≡ Menu

Cooling Out at American Digest: Prep that AC for the Seasonal Global Warming

The level of commenting here is something I value. Yesterday in the midst of discussing “You Bring Out the Boring White Guy in Me” by Jim Daniels, things took a turn towards preparing your air-conditioner for the coming (seasonal) global warming to make sure you don’t burn up trying to cool out…..

ghostsniper [somewhere in the East]
I had an uncooked Spam sando for lunch with a little mustard. And a navel orange. They was good.

I set right there in the yard, in the sun, soakin up that vitamin D while the mutt laid there staring at a cicada shell attached to a dandelion. couple butterflies fluttered by and a chipmunk sat over there hunched on his back feets, I threw a piece of bread but it wasn’t enough to pique it’s interest. Then I stretched the hose out in the yard and cut about a foot out of it where it got kinked in years past and always kinks when it’s used, and screwed in 2 new ends. voila’ fixed! Now it’s time for a nap…but I think I’ll walk down to the creek out back first. Maybe there’ll be some deers down there again. 86 degrees. That just too dam warm. Might have to turn the AC on by next week.

[AC? Did someone say AC?]

Gordon Scott [Somewhere in Arizona]
Wow, 86 degrees, eh? I have discovered the truth about living in Arizona, and that truth is, it gets really hot here. 86 degree days are soon to be wistful memories, now that it typically gets to 100. And 115 is coming.

I discovered what folks like about their electric bills. Mine is $128, and really only 2/3 of a month. And power is inexpensive here, about 7.5 cents per kWh. Except, between 3:00 p.m. and 6:00 p.m., on weekdays, when the price goes to 35 cents per kWh. It is easy to spend more in those three hours than in the other 21. And Salt River Project, which is not a band name but the company that supplies my power and water, will break down your usage for you.

So, I am buying a thermostat which will ensure that my air conditioner will not switch on during that peak time. SRP even tells you to set your programmable thermostat to pre-cool in the three hours before, three degrees lower than your comfort level. And in truth, I should rarely be home during those hours anyway.

But it’s a dry heat! And it is. They sell these VW-sized evaporative coolers that people set up outside, to get a cool breeze blowing on them. I’d install one on the house, but it’s a 1970s trailer, and one has to be very careful about the walls, as they are thin.

Ya know Gordon that if your AC is off for a long period of time when you turn it back on it will run for a long time to catch up. You can thank the thermal bridging, and other things, in the exterior envelope for that.

Let’s say you live in a home that has 2×4 stud walls, plywood exterior structural sheathing, and drywall interior sheathing, and some sort of insulation in the stud cavities. Where the ext plywood connects to the studs and then to the drywall, that is a thermal bridge and it transfers the outside heat directly into the interior space. You can feel this thermal bridging with your hand on the interior walls.

Your best bet is to keep the AC on all the time at a temp you can live with. Keep all ceiling fans on all the time. Block as much radiant heat through the exterior envelope as possible (windows, doors, etc.). And have an expert ensure that the unit is performing as it should. The only variation in this is if there is a substantial exterior heat drop during the night.

There are several things you can do to change this dynamic to your advantage but they are all best, and more affordable if the home is under design or construction as it is much more expensive to existing homes. Consult local experts.

Gordon Scott  
Thank you, Ghost. I am always up for good advice.

It is a 1976-made trailer, single wide 14 x 60. I’m pretty sure the outside walls are 2×4 framed, but the interior walls are odd in so many ways. Some walls are 2×2 framed. This means one has to buy special outlets and switches, as ordinary ones are too deep. Interior doors are 1″, meaning one must buy special doorknobs.

But some walls are nothing more than that 1970s wood paneling around a frame, with nothing behind the paneling. There’s a wall in the living room that has the 2×2 studs exposed with some sort of panel between them. I don’t think there’s any Sheetrock. The exterior is metal.

The windows are single-pane sliding, screwed to the exterior. One-half of the window has a screen. I am told that I should make a frame for the other half, and use this special light-blocking screen material for both. Even though the three windows that get serious sunlight are completely blocked by white mini-blinds, the power of the sun gets through.

