What You Need to Know About Heating System Fuel Consumption - Part 2

Here are the proper steps to designing an efficient andsupply and return piping was the wrong diameter and
cost effective heating system:or the ducts and/or diffusers were the incorrect size.
1. Through in depth discussions with the GC and building3. The number of installed zones (each zone has a
owner, determine exactly what the building ownerthermostat, so count tally them up and that's the
expects from the new heating system - what type ofnumber of zones in your system) was either too many
system will it be? There are numerous options foror, less likely to cause excessive fuel consumption, too
system types and the type of fuel it will utilize. Whatfew.
level of efficiency will the system be capable of?4. The installed zone(s) had too much radiation
What level of equipment quality is expected? Howcapacity connected to it/them. Too much baseboard
many heating zones are desired? How will potableradiation on a forced hot water zone will cause a heat
water will be heated - through the boiler andimbalance in the building and hot and cold spots will
indirect-fired water heater, or a separate heatingensue. The solution is to split the zone into more
source like a direct-fired water heater - gas, electric, oil,"loops".
or solar? In the case of an "indirect" water heater, I will5. Ducts or pipes were not insulated in unconditioned
be sure to add the requisite BTUs per hour for thespaces. You really don't want to inadvertently heat
domestic hot water as needed. Basically, all relevantbasements, attics, crawl spaces and the like, therefore,
information will need to be conveyed withthe ducts or pipes need to be insulated. Ducts also
person-to-person discussions, and the HVACneed to be sealed to prevent air escape.
subcontractor should be able to drive the discussions6. The installer did not set up the combustion process
to the point that all questions will be satisfactorily beto achieve the carbon dioxide, oxygen, smoke, gross
answered so he can proceed to the next step.stack temperature and draft levels that the
2. The HVAC sub needs to obtain a complete set ofmanufacturer intended. Too high a stack temperature
working construction drawings that include all floor(too much negative draft in the smoke pipe) means
plans, elevations drawings, window, door and insulationtoo much heat is escaping up the chimney. Too low a
schedules, and geographical orientation.CO2 percentage of flue gas means the fuel isn't being
3. The HVAC designer will then interpret the drawingscompletely combusted (at least as much as is possible
and harvest all of the necessary data from it to bewith the equipment). Too much smoke in a smoke test
used in the heat loss calculation software. Themeans the boiler or furnace will "soot up" quickly. An 1
software will tell him how many BTUs/hour the building8" of soot is equivalent to an inch of fiberglass
will require on the coldest day and will break the totalinsulation. You don't want insulation on the heat
down by individual room "loads".exchanger, otherwise the heat generated by
4. The designer will then select the proper equipmentcombustion will not transfer into the heating medium -
based on fuel type, "net" heating output capacity (inair or water - and the heat will go up the chimney in
BTUs/hour) and how the heating appliance will beexcessive stack temperature.
vented - through a chimney, sidewall-vented or7. In the case of oil burners and power gas burners, if
power-vented out the side of the building orthe burner output capacity in BTUs was not matched
direct-vented through the roof. He will also account forto the boiler/furnace "input capacity" then the burner
quality and efficiency rating.will either short cycle (burner output too great), or the
5. Then the heat distribution aspect of the design willburner will never shut off (burner output too little).
be worked through. For FHW, he will determine pipe8. The installing contractor selected a boiler with a
sizing and type, circulator (the 'pump' that moves hottemperature limit control that maintains temperature in
water from the boiler to the terminal units)the boiler that is too great for the application. The
performance characteristics, flow control devices andinstaller incorrectly set the temperature limits in the
terminal unit type(s) and sizes.aquastat (boiler) or fan and limit control (furnace). Too
6. The designer will then choose the control systemsmuch fuel and electricity will be consumed as a result.
based on number of zones, energy-savings and9. The wrong flow capacity circulators were selected
safety and code requirements.and installed in the forced hot water system. Not
7. The fuel storage type and capacity will be selected.enough heat is transferred to the space (the burner will
8. A total cost estimate will be generated and ashort cycle) or electric consumption will be too great.
proposal listing all of the major components will be10. The burner - gas or oil - metering device (orifices
drafted and submitted.with gas; nozzle with oil) was incorrectly selected,
This is a basic list of steps. In reality, there are so manywhich usually means the wrong boiler/furnace or
details to creating a competent design and estimateburner was incorrectly selected and installed. Almost
that delineating all of them goes beyond the scope ofalways, the manufacturer of the heating equipment
this article. The most important point is that the heatcharges their engineering department with the task of
loss calculation must be competently performedResearch and Development to determine what nozzle
before any other design step can be taken. The otherof orifice(s) are correct and set up the burners to
important thing is that the proper equipment beinclude the correct ones with their burner/boiler or
selected that answers to the heat loss calculation. Iffurnace. Nevertheless, incompetence can get in the
the equipment heating capacity is guessed at, then theway and that is often messed up in the field.
