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Discussion Starter · #1 ·
I live in Winnipeg, MB Canada in 900 sq foot single story house 60 year old house with an unfinished basement. We have a 30 year old Lennox furnace with roughly 10 year old a/c unit.

The issue is that on hot days like today 32c the house will feel warm even after the outsid temp drops to 24 c . After lots of reading and having a tech out last summer everything thing checks out. Between the intake at the filter and the output by closest vent to the a coil there is a 6 celsuis difference which is roughly 17 degrees Fahrenheit. The air coming out of the vent is 14 but feels warm and registers 78% humidity which it why in think it feels warm. Air flow feels very strong and the furnace fan has been cleaned ( a good size pile of dust was left on the floor. I was amazed.) And the filter is changed regularly ( two cats and a dog)

Water seems to be dripping slowly out of the drain line and using a level the a coil and pan is sloped heavily towards then drain. The coil feels cold to the touch and the coppers pipes on the side of the and the coil itself is sweating a lot. The house away from the registers shows 47% humidity normally.

Any thoughts or other things to check out?

The insulated line coming into the coil is cold and sweating and the warm line is warm ton the touch.
 

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is the basement damp and humid sounds like the return is sucking that into the unit cycling up into the space.does your filter slide into an open track at the furnace...cover that opening on the duct..any openings or joints leaking on that return is a source of pulling that basement condition into the unit...your right about the humidity and feeling uncomfortable..that ac like all types has to remove the humidity first then cool the air....resulting in that condensate running with water..check the returns RH is coming from some place
 

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using the info you posted. Your coil is not cold enough. Either too much air flow, or a problem in the refrigerant circuit. under charged or over charged. could also be a restriction in the refrigerant circuit.
 

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Discussion Starter · #4 ·
is the basement damp and humid sounds like the return is sucking that into the unit cycling up into the space.does your filter slide into an open track at the furnace...cover that opening on the duct..any openings or joints leaking on that return is a source of pulling that basement condition into the unit...your right about the humidity and feeling uncomfortable..that ac like all types has to remove the humidity first then cool the air....resulting in that condensate running with water..check the returns RH is coming from some place
Well the tech that came out suggested I put a cold air return into the basement so I did. The basement does feel humid so I blocked the return vent thinking it was too humid down there. I will put digital temp/humidity inn the basement and see what it registers.

Thanks for the reply.
 

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Discussion Starter · #5 ·
using the info you posted. Your coil is not cold enough. Either too much air flow, or a problem in the refrigerant circuit. under charged or over charged. could also be a restriction in the refrigerant circuit.
The tech did check pressures at the outside unit with a tool with hoses and 2 guages on it. He. Said then freon levels were fine and everything else tested alright. But he did miss or fail to check the fan that had its fins filled with dust. The pile of dust pulled from the fan was 8 to 10 inches around and 2 inches high in the middle.

I will look at changing the fan speed to see if that helps. I have to go into the furnace and change it manually with wires I believe.

I assumed the a coil was cold enough as the inlet and outlet temps are 15 f different.

I will start by recording humidity in the basement and then search for air leaks onnthenreturn side and tape the gap around the air filter.

Its it possible that then coil has a lot of dust in it? It set on top of the furnace so I can get under it to look without pulling itnfromn the furnace and would be worried about breaking lines.
 

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17-20 deg drop across the coil is normal. you DO NOT want to suck air from the basement and should get a portable dehumidifier for the basement. I have one and it makes a huge difference. Make sure you start the AC at 7-8 AM (or let it run all the time) so it gets a head start on removing moisture. people who wait till later have humidity issues as it needs a longer run time to do a better job. if the coil was really dirty it porbably would freeze up but it should be checked and if you had that much fan dirt chances are it is dirty. Post the make and model and serial # of the outdoor unit. If you have a 900 sq ft house you should have a 18,000 BTU unit and unfortunately in the ole days a lot of houses your size got 24,000 BTU units which are oversized and don't dehumidify as well as a longer running properly sized unit. Bigger wuz better was the rule of thumb then.
 

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Discussion Starter · #7 ·
Thanks again for all the input. Electric thermostast is currently set for 72% to keep the ac running while testing. Its been running for 30 minutes and thermostat show its 73 f. My digital temp/rh gauge shows its 72 12 inches below it and 55% rh

Just checked everything over again. Inlet temp is 69.7f with 55% rh in the return plemin in front of the filter. I replaced the cheap filter with a washable one with 8 merv rating.
Outlet temp is 57f with 81% rh in plenium about 7 feet from the top of the furnace. Insulated copper pipe is cold and sweating where exposed going into plenium. Warm line is Luke warm.

Outside compressor is a Bryant with a date code of 06-88. I was way off on how old it is.. 25 years old. Model 569ejx018000abaa. Serial 2588e37648.

Factory charged r-22 3.81lbs power supply 253 max 197 min.
Compressor volts 208-230
PH 1
Hz 60
Rla 8.8
LRA 4.9

Fan motor
Volts 208-230
PH 1
Hz 60
Flat 1.2
HP -

Design/test pressure gauge
Hi psi 450 or kPa 3102
Lo psi 210 or kPa 1448

Minimum circuit amps 12.2
 

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Relative humidity is dependent on temperature. The warmer air is the more water vapor it can hold before it becomes saturated. So air that is 55% @ 73 degrees will show a higher humidity when it is 69.
 

