Watermaker or Separate Oil Burner??
I am replacing a low volume high efficiency boiler (Energy Kinetics). We have never had good luck with it, and it has cost a fortune in repairs. It had an indirect hot water maker – which is the one thing that we were happy with.
We are getting a Peerless 5 section boiler. Since it heats quite a bit of water, and is not as well insulated as the EK2, I am concerned about all that heat. This will work well in the winter – allowing us to draw on quite alot of stored heat to bring the house up to temperature. But in the summer, I have a hard time imagining all of that heat ratiating into our basement – just to heat hot water. Would you have a separate oil-fired hot water heater? Or just continue with the indirect water heater? We also have to consider the expense of a 2-burner maintenance contract.
Thoughts?
Replies
Depending on electrical rates in Conn, an electric DHW tank at 95% efficient may be the off season choice. Using an indirect tank with the new boiler may only be 30-40% efficient and using an immersion coil will be 20-25% efficient.
You might need 40 or 50 thousand btu's for domestic hot water, you may need 200 thousand or more for heat, why run the boiler when you don't need heat? Do the math. What I would do is have a separate water heater tied into the boiler with by-pass valves that would let you use the water heater only during the non-heat season, during the heat season it would be basically a storage tank. I think that cost wise this is the best hook-up. Lots of luck.
Thanks everyone for your feedback. Of everything I have heard, I like the gas fired hot water heater for summer the best. The trouble is that in this part of CT we only have oil, no gas. We are putting in a propane tank for the cooktop. I could get a bigger tank and use propane. Electric is out of the question. We have 4 bathrooms, 2-1/2 baths and a laundry. The bathrooms are on a hot water loop as well (I insulated every pipe in the house).
At this point, I will likely just get a larger propane tank, and wait on the gas hot water heater. We will use the indirect oil heater for a summer and see how it goes. They make nice direct-vent gas waterheaters that would work for the warm months. Any ideas about how big my tank would have to be to heat water by propane for the summer?
Thanks again. Wish us luck with our new low-tech, high-reliability boiler.
You have one other option, a oil fired water heater, check it out. Luck.
Shacko makes an exellent point aswell as Expierenced.
Both would work great as a summertime option
I'll vote with shacko & experienced also.
My BIL had a "summer winter hook-up" for HW, as they are called here. Hated it - cost him too much in the summer.
Went to a gas fired HW heater for summer hot water - his pay back was about 5 years - did not have (or need) a service contract on the HW heater in the 10 years he kept the house after installing the new HW heater.
Jim
Never underestimate the value of a sharp pencil or good light.
About 4 years ago I replace my EK2000 with a burnham 4 section boiler & a 41 gallon boilermate.
I had the Ek2000 for about 12 years and when it was new and tuned up right it would use about 900 gallons a year. Finding qualified peaple to work on the thing is hard, so once it is out of tune it used a lot more oil than that.
The burnham has been in for a few years, it has a beckett burner& standard controls- anyone can work on it. It uses about 950 gallons a year.
I bet your peerles (like my burnham)set up won't be much less efficient than the EK2000.
My sympathies go out to you. I took a picture of the EK2 boiler being pulled out this morning. We probably saved $500 a year in oil and spent $700 a year repairing our burner. It never burned for more than 6 months without a breakdown. We put a lot of money into making our house more energy efficient (including foam insulation). I can deal with a slightly less efficient boiler.
Thanks for your feedback.
At my house we got rid of an 80 gallon electric hot water heater and a 40 gallon gas heater and put in a tankless gas water heater. It put out 3.2 gallon of 140 degree water and you only use the gas when you turn on the water, a big savings on the gas bill.We used the heater for about 3 without any problems. We then wanted to save on heating and I installed a large coal burning stove. We needed the chimney for the stove so we took out the gas hot water heater and put in an 80amp tankless electric heater which does not need venting. The idea of heating water all day, all year is crazy compared to the tankless heaters. You could take a 12 hour shower with these units and not run out of water. The gas heater costs about 300 at HD and the electric cost 400 on line. It took me about 1 to 2 hours to install the units and 1 hour for the electrician.
First, I would wonder why you have such a large boiler. Generally I find boilers need more output for DHW than they do for heating... but I don't know the details of the house you have.
Given that a boiler is properly sized, an indirect tank is usually a better choice than a standalone water heater. Those standalone heater efficiencies are not very good at all. Generally we would recommend sizing a boiler for the winter heat load, and then sizing a storage tank large enough to provide enough hot water at whatever output the boiler is capable of, rather than upsizing the boiler for DHW. I have no idea what a previous poster is talking about as far as needing 200kBTUs/hr for heating. Personally, I've never once ran across a house except the largest mansions that required such an output. Such a home would be poorly constructed indeed, as that is at least four times an average heat load for an average, modern home. I would say if your loads require such a large boiler, that perhaps you should be looking at your envelope for fuel savings more than anything in your mechanical room.
A seperate tankless WH may be a good choice, however you need to be careful with flow rates. Some of those units are quite limited.
Electric may be "95%" efficient, and you should definitely use that number to compare usage between fuel and electric. But never think electric is more efficient overall.. the transmission losses alone, never mind generation losses, are huge. This is why in most areas, electricity is not a good choice for heating or for hot water. But that inefficiency should be reflected in your rates when you do your comparison, so it is a bit of an academic distinction.
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Quote: "Given that a boiler is properly sized, an indirect tank is usually a better choice than a standalone water heater."
That is true if you have a "low mass" boiler that goes back to ambient temps between calls for heat- either DHW or house. If you have an indirect DHW tank on a regular boiler, you won't get much savings, maybe not enough to reasonably pay for the $1,500 - $2,000 indirect tank installation!
Very good point, experienced. Why would anyone use a high mass boiler these days, anyway :D-------------------------------------
-=Northeast Radiant Technology=-
Radiant Design, Consultation, Parts Supply
http://www.NRTradiant.com
A separate oil fired hot water heater is a definite option. No comments on the propane direct vent water heater. Any thoughts on that? It really appeals to me because I know that maintenance will be almost zero.
Just as an FYI, the house is currently 3,900 sf, and we have another rough framed master bedroom area that is 500 sf. 4,400 sf total when we are done (several years from now). There are 3 hyrdo-air zones now. There will eventually be another hyrdo-air zone to the master.
Ok, so your boiler is probably properly sized, that's good. Now, why a high mass boiler?
If you are doing a replacement, I would personally use a modulating/condensing boiler. With a load your size, the efficiency benefit would be significant even with the high temp demands on the system. And if electricity is not economical for you to heat with, then the modcon would supply domestic more efficiently than any standalone heater by a margin of... oh, about 20% or so.Remember; the larger the load, the more it makes sense to invest in better boilers.-------------------------------------
-=Northeast Radiant Technology=-
Radiant Design, Consultation, Parts Supply
http://www.NRTradiant.com
Well, too late now - the boiler is already installed. Is there even such a thing as a condensing oil boiler? Perhaps when I retire in 20 years, I'll pick the higher tech option. Who knows what we will be heating with then.
Wish someone would comment on the separate propane direct vent water heater.
Thanks
Do you know what your domestic load is?-------------------------------------
-=Northeast Radiant Technology=-
Radiant Design, Consultation, Parts Supply
http://www.NRTradiant.com