

Fireplace or Chimney Back Drafting

Fireplaces, wood stoves and inserts sometimes experience back drafting. This is generally blamed on the wind or the chimney not being high enough. To really solve the problem first it has to be correctly defined.

Smoke or fumes come out of the heater when the door is opened, or the fire is difficult to light because of cold air coming down the chimney. In most cases it's because the house is at a lower pressure than outside and the air is being sucked backwards down the chimney. The problem can be worse when it's windy so generally the wind gets the blame. There is a name for this phenomena, it is called Stack Effect.

Stack Effect is occurring because the house is acting as a better chimney than the chimney. All of the air within the house is warmer and more buoyant than the air outside and therefore wants to rise. If there is an opening in the uppermost part of the house then the warm air will find it and leak outwards. This creates a powerful draw in the lower part of the home pulling cold air in through the easiest opening; the chimney. The areas that leak in the upper most parts of the house are the attic access hatch, ceiling light fixtures, and poorly fitting windows. Each of these areas can be reworked to stop the air leaks. By doing this it will not only reduce the Stack Effect but your heating bills will also be reduced. What cannot be changed are the various exhaust fans that blow air out of the house. These can create a Stack Effect which can only be corrected by adding air to the house to balance the air that is being blown out. The cure to Stack Effect is therefore a combination of adding adequate ventilation air and sealing the leaks in the upper most areas of the house. Sealing air leaks only in the basement can aggravate the situation.

Remember for every cubic foot of air that leaves a house, a cubic foot of air must be brought in to replace it.

A US Plusaire« will handle the ventilation and combustion air, the other measures can be easily corrected by the homeowner.

Indoor Air Quality

The Consumer Federation of America cites that indoor air pollution is responsible for up to 50% of all illness. Estimated cost in medical bills and lost work time amount to over $100 billion annually.

The American Medical Association has stated that with the reduction of fresh air entering a home, increased levels of Radon gas and other know carcinogens have been detected. The pollutants are know to cause serious health problems.

Indoor air quality, or lack of it, can be identified by the three "B's" of ventilation. The first "B" is breathing. Consider all of the people and pets breathing in air and out carbon dioxide. Each breath reduces the amount of oxygen that is available within the house. If the house is tight then the oxygen content will lessen and air quality will deteriorate.

The second "B" is blowing. Take into consideration all the fans within the house, bathroom, kitchen, clothes dryer, central vacuum, power vented furnace or water heater each of these blows air out, not one is designed to bring air in to balance itself. Too much air being blown out of a house can lead to depressurization. Smoke escaping from a wood stove is one indication that your house is being depressurized. Few people realize that they have a down draft problem but freely admit to having that nice woodsy aroma. That nice woodsy aroma turns to a nasty creosote smell in the early hours of the morning.

The third "B" is burning and concerns all of the appliances that heat or involve the combustion process. These appliances include a furnace, water heater, fireplace, woodstove, cooker, toaster and toaster oven. When these appliances are working they simply burn up the oxygen again reducing the amount available for breathing. If you leave a fireplace burning, in the early hours of the morning, when the fire is nearly out and the furnace comes on, there is enough draw up the furnace flue to reverse the flow in the fireplace chimney, thereby creating a downdraft and the nasty smell associated with it. This can also work in reverse where furnace fumes can be drawn out of a flue by a briskly burning fire, these fumes are dangerous and could lead to carbon monoxide poisoning.

If your house is closed up and does not have adequate ventilation, when morning comes you can actually smell the residue from the wood fire or the previous days activities, couple these with the household chemicals and the off gassing from furniture and carpets and you can see that you are living in a soup of low pressure polluted air. The easy answer is to open a window in each room however this solution is not always practical since the air coming in will be cold and your heating bills will go up very quickly. Obviously you need fresh air but in a controlled fashion and at the lowest possible cost. What is required is a ventilation system that is able to supply warmed fresh air, be able to compensate for negative air pressures, supply combustion air at a place and time when needed and be cheaper to run than opening a window. Fortunately the US Plusaire« system was designed to do exactly that

Carbon Monoxide

Carbon monoxide (CO) is called the silent killer or the silent threat. This is because it is colorless, odorless, and silent. It is formed as a by-product of combustion of carbon based fuels such as natural gas, propane (LPG), coal, coke, furnace oil, kerosene and wood. Carbon monoxide is absorbed by breathing and is 245 times more absorbent to the body than oxygen. Symptoms of poisoning can be misdiagnosed as flu since they are very similar.

    Symptoms are:

  • Persistent, severe headaches
    Dizziness and blurred vision

  • Nausea and vomiting

  • Confusion, weakness of muscles

  • Insomnia and constantly tired

  • Chest pain

  • Fainting

  • Cherry colored skin

High concentrations of 4000 parts per million can kill in minutes but lesser amounts can produce any or all of the above symptoms. A level of nine parts per million is reckoned to be the maximum safe level over 24 hours which is very little so you can see just how deadly it is. It is highly recommended that CO detectors be installed in your home at places recommended by the manufacturer. These detectors can be purchased for around $30, a small price to pay for protection.

