Boiler Room Insulation

LukeS

We have a Bingham Hydraulics Model V8H boiler used for radiant heat and domestic hot water.



The oil bill is manageable in the spring/summer/fall months but in the colder months it is outrageous. We have tried to manage the use of hot water to lower the bill and it has no effect on oil usage.



The problem is that the water is heated and held in reserve, when the water temp cools the boiler kicks on and heats it back up. When its cold outside, it does this process almost continuously, costing a fortune.



I am interested in insulating the boiler room to prevent the loss of heat.



The room is an adjacent room accessible from our covered carport. The walls seem to be sufficiently insulated, but the door is one of the lightweight wood doors, with a 8"x8" vented opening.



I know that the room needs to be ventilated. Should I install a heavier, more insulated door. And also, is the vented opening necessary? What about a ventilation system that only introduces fresh air periodically?

CMadatMe

Insulate

You can insulate the boiler room and the whole house to your hearts content but its fruitless. If anything you will burn more oil. Your problem is two fold. Short cycling due to an oversized boiler and the non use of outdoor reset.

The right fix would be, heat loss calculation, set up the boiler with the proper nozzle, heat manager on the burn, pri/sec or LLH and then reset the radiant side via a Taco RMB, I-Valve and something that you can provide you outdoor reset.

Approach this way and you would see savings.

Brad White

Thermal Storage

Chris is right, the boiler room is not your heat sink. If you are storing in a tank, insulate that.  Decoupling the boiler stream from the distribution stream with P/S, outdoor reset and stingy metering of prime hot water to the distribution side is good practice. Just as Chris said.



Your boiler room is still way below your water temperature, it is not a means of buffering your load. Insulate any tanks, piping, etc. to manage your parasitic BTU losses.



Combustion air is necessary. That said, an automated system such as Fan in a Can or Tjernlund can make a lot of sense. These are interlocked so that if you do not have airflow (via a pressure switch), your combustion is locked out. Between firings, there is much less infiltration to the space.

icesailor

Radiant heat/insulation:

I think you are seeing the heat loss of the radiant. Or should I saw, heat gain into the conditioned space.

What is the "radiant, floor or ceiling. What is the insulation above or below it? Some radiant floors have been installed with no insulation under the radiation, so you just heat the earth. Sometimes, the loops are too long and the water never gets back hot. The heat loss, fuel use isn't from the boiler sitting in a cool place, it is the radiation giving up heat to a cold space that isn't insulated properly.

It sounds to me like the system is doing what it was designed to do. That someone didn't do their homework and left a glitch in it. If it is reasonable to use when making domestic hot water, and not when you try to heat, something is wrong. Domestic hot water heating us usually far greater in load than the heating load.

Tell more about this heating part of the system.

LukeS

Other Information

First of all, thank you for the responses. I'm learning alot today. I guess you should know that I like fixing my own car when I can, but I am not interested in fixing my landlord's boiler...unless it saves me oil money. Also, I don't know crap about boiler operations technically speaking. I can only tell you what I know.



The boiler supplies hot water for domestic use and hot water for radiant heat. The house has baseboard radiators in each room (2 BR, 2 small BA, 2 medium Living rooms, kitchen and utility room. The radiators seem to be situated around the perimeter of the house for the most part. (at the baseboards of the outer-most walls)



I don't know if the water circulates the entire radiator network in one loop or more. Last year our landlord had the new boiler installed when we told him that the radiators on one side of the house were heating and the ones on the back of the house were not heating. Maybe that can be a clue to you guys about how the system works.



We have put up with cold temps in our house in attempt to minimize oil use during the winter. We leave the thermostat on the lowest setting when we arent home (55 F) and when we are home we leave the thermostat set at a range of 60-65 F.



I am assuming that our domestic HW use is more or less the same from month-to-month, regardless of outdoor temp. (Dishwashing, showers, laundry are the only uses of domestic HW.) And we have really tried hard to minimize the hot water use for radiant heat by keeping the house temp as low as we can stand it in the cold months (55-65F).



