How does the speed control on an AC fan work?
The speed control chooses the speed of the motor by changing the resistance in series with the DC fan motor. These resistors are all attached to one board with shovel plug attachments and the whole assembly is stuck in the air vent to keel them cool. The motor drives the air to cook its own resistors.
How do you set the fan speed on an air handler?
Inside the air handler, usually on a control board (a printed circuit board) there will be one or more switches or little jumpers that the service technician can set to control the fan speed or speeds on the particular air handler. It’s usually a switch or jumper change, or occasionally on older air handlers, moving a wire from one pin to another.
Where can I find an intermittent extract fan?
Intermittent Extract is a classic method of ventilation and identified as System 1 in the Building Regulations. The provision of ON-OFF ventilation through ‘in room’ extractorfans – bathrooms, kitchens WC’s etc and background ventilators located in windows and walls.
Which is the longest serving intermittent ventilation fan?
The P Fan is one of the intermittent fan range’s longest serving members. Launched in 1970, this two room ventilation fan continues to replace existing installations and is ideal where bathroom and WC rooms are located next to each other. Silent shower kit offers 70% less noise that standard fans.
Why does my Furnace Fan blow cold air then heat?
Owner not a technician but understands mechanical/heating concepts. When heat called for and fan comes on it blows cold air, then heat, then cold, then off. It has always done this. Limit switch is at off 100, on 125 off 150. Changing set points on limit switch does not seem to change pattern. I do not dare force it.
How does the Honeywell fan limit switch work?
With Honeywell fan limit switch, outside fresh air intake and draft motor. We have owned home 12 years. (has AC). Owner not a technician but understands mechanical/heating concepts. When heat called for and fan comes on it blows cold air, then heat, then cold, then off. It has always done this. Limit switch is at off 100, on 125 off 150.
What should the temperture of a Furnace Fan be?
At the supply plenum (right at the furnace) you may see tempertures between 140F and 170F, lower than that (by about 30F) for a newer high-efficiency unit. BUT if you measure air temperature right at the supply register in the occupied room it’s going to be much lower – maybe 80F.
What does it mean when your heat pump is icing up?
In the winter, heat pump icing up is often perfectly normal. Every so often, the unit will go into defrost mode to remove that frost. However, if the top of the unit has a heavy coat of ice, the coils are encased in ice, or the entire unit is covered with a thick sheet of snow and ice, this indicates a problem.