Closing Heating/Cooling Registers - Yes or No?

This is a question/situation that we deal with on a daily basis, especially this time of year.  Customers have a room/rooms or an entire floor of the home that is uncomfortable and they do what they are able to attempt improving the comfort in their home.  Besides adjusting the thermostat up or down, the only other readily accessible "control" they have over their heating and cooling is the supply registers in their living space.  Some fine tuning of the supply registers to balance the system and direct airflow is reasonable and acceptable; however, more often than not we find folks have completely closed off entire rooms or even floors in attempt to direct their heating or cooling airflow to uncomfortable areas of their home or perhaps in a misguided attempt at saving money on heating and cooling costs.  Let's look at those reasons in more detail and talk about why it really isn't a good idea in almost every case.

First, let's talk about energy savings because that one is pretty clear-cut.  Closing vents to save money in heating and cooling costs will generally not work and could even cost you more.  That might sound counter-intuitive - if I'm heating/cooling less of my home, how can that cost more?  There was actually a study performed by Lawrence Berkeley National Laboratory back in 2003 that showed just that.  Now, that test simulated a home in California with a single, large central return and ductwork in unconditioned space.  Here in Northwest Indiana and South Chicagoland we typically have ductwork in conditioned basements with return registers in most rooms rather than a central return.  So, I believe the conclusion is the same but for a couple of different reasons.

When you close off the supply registers to a room you do a couple of things.  We'll assume it's heating season and you're trying to save some money by not heating a room you don't use often, so you close the register(s) in that room and close the door.  What you can't keep from happening by doing that is the cold coming through the walls, ceilings, floors, and windows.  It will cool off that room just the same as it did before.  In fact, if it gets cold enough, you may find yourself fighting condensation problems on the walls and ceilings of that room which can damage materials and even lead to mold growth.

Two things then occur -- since very few people have insulation inside interior walls and doors, that cold will come into the house just like it always has.  Also, the return duct inside that room is going to draw in the now colder air from within the room, and since we've shut off the supply vent it will create a negative pressure inside the room that will increase the infiltration of cold air through any cracks or crevices.  

You also increase what is known as the static pressure inside the ductwork of  your home.  Higher static pressure is going to affect the airflow through your furn and to your entire home.  If you have a standard blower motor on your furnace, higher static pressure is actually going to slow down the fan and decrease airflow to the entire home.  It can actually get low enough that the heat being created inside the furnace is unable to get out quickly enough and the furnace can overheat and hit the high limit, causing it to shutdown.  Repeatedly running on high limit is terrible for the furnace and will significantly shorten the life of the components, especially the heat exchanger.  The problem is similar in the summer - low airflow can lead to a frozen coil which could lead to liquid refrigerant making its way to the compressor which can kill that vital component in short order.  In other words, you can literally destroy your important and expensive heating and cooling equipment with something as seemingly harmless as closing a few vents.

So what should we do when we want to save money on Heating and Cooling?  Installing more efficient equipment is a surefire way to reduce your energy cost/consumption.  What else?  Reducing your load by better sealing, windows, and insulation is another option.  By simply reducing the amount of heat that is being gained/lost through the walls, ceilings, and floors we make less work for the HVAC equipment.  Finally, turning the temperature in your home down in the winter and up in the summer can make a big difference.  Either all the time (wear sweaters in the winter) or through the use of a properly programmed thermostat can make a large dent in one of your largest costs.  Finally, getting your equipment professionally tuned-up every year can make a huge difference in efficient and safe operation.

If you have a variable speed blower in your furnace you are benefiting from the more energy efficient design of the motor at regular speeds. However, when faced with increased static pressure from closed vents, a variable speed blower will do what it can to still match the requested airflow which means spinning faster and working harder, sometimes to an extreme.  At that point you are using much more energy to run the system, it will be much noisier and you certainly won't be saving any money.

The event that inspired this article was a customer with a 3 year old furnace that needed to have the heat exchanger replaced  last year once again had over 50% of their registers closed in the home.  That customer must have comfort issues they are trying to solve by closing registers, so let's talk about that.

If  you have a single room that is getting too much heat in winter (or cooling in the summer) I think it is alright to close the register into that room.  Assuming you have at least 10 registers in your home, you're reducing available airflow by less than 10%, something most systems can handle. What isn't OK is when people have a single room that isn't getting ENOUGH heat so they try to close all the OTHER registers to "force" the air where they want it.  As we discussed before, closing registers will actually decreases all the airflow in the house to the point that it may be causing damage to your heating and cooling equipment.  Also, decreased airflow throughout the home is likely to cause new comfort problems in other rooms where there were none before. 