You can hear the radiators when they are warming up. And you can hear the boiler when it fires. I assumed that, since the boiler cycles way more during the winter than the summer it was due to outdoor temp, and insulating the boiler room may help. What drives me crazy is when I hear the boiler fire, while we aren't using domestic HW and the radiators arent heating up. My thinking is that the boiler is just heating the water reserve to the temp setting. If we aren't using domestic HW or the heat, then what other reasons would the boiler need to fire so frequently during the winter if not because the water reserve/tank got too cold. (I just heard the boiler fire as I'm typing this...not using domestic HW or the heat today.)



We live in the mountains of NC and it gets very cold here, last year we went over two weeks with the temp not going above 10 degrees. Does that justify a nearly 4 times higher oil bill than the summer months? $120-$450.



HVHEHCCA "The right fix would be, heat loss calculation, set up the boiler with

the proper nozzle, heat manager on the burn, pri/sec or LLH and then

reset the radiant side via a Taco RMB, I-Valve and something that you

can provide you outdoor reset."



I have no clue what any of that means, except outdoor reset was easy enough to understand. What kind of cost am I looking at to have these fixes? And now I want a taco.

CMadatMe

Boiler Has a Coil

That boiler has a tankless coil in it. That my friend is the death warrant and the cause of the high oil costs. Boiler is maintaining temp all day long no matter if the heat calls or you turn on the hot water tap,



Here is the solution...Start with a heat loss of the home. The boiler most likely will need to be downfired (different nozzle). Get rid of the coil and add an indirect hot water heater, add a heat manager to the burner, pipe the boiler pri/sec or LLH, add some type of outdoor reset control for the radiant system. Pray your landlord or you our willing to spend a considerable amount of money to do this. If not, continue to pay a big oil bill.

Ironman

Need more info

It sounds like you have a boiler with a tank-less coil to heat your domestic. With this setup, you will have a cold line going to the coil in the boiler where the water is heated and then a hot line out of the coil to your fixtures. If you have this setup, the boiler control must keep the water in the boiler @ 180deg. constantly to heat the coil any time domestic water is drawn thru it. The down side of this set up is that there is a great amount of standby loss up the chimney from the boiler being hot constantly. This is would be why you're hearing the boiler fire with no apparent demand on it.



A much better setup is to have an indirect tank which has its own loop from the boiler and only heats when the aquastat on the tank calls for heat. With this setup, the boiler only fires when there is call from a heating zone or the tank. It then becomes a "cold start" boiler. You would have to have some control changes in addition to the indirect. Outdoor reset is also a big energy saver as Chris said.

Ironman

No redundancy intended

Sorry Chris,

I was typing my post before yours had gone up. Didn't see yours until after mine had posted.

CMadatMe

No Apology

No need to apologize. If I was a tenant of this house I would be looking for a new one. There is no way the landlord invests enough money to make the fuels cost reasonable and affordable..Def woulnd't be investing my hard earned money into someone elses problem.

icesailor

Boilers:

You can do everything you want to do at a fraction of the price by installing a hot water storage tank on the tankless. You do not need to repipe the heat system or add expensive controls. You can downfire the boiler to whatever amounts turn out to be technilally feasable, and will save tons of money. Because the boiler already has a tankless, you don't even need to install any other controls. The storage tank uses the bottom thermostat to operate the bronze circulator that pumps domestic water through the domestic coil.

What is more efficient as a heat transfer device? A boiler, designed to convert vast amounts of heat energy to water through a tankless (made of copper tube)coil? Or a stainless steel or copper coil stuck inside a water tank to transfer the heat energy to the potable water in the tank.

If I was approached to look at this job, and the person writing about this was going to foot the bill for the work, I would suggest doing the storage tank thing. You can play with all the other problems with this system. Or should I say, "I" would try to figure out what other problems this mess has.

Ironman

AGREED

I almost wonder why contractors keep installing tank-less boilers other than it's a cheaper way to replace.