I was home today because I engaged a contractor to look at the combo heating/cooling system, and explain it to me. I’m not familiar with these at all; I don’t even know where the filter is. There must have been an older system, as there are ceiling vents in all the rooms. The current airflow comes through the floor vents.

Sadly the contractor did not show or call.

I made the mistake of clicking through on a solar panel ad. It was amazing. Three seconds after I finished entering my information my phone rang. It was the first of three calls from the same referral service. But it turns out they mostly don’t want to do trailers, which cuts out at least a third of the housing here. Some contractors will if it’s off the wheels and affixed to the ground, and you own the lot. Those don’t apply to me, so no one wants to sell me $20,000 of subsidized Chinese solar panels.

Gordon, you NEED to find the AC filter and change it out ASAP. Don’t delay, this is dangerous. 1/4 of all *residential fires* in Florida come from blocked AC intakes with clogged filters. We change ours every 3 months.

Find your AC unit inside the trailer. Figure out how to remove the panel(s) on the front. After the panels are removed, look along the inside of the sides of the unit for anything that looks like a filter. It should slide right out. Turn the AC off and try to vacuum where the filter was located on the unit. If the filter has not been changed for a while there is most likely some dust and debris build up around the area. Take the old filter to the big box and buy several of them to have on hand. Install filter and reverse the steps above. You should notice a marked improvement in performance.

The windows. While at the big box buy a roll of “mirrored” window tint and cut and apply it to the windows. Go slow if you haven’t done it before. Clean the glass and the frames. Measure and cut the tint. Wet the glass with soapy water. apply the tint, use a small squeegee to squeeze all the water out. Clean up all the excess water. The mirrors will reflect the sun and UV and the tint will cool the interior. You can also get some inexpensive black curtains at the Dollar Store.

Next week will be hotter than this week and if you do the above this week you should be more comfortable and less broke from AC costs next week.

** When the AC filter is blocked the fan motors must work harder to keep up with the signal the thermostat is sending. The motors will have to run longer to compensate. If the motors are old this is even more dangerous. Hot motors spontaneously catch fire and can blow flames through the ductwork catching the whole place on fire. In newer AC units there are sensors installed that can tell if this is the problem and shut the whole thing down. The typical homeowner has no idea what happened. They just know the little digital box on the wall doesn’t make the house cool and everything is turning 900 degrees right now! The AC techs love this stuff and have you at the disadvantage. Instead of resetting the tripped solenoid, they are going to sell you a $600 fan motor + $300 in labor. They will send your old working fan motor back to the manufacturer and collect a fat “core charge” for it. WIN-WIN! YaY!!!!

Now, where do I send my consultation invoice to? Just kidding. lol

Gordon Scott
Ghost, does the mirror tint go on the inside?

After looking at the outside unit, I could not find a logical location for the filter. But I did find one under the air return grate. It is that stiff black plastic mesh stuff, and it’s really dirty. I shall go visit the large orange store for a replacement….

[Later] ….Filter issues resolved!

Gordon, yes, the tinted film always goes on the inside.

If you have a “split package” AC system the outside part is the compressor and there is nothing for it to filter. A split package consists of 2 separate units, the outside unit is the compressor and the inside unit is the condenser. The condenser is the part that actually circulates the air through the ductwork.

The ductwork has 2 systems, the Supply, and the Return. The Supply is the cold air you feel coming out of the smaller ducts in each room. In most places under say, 2000 square feet living area, there will be 1 Return air duct or register and it is usually bigger than the other ducts.

The Return ducts and register pull the air from the space and cycle it back through the system before sending it back out into the space via the Supply ducts. In typical residential applications, the return air filter is behind the Return air register or grill. In a trailer, I will assume this register or grill is located close to the floor. As far as the black mesh, that sounds like somebody’s make-shift idea on how to get buy if they didn’t have a real filter. Dunno. Anyway, I hope you get it all squared away. With summer coming and prices rising it’s only prudent to find every way possible to cut costs.

