Furnace guy said my filter and filter opening looked to small 16x25x1
for the 90% Tempstar N9MP1100F14 gas furnace. I am having a lennox
hc16 filter put in. Will increasing the size from my 16x25x1 to a
larger opening of 20x20x5 or 20x25x5 give me less air flow at my vents
on the first floor, the air flow now is seems to be on the lite side.
The tempstar book on my furnace list a 16x25x1 size that's why im
asking, it must not be too small it that is what it calls for. Dont
mind going to a larger opening if it will help with dust and air flow.
Ok, thanks, in that case I hope they put the 20x25 in. I looked at the
place were it would go and the furnace does not look like it could
take a 20 or 25 in height. 16 is about it as it would be in the area
were the upper part of the furnace would be unless they taper it down
from the larger opening to the smaller one on the furnace. I guess
that would work. Thanks for you reply . The furnace has a heat pump
also that is why I had them come out, it sticking in defrost and going
in defrost even when it's 50 outside. Already replaced the defrost
board but now they think the evaporator has a restriction and they
are going to put a pump on it and said a screen sometimes in their
gets clogged, or it could be a sticking reversing valve, pumping cost
like 450.00 and if its the valve a total of 850.00 and that under
warranty, I pay for labor. it's only 4 years old. Worked fine in the
summer in air condition but now he put in air condition its not
switching so it still tries to heat. He showed me on the evaporator
were its getting about an inch or so of frost that is were he thinks
the restriction is and I guess the screen that clogs, the charge was
right so it was not that. I use propane and with the heat pump not
working right and the price of propane I would even pay for a new heat
pump propane cost so much.. Again thanks for you info on the filter
jamesgangnc said: "You can't harm the system by having less supply
And just what school did you go to that said that? I'm guessing the
manufacturer just supplies all those charts of graphs with phunny little
numbers on them so well "all" would "think" there's more to it then just
duct and tape.
The wildcard is the x5, it sounds like he's thinking a much t hicker pleated
filter. A 16 x 25 x 1 is a very common filter size which is found at most
hardware stores, and at all the Walmarts near me. The other one with the x5
thickness is likely a specialized filter which may be harder to find.
The 5 inch thick filter likely has a LOT more surface area, and very likely
would provide better air flow and better filtration. I'd want to ask if they
are available at box stores, or if you would then be locked into a service
contract for replacement filters.
You know, Mr. ZZZZZ - I'd be more concerned that the tech can't diagnose the
problem at the evaporator. You comments about it being either, this, or
this, or that, or maybe that, and the defrost stuck thing -
All things being equal, your HVAC heat pump tech should have no problem
finding "the" problem. I'm not sure 'what' you meant by "pumping" the
evaporator [indoor coil in heat pump terms]. If there's a clogged screen
near the TXV / metering device that needs clearing, then he needs to recover
the refrigerant, take it apart, clear it, dehydrate, and charge [after
installing a bi-flow liquid filter drier.]
Then I'd worry about the filter. --
This is the second company i had, the first one told me is was the
defrost board so he put a new one in under warranty i paid 128.00 for
the labor he wanted to eliminate the fossil fuel board and re-wire it
I told him no it had worked fine for 4 years that i just wanted to to
work the way it was. The defrost board did not fix it. So i called
another company that the builder of the house uses. They cam out and
checked it and said the reversing valve was not working right but said
it sounded like it was switching that he thought it was a restriction
in the evaporator not letting enough pressure through to reverse the
valve and some screen don't remember what one can clog and cause that.
But if that did not take care of it they would need to replace the
reversing valve. I got the phone number of the first company right off
Tempstar's web site, the one who wanted to wire it with out the
fossil fuel board and some other board he said it did not need.
Tempstar people put it in new so i think it does need the boards.
Any way I will never get a Tempstar again when the people they list on
the Tempstar web site can not or don't know how to fix it. It leaves
the customer who knows nothing about heat pumps to wonder just who to
call when the tempstar authorized technician seem to know nothing. I
just hope someone gets it fixed. Your right the filter should be the
last thing i should be thinking about, but the second company in, the
one who is going to be working on it tomorrow seem to think the filter
was to small and before the heat pump broke we were thinking about a
better filter system.
I called the guy who is working on it, they they are taking the gas
out and replacing the dryer and some screen, I sure hope this fixes
The material that generally stops up filter screens [and the small capillary
line in the reversing valve] is copper oxide. The copper flaking is from
the "original install" of the refrigerant lineset by the installing
contractor. If he would have used Nitrogen during the brazing process, it
would have minimized or even eliminated the copper oxide flaking. Or he
could have installed a bi-flow liquid line filter drier. In either case,
Tempstar is not the problem, the installing contractor is likely the root of
the problem. Albeit Tempstar is a "track side" / ecomomy unit, if it is
installed properly will give years of service.
You need to check with your family and friends about who they've used to
repair their air conditioning & heating.
Your current choices aren't working well. A good technition will identify
your problem and not say somthing like "it might be this, or might be that."
He / she will find the problem, give you a solid quote on cost to repair and
back their decision up with a warranty. [Unlike many medical doctors will.]
Because if you find a qualified HVAC tech, he's not "practicing", he's
I'd get my heat pump fixed first, then maybe think about filter / return air
upgrades. And, BTW: some heat pump fan coil units [BDP and CARRIER come to
mind] that if you offer less than 2/10" w.c. static on the return, and less
than a total of 5/10" w.c. on the complete system, you WILL have condensate
blow off on the evaporator from too much velocity. Check the install sheets
if you don't believe me. Their available online.
The guy came out today and replaced the dryer and the screen at the
evaporator. He did use the Nitrogen to blow through the lines. he
pulled the vacuum for about 4 hours then put 12lbs of R-22 in he was
surprised it took that much and double checked the info on the side of
the outside unit and it was 13lbs. He had a thing that showed the
amount going in, he pot 3 extra oz in before it closed the valve and
said that was fine that way. He put the filter in while the vacuum was
going. That took some time as he had to take that part of the duct
down and cut and make it different to go in. He did tell me that my
return air vents were about 4" to small, the company that put it all
in had gone out of business and they were doing all the warranty work
for the builder that used them and all the one's they seen so far had
the return vents to small.
Anyway so far it seems to be working fine, it's like 28 outside and
anything 37 or so and below before kept sending into that defrost all
the time and sticking, plus the air condition part is working again,
it would not go into the air condition before, it must have got that
copper oxide stuff when i switched over to heat this year. If it works
right tonight I think that it will be ok !!
Sure hope that copper oxide stuff does not do that again.
Thanks everyone for your help and info
That may be happing, the evaporator sure looked rusty all the way up
and down on the part were all the copper loops come out of the
evaporator. It will be 4 years old in march and the rust was all over
it. I was going to spray it with that stuff that stops rust be forgot
and it back togather now. If it goes again I might think about getting
a Lenox or find a deal with parts and labor on something but i hope i
get a few more years out of what i got now..
I talked to a friend tonight he is replacing his Air and furnace, Home
Depot is having some heating company do it. He is getting the upper
end i think as he said it was going to be $10,000 but they also gave
him in writing that that would cover 10 years parts and the labor, may
not be to bad as it just cost me around $550.00 for what i had done
and that don't count the filter, I think i got a good price on the
HC-16 Merv 16. All that vent work to install plus the Hc-16 for
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