system will most likely be over-sized...for the life of the11. The installer did not set the correct metering rate for
system. Next is as important - the efficiency of thethe requisite gas input rate for the burner. This means
equipment is crucial to future fuel consumption and athat he did not adjust the "manifold pressure" for the
true professional HVAC system designer will promotegas after the gas valve on the gas burner. With
the highest efficiency available. Spending a fewtoday's high efficiency, multi-stage firing burners, this is
hundred dollars initially is always more advantageousa very technical set up feature that absolutely must be
financially than forever burning more fuel due to poordone. In certain cases, a gas explosion can result if the
efficiency. Consider higher efficiency equipment as anmanifold pressure in each firing stage is not set
investment in future fuel savings.correctly. This must always be done in the field after
If any of the steps outlined above are skipped, thencomplete system installation.
greater operating and service costs will result. Some12. The installer did not follow the manufacturer's
HVAC subs do not design the systems they install,installation and/or service instructions to the letter. Too
their equipment/parts suppliers do the calculations formuch fuel or electricity will be consumed, too much or
him and he automatically believes they did thetoo little heat will be generated, and/or a safety issue
calculations right. Often a lot of rounding up gets donewill result.
in the HVAC design world, as nobody wants to be left13. Water through pipes and/or air through ducts was
holding the bag if too small a system is installed, thennot properly balanced, causing heating imbalance in the
doesn't sufficiently heat the house on the coldest daysconditioned space and excessive electrical
of the year. And that rounding can account for 25% ofconsumption by circulators and blowers.The bottom
the system capacity - it will be too over-sized andline is if the designer did not properly design the
cost the building owner more money to heat.system, then:
I can't express enough how many HVAC systems are
incorrectly sized and designed. I see them every week1. Too much electricity and/or fuel will be consumed.
I am out in the field. It is more normal for systems to2. The system will most likely never work correctly.
be designed incorrectly than to be designed correctly.3. The system can become a danger to people and
Yes, I repeat: most heating systems are designedproperty.
incorrectly and burn too much fuel!4. Consequential damage costs can result.
While plumbers and HVAC companies are often5. Civil litigation costs can be expected.
incompetently designing and installing heating systems,6. The installed cost of the system will not be
fuel companies are more often intentionally designingaccurately represented.
systems to burn the greatest amount of fuel their7. The environment will suffer.
systems can get away with. Again, not all fuel8. The building owner will pay with his money, time and
companies are doing this, only the unethical ones are.frustration level.The bottom line is if the installer did not
Still, there is a great amount of ignorance in heatingproperly install the system, then:
system design. HVAC sales engineers (like myself -
see my resume at my website) are few and far1. Too much electricity and/or fuel will be consumed.
between. Companies will pay great money to acquire2. The system will most likely never work correctly.
a competent sales engineer. Conversely, HVAC3. The system can become a danger to people and
companies aren't looking for them because they knowproperty.
it is a futile search.4. Consequential damage costs can result.
Residential building owners are the most taken5. Civil litigation costs can be expected.
advantage of by companies through deliberate and6. The installed cost of the system will not be
unintended shoddy heating system design, installationaccurately represented.
and service. This is true because homeowners do not7. The environment will suffer.
have the desire to learn about their heating system,8. The building owner will pay with his money, time and
nor the time to get over the learning curve. Therefore,frustration level.The bottom line is if the service
they do not know the right questions to ask of a GC,technician did not properly service the system, then:
HVAC or fuel company. They often are meticulous in
scheduling the annual cleaning/inspection of their1. Too much electricity and/or fuel will be consumed.
heating system, yet lack the important knowledge to2. The system will not work correctly until a technician
determine if the cleaning was done right. They willwho knows what he is doing fixes the problem(s).
never know if the system was designed and installed3. The system can become a danger to people and
right and if the technicians who have worked on itproperty.
through the years knew what they were doing. Any4. Consequential damage costs can result.
incompetence along the lifespan of the system, from5. Civil litigation costs can be expected.
design to the last service call before the system is6. The service cost of the system will not be
replaced, will cost the homeowner more money.accurately represented and will always end up costing
Mostly, homeowners are oblivious to the extent theymore.
are being ripped off!7. The environment will suffer.
