Window a/c units question

[ocnblu]

OK I love summer weather.  I wear long sleeves @ work all year.  But last evening I broke down and stuck my window units in here at the house.  One, a Maytag, just works, never an issue, it hums merrily along.  The other, a Frigidaire, runs fine when I first turn it on, cools, blows plenty of air... but it always seems to "bind up", or freeze.  The compressor gets loud, and the air flow diminishes.  It seems to be leaned far enough to let condensation drip away like it's supposed to.  The air stays cold, it just doesn't "move".  If I shut it off, I can eventually hear it "crack", like it is thawing somewhere.  Any tips?

[balthazar]

Long sleeves all year????? 🤒

No tips, tho there must be folk talking in an A/C forum somewhere online.

[ocnblu]

Yeah, I like to look professional.  My job is a blend of blue and white collar, I'd say.

Yeah so, that a/c sounded like an iceberg breaking a few minutes after I shut it off.  It does it every year.  I hate to junk it, it's not that old.  I have another unit, an ancient Whirlpool that came with the house.  I bet it would freeze the nuts off a polar bear, but I'm sure it uses a lot of electric, so I hesitate.  Lowes has a yuge display right now...

[balthazar]

In reading folk talking about old refrigerators 🤔 I’ve seen claims that those who have plugged old units thru a ‘watt meter’ show they don’t hardly use any more electric than modern units. May have been much better insulated back in the day. Don’t think such a scenario would be present with A/C units, obviously. 

Keep tabs on fridges; I have a ‘58 GE I’d like to sell.

Edited July 6, 2019 by balthazar

[daves87rs]

5 hours ago, ocnblu said:

Yeah, I like to look professional.  My job is a blend of blue and white collar, I'd say.

Yeah so, that a/c sounded like an iceberg breaking a few minutes after I shut it off.  It does it every year.  I hate to junk it, it's not that old.  I have another unit, an ancient Whirlpool that came with the house.  I bet it would freeze the nuts off a polar bear, but I'm sure it uses a lot of electric, so I hesitate.  Lowes has a yuge display right now...

Neighbor has an old one like that....trust me, very worth the extra 5 bucks to run!!!

[KevinW]

Ice build-up that starts near the inlet of the evaporator is usually a sign of a low refrigerant charge.  Most modern units won't hold the charge as long due to corrosion/manufacturing issues.  If the entire evaporator develops ice evenly across the core, maybe a temperature sensor needs to be repositioned.

Antique refrigerators were designed to run efficiently because the cost of electricity was high.  They're much more efficient than any modern frost-free design that runs a 500+ W heater for 10-20 minutes almost every day; some even use additional heaters to evaporate the collected condensate.  The main advantage of a modern design is the improved insulation materials which permit more interior volume for a given footprint.
 

[Robert Hall]

I had the ice buildup and no cold air issue w/ my ancient Rheem central air unit last summer.  The HVAC tech I called added some refrigerant and re-sealed a couple of the connections with Leak Lock and it runs great now.    If I can get another summer out of it, that would be great (1991 vintage unit). 

Edited July 7, 2019 by Robert Hall

[ocnblu]

4 hours ago, KevinW said:

Ice build-up that starts near the inlet of the evaporator is usually a sign of a low refrigerant charge.  Most modern units won't hold the charge as long due to corrosion/manufacturing issues.  If the entire evaporator develops ice evenly across the core, maybe a temperature sensor needs to be repositioned.

Antique refrigerators were designed to run efficiently because the cost of electricity was high.  They're much more efficient than any modern frost-free design that runs a 500+ W heater for 10-20 minutes almost every day; some even use additional heaters to evaporate the collected condensate.  The main advantage of a modern design is the improved insulation materials which permit more interior volume for a given footprint.
 

Thanks Kevin, I appreciate the info.  Weird thing is, after having it off and on a few times over the last couple of days, it seems fine now.  But I don't trust leaving it on while I'm away.

[daves87rs]

Now I need an old fridge.....

[balthazar]

Buy mine!

[Robert Hall]

Funny thing about A/C and summer weather..when it's 80 around here, I see people out and about in shorts and t-shirts, but I'm inside w/ a hoodie and the A/C at 70.   I even go outside and am comfortable in a hoodie over my t-shirt...I guess even after 2 years here, 'm still used to Arizona weather and 80 doesn't feel that warm to me...  

I find w/ my split level house and the A/C I find the upstairs gets warm, have to crank it down to 65 at night to sleep. 

Edited July 8, 2019 by Robert Hall

[David]

Heat Pump for the whole house is a better way to go than AC. Just saying you get a much more consistent comfortable zone with a Heat Pump.

[loki]

just curious, would the position of the window make a difference, like a north window vs SE window, or shaded vs full sun?
would it be a huge pain to switch the positions of them to see if it changes?

[ocnblu]

4 minutes ago, loki said:

just curious, would the position of the window make a difference, like a north window vs SE window, or shaded vs full sun?
would it be a huge pain to switch the positions of them to see if it changes?

