Jump to content

Recommended Posts

American Standard 90% propane furnace, and from what I can see there is no paper filter, just this electronic air cleaner that's (a) not turned on and (b) connected to a clock timer for some reason. I'm confused. What gets the big stuff if there's no paper filter? And, why put the electro on a timer?

Click to Enlarge
tn_201422022732_02_19_14%20008%20RS.jpg

42.11 KB

Click to Enlarge
tn_201422022759_02_19_14%20009%20RS.jpg

85.58 KB

Link to post
Share on other sites

https://customer.honeywell.com/resource ... 9-0756.pdf

Those Honeywells have a test button you press when the furnace is running to see if its working. It makes a tick tick sound.

There are 2 large cells and 2 skinny pre-filters. I turn off the power button and pull out the first cell to see if it looks dirty.

I once put a cell back in backward and broke it. I bought a replacement at an HVAC dealer. One cell costs $240.

Link to post
Share on other sites

There's no need for a "paper" filter. There's a pair of screens called prefilters preceding the pair of cells of the air cleaner.

The air cleaner should be energized when the blower starts. Timer be stupid.

Do the pre-filters have to be maintained? By owner or technician?
Link to post
Share on other sites

OK, mystery solved. I went back and looked at this again, and realized that there are slots for thin metal filters in frames, and that they were not installed. They are a sort of coarse, swirly mesh that you can see through, and would only get the big stuff. That being the case, do these things work well if turned on, and why might a clock timer be connected? I rarely see these, most folks here use the 3-for-$10 pleated paper filters from Ace.

Link to post
Share on other sites

I see the electronic cleaners frequently. Yes, they just catch the big stuff. The large energized cells do the rest.

Timer is unusual if it's tied to the filter; however its a very common piece of hardware for controlling the whole-house ventilation feature of the air handler. IOW, it's supposed to set to run the blower intermittently. It may also be linked in with a bathroom fan and/or isolated intake duct with a motorized damper pulling fresh air in to the system from outside.

Link to post
Share on other sites

There is an intake duct from outdoors, piped to a return, with a motorized damper. The lo-vo wire exiting the bottom of the timer goes into the furnace cabinet, the wire from the damper is not the same one. The electronic air cleaner is plugged into the outlet that is just above and in contact with the clock. I assume the flex going into the clock is its power.

I often see timers for running the air handler, and most have the outside air duct also. Many do not have a damper on the outside air. Maybe the air cleaner is "slaved" to the air handler somehow, except that it's power switch is off.

Link to post
Share on other sites

Maybe the air cleaner is "slaved" to the air handler somehow, except that it's power switch is off.

David, the normal (never seen one different) set-up is for the air-cleaner to only have AC power when the blower is working, whether that's during normal heating/cooling or when the fresh air ventilation timer starts up the circulation. Of course it does need to have the switch on, but even then you will only see the filter power light come on when the blower is running.

I have always assumed the filter electrical power is just connected to the same leads or terminals as the blower motor.

On a side note, there are slots for the pre-filters above and below the large electrostatic ones. Make sure the pre-filters are up-stream, or first, in the air-flow. I usually include this link in the report for my clients...

https://customer.honeywell.com/resource ... 9-0756.pdf

Link to post
Share on other sites

There is an intake duct from outdoors, piped to a return, with a motorized damper. The lo-vo wire exiting the bottom of the timer goes into the furnace cabinet, the wire from the damper is not the same one. The electronic air cleaner is plugged into the outlet that is just above and in contact with the clock. I assume the flex going into the clock is its power.

I often see timers for running the air handler, and most have the outside air duct also. Many do not have a damper on the outside air. Maybe the air cleaner is "slaved" to the air handler somehow, except that it's power switch is off.

Unless it's an issue of semantics or I'm mis-understanding, what you've described is the setup I mentioned in my previous post.

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...