So, what's a person to do when they have comfort problems in their home?  Here at Illiana, we face a lot of these comfort concerns every day and we thankfully have a number of solutions to offer.

Multi-stage and variable capacity equipment can go a long ways to improving home comfort and often improve efficiency at the same time.  Being able to more closely match the output of the heating and cooling equipment to what your home actually needs at the time allows for longer run-times which allows airflow to circulate through all the rooms of the house at a slower rate, rather than experiencing the "blast furnace" effect with equipment that is larger than it needs to be in the winter or the "meat locker" in the summer.  

That 2-stage or variable speed equipment also comes with a critical component - a variable speed blower motor.  A key feature is the ability to run the blower all the time - even when not heating or cooling - at a low speed that is quiet and energy efficient but allows air to circulate throughout the home to keep temperatures much more even between rooms and even between floors.  If you're not due for or can't afford new equipment, there's good news - we can retrofit a version of the variable-speed motor into most furnaces to get the same energy savings and comfort benefits.

What about homes with multiple floors that just aren't comfortable?  That's a great application for zoning.  Properly designed and installed zoning systems allow different temperature zones within a home with existing equipment to provide comfort and savings unavailable any other way.  In my own home, a zoning system was the only way to have both floors be comfortable at the same time.  Before I installed the zoning system it was either way too cold or way to hot upstairs depending on the season and I simply could not get it right up there for any length of time.  Zoning simply solved the problem for me.

Finally, the addition of another source of heating or cooling may be the solution.  We've helped a number of folks that have beautiful 4-season rooms and bonus rooms that were never comfortable until we added a ductless Heating and cooling system for them.  Sometimes areas have insufficient ductwork or have a temperature and climate so different from the rest of the home they simply need their own heating or cooling.  We've even done bedrooms in homes where someone needed different temperatures than the rest of the house and a ductless system solved that problem.  By simply adding an independent source of heating/cooling to the problem area you are then free to let the main system take care of the rest of the home as intended.  While a higher cost option, sometimes it is the only thing that can truly make things comfortable and efficient.

So, to recap, here are the downsides to closing registers:

  • Lower airflow with standard furnace blowers
  • Higher energy usage and noise with a variable speed blower
  • Increased room infiltration possible from localized negative pressure
  • Possible condensation in closed off rooms, potential mold growth
  • Comfort problems from reduced airflow throughout the home
  • Frozen evaporator coils that cause cooling problems
  • Dead compressor from frozen coil
  • Cracked heat exchanger from low airflow through furnace which leads to potential Carbon Monoxide poisoning

So, if you find yourself with comfort problems or you're looking to reduce your heating and cooling bill, don't close registers.  Instead, give us a call and see if we can't help give you a real solution to your comfort needs.  After all, we're Your Christian Owned and Operated Neighborhood Comfort Specialists Since 1987!

 

Making the Case for Geothermal

At Illiana Heating, we don't do a lot of Geothermal installations in a year, but when we do, we try to do them very well.  Recent developments in the world of Propane pricing have inspired me to put together this post with the hope that it reaches some folks that are experiencing the pain of high propane prices and may not realize there is a very real and reliable solution available that will solve their home heating problems once and for all.  That solution is a heat pump - more specifically a Geothermal or ground-source heat pump (or "Geo")

I wrote that paragraph over a year ago.  I don't know why I stopped after that point, but I did and I just couldn't get the rest out for some reason.  I love Geothermal heat pumps - I think they're wonderful technology that provide very comfortable heating and cooling at unbeatable efficiency.  They're not for everyone, but that's largely a factor of cost more than anything.  However, the past couple of weeks have once again reminded me everything to like about Geothermal heat pumps and why for some people they are just about the perfect answer to  the question "What's the best way to make my home comfortable without spending a fortune on utility bills?"

A little over a week ago we completed the installation of 2 new Geothermal systems in an existing home.  The home was currently served by two very old natural gas furnaces and matching air conditioners.  The furnaces were huge - physically and capacity-wise - and were in need of replacement.  Although the homeowner had the option to install state-of-the-art natural gas furnaces and two-stage or variable speed air conditioners, he chose to go with Geothermal and I'm glad he did.  I was reminded of all the benefits of Geo when performing the startup testing on the new units last week.  Quiet, comfortable, efficient...the list goes on.