Good question.  In yerrs past, I've used this unit in a north facing window, this yerr I have it in a south facing one... same performance either way.  I have to shut it off after a while and let it thaw... but so far since its first episode (this season), it has been OK.  *crosses fingers*  The Maytag (trouble free unit) is nearly able to cool the entire area I need (my house is only 900 sq ft, downstairs is "walkout", so it is partially below ground level and does not need artificial cooling).

[Drew Dowdell]

I've always understood the Freeze/Thaw scenario to mean that it was low on refrigerant. 

[ocnblu]

Can a home window unit a/c be charged and checked?  Prolly cost more than a new one.

 

[Drew Dowdell]

Just now, ocnblu said:

Can a home window unit a/c be charged and checked?  Prolly cost more than a new one.

 

Yes and Yes. 

[ocnblu]

All this crap made in China.  Home appliances were dear when they first came on the scene, and their construction, in turn, served the public well.  Brand loyalty was instilled, which ensured a company's longevity.  Now everything's a commodity and it is a sad state.

[Drew Dowdell]

1 minute ago, ocnblu said:

All this crap made in China.  Home appliances were dear when they first came on the scene, and their construction, in turn, served the public well.  Brand loyalty was instilled, which ensured a company's longevity.  Now everything's a commodity and it is a sad state.

Some things are worth saving even if it costs more than a new one.  I have two Kirby vacuum cleaners from the 1970s (bought one, one was given to me later) that I rather repair and keep using instead of buying new.  I don't care that I can get a new vacuum from target for $75 and it will cost me $75 dollars to service the Kirby. The Kirby will outlive me if I keep up on parts and such for it.   Both of them pre-date me in the first place.

They'll suck the nails out of the floorboards if you let them... no modern household vacuum can do that. 

On my A/C, I did replace my window units with central air and got a new furnace out of it, but my window units weren't that great at keeping the house comfortable and I had to run 3 of them at the same time just to make it tolerable. Central is so much better than window units. 

[David]

Growing up in a household where my dad worked in the commercial AC / freezing business, sadly while all these portable or window based units could be recharged, it is cost prohibitive. Yes they ice up and go through iced / thaw cycles when low. Most units are built cheap and compact to minimize cost and so the tubing usually also is part of the condenser tray which causes the tubes to corrode and leak.

Best to just recycle the unit and buy a new one. Better yet get a Heat pump for your house and you will love it.

[KevinW]

A Bullet Piercing Valve costs less than $10; just make sure it's attached to the low (cold) pressure side.

Heat pumps don't work well in areas that receive measurable snow accumulation. 

[David]

17 minutes ago, KevinW said:

A Bullet Piercing Valve costs less than $10; just make sure it's attached to the low (cold) pressure side.

Heat pumps don't work well in areas that receive measurable snow accumulation. 

I am going to have to disagree with you. As growing up around blast cells on fishing ships to canneries all over Alaska and Canada and seeing heat pumps all over, their ability to manage and maintain the comfort zone of a 15% humidity level so things do not dry out and having them buried in snow and still work would tell me otherwise.

Yet with that, I can also say I have seen my fair share of poorly installed heat pumps with no overhead cover for those areas that do get heavy snow fall fail.

Like they say, your mileage will vary depending on installation and maintenance.

[Robert Hall]

I've heard of heat pumps, don't know how common they are here, though.   They would replace both furnace and A/C units?  

Edited July 9, 2019 by Robert Hall

[David]

1 minute ago, Robert Hall said:

I've heard of heat pumps, don't know how common they are here, though. 

Once you go heat pump, ya never go back to AC.

They are just a little more expensive than AC, but like I stated, they do a superior job of maintaining the humidity level inside a house. Spring, Summer, Fall or winter you always have the perfect comfort level in the home year round.

[Robert Hall]

The biggest frustration I have with my central air (and heat) is more of a factor of the house...being a split level, I have 4 separate levels, and there is a lot of temperature variation between upstairs, the central level (kitchen, dining room, living room, the sunken family/tv room, and the basement.      tv room is always colder than other other parts, the bedrooms upstairs always warmer... 

[Drew Dowdell]

7 minutes ago, dfelt said:

Once you go heat pump, ya never go back to AC.

They are just a little more expensive than AC, but like I stated, they do a superior job of maintaining the humidity level inside a house. Spring, Summer, Fall or winter you always have the perfect comfort level in the home year round.

A/C can do that too... mine does. 

[David]

Just now, Drew Dowdell said:

A/C can do that too... mine does. 

That is interesting as I have never seen an AC system that regulates humidity levels. Sounds like maybe they are merging the two into a single unit.

[Drew Dowdell]

33 minutes ago, dfelt said:

That is interesting as I have never seen an AC system that regulates humidity levels. Sounds like maybe they are merging the two into a single unit.

Yep.  My A/C has a dehumidify function and my furnace has a humidify function.  I do have to manually enable/disable them in the fall/spring when we switch over, but that's just done on the thermostat. 

[David]

4 minutes ago, Drew Dowdell said:

Yep.  My A/C has a dehumidify function and my furnace has a humidify function.  I do have to manually enable/disable them in the fall/spring when we switch over, but that's just done on the thermostat. 