CMadatMe

Expensive Controls

Please define expensive controls. If my control could save 20 percent is it expensive or an investment? If I can repipe my system to ease short cycling which could add another 5 to 10 percent savings and help the wear and tear of the boiler is that worth more to me or the fraction of not having to do it? The one thing I did not read in your post to substantiate your thoughts was the need to do a heat loss. I believe that was the first thing I said needed to be done. Without it none of the above could even be possible.

Let's go with your thought. So I have a 100,000 btu boiler with a heating load of 45,000 btu's. What is the recovery of that tank on 55,000 btu's? Get rid of the coile and add my expensive control allowing me to give all 100,000 btu's to the tank what is my recovery? Which is more efficient?

Ironman

Icesailor ,Please Explain...

How will this stop the amount of standby loss from the boiler being 180deg. constantly?

LukeS

Tankless Coil

Thank you so much guys. For three years we lived here and I have tried hard to figure out how this heater works. You guys are right. This boiler is equipped with a tankless coil.



I still don't understand why my oil bill increases so drastically during the winter. If anything shouldn't the oil usage be abnormally high in the summer and rather consistent through the winter?



Am I wrong to think that with a tankless coil there is no benefit to keeping your house's thermostat set really low. Since the boiler is going to be running anyway, shouldn't we at least use it to get some hot water flowing through the radiators?



The landlord might buy an indirect water heater, if he doesn't have one already. He's pretty cool about that stuff. Not to mention the thing would pay for itself within 4-5 year i would imagine (maybe less). I will talk to him on Monday and see what he says.



It looks like the indirect water heaters cost $1000-$2000 new. Would the installation be expensive or cheap (relative to the cost of the heater)?



Finally, what does "heat loss your home" mean? I'm guessing it helps you pick the right size water heater?

Bob Bona_4

that method's

performance would depend on the condition of the tankless coil. Not to mention the boiler having to maintain anyway.

Not liking it.

Bob Bona_4

oil use

goes up in the winter b/c when the boiler runs for heat, the aquastat let's it run up to it's high limit, vs summer use when the boiler maintains a minimum temp.

So, the answer to your second question is that keeping the stat low just helps save some fuel, but the boiler will still maintain a minimum to keep the hot domestic water ready.

Adding the indirect will turn a boiler that used to maintain temp 24/7/365 into an "on demand" unit, providing it was installed and wired correctly.

Might want to add a grand to those numbers for a ballpark installed cost.

Heat loss calcs tells you how much heat the stucture loses over a given amount of time (BTU per hour). This creates the blueprint for getting a boiler sized to meet that heat loss. Sometimes the heat loss turns out to be greater than the indirect's required input BTU, other times the indirect's input is greater- depends on the hot water needs, and the structures heat loss. Either way, we prioritize the indirect's needs so that when the boiler is sized, it's usually sized for the greater need. One does not want to add the heat loss BTU and the indirect's required BTU together..the boiler would be grossly oversized. 



The indirect is sized based on the hot water demands of the house,the fixture flow rates, occupant habits and lifestyles.

LarryC

How about turning the indirect setpoint down to 140 degrees?

Disclaimer:  I am a homeowner not a heating professional.

 

Wouldn't the most immediate savings action would be to turn down the on set point of the indirect down to 140 degrees?  Warm enough to prevent Legionnaire's bacteria growing, but 40 degrees cooler to reduce the standby losses.  I understand that the setting of correct aquastat dial may not be 140.  You have to use the differential value too in order to get to the correct values.

 

Insulating the Hot water lines near the boiler will also reduce the standby losses.  I would also look for HW leaks to see if something is sucking the hot water out of the boiler.  Is there a recirc pump in the HW system?  That could be pulling hot water out of the coil and triggering the boiler.

Good Luck.

icesailor

Energy savings/Tankless:

Most likely, I am the old fart here.

I've been doing heat loss calculations when I found out that my supplier used "The (insulated) wall rule. Cover 1/2 the outside walls if fully insulated, 3/4 if partially insulated and the whole wall if it isn't insulated.