This past weekend we had a chance to visit with some great friends at their home that is now a little over two years old.  We had the privilege of installing Geo in their home when they built it.  Their situation was different - they didn't have natural gas available so they were looking at using either propane or electric to heat their home.  With Geothermal in place, their overall cost of living in their home, between utility bills and mortgage payments, is lower from day one because of Geothermal.  When their neighbors were suffering with $700 propane bills for a single month and electricity bills on top of that, their highest electric bill was less than $300 for heating their entire home along with lights, appliances, computers, etc.  I should also remember to mention just how comfortable their home was on this warm weekend.  75 degrees inside, less than 50% humidity without a dehumidifier running, and no noisy condenser outside interrupting conversations in the back yard.

So, that's what inspired me to finally come back and finish what I started over a year ago.  So, without further, ado, I'm going to do my best to make a case for Geothermal as a great solution for your Heating and Cooling needs.

To help understand why a system like this can save you money, it’s important to understand a bit about how Geo works and why it is so efficient.  First of all, the system itself does not create heat like a gas furnace by burning fossil fuel.  Instead, it is a heat pump and, being a pump, it simply moves heat from one place to another.  You already have at least one heat pump in your home - you probably have two or three.  Your refrigerator and your air conditioner unit are both heat pumps, they're just configured to work in one direction only.  They take heat from one place (inside your fridge or home) and move it somewhere else (outside your fridge or home).  It's that simple - move the heat.  A Geothermal Heat Pump uses that same concept to either cool or HEAT the inside of your house.  However, instead of transferring heat to the air, like your fridge or AC, it uses a series of pipes that run underground (or water from a well) and exchanges heat with the earth.  Being a reversible heat pump, it takes heat from the ground to heat your house in winter and, to cool your home in the summer, takes heat from your house and deposits it in the ground.

Where do the savings come from?  Traditional furnaces are rated in AFUE (Annual Fuel Utilization Efficiency) and air conditioners are rated in SEER (Seasonal Energy Efficiency Ratio).  Since we use much more heating than cooling in our region of the country, I will focus on heating performance as that will be where most if not all the savings come from (in residential at least). Today’s most efficient furnaces are rated around 97% AFUE – that means for every dollar of gas you burn, you get $0.97 worth of heat delivered to your home.  Given that many furnaces in homes today are 80% efficient or lower, and with today’s fuel prices, that's a lot of dollars going up your chimney.  Geothermal Heat Pumps, on the other hand, are rated using a value called COP (Coefficient of Performance) to rate their heating performance.  COP measures how much energy is delivered for every unit of energy used.  Geothermal units have a COP of around 4 or higher – that means that you get $4 of heat for every $1 of electricity used.  So, if we rated a Geothermal unit like a furnace, it would be 400% efficient!  But, that efficiency isn’t magic - it’s because we’re not creating heat; we’re just moving it from underground where it's been heated by the sun conveniently stored for us in the yard.  Geo simply takes advantage of the heat already there and puts it where you need it.  

So, why doesn't everyone install Geothermal?  For one thing, there is a large cost to installation vs. simply replacing or installing a forced air furnace.  The units themselves are more expensive but you also need to install an expensive loop field that you don't have with a traditional furnace and air conditioner.  If you have natural gas available, the savings aren't as great - not because Geothermal is any less efficient, it's simply a factor of the cost of energy.  To show what that looks like, we'll figure out how much 100,000 BTU of energy costs when you buy it from  your utility or propane supplier.  I used average on-bill costs from my own utility bill (I have NIPSCO for gas and electric) for the cost of natural gas and electricity.  I used information found here to determine an LP price of $2.29 per gallon.

For natural gas, one therm (what you pay for) equals 100,000 BTU.  My average price per therm is around $1.10 per therm. So:  Cost of natural gas = $1.10 for 100,000 BTU.

For propane, one gallon contains 91,502 BTU (as found here).  With a cost of $2.29 per gallon we find that 100,000 BTU = $2.29 per gallon * 100,000 BTU/91,502 BTU per gallon = $2.50 for 100,000 BTU worth of propane.

For electricity the conversion is a little trickier, but still simple enough, we just need to get from kilowatt-hours (how you're billed) into that same unit of BTU.  On my bills, one KWH costs $0.12. One KWH equals 3,412 BTU, so to calculate the price of 100,000 BTU, we use this equation:  Cost of electricity per 100,000 BTU = $0.12 per KWH * 100,000 BTU / 3,412 BTU per KWH =  $3.52 for 100,000 BTU worth of electricity.

So, as you can see, we only need to buy $1.10 worth of natural gas to get the same amount of energy as $3.52 worth of electricity provides or $2.50 of propane.  Using a Geothermal with a COP of 4, however, with that $3.52 worth of electricity, we can provide 400,000 BTU of heat to the home.  Buying $3.52 worth of gas gets us 320,000 BTU, but with a 97% efficient furnace, we only deliver 310,400 BTU of heat to the home.  $3.52 of LP is 140,649 BTU which as 97% delivers 136,430 BTU of heat into the home.  

