Tony Shelton
BS Detector, Esquire
I just went to one of our accounts where they had a problem with a couple of units. I've reported these two units as being in need of evaporator coil cleaning for over a year now. The tech (or staff) probably responded to a frozen coil or low air flow and yanked my filter and put a 1 inch pleat in it's place.
First, this is a no no in units designed for 2 inch pleats. If you take a one inch filter apart and pull it out like an accordian a 20x20x1 will actually be a 20x32 or so in total paper. But a 20x20x2 will actually be 20x42 or more. (depending on pleat count). This is for a reason. More surface area means higher air flow and more face area for dust to accumulate. Therefore, a 1 inch filter has a little more than half the flow of a two inch and will only last in the unit half as long because it can only capture half the dust before clogging.
Electrostatics are DEPTH LOADING, meaning they are a full one inch of media. When particles are trapped on the electrostatic layer at the front of the filter they accumulate until air is slowed down, then break off and go into the one inch polyester maze and remain there until cleaned opening up airflow where the particles broke off. Because of this electrostatics can hold a LOT of dirt and can remain in the units for longer periods.
In our testing we've found that pleated filters start off with a lower resistance to air flow, but as they face load, the resistance quickly surpasses that of the electrostatic.
Here is the email I sent to the manager of the building. Did I explain this well enough? Was I an a-hole?
Hello Sam.
Your units look pretty good for the end of the summer. I sent you guys a bid for cleaning the condenser coils, but it looks like you either tried to do it yourselves, or had someone else do it.
They left a gallon of coil cleaner on the roof. The coil cleaner being used is acid (hydroflouric - the same kind used to brighten semi-truck wheels.) If your guys are using this be very careful. HF can get on your skin and you won't know it for a few hours later. Even then, your hands will show no signs of redness or swelling but will hurt really bad. That pain is the HF pulling calcium out of your bloodstream and bones. A spill on 1/10th of your body will cause death. Most HVAC companies do not clean with acids anymore.
I can't imagine an HVAC company cleaning a few coils then leaving the rest so I am guessing you guys are cleaning your own.
If you would like us to finish the job just let me know.
Some one pulled three of our electrostatic filters out of two of your small units and replaced ours with 1 inch pleated filters. This was done on the two units I have repeatedly reported as needing coil cleaning. I'm guessing that a tech pulled our filter, looked at it, thinking it was too dirty to be effective and decided to replace it with a pleated filter thinking that would restore air flow. The air flow problem was not the filter, it's the coil.
I took some video to show why we use electrostatics for three month service instead of paper. Paper will not make it three months - especially one inch pleats.
Here are the 1 inch pleats that were put in one of the units. They could not have been in here very long. They are already filled to capacity and are choking flow. This video shows that flow through the filter is less than 200 fpm. I also pull the filter and show that flow through the coil alone (without a filter) is about 550 fpm. This unit should pull about 700fpm with a clean coil AND a filter in this unit reaches the END of it's service life at around 350 fpm. This filter is well on it's way to causing damage. It was the wrong filter choice for this unit especially since this unit calls for a 2 inch pleat when paper filters are being utilized.
http://www.youtube.com/watch?v=jAHm4W1BRWU
On the other hand here is one of your other units that still has our electrostatic installed. This filter has been installed for the full 3 months and yet still reads over 400 fpm. That is why we installed these filters in those particular units.
http://www.youtube.com/watch?v=Rwvxc5UqV2E
Here is that same filter in the light. It LOOKS dirty, but only in the eyes of techs who are unfamiliar with the properties of an electrostatic filter. Reading 400fpm on this filter lets me know that this filter has at least another 3-5 weeks of useful life still left in it. Did your tech take readings or just look at the filter and determine it was dirty?
http://www.youtube.com/watch?v=T3CGLTEuU9M
This is the dust captured by the same filter. A paper filter can't even come close to capturing that much dust without clogging. And our filter did it and still reads over 400 fpm.
http://www.youtube.com/watch?v=DPge3QDpQKE
I don't know where our three filters went. I believe they were one 20x20 and two 20x30's or 20x25's. I hope whoever changed them brought them down and left them with you guys. If not, they are going to have to replace them at $75.00 each. Our number is clearly marked on each filter and a there is a warning indicating that removal without calling our number first will be treated as theft and will be prosecuted.
On the other hand, if your maintenance personnel replaced them, that would be understandable. Your guys would not be expected to know the details of how different kinds of filters work and would just simply think they were dirty. An HVAC company doesn't have that excuse and should have put a meter to the filters before removing them. Either way, I hope they are just put away somewhere in Alan's office.
Sam, call me about this when you get in Monday if you need to clarify anything. Either way, on Tuesday could you have Alan call me and let me know where those three filters are and if you guys need us to finish the coil cleaning.