Comments on this entry are closed.

  • ghostsniper May 25, 2021, 2:27 PM

    It’s a good idea to check your AC filter(s) at least every 3 months. By doing this you will learn if that is frequent enough. All AC units have their own particular filter size and it needs to be the correct size in order to work properly. Filters can get expensive especially if you are lured by the hype. HEPA, various stages, etc. We buy the least expensive type, don’t remember the brand name right now. A light brown cardboard frame and the filter material is a mesh of loosely matted blue fiberglass. On the edge of the filter you will see an arrow indicating which direction the filter should be mounted. The arrow should point toward the AC unit. A conversation with the top Lee County, Florida Fire Marshall informed me of the importance of properly addressing the the AC filters.

    When I was born in 1955 my newly wed parents were living in an Airstream trailer parked at the back of my dad’s parents property. The Airstream didn’t have AC but it did have a propane fired furnace and it had a filter that required regular maintenance. One night while everyone was sleeping and I was less than 1 year old smoke caused me to start crying in the crib. My crying bothered the dog and it started barking which woke up my dad. Lo and behold, the trailer was on fire! My dad woke my mom, grabbed me and some picture albums and jumped out the door just as the trailer exploded. The 100 lb propane tank on the tongue of the trailer caught fire and leaned back into the burning trailer blowing 50′ flames arcing out over the trailer roof burning everthing in sight. We survived, and I have no memory of this of course, but the mutt didn’t make it out.

    Jump about 43 years into the future.
    In 1998 the largest home builder in the country, First Homes of Florida, Inc., hired me to design 6 brand new homes for their multi-million dollar model home center.
    The homes ranged in size from 1200 sf living area to 2400 sf, all 1 story homes. They were going to market these homes in such a way that they would sell 100 or more per day to potential buyers all across the country and around the world. Each of the 6 models would feature 3 different exterior elevations, or looks/styles. That is 18 different homes total.

    I did preliminary designs on all 18 plans and met with the 2 owners, Pat and Jim, and discussed final tweaking before going ahead with the full construction drawings. During this many hours discussion mostly small revisions were suggested by all of us and the meeting was proceeding nicely. One of the things decided on was the placement of the return air duct. Typically, homes in Florida have the AC condensing unit mounted in the attic and all of the ductwork is ran through the attic. Generally the ductwork for the “Supply” of the system is about 12″x12″ in width and height but the return air ductwork is usually about 18″x24″, considerably bigger. Return ductwork is also more expensive due to the size. Pat and Jim chose to locate the return air register as close to the AC unit as possible in an effort to trim costs. These homes would be built hundreds of times so a saving of $50 per home would add up quickly. They chose to mount the AC condenser units on the floor in the laundry room next to the wall that separated the laundry room from the living room. The return air grill would be mounted low on the wall in the living room. No problem.

    Except, one particular model of these homes was laid out in such a way that the only wall in the living room in which the couch could be located was in front of the AC return air grill. I didn’t like this idea because the couch would block the flow of air to the return air duct, and it would hide the filter from the homeowners so that the filter would not be serviced as it should. I told Pat and Jim this and suggested on this particular model that it would be better if the AC condenser was located in the attic and the return air filter located somewhere other than behind the couch. This suggestion would add about $150 to the overall cost of the home, but I seen no other way around it.

    A hush fell over the room as I and Pat and Jim stood around the table looking at the floor plan and thinking, analyzing. Pat and Jim looked at each other, then at me, and Pat said, “I don’t think our customers are astute enough to figure it out.”, insinuating that by the time the customer realized it would be problematic where the return grill was located (behind the couch) they would have already signed the legal contract and be moved in.

    It was an awkward moment. It was a defining moment. I was under contract with these 2 guys to provide hundreds of sets of building permit drawing into the indefinite future and most likely expand my architectural design business dramatically and of course inflating my wallet to the stratosphere. It all pivoted on my response to Pat and Jim’s insistence that their customers were not worth the benefit of my experienced suggestion.