The appliances that can generate CO within your house are the furnace, boiler, water heater, un-vented fuel burning heaters and solid fuel burning appliances. The three main problems are improper installation, chimney or vent blocked by bricks or birds nests etc. and inadequate ventilation, providing insufficient air to properly fuel the combustion process.

Improper installation can be easily checked by referring to the manufacturers installation instructions and by having your heating system checked yearly by a qualified professional. A flue system should be checked by a professional at the beginning and end of each burning season and cleaned accordingly. A flue that is in poor condition will be easily spotted and the appropriate action taken prior to disaster.

Supplying adequate combustion air is very simple. A window opened in the room of the appliance is a good, cheap method but not too practical since it will allow cold air in unless you close it when the appliance goes off. A better solution is a US Plusaire« correctly sized for the house. It will supply not only adequate combustion air but also ventilation air to compensate for any of the exhaust fans that tend to depressurize the house.



Radon is the second leading cause of lung cancer.

Radon is an odorless invisible gas that is produced naturally by the decay of the element of uranium. On average about six atoms of Radon emerge from every square inch of soil per second. In the air Radon is diluted to about 2 Pico curies per liter of air which is not dangerous but in concentrations it has been found to cause lung cancer.

Radon gas can enter a house through a soil floor or through any crack or hole in or around the basement.

Since prevention is better than cure it would be wise to prevent any Radon from concentrating within the house. This can be done in two ways:

First, by sealing up any crack or hole in the basement wall and covering any earth floor with plastic sheeting. There are companies that specialize in Radon protection sealing.

The second is to increase the ventilation in the house so that concentrations cannot build up. All houses should have a complete air change every three to four hours. This level of air change has been found to be the most economical balancing air quality with heating costs.

Supplying adequate air is very simple. A window opened in each room is a good, cheap method but not too practical since it will allow cold air to enter. A better solution is a US Plusaire« correctly sized for the house. It will supply not only adequate ventilation air but also combustion air to compensate for any of the combusting appliances that burn up the oxygen in the house. 


Tight House Problems

In the mid 1970's new houses were constructed and were advertised as being energy efficient. This trend has grown to the present. Now the houses are so energy efficient that some people boast of $300 yearly fuel bills. Building an energy efficient home really meant using better built windows and doors and sealing up the structure to stop the outside air from leaking in and the inside air from leaking out.

Unfortunately what was not apparent was that the older houses had air leaks which supplied combustion and ventilation air. What was starting to happen was that the energy efficient houses were becoming tighter and indoor air quality was deteriorating as a result. The tighter the house the worse the condition. Combustion and ventilation air is not able to infiltrate into the house and combustion devices are being starved of air. There is no replacement air for the exhaust fans to blow out which causes the house to depressurize. Depressurizing a house can lead to a new set of problems including carbon monoxide poisoning. The problem is not confined to new houses.

Anyone who has renovated with a few tubes of caulking, new windows, doors or siding, has changed the air infiltration rate. In every case the cost of heating would be less, but, tightening up the structure, without considering the need for combustion or ventilation air, can invite disaster.

Symptoms of a too tight house are condensation on the windows, smoke escaping from the fireplace or wood stove, mold or mildew growing in corners or cupboards, residual smoking or cooking odors and a general stale smell especially in the mornings. Another common sign is a high humidity level that cannot be corrected.

While these symptoms are unpleasant and undesirable, symptomatic health problems can be far moreserious. Constant headaches, dizziness, sleepiness, watery eyes, coughing, breathing difficulties and in some cases death can be attributed to houses with poor air. Most susceptible are the very young and the elderly. Asthma sufferers and people with allergies are especially susceptible to poor quality air.

Since the tightness of the house is causing the health problems then it follows that if the house is made less tight then related health problems will also cease. The common thread linking all of these symptoms together is the lack of ventilation, and this can be verified quite easily by following some simple steps. Begin by opening a window about 1", on each floor. Leave the windows open for 24 hours or until the house symptoms are gone and then close the upper most window each day until the symptoms reappear. This test requires very little effort and will only cost some heat. Measure the amount of opening that is left and that is the amount of opening that must be provided in the outside wall. This test will verify that you have a lack of ventilation air.

The simplest form of adding ventilation and combustion air is to keep the windows open but since the air coming in would be freezing cold it is not too practical. What is required is a device that brings in outside air, warms it, delivers it around the house and is as cheap to operate as opening a window. A US Plusaire« correctly sized for the house is such a device.

For even more information visit www.plusaire.on.ca

For wholesale or retail pricing information please call us at 816-461-3665


 HearthMasters, Inc. 
Padgitt Chimney & Fireplace   Padgitt Forensic Investigations     
 816-461-3665  www.chimkc.com

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