When we look at the numbers that way, it's not hard to see why Geothermal vs. Propane is a no brainer, but it's a little harder decision if you have natural gas.  But guess what - you can't build a furnace that's more than 100% efficient, but there are already Geothermal systems on the market with a COP approaching and in some configurations exceeding 5.  That means that for every $1 in electricity you buy you get $5 worth of heat.  In other words, there's still room to improve Geothermal performance in coming years while traditional furnaces have just about reached the end of their possible improvements.

Geothermal has a number of other benefits as well: 

  1. Federal Government Tax Credit- System are still eligible for a 30% uncapped credit – that means a $25,000 Geo installation would get you $7,500 in tax credits!
  2. Water Heating Cost Savings - Geo has the ability to generate some of your domestic hot water in addition to heating and cooling your house with the same great efficiency to save you even more.
  3. Longevity - Geothermal Heat Pumps last 30 years!Why so much longer than traditional systems?It's because the units are not subject to the wear and tear generated by the heat of an internal fire (like a furnace), and don't have to live outside year round (like an air conditioner).One Geo system could outlive two traditional Furnace/AC systems, saving you money all the while.
  4. Comfort and Cleanliness - A Geothermal system, installed by Illiana Heating, provides you with 3 stages of Heat and 2 stages of Cooling along with a variable speed blower motor.This means the system will be providing just as much heating and cooling as you need for improved comfort and savings while also allowing for constant air filtration and circulation.

So, if you have any questions about Geothermal I recommend you visit our Geothermal page or ask a question on our Facebook page.  Thanks for reading!


A Visual Explanation for Preventative Maintenance.

We are big proponents of preventative maintenance of your heating and cooling equipment.  We recommend it to all of our clients because we believe that it really does make your equipment run more efficiently, safely, and reliably.  If we can imagine for a minute that your furnace is a car and a Chicago winter is a long, not particularly enjoyable, trip you're about to embark on.  If the average speed of that "trip" was 60 miles per hour, you would travel over 140,000 miles and turn off and start your "car" at least 10,000 times - in a single season. (see the end for the math)  

Many people never drive a car that far the entire time they own it, and 10,000 starts is probably enough to last most folks 8 or 9 years, but I'm guessing that every single person would have had maintenance performed on their car at least once in that span of time.  We change the oil every 3,000 to 5,000 miles and might even get a tune-up at 30,000 or 50,000 miles (especially  if we buy the car new!).  Furnaces?  Air Conditioner?  Every day we see decade-old units that have never been touched since the day they were installed and unfortunately these wonders of modern technology often face expensive repairs and premature deaths that often could have been avoided.

Get on with it already

Now, I promised pictures and all I've done is type, so I'll get to the point.  Below you will see the picture of a set of burners that was keeping a furnace from running properly.  The problem, as you can imagine from their appearance, is the the flame was not properly and consistently spreading across the burner faces to all the burners and was consequently tripping the flame-sense safety feature of the furnace.  

As you can see, they're not pretty.  This is much more than surface rust - this has actually corroded and eaten away at the metal of both the burner face as well as the crossovers, some of which are completely closed off from the rust.  So you might be thinking to yourself, "Wow, that's bad, but I bet this is from a 20 year old furnace that needed to be replaced anyways."

NOPE!  These are from a 3 year old furnace.  Can you guess now much maintenance work has been done on this unit?  None.  The rust that could have been cleaned off when it was still just surface deep during an annual cleaning was instead left to its own devices and caused the customer to have a no-heat situation as well as an expensive repair.  Let's see what those burners are supposed to look like

These are shiny and new and after a season of "driving" a long Chicago winter they will probably show some surface rust, particularly if they are used with LP gas as the worn ones were.  However, annual cleaning of the burners as well as the rest of the unit will keep these lasting much longer and keep the customer from waking up to a cold house some morning when the heat is needed the most.  

It's amazing what we find inside of people's furnaces during Precision Tune-ups that people would have had no idea about except they had a thorough inspection and cleaning - water leaks, animal nests, failing components, etc.  Things that can cause equipment to break down and wear out much more quickly than if they were properly maintained.  

Let's be honest, when's the last time you even thought about the condition of your furnace, let alone opened it to thoroughly inspect and clean it.  On second thought, leave the cleaning and inspection to trained professionals or better yet, get on an maintenance plan like our Goldstar program so you don't have to worry about forgetting to keep your "car" running right for years to come. 

