Roseholme Cottage is an old house. It's been upgraded through the years, but it was designed to have a roaring coal fire in the basement furnace all winter and have the windows opened at top and bottom in the hottest summer months.
It wasn't designed for air-conditioning. The system copes pretty well nevertheless, right up to about 95°F outdoors and then it...doesn't. That's what happened Friday evening. It crept up slowly; doing the dinner dishes, I realized the house was either unusually warm or I was. (I'm old. It happens.) A look at the thermostat showed the house was four degrees above the set point and airflow from the registers felt reduced. So I shut off the cooling and left the fan running while I checked the furnace for water leaks. Nothing, but the box around the A-coil was colder than usual. I changed the filter on general principles, but the old one didn't appear to be very dirty. I had been self-indulgent with the setting, going as low as 73° in the morning, and that was clearly asking too much during extreme heat.
A couple of hours with the fan on and indoor temperatures slowly rising got airflow back to normal, which meant the A-coil was clear of ice. I ran the cooling for fifteen minutes and set the thermostat a degree above the resulting temperature: 82°.
That may sound terrible, but it's not: as hot as it was outside, the system was running enough to bring the humidity way down and with the blower set to run all the time, the house was comfortable enough for me to sleep under the covers.
Saturday was as least as hot as Friday. I paid attention to the airflow and temperature, but it never froze up. Sunday was better and by evening, I stared bringing the temperature down. By bedtime, it was back at 75°, and I'll leave it there until the next hot spell.
We are a mixed couple: Hunky Husband wears gloves in the house most of the time. He always feels cold. I OTOH am prone to passing out if I get too hot and do not even attempt to do yard work when the OAT is above 74 degrees.
ReplyDeleteIn hot weather such as we are now experiencing, as you mentioned, it's the humidity, inside. Early in the day (4am or 5am) I try to cool the house down to the OAT, as long as that is not below 74 degrees. During the day, I raise the temperature on the A/C one or two degrees at a time until it reaches 79 or 80 degrees. Sometimes I have to back off of that 79 or 80 degrees, but the lower humidity usually lets me get away with it. (Try doing that schedule with a programmable controller. I don't even try. The thermostat display includes OAT, but as far as I know, the system, unlike industrial installations, does not take it into account.)
We started off the season with cooling issues on hot days. No ice, coils inside and outside were clean as a whistle, filter is being changed monthly or sooner, because of remodeling in-progress. The system is nearly 20 years old, and I've replaced most things electrical on the system. Can't do refrigerant, though, so I called in the HVAC tech. It was a little low on charge. Need to start saving for a new system that uses R410.
ReplyDeleteLast week on the hottest day, the system wasn't keeping up, and I started to panic when I realized the compressor wasn't running, then I saw the red light on the power company curtailment box. Of course. I'm not as aware of peak alert days as I used to...we used to have to drop the transmitter site off-grid and run on the genny, but in these DTV days, we don't draw enough juice to matter that much.