UPDATED May 13th

QUESTION: Why Hasn’t The AC Been On More Often – My Unit Faces The Sun And It Is Boiling

ANSWER: As your Property Manager, I get this question a lot, and I can relate. I live in a building with a similar HVAC system, and in the afternoons during the Spring and Fall it can really get warm. It has several times the past month.

Sadly, this time of year (and this type of weather) is the hardest. The sun facing units want cooling during the day and much of the building wants heating at night. And during the day with full sun, when it is 58 to 62 degrees outside, it is extraordinarily difficult to provide cooling. Even more challenging, the past couple weeks we have had a lot of sunny days with the wind off the lake. This keeps half the building (the shadow side) in the cold.

The following graphic shows the temperature overnight on Saturday May 11th and into Sunday May 12th. Forgive the crude handwritten notes but I’ve tried to illustrate here the challenge:

The graph shows the outdoor temperature from overnight Saturday through Sunday. It is marked ORANGE when we had heat, the YELLOW is the transition period, the GREEN is where the water is still relatively warm but the AC is on, and the BLUE shows when AC was available. It took roughly 6 hours from 7:30am to 1:30pm, for us to transition from the point we were obligated to provide heating, to the point the water in the system had cooled down enough for us to turn the Chillers on. Sadly, by that point the outdoor temperature was approaching 80 degrees, having shot up by 30 degrees in about 7 hours. We could not transition as fast as the weather was changing.

Another bigger problem we’ve experienced recently, is the cool sunny weather. Bright sunshine, but only mid-50s to low 60s outside. But that sun comes through our windows and heats the units up quickly. When we cool the Chiller water, we can only go down in temperature so far before it gets too cold and can damage the mechanicals. While you might be boiling in your unit, only just a few tiers may be running their ACs. That would not extract enough energy from the water to warm it up enough when it runs back through the chillers. If we allowed this to happen, it can cause them to “surge”. They can vibrate and make very loud noises…call it “belching” if you will. And it is because the water in the system is too cold. Some lines could even freeze up and the mechanicals can be damaged.

The system was not designed to go back and forth between heating and cooling this time of year. So they did not design it to provide cooling when it is relatively cool outside. That’s why, some would say, they designed windows. Many years ago, it was simply either or; we would having heating only up to a certain date, and then only cooling after. A lot of buildings do this still. And the only other option, say if it is too hot out during heating season, was to simply have the heating turned off. Similarly, we can have cool days during the summer. The system was not designed for us to provide heating over summer. We actually have the plant completely off for professional inspections and maintenance for about two months.

So, while I can personally relate to the discomfort of our sunny side residents, we have built in limitations we have to work with.

UPDATED April 22nd

Maintenance Reports That Our Cooling System Is Ready To Go

If timing and weather allow, we will switch to AC as we are able. However, keep in mind that heating will be a priority, and it’s not just a flip of a switch. The temperature of the water in the pipes has to properly modify before we can switch from either heating to cooling or cooling to heating. To explain, we can’t put cold water into the boiler system and we can’t put hot water in the chillers. The transition process can take 6 to 8 hours. Otherwise, we risk damaging pipes and mechanicals.

This makes it awkward if we expect to have to switch back to heat, for example, overnight. Read more about this process in our Original Post below.

UPDATED April 11th

Our Team Advised That Cooling Tower Preparation Is Underway

We expect to finish the main cooling tower prep work this week. We may be filling it in the next several days, in final preparation for cooling season.

Once that step is complete, our team will be working with our HVAC maintenance crew to pick a day to get the system tested. That may be as soon as this upcoming week. Weather needs to be good enough that we know heat can go off most of the day. That is extraordinarily difficult this time of year, when we know heating service will need to be on at night.

Assuming testing goes well we would be able to start providing cooling on days it is expected to be warm enough and we are able to coordinate a transition.

We will update this post as we know more.

ORIGINAL POST March 13th

Not Quite Time For Us To Be Able To Switchover To AC

Spring is arriving and our team is beginning seasonal preparations to ready our cooling system.

We will continue providing heating as weather requires, and considering the present weather outlook we are looking at early to mid-April for cooling availability. The biggest obstacle right now is the overnight cold temperatures. We can’t fill our cooling tower, until we have a very low chance for freezing temperatures.

Once cooling is available, our team will balance any day to day change over as best we can until the heating system goes offline for the season. In general, our team is aiming to maintain hallway temperatures in the low 70s which tends to support unit temperatures in the low 70s as well. Many variables influence this process.

Given the time of year, heating remains our priority until June, consistent with the Chicago Heating Ordinance. Typically we need to default to heating service and only switch to cooling if conditions are expected to result in discomfort. At times in the Spring, this can be very difficult to navigate, particularly when we have relatively cool outdoor temps but full sunlight during the day.

It’s not just a flip of a switch. The temperature of the water in the pipes has to properly modify before we can switch from either heating to cooling or cooling to heating. To explain, we can’t put cold water into the boiler system and we can’t put hot water in the chillers. The transition process can take 6 to 8 hours. Otherwise, we risk damaging pipes and mechanicals.

Typically we expect the need for heating with outdoor temps in the mid to low 50s or colder. For cooling we aim for AC availability when the sun is out and temps are around 60 degrees or higher. When the weather changes quickly, switchovers can be challenging. When it’s 40 degrees in the morning, and climbs into the 70s in the early afternoon, the transition will be slow, if it happens at all. Our staff has to consider whether heating will be needed again that night, and the time it takes to switch back over to heat. We realize full sun during the day heats some units very quickly, but there will be times we may not switchover because of the timing.

There are other variables. We have sensors throughout the interior and exterior of the building, which help us analyze conditions. Also, feedback from residents can help trigger manual adjustments which may improve comfort. It will not be 100% comfortable for 100% of our residents, 100% of the time this time of year, but resident comments and observations can help us make adjustments and improve conditions as much as possible. Contact us at parktowercondo-mgmt@habitat.com, or call the office 773-769-3250.