Honeywell ByPass FlowThru Humidifier w/H8908 12 gpd

Space Needed for the HE225

The HE225 is best mounted as shown below. Check that you have enough room. The HE225 overall size is14h x 12w x 9½d".

Skuttle Current Sensing Relay A50

• Sensing Relay

The relay is clamped on to the blower wire and has an internal switch that closes when the blower receives current. The blower voltage can be 120v or 240v, only the is amperage important. The internal switch is electronic and can only switch on or off 24 volts, such as any 24 vac humidifier.

What is Flow-Thru Humidifier?

The term Flow-Thru refers to water trickling through the water panel and out a drain. The advantages of a flow-thru design is reduced maintenance and no standing water. Scale from calcium and lime gets flushed out of the water panel and down the drain. The water panel is an aluminum mesh with a porous coating that inhibits growth of slime and is easy to change (once a year).

The disadvantage of the Flow-Thru is water usage. We are in the northeast where this is not an issue. We get a flat rate water bill unless there is excessive usage then the rate goes up. The Flow-Thru humidifier does not cause excessive usage.

The Flow-Thru is an evaporative humidifier and requires hot air. If not using hot air then hot water should be used. We see little humidity gain if our Flow-Thru humidifier is operating with cold air (and cold water). We run our blower on constant to best utilize our electronic air cleaner, but our humidifier is wired to only operate only when there is hot air and works very well.

By-Pass Versus Power Humidifier

The term By-Pass or Power refers to the driving force behind the air flow. The Power humidifier (aka Fan Power) uses a fan to draw the air thru the humidifier. The ByPass humidifier uses a 6" diameter duct that connects the supply to the return duct.

In the ByPass configuration the air leaving the furnace is routed back to the supply. The warm air leaving the furnace takes this short-cut of least resistance and bypasses the long trip down the duct work, in to the house, and back through the return. The ByPass is the 6" round duct work shown to the left. During the the hot humid A/C season the ByPass duct should be closed with a butterfly valve since the air flow through the humidifier would not be needed.

The Power humidifier uses a fan to draw air in from the duct and through the humidifier and exhausts back out in to the duct. The air is drawn in through duct at the center of the humidifier and back out in to the duct at the sides. The power humidifier should be mounted in vertical warm air flow.

The HE225 and HE265 are ByPass humidifiers. The HE365 is a fan powered humidifier.

HE265H Versus HE265D

In 2007 Honeywell devised a new naming convention for their humidifiers. The HE265 model number now have the humidistat model for the suffix; H8908 or DG115.

The HE265H8908 includes the H8908 manual humidistat. This humidistat is a wall mounted spst switch. The term manual refers to lowering humidity based on outside temperature. Sacrificing humidity with colder outside temps is necessary to prevent windows dripping with condensation.

The HE265DG115 includes the DG115EZIAQ Digital Automatic Humidistat and outdoor temperature sensor. This humidistat automatically adjusts the humidity based on outside temp. Also displays outside temperature and humidity.

The HE265 models prior to 2008 were the Honeywell HE265A1002 and HE265B1005. The HE265A1002 is identical to the HE265H8908 and came with the manual humidistat H8908B1002. The H265B1005 humidifier came with the automatic humidistat H1008A1008.

• DG115 Humidistat
• H8908 Humidistat

Honeywell HE225 Versus HE220

The difference between the Honeywell HE220A1001 and HE225B1004 is the antimicrobial AGION® water panel. The HE220 humidifiers come with the standard water panel HC22A1007. The H225 humidifiers come with the antimicrobial water panel HC22E1003. The HE220 water panel can be replaced with the HE225 antimicrobial and visa versa.

The HE225 series was introduced under the Honeywell Enviracaire Elite brand. This new brand was designed to be more appealing to the residential customer. The Enviracaire Elite brand has a new bold look of blue and white. The HE220 series was under the traditional Tradeline brand with the slate color scheme. With the success of the new look, the tradeline color scheme was phased out. All current production Honeywell humidifiers now have the bold blue and white color scheme.

The HE225 models come with a five year warranty whereas the HE220 models had a one year warranty. See the HE220 or HE225 Owners manual for complete warranty info (page 10).

• HE220 Owners Manual
• HE225 Owners Manual

Manual Versus Automatic Humidistat

The indoor humidity level needs to be set based on the outside temperature. This is to prevent water from running down the windows. The cool air near the windows can not hold the humidity and water will condense on the glass. To prevent this condensation, the indoor humidity level is sacrificed by lowering the humidistat.

An automatic humidistat (Aprilaire 60 or Honeywell H6062A) adjusts the humidity by using an outside temperature sensor.

Manual humidistat as used in earlier humidifiers (Model 4655 or H8908b1010) requires adjusting the relative humidity based on the outside temperature. A manual humidistat needs to be set back as the season gets colder. The chart below shows the humidity setting for a range of outside temperatures.

When The Outdoor Temperature is	This Relative Humidity Should Be Maintained
+40°F	45%
+30°	40%
+20°	35%
+10°	30%
0°	25%
-10°	20%
-20°	15%

• Model 60 Manual
• Humidity Information