Here's a rip-off scenario of a different kind. People8. The building owner will pay with his money, time and
think they have to spend $30,000 to save a grand afrustration level.The bottom, bottom line is any of the
year in fuel cost! They are lead to believe this routinelyabove bottom lines can be combined and the result will
by energy auditing "professionals". In a blog post tobe a veritable nightmare for the building owner. I see
come I will explain how "energy auditing" firms arethe outcome on a regular basis and this is why people
duping their clients into believing they need some kindhire me - to fix these screw-ups. At least 90% of my
of sophisticated analysis to determine how their clientwork is generated from the screw-ups of other
can save money on fuel, and that they need high techHVAC designers, installers and service technicians.
HVAC equipment to save money on energy costs.This is not to say that we don't all make mistakes. We
This is a huge scam, considering the energy auditor willdo, I do. Some who make mistakes offer no solutions
charge tens of thousands of dollars to evaluate theiror apologies for their mistakes. I do.
building before any energy efficiency measures areSo what can you do when you suspect that someone
carried out. They fly under the flag of the monetaryhas made mistakes with the design, installation or
incentives for the building owner provided for in theservice of your heating system, or any HVACR
The American Recovery and Reinvestment Act ofsystem in general? Contact me. This is why I offer
2009 - The "Economic Stimulus Package".design, installation, service, consulting and expert
Recently, I was contacted (through a referring partywitness services in the Heating, Ventilation, Air
who worked for the New Hampshire Public UtilitiesConditioning, Ventilation, Refrigeration, Humidity Control,
Commission) by a woman who had been aExhaust and other aspects of the "HVAC" realm.
policymaker with the same state agency for 20 years.There's a huge market for it.
She inquired about converting 3 heating systems in 2Here's what you need to do to prevent the mistakes
apartment buildings to higher efficiency gas-firedfrom being made in the first place:
boilers, so she could do her part in reducing her carbon
footprint and qualify for benefits under the U.S.1. Research your prospective HVAC installing
"Stimulus Package". I told her the ramifications ofcontractor's background - ask for references, his
changing her chimney-vented boilers to direct-ventedtraining history, employment history, his website, his
types would be a costly endeavor, approachingspecialization(s), if any.
$10,000 apiece. I also told her that I could make her2. Ask your installing contractor, or general contractor,
cast iron mid-efficiency FHW boilers burn as much aswho is responsible for the design of your system. If
15-30% less gas. Of course, she was all ears. Shethey say their parts supplier, tell them you are not
hired me for a couple of grand to install temperatureinterested. You must hire an installer who does his own
modulation controls on the 3 boilers and make a fewdesigns. That way, if things go wrong he is solely
other modifications. The end result means she willresponsible for the system shortcomings. In the worst
spend about the same on fuel as the new technologycase scenario, you do not want to have to sue multiple
high efficiency boilers would require, and she got thesecompanies/individuals, or your legal bills will preclude
modifications for about $28,000 less!your success.
Commercial building owners are generally more3. Make sure you get a copy of the heat loss
required by job description to know important thingscalculations...in their entirety! If they can't offer you a
like, the benefits of heat loss calculations, propercopy (this means they have not done the calculations
equipment output capacity and the steps required ofin Wrightsoft, Elite, or an equipment manufacturer's
technicians doing maintenance. This is not to say thatproprietary software), then fire them before you hire
commercial building owners are not somewhat in thethem!
dark, too. Not all commercial buildings are managed by4. Ask your installing contractor to see his portfolio of
people who are wise to HVAC technologies and thepast installations and the names and contact
tricks-of-the-trade, shall we say. Nevertheless,information of his customers with those systems. If he
commercial systems naturally consume greatercan't provide that information, then move on to the
amounts of fuel - the space to be heated is biggernext installer who can.
than homes - and when they burn inefficiently the5. Ensure that you speak directly with the installing
wasted fuel is also greater than that wasted incontractor. If your general contractor/builder does not
residential applications. Therefore, it is more imperativeallow this...fire him before you hire him!
for commercial building owners to make sure they are6. When you speak directly with the prospective
getting the correct answers from their HVACinstalling HVAC contractor, make sure you discuss the
professionals.type of fuel you intend to burn; the type of venting
Like the fox that guards the hen house, your fuelmethod you will be using (masonry chimney, high
company is not unlike the fox. The more fuel yourtemperature metal chimney; sidewall/direct-vent, or
heating system uses, the more money you pay your"ventless") and the efficiency range (mid-efficiency or
fuel supplier. It's logical then to believe that the greatesthigh-efficiency) of the equipment that you desire. Also,
amount of fuel they can sell you is what theydo some research on heating system types, product
endeavor to sell you. Like the fox scheming to eat thetypes, brand names, furnace and boiler material
hens, fuel companies can and do design and serviceconstruction types (cast iron, steel or cast aluminum)
heating systems in ways that demand the burnerand the approximate costs for each versus what your
burns more fuel than is otherwise necessary to heatreturn on investment (ROI) will be for each.