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Discussion Starter · #9 ·
Heres an album of the inside setup with bacon duct tape.. when I took off the cover on Monday to check to see if the a coil was sloped towards the drain the store were closed due to Canada day so I had to use the bacon duct tape. Proper foil tape will replace it.
 

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Discussion Starter · #11 ·
Relative humidity is dependent on temperature. The warmer air is the more water vapor it can hold before it becomes saturated. So air that is 55% @ 73 degrees will show a higher humidity when it is 69.
Thanks.. i understand that but shouldn't the cooling process over the coils remove the humidity before pushing the air down the vents?
 

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It's too bad the A/C has been promoted as a dehumidifier for so long. Granted your A/C system does remove some moisture from the air but it was never intended to do what a dehumidifier does.

Being humidity is a concern a dehumidifier may be necessary or lower humidity can be achieved, as polecat mentioned, by raising the temperature and possibly a ceiling fan for more comfort.
 

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Discussion Starter · #13 ·
It's too bad the A/C has been promoted as a dehumidifier for so long. Granted your A/C system does remove some moisture from the air but it was never intended to do what a dehumidifier does.

Being humidity is a concern a dehumidifier may be necessary or lower humidity can be achieved, as polecat mentioned, by raising the temperature and possibly a ceiling fan for more comfort.
We have a fan blowing in the living room the house still feels sticky when its 22c or 24c.

We had a dehumidifier in the basement last year to try and help but it didn't seems to make much of a difference. It seems like the AC is ADDING humidity to the house when its running.. which i thought was supposed to be the opposite.
?
 

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you have a 018 which is 18,000 btu and the right size. however at 25 yrs old the compressor has a LOT of miles on it and is worn and you are getting about 80-85% of the cooling it did when new. that is why it is not doing so well. also that furnace has about a 95% chance of having a cracked heat exchanger. the ac coil is on top of the heat ex so you cannot get under it to clean it. hate to say it but you really should be looking at a new furnace and ac pkg soon. get about a $500 discount as a pkg. and there are some good summer promotions on now. best bang for your buck $$ IMO is the basic Rheem but they can be a bit noisier but work very well. depends on whether you want a good meat and potatoes unit ( it is) or quieter but more expensive Lennox or others. trying to give you good $$ advice.
 

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Try increasing the room temperature to 25c or 26c for a lower humidity. It will take a few days to become acclimated to the change but that's not an uncommon temperature setting.

There are people in TX that would love it.:laughing:
 

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yah, but you should see our extreme -30 to -40F with a 30 mph wind in the Winter. Texas extreme HOT, WPG extreme COLD.:yes:
 

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Discussion Starter · #17 ·
you have a 018 which is 18,000 btu and the right size. however at 25 yrs old the compressor has a LOT of miles on it and is worn and you are getting about 80-85% of the cooling it did when new. that is why it is not doing so well. also that furnace has about a 95% chance of having a cracked heat exchanger. the ac coil is on top of the heat ex so you cannot get under it to clean it. hate to say it but you really should be looking at a new furnace and ac pkg soon. get about a $500 discount as a pkg. and there are some good summer promotions on now. best bang for your buck $$ IMO is the basic Rheem but they can be a bit noisier but work very well. depends on whether you want a good meat and potatoes unit ( it is) or quieter but more expensive Lennox or others. trying to give you good $$ advice.
Thanks yuri.. I'm aware of the Heat Exchanger Issues that is common with this furnace.. My uncle that is in plumbing and heating (gas ticket and heating) inspected the heat exchanger last fall and did not see any cracks and we have a carbon monoxide detector in the house just in case. It alwasy reads zero unless i put it in the garage with the truck running :)

Manitoba Hydro has financing for furnace and ac upgrade as long as the ac is 13 seer and the furnace is 95% efficent.. Crazy temp swings here. -35c in the winter and 35C in the summer :). Seeing as you are in winnipeg do you have any recommendations for a/c / furnace installers ?
 

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We have a fan blowing in the living room the house still feels sticky when its 22c or 24c.

We had a dehumidifier in the basement last year to try and help but it didn't seems to make much of a difference. It seems like the AC is ADDING humidity to the house when its running.. which i thought was supposed to be the opposite.
?
According to the readings you posted in post #7, your supply air has 2 quarts more moisture per hour in it then the return air does.

The tech you had out. Didn't do a full check on the system. Pressure alone doesn't tell you much about a system.
 
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Discussion Starter · #19 ·
According to the readings you posted in post #7, your supply air has 2 quarts more moisture per hour in it then the return air does.

The tech you had out. Didn't do a full check on the system. Pressure alone doesn't tell you much about a system.
This is using a house hold digital temperature and rh thing that sits on a shelf. The temperature takes a long time to move but the RH jumps pretty quick..

I have a THUM unit from our disassembled from our obsolete server room so i will try that out tomorrow when i have more time.. It has very acurate readings but i didn't grab my laptop before i left work.

http://practsol.com/thum.htm
 

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Discussion Starter · #20 ·
After changing the fan speed from high to low (ther is med high, med -low as well) the temperate dropped to 54f 10 feet from the top of the furnace and more water is coming out of the a/c drain hose. RH in the duct is showing 81% at 13C.
 
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