    A fork in the road. Choose the one road and I’ll be wealthy and able to provide for my family as I believe they deserve. Or choose the other road and continue to work 80 hour weeks for the rest of my life.

    Pat said, “Let’s move ahead with the permit drawings with the AC mounted as it is.”
    He threw down the gauntlet.
    I hesitated not a second.
    I picked up that gauntlet and told Pat and Jim, “In good conscience I cannot move ahead with the design of this project for I believe that doing so will cause potentially major problems for the people that will live in these homes”.

    Again, another uncomfortable pause and Jim told me he was disappointed in my response and didn’t see how we could move together as a team if our idea’s were not in unison.
    I agreed and said I will not do as they asked and they should find another way to complete their projects for I will not be a member of the team. I split.

    A week or so later I received a letter from the First Homes attorney along with a certified check for $10,000.00 for the release of all plans. I signed the letter and had it notarized and sent it back and I signed the check and deposited it. Then I left the office early, bought a case of Bud tallboys, and went home and sat out by the pool getting schnockered. Wondering if I had done the right thing.

    It is now 22 years later and with the added benefit of hindsight I know I did the right thing. I am still not wealthy but I no longer work 80 hour weeks. My family continues to do well and I still choose what I believe is right on every project I design. In 2003 Jim died from a heart attack and in 2006 Pat crashed his Ferrari at high speed and died in a fireball and that same year I and my wife of (then) 22 years moved to the great white north. I don’t dwell much on what could have been if I had chosen money over right. I do dwell on being content with what I have.

  • H (science denier) May 25, 2021, 3:07 PM

    Damn straight, Ghostie. In 1987 I came to a similar fork in the road. I chose the one less traveled and in short order was issued a cardboard box and given a few minutes to collect my personal effects before being escorted off the property. The escort was not necessary, but good riddance anyway. Everybody who took the other fork ended up in big trouble with the IRS for tax fraud and an assortment of other legal inconveniences and never worked in that industry again. Good riddance, Part II, to those guys, too. I got out with my good name intact and eventually retired much more than comfortable. Later called out of retirement, now I work because I want to, when I want to, and how I want to, and not because I have to. Not a month goes by without somebody wanting to cut corners full round on something. No. You go ahead, I tell them. I’ll stop back by in a few months and see how things worked out with you and whatever critter you find that will do that to you. Sometimes that gets their attention and if it doesn’t, that would be good riddance, part III. At every level, actual and imaginable, it ain’t worth it.

  • Joe May 25, 2021, 4:19 PM

    The turn towards A/C was interesting and informative, but I laughed out loud with the leap to spam!

  • John the River May 25, 2021, 4:37 PM

    ” Not a month goes by without somebody wanting to cut corners full round on something.”
    And China is an entire nation of such somebodies. But now we have quite a lot of some-such assholes here.
    Gordon, the “stiff black mesh stuff” is usually can be vacuumed or washable.
    I use HEPA filters since I have serious allergies, those must be replaced. A good trick is at the end of the AC season to remove the filter and place it in a plastic trash bag and put it back in place so that over the winter (New England) it blocks the movement of heated air into the colder attic. Then in the summer the filter is already in a bag and ready to dispose of. Also negates the issue of forgetting to replace the filter since a bagged filter will pass NO air.

    On my house while it was being constructed the AC contractor converted the attic access panel into the return air register, since that saved him the effort of constructing another opening into the interior space. But it left me without any access to the attic. When I called him on it he told me the general contractor had OK’ed it. That would be my Brother-in-Law, yeah I was that stupid.

    Of course all this talk is going to be rendered obsolete since AC (for the masses) is bad for the planet, only the Party Loyalists really deserve the blessings of Air Conditioned air.
    They will be coming for your air conditioners, soon. But first they will make them prohibitively expensive. Prohibitively expensive for the middle class that is. Bill Gates, Bezos and Barry will be fine.


