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welcome Welcome to Aprilaire Aprilaire, Your Partners In Comfort and leaders in humidification technology for over 50 years offers a complete line of whole-home humidifiers designed to meet the ever increasing needs of today’s consumer. This guide is designed to educate and assist you in selecting the correct humidifier based on the humidification needs of the residence and the HVAC equipment application.
TABLE OF CONTENTS Table of Contents 1. 2. 3. 4. 5. 6.
story of humidity
THE STORY OF HUMIDITY The Story of Humidity Humidification – the process of adding moisture to the air – is one of the most important aspects of total indoor comfort, yet it’s one of the least understood. One reason for this is that humidity is an intangible. It can’t be seen, touched, or smelled. It has no color, no sound. However, its presence, when properly controlled, offers many proven benefits.
THESE BENEFITS CAN BE GROUPED INTO FOUR GENERAL CLASSIFICATIONS: • • • • Comfort Health Preservation Energy Conservation Comfort Did you ever step out of your shower in the morning and notice how warm it is in the bathroom? It is actually muggy. It is probably about 75°F, and the RH may be 6070% because of the water vapor being added to the air while showering.
What are the effects of this constantly changing or constantly low moisture content in the air? Furniture construction is affected as glue dries out, joints separate, rungs fall out, and cracks appear. Plaster and drywall dries out, resulting in unsightly cracks and popping nail heads. Joists and studs shrink. Wood paneling separates and cracks. Floors separate. Pianos, organs, and other musical instruments lose their tone. Pieces of art, books, and documents dry out and can break or crack.
selecting a humidifier
Humidifiers are classified as two general types: consumers peace of mind when installed properly; making expensive, time-consuming call backs a thing of the past. • Evaporative-Type Units • Steam-Type Units With precise operation, Aprilaire evaporative and steam humidifiers are designed to perform at your customer’s expectations. There are many humidifier brands that are in the market with varying capacities, controls, and efficiencies.
Evaporative or Steam Product Selection Evaporative and steam humidifiers are very different in their technologies. Evaporative humidifiers do not heat the water but use hot air flow through a water panel and the HVAC system’s heat draw to turn the water to vapor. Steam humidifiers heat water to the boiling point, producing steam. Both technologies use the system blower to distribute humidity through the ductwork. Steam units can be mounted with a blower pack, if a ducting system is not available.
SELECTING A HUMIDIFIER It is important to select the right type of humidification product for your customer based on their individual needs, home structure, and geography of their house.
sizing
Sizing SIZING Sizing for humidification is similar to sizing for heating and cooling. The humidifier capacity required will be determined by various factors such as: A. The volume of area being humidified B. The air change rate (infiltration or ventilation) C. Humidification load determination A. The volume of area being humidified The volume can be determined from a floor plan or from measurements taken within the home. It’s important to determine the volume, not just the square feet.
control: wiring
Humidifier Control Outdoor Temperature (˚F) Recommended Humidity (%) +40 +30 +20 +10 0 -10 -20 45% 40% 35% 30% 25% 20% 15% CONTROL RECOMMENDED INDOOR HUMIDITY LEVELS What Indoor Relative Humidity is Correct? While some humidity conditions may be ideal for comfort, these conditions are, in many cases, less than ideal for other reasons. An indoor RH of 60% may fulfill all the requirements for comfort, but it can result in damage to walls, to furnishings, etc.
evaporative
Residential evaporative humidifiers are generally designed in one of two styles, bypass or fan powered. The design difference is how the air is delivered to the humidifier. In the bypass design air is passed from the supply to the return and the powered version uses a fan to blow air through the unit. At the heart of the fan powered and bypass humidifier is the Water Panel evaporator. Dry, hot air from the HVAC system is moved through the moisture-laden Water Panel where natural evaporation takes place.
WHAT YOU NEED TO KNOW ABOUT THE APRILAIRE EVAPORATIVE HUMIDIFIER Capacity Evaporative humidifiers efficiently use the HVAC system to operate. The plenum temperature and blower from the furnace or air handler are used to produce humidity. The amount of time the plenum temperature is raised from a heat call is variable and so is the actual temperature; with heat pumps around 90 degrees and gas furnaces at 120 degrees.
Duct Location Fan Powered humidifiers are designed to be installed on the warm air supply plenum of forced air up-flow furnace or heat pumps. They can not be installed on a horizontal system due to reduced capacity. If there is no space on the warm air supply plenum for the humidifier, the unit may be installed on the cold air return duct; however, you will need to supply the humidifier with hot water because the hot water will be the only heat source.
steam humidification
Residential steam humidifiers are generally designed from two fundamental technologies, electrode and resistive. The end result of both technologies is steam, but the way they produce steam is different, leading to performance and maintenance characteristics that are significantly different. Aprilaire humidifiers utilize electrode technology because it offers a design that is simple, and requires easy annual maintenance.
WHAT YOU NEED TO KNOW ABOUT THE APRILAIRE STEAM HUMIDIFIER Capacity The Aprilaire Model 800 will produce up to 23 gallons per day (gpd) of steam. The unit will increase capacity as the voltage increases. Voltage kW Maximum Steam (gpd) Current draw (amps) 120v 1.4 11.5 11.5 208v 2.4 20.5 11.5 240v 2.8 23.3 11.5 The unit requires an electrical draw 11.5 amps ± 10%, use 12.7 amps when sizing circuit and it’s recommended the unit be installed at 240v to achieve maximum capacity.
The distance the steam absorbs into the air depends on the air temperature, RH set point, and air flow velocity in the duct. In general if the distance from the dispersion tube to an obstruction is less than 28” the steam will have enough distance to absorb into the air. If the distance is less refer to the chart to the right.
Form No. 252 7.10 Printed in USA © 2010 Research Products Corporation www.aprilairepartners.com P.O.