Very Cool, I am working on a Major Remodel for my house and with it will be retiring the 1952 heater that just works, as I am going to go with a modern system with at this time Heat pump that does the Humidity control year round. 

With you info, I will take a look at that design also to see what the cost is and pros / cons of the system.

Thank you Drew!

[Drew Dowdell]

18 minutes ago, dfelt said:

Very Cool, I am working on a Major Remodel for my house and with it will be retiring the 1952 heater that just works, as I am going to go with a modern system with at this time Heat pump that does the Humidity control year round. 

With you info, I will take a look at that design also to see what the cost is and pros / cons of the system.

Thank you Drew!

We have a high-end Lennox system, purchased through Costco.  With the executive membership, I got 3% back on the already discounted price.

[balthazar]

15% humidity is really too low inside a house.

[David]

6 minutes ago, balthazar said:

15% humidity is really too low inside a house.

Wine cellars are 25%, too much and you get mold. 15% is what I was taught years ago, yet now that I look this up it is interesting to see that 35% to 50% max is considered Ideal.

https://www.hvac.com/faq/recommended-humidity-level-home/

Lots of good info at the link above, but the best bits are as follows:

Ideal Indoor Relative Humidity Levels by Outdoor Temperature

The most comfortable indoor humidity level will vary from one household to the next, depending on personal preferences. In general, this temperature guide will show you where to keep your indoor relative humidity levels to ensure comfort.

• Outdoor temperature over 50˚F, indoor humidity levels shouldn’t exceed 50%
• Outdoor temperature over 20˚F, indoor humidity levels shouldn’t exceed 40%
• Outdoor temperature between 10˚F and 20˚F, indoor humidity levels shouldn’t exceed 35%
• Outdoor temperature between 0˚F and 10˚F, indoor humidity levels shouldn’t exceed 30%
• Outdoor temperature between -10˚F and 0˚F, indoor humidity levels shouldn’t exceed 25%
• Outdoor temperature between -20˚F and -10˚F, indoor humidity levels shouldn’t exceed 20%
• Outdoor temperature at -20˚F or lower, indoor humidity levels shouldn’t exceed 15%

[ocnblu]

Kevin, I heard that about heat pumps as well.  When it is super cold outside, there is no heat to pump in.  I need it warm everywhere but the bedroom in winter.

[David]

32 minutes ago, ocnblu said:

Kevin, I heard that about heat pumps as well.  When it is super cold outside, there is no heat to pump in.  I need it warm everywhere but the bedroom in winter.

That makes no sense since the Heat pump works with the furnace for control of the humidity and temp, even during deep winter below zero temps, a proper heat pump / furnace system should work just fine with heat.

Now for a smoking hot young man like you, having a zone control installed also would allow you to have the bedroom chilled why the rest of the house is warm and toasty.  

[Drew Dowdell]

54 minutes ago, dfelt said:

That makes no sense since the Heat pump works with the furnace for control of the humidity and temp, even during deep winter below zero temps, a proper heat pump / furnace system should work just fine with heat.

Now for a smoking hot young man like you, having a zone control installed also would allow you to have the bedroom chilled why the rest of the house is warm and toasty.  

Ah that's where you're getting confused.  You can buy a heat pump only system in the southern states, they have no furnace.  What you're describing is a dual-fuel system where there is a heat pump for the cool day and there is the furnace for absolutely frigid days.  I looked into getting one of those, but the cost of natural gas around here is so cheap that there was no point.

[balthazar]

Outdoor temperature over 50˚F,……..

If your house is well insulated with good windows- you still should not see such a huge intentional swing in humidity.
It WILL change with the outside weather, obviously, but to intentionally try & keep the inside of your house below 15%; you're already (physically) dried out due to low external humidity and non-stop heat. I've always heard 35%-50% is the goal, year-round.

[David]

6 hours ago, Drew Dowdell said:

Ah that's where you're getting confused.  You can buy a heat pump only system in the southern states, they have no furnace.  What you're describing is a dual-fuel system where there is a heat pump for the cool day and there is the furnace for absolutely frigid days.  I looked into getting one of those, but the cost of natural gas around here is so cheap that there was no point.

Very interesting, never knew that they had separate systems. All the systems sold here are Natural gas Furnace / Heat pump systems. Course electricity is cheapest in the country and the natural gas is right behind it so no real big deal on the dual system.

[loki]

22 hours ago, Drew Dowdell said:

I've always understood the Freeze/Thaw scenario to mean that it was low on refrigerant. 

i wasn't suggesting otherwise, just other factors could exacerbate the issue, especially if the refrigerant was barely low.

[daves87rs]

On 7/8/2019 at 1:30 PM, balthazar said:

Buy mine!

Not sure how it would get here though..... 🙂 

 

 

We just installed a Fridgeair branded one and it works much better than our old Kenmore AC one......

[ocnblu]

So yeah that thing woke me up at like 2 a.m. sounding like a redwood cracking in half.  I shut it off.  It was spitting condensation into the room.