  • ghostsniper May 25, 2021, 6:00 PM

    @John, the building code requires all homes to have at least 1 attic access. If the home has a volume ceiling it must have an attic access on either side of the volume ceiling. The reasons are, so that the building inspector can verify that insulation was properly installed in the ceiling, and, to provide access to MPE’s that may be installed in the attic. MPE= mechanical plumbing electrical. Jurisdictions respect the building and zoning codes variously.

  • EX-Californian Pete May 25, 2021, 8:35 PM

    Holy crap, Ghost-
    That was about the most thorough info I’ve seen posted in ages on HVAC/AC units and safety warnings concerning them.
    As much as you and I occasionally enjoy busting each other’s chops in jest, (and for sport) on other topics, I gotta (sincerely) tip my hat to you for the ‘leg up’ you provided for everyone here on the dangers, and importance of maintaining an HVAC system.

    Respect, brother- and that’s coming from a retired “A” and “B” licensed Contractor in Commiefornia.

    Seems now my only reason to feed you crap is for eating “food by-products” made of slaughterhouse floor sweepings. Dang, not good enough- gimme something better than that, OK?

  • Gordon Scott May 25, 2021, 9:23 PM

    Hey, I yield to no one in the “busting Ghost’s chops” realm. Sometimes I succeed, but not often.
    The HVAC guy showed up today and explained the system to me. It’s older, but has a lot of newer parts, and has been well maintained. The whole thing sits outside, with just a duct going into the house (and presumably another coming out).

    Yeah, I let him replace the condenser. That’s because I pestered him with about a hundred questions. He earned it.

    I bought some of the window film, the top of the line stuff. While cleaning the window I discovered there is already window film. I removed it, but it may take some kind of solvent to get the adhesive all off so I can do the new stuff. I tried to find replacement windows, thinking that a low-e version might be worth the cost. Apparently no one sells replacement slider windows for 1975 manufactured homes. And windows are often non-standard.

    Suppose I replace this unit. I get two of those newer casement windows, the ones you just screw to the outside, and mount them side by side. I’d put something in the middle of course. I think the outside walls are 2×3, so I could put one of those in there. It should be covered on the outside by the frames, and I can trim around the inside. This looks a lot less expensive than tracking down a big slider, and I can get double pane with low-e.

    Does that make sense, here on the This Old Trailer House blog?

  • julie May 25, 2021, 10:01 PM

    Ghost, interesting stuff about the AC. I learned a ton after we moved from Arizona to Florida around 2013. In AZ, even though it runs three quarters of the year ours was fairly low maintenance. Kept the filters changed and had it serviced a couple times a year, rarely had any trouble.

    South Florida was a whole ‘nother ball game. We had constant problems with algae growing in the drain lines to the point where the line would clog up and fill the unit with water if it wasn’t flushed every month. The drain line actually burst in the wall a couple months after we moved into our house, and we had a stream running out our garage. Thought it was the water heater because the flow went straight under it and out. Plumber came out, put in a new water heater, we still had a stream. Then when he couldn’t ignore the drain line, he told us that was the AC guy’s job. The AC guy never came back. Ended up fixing the line and the wall myself, figured if it happened once it could happen again, so I made an access panel there instead. We finally got a good, trustworthy AC guy; pretty sure there’s a special place in heaven for him.

  • Gordon Scott May 26, 2021, 1:34 AM

    Oh, hey, I had that drain hose issue. When we replaced the big octopus formerly coal/upgraded to natural gas gravity feed monster, we wound up with three separate drain hoses (humidifier, furnace, ac) that joined together and traveled 12 feet to the floor drain. Oh, those hoses get clogged. It could be dust. It could be the fungus that comes out of the floor drain and into the hose outlet. Either way, I had to disconnect each hose, pinch the others and blow through. And every time I thought about it, about an ounce of bleach down the hose, which killed off the fungus.

    No more. It’s 1500 miles away.