I do a heat loss calculartion on every job I look at to "fix" and I do all my own heat loss and piping designs. I've never had a problem. I don't think you understand the genus of the "Indirect". When oil was king (along with coal and gas) and gravity was the piping dujour, you needed a seperate water heater for domestic potable hot water. Someone making oil hot water boilers figured out that you could add an indirect coil (tankless) to a boiler and save the space of the water heater tank. Small residential oil boilers evolved with tankless heaters. Studies done by IBR and the Hydronics Institute showed very little excessive costs from running HW boilers at high temps. I don't agree but that is another story. Gas hydronic boilers developed without tankless coils and water heaters were needed. They worked as ravity boilers/systems. Thermostat on, gas valve on. Thermoatat off, etc. When the gas suppliers agressively went after the oil market, they needed a way to heat water to compete. So, guess what, they moved the tankless coil into THE WATER HEATER and called it an indirect! Now, instead of being controlled by the stand alone boiler controls, it had to be piped as a heating zone and controlled as such with pumps. Expensive install.

I installed "HW "Booster Tanks" when I was employed. They were complicated to pipe and there seemed to be no agreed upon piping method. And they didn't work as advertised.  When I went in business, I tried something new. A different piping method of piping the tankless to the heater tank. Like a "side-arm" heater. Full flow and pressure through the tank, restrictions through the coil.  The net price to me for a stand alone "aqua booster" was what I could sell a electric hot water heater of a bigger size. The Aqua boosters were just gas water heater tanks. And they use the control taping for the hot water ging back in. I use electrics. I return the water (heated) back to the tank through the dip tube  which puts it back to the lower portion of the tank. I suck out of the bottom.

So, here's a practicle business example for you/us.

Twin brothers live side by side on a street with identical houses. They both have W/M WTGO oil boilers with tankless heaters. They both call you and I to solve their problems of running out of hot water. You recommend your way and give them a price. I do mine. I tell them that they can do all this stuff with a indirect heater, circulator, relay, valves etc. and all controls and the cost of install and wiring. Or, mine. A 40 or 50 gallon electric water heater, being the cheapest insulated tank you can buy, prewired with thermostats etc. It isn't hooked up electrically to heat water through the elements. I will pipe it up like a water heater, 3/4" in and out. Take out the drain and replace it with a 6" brass nipple with an offset and install a Taco 006BT bronze threaded circulator, pumping out of the bottom, through the tankless and into the top of the heater through the cold inlet. I pipe it 1/2" tube with a check valve to control circulation. The only electrical connection is a cord whip connecting the 006BT to 110 volt power and use the bottom thermostat as a switch leg to turn the pump on and off. When I am done, I can hook it up with an extension cord. Until they can get a electrician to clean it up.

I will set the high limit to 160 or whatever I need because the only time this is needed is on the coldest day in the winter. I know that this house only needs 60,000 BTU max on the worst heating day. I set the operating (low limit circulator) control to 140' and eliminate the killer of all boilers, condensation. When the returning water drops below the differential, the pump stops until caught up. There is no physical electrical connection between the water heater storage tank and the boiler.

My sell cost will be half of yours and the brothers will not go with you. If one does, and one goes with me, there will be no difference in operating costs. When you factor in the install costs, mine will be cheaper. I will get the job. You won't. At least that is my experience. There is a number that people will be willing to spend on a "minor" job. This may fall into the amount. The cost of doing what you suggest may fallout of the range and they would not do it. They would just live with it. If you are not a licensed plumber, you shouldn't do this job.

I fear that you are a "Heater". I am a "Plumber" and a "Heater". Domestic hot water is a plumbing issue. A WTGO is oversized for the heating but undersized for domestic hot water heating. If you drive a car at 55 MPH, you get the best gas milage. It you drive it 75 MPH, the gas milage drops off. It takes longer to get there at 55 MPH but you get there just the same. Dropping the operating tempreture of a boiler will increase the efficiency. Condensing flue gasses in an oil boiler will dirty it up and will negate any savings you make by going cold start.

I've got to go. I'll be back later.

jk2

plumber

how to install radiant heat in boiler room

SWEI

Good question

but we need more information.  Start a new thread with an appropriate title and you'll get more eyeballs on it.