The Math

Chicago has around 6,500 heating degree days according the National weather service.  To get that into Heating load hours we need a few more pieces of information.  24 hours in a day - that was an easy one.  Design temperature for chicago.  We're going to use 0 degrees, but you could use 2 or -2 or any number of other values depending on which weather station you use.  We're going to use zero.  The heating degree days are based on 65 degrees as the base temperature.  So:

Heating Hours = (Heating Degree Days)*(24 hours/day) / (65 degree [base temp] - 0 degrees [design temp])

Heating Hours = 6,500 * 24 / (65 - 0) = 2,400 hours

Driving 2,400 hours at 60 miles per hour = 144,000 miles!! And that's just a single heating season!

'Tis the Season....To Be Aware of the Dangers of CO Poisoning

I have addressed this a few times before but it's worth another look.  Carbon Monoxide poisoning is something that most people have heard of, but many don't realize the real danger that it poses.  The Centers for Disease Control website does a great job summarizing all aspects of CO dangers and I recommend you visit it to get all the details, but I'll highlist a few excerps here:

What is carbon monoxide?

Carbon monoxide, or CO, is an odorless, colorless gas that can cause sudden illness and death.

found at http://www.cdc.gov/co/faqs.htm

found at http://www.cdc.gov/co/faqs.htm

What are the symptoms of CO poisoning?

The most common symptoms of CO poisoning are headache, dizziness, weakness, nausea, vomiting, chest pain, and confusion. High levels of CO inhalation can cause loss of consciousness and death. Unless suspected, CO poisoning can be difficult to diagnose because the symptoms mimic other illnesses. People who are sleeping or intoxicated can die from CO poisoning before ever experiencing symptoms.

Who is at risk from CO poisoning?

All people and animals are at risk for CO poisoning. Certain groups — unborn babies, infants, and people with chronic heart disease, anemia, or respiratory problems — are more susceptible to its effects. Each year, more than 400 Americans die from unintentional CO poisoning, more than 20,000 visit the emergency room and more than 4,000 are hospitalized due to CO poisoning. Fatality is highest among Americans 65 and older. (emphasis mine)

How can I prevent CO poisoning from my home appliances?

  • Have your heating system, water heater and any other gas, oil, or coal burning appliances serviced by a qualified technician every year. (emphasis mine)

So, you can't see it, you can't taste it, you can't smell it, and it makes you feel sick.  This time of the year a lot of things can make you feel sick, but not all of them will kill you if not addressed.  Unfortunately there are stories every year about families that have been affected by Carbon Monoxide poisoning.  I found 4 within the last month.  I want to share them here and highlight something they all share in common: 

CO scare at Rutland home - "Fire officials say they did find unsafe levels of carbon monoxide in the home and determined it was due to a faulty furnace."  The carbon monoxide detector probably saved their lives

Day after Mooresville family replaces batteries, CO alarm sounds "Ted Freshwater looks over the gas furnace that is a suspect in the CO poisoning at the home on Sunday morning. Carbon monoxide sent four familiy members to the hospital Sunday morning. They had been sick for a few days."  “Everything didn’t really point back to (carbon monoxide) until after the fact, unfortunately,”

He said inspectors found a crack in an internal part of the furnace Monday afternoon and would replace the unit later this week. It’s unclear when the crack appeared.

 

Furnace problem sends 8 to hospital in Des Moines "...she had a headache for the last four days"

"Brown said the occupants of the home could’ve easily been killed by the CO gas had the 911 call not been placed. “Our meters read 500 parts per million and it alerts at 25 parts per million, so it was way over…1,200 parts per million in a home is immediately dangerous to life and health,” Brown said.

The source of the gas leak was traced to home’s furnace [emphasis mine]. Brown said it appeared moisture from the air conditioner dripped onto the heat exchanger, causing rust and the buildup of carbon monoxide."  In other words - the heat exchanger had rusted through and the furnace was putting carbon monoxide in deadly levels into the home.  

2 Minnesota men died of carbon monoxide poisoning "a damper on the furnace of the rural Springfield home was not functioning properly."  So it doesn't appear to have been a heat exchanger, but part of the furnace that appeared to be functioning normally was in fact the cause of death for 2 people.

So what's the takeaway?  What's the lesson we should learn here?  Furnace safety matters.  It's a life or death situation for some people.  Annual preventative maintenance and inspections are one great way to keep your family safe.  Carbon monoxide detectors are another.

I keep talking about this subject because it's important, and like I said before, people don't necessarily understand the potential danger.  We have received more phone calls and gone through more trouble related to failed heat exchangers that we find than any other problem we encounter.  People are furious that we have told them they have a dangerous situation and shut down their equipment.  People call angry that we've left their elderly parents without heat "for no good reason".  They call insisting we're trying to rip them off and don't believe they have an issue.  They won't let us come back to show them again when we offer, either.  We've been called unethical, liars, cheats, you name it, but we're going to keep informing customers when we find cracks in heat exchangers because it truly is a safety issue.

