Archive for May, 2009
It’s all about heat exchangers
Saturday, May 16th, 2009OK, lets talk HVAC! I decided that the first discussion dedicated to Heating and Cooling, should be about the most basic central component of any system - the heat exchanger. What is that, you ask? Well i’m glad you did.
As you likely already surmised, what a heat exchanger (hereinafter referred to as HX) is, can be found by simply studing the name: it “exchanges” heat - that is it passes heat (or cold, a lower level of heat) from one medium to another. A medium is simply the air or water you are heating or cooling, or the “products of combustion” from your fire. In commercial systems the mediums may be an antifreeze mixture, steam or other possibilities. Let’s look at a few examples to help you get a better idea of what’s going on.
Example: your typical home furnace burns fuel, then passes the “products of combustion” through a HX to the chimney, or more often these days to a sidewall vent using a forced blower. On the other side of the HX the furnace uses a blower to force the air from your home through and it picks up the heat the “products of combustion” are giving up, increasing the temp in your house.
Example 2: your window air conditioner forces freon to evaporate inside a HX with your room air blowing across the other side, the room air gives up heat and the freon changes from liquid to vapor (evaporates or boils). The AC moves the warm vapor to a second HX while increasing the pressure, which increases the temp - while outside air is forced over the other side which picks up the heat and discards it to the outdoor air. Meanwhile your room air is returned to your room with less heat - that nice cool breeze is why we pay the electricity to run the AC.
Example 3: your boiler burns fuel and discards the “products of combustion”, but not before putting them through the HX - the heat passed into the water that circulates through another set of HXs, your radiators or baseboard heaters. The room air moves through the radiators by “convection” and warms the house.
So you see, “heat exchangers” are all around us. They are our friends. Without heat exchangers we would all still have to burn our fuel in a fireplace, possibly get the “products of combustion” into the air we breathe and soot up the house, to say nothing of the fact that when you leave the area of the fireplace, you leave the heated area.
A word about “products of combustion” - that is a term for the mixture of soot (carbon) CO2, CO, water vapor and excess air that comes off a fire in varying amounts. The mix is determined by many factors that we won’t get into here. But lets just say we want it removed from the living space for health reasons after we take as much of the heat out as possible.
Congratulations! you now understand (you do understand, don’t you?) the basis of all heating and cooling equipment. The heart of every furnace, boiler, air conditioner, chiller, fan coil etc is the Heat Exchanger - keeping mediums separate while passing energy between them.
New Phone
Sunday, May 10th, 2009Hurray! I can see my contacts again!
My previous phone had lost the display. So over 200 contacts - inaccessible.
Phone still worked, and luckily my family was still accessible via the one key speed dials. Also they all had a different ring so i could tell it was one of them calling.
But how many people do you know who keep a printout of their contact list, so they can manually enter the numbers? Yeah, i thought so.
Fortunately my new phone waiting period was up just 2 weeks after this occurred. So this morning, a little bleary eyed, i went to the phone store and picked up a new LG Chocolate 3. So far this is a really cool phone - and - i can see my contacts again!
It’s just pathetic we rely on these gizmos so much. Why, back when i was a boy . . . . well you know. Let’s face it we all love (more or less) our phones, and especially the convenience.
Hopefully my next post will be more useful. I just wanted to let someone know of my relief of having a new, cool WORKING phone.
Maybe i should get the insurance - but it just seems way overpriced to me.
Long Dark Winter
Wednesday, May 6th, 2009Hello. It’s been way too long. Nearly a year. No way to run a blog, i know.
But i been really busy. Remember my 12 hour job w/ the hour commute? Still there.
Also helping remodel apartments w/ my son-in-law. That takes care of all my free time. And just in case, my job is at night, remember? So on all those “free” days (read: everyday) many times i sleep them away. Truly, there ain’t no free lunch.
In other words, my body clock is so screwy that its hard to use the days, because i am now a nocturnal creature. I have always been somewhat like that - easy for me to stay up at night. But now, it’s often hard to stay up at day. And to sleep during the day is pretty weird too. You must have dark or it’s no good. If the room is light you can only sleep for a short time, then the light wakes you. The dark blue blanket over the window gets me there.
Well enough about that. I have news - just added three categories: HVAC, Food and Gluten. Strange combo you say? True enough. For those who may not know - Heating, Ventilation, Air Conditioning = HVAC. My life of employment has been here. I will write more on this.
Food - one of my good friends at work is a food guy. He attended a really good chef school and ran a deli business for a number of years. He has a great talent with food, and love for it. It’s really funny, often we speak of food, and he will always say his mouth is starting to water. So hopefully my blog will incorporate food items and recipes from the “Mystery Chef”.
Gluten? What is that you may ask. Well is a sticky substance that naturally is in wheat and some other grains. So what? So my wife is allergic to it. There are degrees of intolerance to the stuff. Some folks are bothered by it enough that it is almost like a poison to them. Most are less so. And the medical community and society at large are relatively ignorant on the subject. Although many restaurants are starting to get with the program. Yup, attach dollars signs and people take notice - good old American commerce is still alive and well. I will attempt to get my wife to write on this issue, or help me with it. She is somewhat of a local expert (had to become one of necessity). Many who have this issue may not know it, and wonder about their health issues - why can’t the doctors figure out what’s wrong? Listen, don’t get me going on that one! But just imagine if you couldn’t eat anything with wheat - no bread, no bagels, cookies, no pasta - sounds a little impossible doesn’t it? Well once you get the hang of it, it’s not so bad. There are substitutes for wheat flour (rice flour combinations) and other ways to go. But enough for now - just hopefully you will see some pieces on that subject here.
I will start using my “can’t sleep at night on my day off” time to blog more. The long dark winter of no writing has (hopefully) turned to spring. Wish me luck.