  • ghostsniper May 26, 2021, 4:59 AM

    @Julie, Another 5 min block of instruction on everything AC. In addition to cooling the air and air conditioner removes the humidity. “It ain’t the temperature, it’s the humidity” that is uncomfortable. Humidity is moisture, is water, and that removed water must go somewhere. There are typically 2 drains on a modern AC condensing unit. 1 drain is on the unit itself and drains to the outside of the building. As a back-up the AC condensor is mounted over a large plastic pan which also has a drain that passes to the outside of the building. Florida being Florida, bugs and lizards are everywhere so it’s a good idea to prevent them from entering the drains. Typically, the drains are 1/2″ PVC pipe and many times they terminate close to the outside finished grade in an elbow or even a sort of “loop” or dip to prevent rain from getting inside. I advise taking a small piece of window screen, maybe 4″x4″ or so and putting it over the end of the drainpipe and securing it with a zip tie to prevent anything from getting inside it. Algae is everywhere in FL so you must check this procedure every now and then to make sure the algae has not built up on it and blocked it.

    A horror that hapened to me one time was while living in a house that had “blown in” insulation in the attic, which I am not a fan of. Air circulates thru the attic via the soffit vents and roof peak vents causing air flow thru the space. Blown insulation got into the overflow pan on the AC condenser and clogged the drain. The pan filled up with condensation and being thin plastic the weight of the water caused the pan to crack allowing the water to run out into the wall between the living room and the garage and wick into the cathedral ceiling drywall. What a mess. I didn’t know there was a problem until I noticed the stain migrating across the ceiling. Because the condensor was mounted in the attic and was too big to be extracted out through the attic access it had to be disassembled inside the attic and removed 1 piece at a time. It had to be removed to access the broken plastic pan it was mounted over top of. When the condenser was reinstalled I mounted it up against the underside of the ceiling in the garage and ran duct extensions to the existing ducts in the attic. So, check the condensation lines frequently. If you mow your own lawn, find your drains, and monitor them when you mow. Don’t just look. Get down on your knees and inspect them. Get in front of potential problems and keep them in that “potential” category.

  • James ONeil May 26, 2021, 12:23 PM

    I know it t’ain’t true but I’m beginning to feel I’m the only one left around who is not now and who has never ever lived in a house, or even an apartment or dorm room, with air conditioning.

  • Kevin in PA May 26, 2021, 3:38 PM

    Kudos to Ghost for his excellent treatise on AC.
    Having said that, I will inform James O’Neil (IIRC you live in Alaska) that he is not alone. I do not like AC. I never have. It messes with my sinuses….and when it is all said and done you still have to go outside at some point and endure the heat.
    My home has an attic fan and if I open up the door to the cellar I can get a nice flow of cooler air from down below the house circulating through. It’s cheaper than running AC as well.
    Here in the Poconos we simply don’t have a prolonged heat for more than a couple of weeks – Dog Days of August and then it’s gone.

  • julie May 26, 2021, 8:00 PM

    Ghost, we moved away from Florida; SoCal now, and thankfully no algae in the lines. I did learn about keeping them clear, though. Last year I noticed the drain line overflow dripping. Found the end of it, buried under the dirt for who knows how long. Got it all cleared out, no more problems. Helps that for a lot of the year, we don’t need to run the air or the heat here.

  • Nori May 26, 2021, 8:21 PM

    Really good HVAC lesson,Ghost,and entertaining! Especially the part about a/c removing humidity,so true. Same thing applies in vehicles,blast the a/c & watch the windshield fog disappear.

    Do you know they make Spam in Turkey,and Jalapeno flavors now? I did’nt. The commie BatFlu supply shortage revealed these new delicacies. They’re in the pantry now,silently wooing me to dare try them.

  • Gordon Scott May 27, 2021, 6:49 AM

    Do a search on “spam in Hawaii photos”

    They have flavors you would never imagine, and whole sections of grocery stores devoted to Spam.

  • Nori May 27, 2021, 2:02 PM

    Gordon,wow,you were not kidding!! I expected the Teriyaki Spam,but Mezclita?? Turns out it’s a Puerto Rican jamonilla & cheese mix. Bet it’s good,too.
    I will however take a pass on the Pumpkin Spice Spam…
    Thanks for the trip to the islands 🌴