The reason for their frustration is fairly simple - the furnace appears to still be running fine, and they have carbon monoxide detectors that aren't going off.  

The reason for our insistance on addressing the issue with a new heat exchanger or new equipment is also fairly simple -- what seems like a small crack or hole could in fairly short order become a crack or hole large enough to kill them and their family.  Literally.  

 

Beauty and the Beast

A number of months ago we were approached by a church and given the opportunity to develop a hydronic heating solution for their main sanctuary and meeting area.  The existing system that served the church was a 1.5 MILLION BTU cast iron boiler.  To put that in perspective it's about 15 - 20 times larger than a furnace found in most residential homes.  That is also a measure of how much natural gas it is designed to burn, not how much heat it actually delivers to the space.  Even if we assume 70% efficiency (which might still be generous) it's over 1 million BTUs of heat being generated by this beast.  I think it really earns that name too, I mean, just look at the thing:

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To give you a sense of scale, that's a 6 foot ladder you can barely see behind it and I think that's a 12 or 14 inch exhaust pipe you're looking at.  It even has an angry face from the other angle:

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We're pretty sure this was original to the building, a suspicion that was confirmed when removing it we discovered the concrete floor was actually poured AROUND it!  So, after it was removed and the hole patched appropriately, it was time to replace the Beast with something a bit more modern and efficient, but what to use?

We began this project as we do any other, by conducting a survey of the building and calculating the heat loss using the Manual J calculation.  As I said before we were serving the sanctuary, narthex, organ loft, and basement as well as replacing another small boiler that served a new entryway on the back of the building.  I'm sure at some point in the past someone much have thought 1.5 million BTUs seemed about right for a building of this size, but I wasnt' sure.  The very conservative heat load (no one really seemed to know how much, if any, insulation was in the walls between the plaster and the brick, so I assumed there wasn't any) revealed that the total heat load for the entire building was 400,000 BTU/hr.  Remember that include the new entryway with lots of windows that added over 75,000 BTU or heat itself and that 400k is on the coldest day of the year.  Needless to say, "The Beast" was extremely oversized from day one and had been consuming far more than his fair share of gas the entire time.

Gas wasn't the only resource being consumed more rapidly than it needed to be, though.  The old system used modulating valves to control the amount of heat and the rate it was delivered to the spaces.  I was actually impressed by this arrangement and in theory it should provide very even temperatures.  The valves were opened and closed by thermostats that sent an electrical signal that varied depending on how far away the set point was from the actual temperature.  I'm not sure exactly how it was configured, but if you can imagine the sanctuary was 65 degrees and  you wanted it to be 66, the valve would open a little to heat it up a little, but if it was 60 degrees and you wanted it to be 65, it would open a lot (or all the way, probably) to warm up as quickly as possible until it tailed off the closer it was to the setpoint.  Not bad as far as comfort control is concerned for a 50 year old system.  

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These aren't the pumps, but they're similar

There was a problem, though.  The pumps for the system ran continuously.  They were actually on lightswitches and would run from roughly October to March every year.  24/7.  That doesn't seem like it would be a huge deal until you start to do the math.  These were larger commercial ciculators - I'm pretty sure some were larger than others, but we'll be kind and assume they were all of the 1/6 HP variety with an amp draw of 2 amps.  I'll spare you the math (See the bottom of this article if you want to see it worked out) but it works out to - near as makes no difference - $120 per year.  Per pump.  and there were 4 of them.  So, $480/year was being spent just to run the 4 circulator pumps continuously for  6 months.  

Needless to say, there was plenty of opportunity to improve on the efficiency side of the equation for the church, but we wanted to make sure we were putting together a system that was reliable and effective as well.  The initial plan involved three smaller modulating-condensing boilers similar to what we had put in our own shop when we built it.  The idea was to apply the KISS principle and two of the boilers would simply supply the two largest areas of the church - one for the sanctuary that had radiant floor heat and would use lower temperature water, and another for the basement that would use high temperature water for the fin-tube wall radiators.  The third would be the "complicated" one and serve 3 lower temperature zones and the indirect domestic water heater.  