your building. All they have to do is skip the heat loss7. Pick your installing contractor's brain for his reasons
calculation and pick an inefficient, oversizedfor selecting the types and brands of the equipment
American-made boiler and sell it to you. You trust themand materials who chooses to install. If his reasons
and are confident that the new boiler will heat yourdon't sound quite right, then there is a red flag. Get
house reliably. You hope you will save money on fuel,other installer's opinions and recommendations and go
but at least it won't break down soon. Unfortunately,with your gut feeling.
the fuel company salesman didn't tell you the new8. Tell your general contractor/builder that you want
boiler is a single-pass flue design and has a grossseveral alternate HVAC installer quotes...then go with
stack temperature of 450 degrees. He also didn't tellyour gut feeling on which one to select for your
you that you could have bought a European boiler withproject.
a triple-pass heat exchanger and resulting 300 degree9. Educate yourself as much as you can with all that
gross stack temperature. He also didn't offer to sellyou can stand to know about heating systems. "An
you a temperature modulation control and anEducated Consumer is Our Best Customer!" You've
indirect-fired water heater. Instead, you got a boilerheard that slogan before. Be that educated consumer.
with a "tankless" coil (for domestic hot water) that10. Never buy a system because it was the low bid!
requires the boiler maintain constant temperature 24/7You virtually always get what you pay for. "Pay Now
all year long. All the while, heat constantly escapes upor Pay Later!" You've heard those cliché's as well.
the chimney into the atmosphere.11. Let me design your heating/HVACR system(s).
What if you are considering the purchase of a building?Then you will know you covered all the important
You walk-through the building and make note of asbases. I will provide you with a heat loss analysis, Bill Of
much detail as you are able to in a limited number ofMaterials (estimate for every single part that your
walk-throughs. You calculate the cost of things likesystem(s) will be comprised of, down to the last screw
paint, landscaping, obvious mechanical systems repairsand wire nut), Proposal with all the essential information
and the like, but you most likely know very little aboutand legalese, in an understandable presentation, and
heating technology, but do you know how fuel efficient,any and all product specifications that comprise your
or inefficient the heating system is? You can ask whatsystem.
the past fuel costs have been, but without knowing12. If you don't hire me for your designs, estimates or
what the infiltration rate of the building is and howproposals, then let me review those of your installing
many BTUs are required to heat the building on thecontractor so I can pinpoint any shortcomings.
coldest day of the year, then you will not be able to13. If you live in my area of business, then consider me
make any educated conclusions about the heatingfor the system installation and service.
system's efficiency and effectiveness. Therefore, you14. If you hire someone else, then let me inspect his
will not be able to accurately predict the cost to heatwork...before you make the final payment to him! That
the building. If you buy the building you will find out in theway you will have leverage if he did something that is
first year what the heating system consumes in fuel,wrong and the system won't perform as intended. He
assuming the weather is typical winter weather.will come back to fix a problem if he knows he will get
Here are the mechanical reasons behind high fuel andpaid when the problem is fixed.
electricity cost:15. Make sure that the installed system is inspected by
the local Municipal mechanical inspector and/or the Fire
1. No one did a heat loss calculation before the heatingChief. But don't rely too heavily on the "rubber stamp
system was installed and they guessed at the BTUof approval" from the inspector, as a good majority of
capacity of the heating appliance (boiler or furnace)inspectors have no idea what they are even looking at.
and/or the radiation (baseboard or duct and diffusers16. Check with your state's Public Utilities Commission
sizes) capacity was undersized. A boiler/furnace thatto see if they prescribe and enforce energy efficiency
is too big, as discussed, will short cycle and consumemeasures and codes. You will be surprised how many
too much fuel like city driving. A boiler or furnace that isinstallers do not know of or follow these prescribed
too small will not adequately heat the building, thecodes and measures, or if they even exist.I could tell
conditioned space will not reach the desiredyou volumes more about HVAC systems efficiency
temperature so the thermostat will never be satisfiedand safety, but that will have to be seen in past and
and the boiler/furnace will never shut off - and burnfuture Blog postings. In the meantime, good luck and be
too much fuel.educated!
2. The boiler or furnace was installed incorrectly. The