Thank you
Tony Shelton
Director of Operations
Sonitx, Inc
845 S. Kenny Way
Las Vegas, NV 89107
702-358-7477
http://www.sonitx.com http://www.youtube.com/sonitx
tonyshelton@sonitx.com
First, this is a no no in units designed for 2 inch pleats. If you take a one inch filter apart and pull it out like an accordian a 20x20x1 will actually be a 20x32 or so in total paper. But a 20x20x2 will actually be 20x42 or more. (depending on pleat count). This is for a reason. More surface area means higher air flow and more face area for dust to accumulate. Therefore, a 1 inch filter has a little more than half the flow of a two inch and will only last in the unit half as long because it can only capture half the dust before clogging.
Electrostatics are DEPTH LOADING, meaning they are a full one inch of media. When particles are trapped on the electrostatic layer at the front of the filter they accumulate until air is slowed down, then break off and go into the one inch polyester maze and remain there until cleaned opening up airflow where the particles broke off. Because of this electrostatics can hold a LOT of dirt and can remain in the units for longer periods.
In our testing we've found that pleated filters start off with a lower resistance to air flow, but as they face load, the resistance quickly surpasses that of the electrostatic.
Here is the email I sent to the manager of the building. Did I explain this well enough? Was I an a-hole?
Hello Sam.
Your units look pretty good for the end of the summer. I sent you guys a bid for cleaning the condenser coils, but it looks like you either tried to do it yourselves, or had someone else do it.
They left a gallon of coil cleaner on the roof. The coil cleaner being used is acid (hydroflouric - the same kind used to brighten semi-truck wheels.) If your guys are using this be very careful. HF can get on your skin and you won't know it for a few hours later. Even then, your hands will show no signs of redness or swelling but will hurt really bad. That pain is the HF pulling calcium out of your bloodstream and bones. A spill on 1/10th of your body will cause death. Most HVAC companies do not clean with acids anymore.
I can't imagine an HVAC company cleaning a few coils then leaving the rest so I am guessing you guys are cleaning your own.
If you would like us to finish the job just let me know.
Some one pulled three of our electrostatic filters out of two of your small units and replaced ours with 1 inch pleated filters. This was done on the two units I have repeatedly reported as needing coil cleaning. I'm guessing that a tech pulled our filter, looked at it, thinking it was too dirty to be effective and decided to replace it with a pleated filter thinking that would restore air flow. The air flow problem was not the filter, it's the coil.
I took some video to show why we use electrostatics for three month service instead of paper. Paper will not make it three months - especially one inch pleats.
Here are the 1 inch pleats that were put in one of the units. They could not have been in here very long. They are already filled to capacity and are choking flow. This video shows that flow through the filter is less than 200 fpm. I also pull the filter and show that flow through the coil alone (without a filter) is about 550 fpm. This unit should pull about 700fpm with a clean coil AND a filter in this unit reaches the END of it's service life at around 350 fpm. This filter is well on it's way to causing damage. It was the wrong filter choice for this unit especially since this unit calls for a 2 inch pleat when paper filters are being utilized.
http://www.youtube.com/watch?v=jAHm4W1BRWU
On the other hand here is one of your other units that still has our electrostatic installed. This filter has been installed for the full 3 months and yet still reads over 400 fpm. That is why we installed these filters in those particular units.
http://www.youtube.com/watch?v=Rwvxc5UqV2E
Here is that same filter in the light. It LOOKS dirty, but only in the eyes of techs who are unfamiliar with the properties of an electrostatic filter. Reading 400fpm on this filter lets me know that this filter has at least another 3-5 weeks of useful life still left in it. Did your tech take readings or just look at the filter and determine it was dirty?
http://www.youtube.com/watch?v=T3CGLTEuU9M
This is the dust captured by the same filter. A paper filter can't even come close to capturing that much dust without clogging. And our filter did it and still reads over 400 fpm.
http://www.youtube.com/watch?v=DPge3QDpQKE
I don't know where our three filters went. I believe they were one 20x20 and two 20x30's or 20x25's. I hope whoever changed them brought them down and left them with you guys. If not, they are going to have to replace them at $75.00 each. Our number is clearly marked on each filter and a there is a warning indicating that removal without calling our number first will be treated as theft and will be prosecuted.
On the other hand, if your maintenance personnel replaced them, that would be understandable. Your guys would not be expected to know the details of how different kinds of filters work and would just simply think they were dirty. An HVAC company doesn't have that excuse and should have put a meter to the filters before removing them. Either way, I hope they are just put away somewhere in Alan's office.
Sam, call me about this when you get in Monday if you need to clarify anything. Either way, on Tuesday could you have Alan call me and let me know where those three filters are and if you guys need us to finish the coil cleaning.
Thank you
Tony Shelton
Director of Operations
Sonitx, Inc
845 S. Kenny Way
Las Vegas, NV 89107
702-358-7477
http://www.sonitx.com http://www.youtube.com/sonitx
tonyshelton@sonitx.com