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Like this, but x 3

This is actually the concept we were planning on using until our vendor suggested we consider doing a cascade of two larger boilers rather than 3 independent systems.  The cascade system would simplify some aspects of the install while complicating others, but brought with it some very tangible benefits.  I should first explain what I mean by a cascade system.  A cascade of boilers is simply multiple boilers that are connected to the same piping system and controlled in such a way that the capacity of both are able to supply heat to the space as well as provide redundancy for the boilers.  The cascade controller handles both; bringing on enough boiler capacity to meet the heating demand as well as making sure both boilers are used an approximately equal amount of time as well as allowing a fail over if one should stop working.

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The upper left is the cascade controller, the upper right is the outdoor reset, and the lower green control is the pump controller

The largest complication of switching to a cascade system vs the independent boilers was the different temperature zones we would need to have.  The majority of the zones are low temperature radiant floor heating, but the lower level has radiators and the indirect water heater that need hotter water to work correctly.  That problem was solved through the use of mixing valves that take the high temperature water produced by the boiler for the radiator zone and mixing it with water returning from the zone to make the water the lower temperature needed the radiant floor zones.  We used 4 individual mixing valves so we could adjust the zones independently to balance heating capacity with comfort. 

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This valve allows mixing hot and warm water to make hottish/warmish water for the radiant zones

In addition to the mixing valves and cascade control, the system had two other controls that help maximize efficiency and flexibility of the system while remaining very simple to control.  The first is the outdoor temperature reset control.  In a nutshell, it changes the temperature of the water produced by the boilers based on the outdoor temperature and by association the heat load of the building.  Lower water temperatures means the boilers don't have to get as hot and allows for maximum condensation of the flue gasses, maximizing boiler efficiency.  That works great for allowing the boilers to make 140 degree water to send to the radiators when it's warm outside, but that doesn't work very well for making 120 degree water in the indirect water heater.  That problem is solved by the cascade controller and the next control, the Enhanced Switching Relay, or more simply, the pump control.

The pump control takes the input of the thermostats from around the building and brings on the appropriate pumps and sends a signal to the reset control that it would like heat.  The reset control takes that signal, determines what temperature water it would like from the boilers and sends it on to the cascade control that determines which boiler to bring on and at what firing rate to satisfy the temperature requirement from the reset control.  Let's simplify that a little:

Thermostat > Pump Control > Reset Control > Casade Controller > Boilers

As more zones come on, but boilers adjust their firing rate and even bring on both boilers to try to get to the temperature requested by the reset control.  This all happens automatically, and at any given time there is exactly as much heat being produced as needed and it is doing so as efficiently as possible.  But what about that water heater I mentioned earlier?  Doesn't it throw everything off?  After all, you don't want to try to heat 50 degree incoming water to 120 degrees using 140 degree water - it would get there eventually, but it would take forever.  Something I forgot to mention, the reset control won't even let the boiler come on if it's more than 70 degrees outside.  

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So does that mean no hot water in the summer?  No, we've got a little trick up our sleeves.  You see, the pump control has a special priority zone that we can hook the water heater up to.  When the aquastat on the water heater says it needs heat a few things happen.  First, the pump to the water heater turns on and the other zones turn off - that is the priority part - it jumps to the front of the line.  The pump control also has a priority output that connects directly to the cascade controller - bypassing the outdoor reset control and brining the boilers on at high fire - producing 180 degree water for as long as the water heater needs it.  So to recap, it looks like this:

Aquastat > Priority zone control > Cascade controller > Boilers

This arrangement allows us to make hot water very efficiently and in very large quantities. 

Some of the other efficiency and performance features of the system are the thermostats and the pumps.  The thermostats are internet connected and allow for system monitoring, adjustment, and scheduling remotely.  They will also send an alert to email addresses if there is a power loss, high or low temperature problem or any number of other conditions that can be set in the system.  The pumps are also special - they aren't simply fixed speed pumps (with the exception of the indirect water heater) but rather vary their speed based on the temperature difference between the supply and return water and get as close to 20 degrees as possible.  That means that the pumps are able to speed up or slow down throughout the heating call to get the zone up to temperature as quickly as possible (by flowing more water initially) and then slowing down as the pipes heat up to minimize energy use and maximize comfort.  Where the old pumps used over 240 watts to run, these pumps, that only run when there is a demand, only use about 40 watts at the most and run even lower as conditions allow.  The pumps alone should save over $400 a year in electricity.  

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That's 40 watts and 12.1 GPM showing on these two pumps

 So I titled this entry Beauty and the Beast - we've already met the Beast - and while I think the new system and its installation is a thing of beauty, the real Beauty is the savings that will be achieved by this system.  By using available technology, properly sizing the system, and designing intelligently to maximize efficiency, effectiveness and reliability the church should see tremendous gas and electrical savings vs the previous system.  Maybe some day I'll be able to post a follow up to this, but I wouldn't be surprised if the savings approach 50% and that, my friends, is a thing of beauty.

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The Math:

2 amp x 120v = 240 watt per pump

240W x 24 hr/day /1000 = 5.76 kWhr/day/pump

5.76 kWhr/day x 180 days/year = 1036.8 kWhr/year/pump

1036.8 kWhr/year/pump * $0.115/kWhr = $119.23/year/pump

4 pumps x $119.23 = $476.92 ~ $480/year pumping cost.

A tour of our new office HVAC system

Almost a year ago we began planning the HVAC system in our new office and had to decide what we wanted to do. We knew we didn't want to do the "normal" of a forced air heating and air system as that is what we were coming from and recognize the shortcomings of that system. Even with a heat pump and zoning we found ourselves constantly fighting the temperature in the office and it was not particularly efficient overall. We also didn't have an unlimited budget, so we had to balance comfort, efficiency, Indoor air quality and price.

In the end we decided on radiant heat in the concrete slab floor of the offices, a hanging heater for the warehouse area (to keep it above freezing mostly), and mini-split heat pumps in every office space.  If a customer wanted to have the best comfort and efficiency, this is the direction we would point them as well.

Radiant tubing attached to the grid before the floor is poured

The radiant floor heat will provide a very even baseline temperature throughout the office (and keep our toes warm). The thermostat controlling the system has a floor temperature sensor and an air temperature sensor to make sure we're keeping the slab warm without overheating the air above it and making sure the floor maintains at least a minimum temperature throughout the heating season.  

The mini-splits are part of a heat pump system, which means they can both heat and cool the space they are in.  In the cooling months, they provide precise, quiet, and efficient cooling to each area.  That means that when Tom wants his office 65 degrees he can do that without making everyone else cold. When Pat doesn't want any cooling in her office, she can do that too.  In the winter, we have the heated floors providing a baseline temperature for the entire office while the ductless units take care of fine-tuning the temperature in every room above the heat the floors provide.

The Ductless heads blend in nicely with their surroundings

Every single space having its own temperature control takes a little getting used to. Just like you would turn a light off when you leave a room you don't intend to come back to or aren't using we try to simply turn the system off when we leave for the day or in the case of a conference room on turn the system on only when it is used. Between the super insulated and air sealed exterior and the quick recovery of the system the room can be made comfortable in matter of minutes.  After a few months it looks like the new building will cost the same or less than the old building that was one third the size.

Speaking of the building, lets talk about its role keeping us comfortable and minimizing the monthly energy bills. The building is a pole framed building over an insulated concrete slab.  The exterior walls and the underside of the roof deck were sprayed with at least 6 inches of open cell foam insulation.  When combined with the steel siding and roof and the house wrap below it, things are very tight from an air leakage perspective.  

With that tightness in mind we wanted to make sure we didn't forget the "V" in HVAC - ventilation.  The last thing we want is a temperature controlled Petri dish - we want to make sure we have a way to bring in fresh air and exhaust the stale.  To that end, we have an Energy Recovery Ventilator.  This unit takes in air from one end of the building, exhausts it outside and brings in fresh outside air to the other side of the building.  This isn't just like opening a window, however.  Both air streams pass through something called an enthalpy core where they exchange their heat and humidity.  That means that in the hot summer we don't just send out nice cool and dehumified air and bring in hot humid air.  Instead, the ERV moves most of the heat and humidity from the incoming air into the air leaving the building.  That way we get the best of both worlds - fresh air and energy savings vs. just bringing in outside air unconditioned and "throwing out" nicely conditioned air.

The inside of the ERV

Overall we've been very happy with the system and being able to set your own temperature is a nice luxury to have. We'll see what the cold weather brings, but we have every reason to believe the choices we've made will allow us many years of trouble free comfort.  Check out the gallery below for even more pictures.

 

Putting the "Bonus" in Bonus room

Putting the "Bonus" in Bonus room

Bonus rooms, or my favorite acronymn used to describe them F.R.O.G (Finished Room Over Garage), are a somewhat newer phenomonon, but the  concept is ages old: convert what would otherwise be unused and unconditioned space over a garage or other portion of your home into "living" space by insulating, drywalling and adding some kind of HVAC into it. 

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Carbon Monoxide Poisoning is Real and Close to Home.

Carbon Monoxide Poisoning is Real and Close to Home.

if your furnace or boiler was a car driving at 60 miles an hour, it would drive over 50,000 miles per year.  You would definitely have your car checked out at least every 50,000 miles - probably get the tires changes and the oil and filters too.  Make the investment in your peace of mind and get your equipment checked out today. 

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