Oil heat cost reductions?
Hi, we have just purchased a new to me house in Hartford CT. The house is 5100 sf built in 1998, with a Weil-Mclain Ultra **** oil fired boiler and 2 air conditioners. The system runs on glycol with a 75 gallon indirect hot water tank, there are two zones on the first floor, (front and back) and two zones upstairs. The main upstairs portion of the house is one zone with a 600 sf bonus room over the garage having its own zone. The system appears to be set all the time at 180F.
In a week in February with the heat set at 58F, we used 100 ga. of oil. Unfortunately there is no natural gas in the area.
We basically inherited this house and are really worried about the energy costs. We asked some contractors to come out and see what we could do to save energy. One of the contractors seemed to have some great ideas, when I received the proposal I was surprised at the cost with vague potential savings.
1. He said our biggest savings would be from a networked energy management system that would keep the zones from independently asking for heat. Some how all of the zones know what they are asking for and keep the system from short cycling. I think this needed 4 new Honeywell HD thermostats and some sort of Honeywell energy management system. The thermostats, 2 new zone controls, and the management system was $5k. I can't find any information on a system like this from honeywell and how much money I could save. He also mentioned outdoor reset with this.
2. Install new heat manager, Beckett maybe? Beckett claims 10-20% savings at a cost of $750
3. Install new heat manager aquastat? $1100 I am not sure what this actually does better than my current aquastat
I would love any guidance or information someone could provide. I was wondering even if I could get a brand new boiler that would save more money, or install a couple of propane fired instant hot water heaters instead of the gigantic tank and turn the boiler off during the summer.
Re: Oil heat cost reductions?
Unfortunately, I don't really like any of the 3 suggestions listed, made by heating equipment dealers who seem to be anxious to sell you products & really don't care if they work or not---I hope at least one of them had the decency to mention that the essential problem is that 1) you simply have a fairly large house with a lot of square footage of 5100 sq.ft.; 2) you live in section of the U.S. that has very cold winters; 3) your indirect hwh is TWICE the size of a standard indirect which holds 30 gal or 40 gal---it takes burning a lot of fuel oil to keep 75 gal of water in the indirect hot---even a good size family could easily get by with a 30 or 40 gal indirect; I hope at least one of the dealers also had the decency to ask you some of the questions below about your house, the heat output of the boiler, offered to do a professional computerized HEAT LOSS CALCULATION to determine how much heat (BTUs/hour) the house needs to keep it warm.
You would have to give us more info as to the a) heating capacity of the Weil-McLain boiler; this would be on a small faceplate on the front of the boiler, and is usually listed as an IBR or DOE number on the number of btu heating units it puts out in an hour, such as "178,000 btu/hr", or "204,000 btu/hr."; b) if you don't have the WM installation manual, try to google "Weil-McLain Ultra G0ld boiler installation manual" to see if you can get the recommended or standard NOZZLE SIZE ----you may have a nozzle in the boiler that is putting out 3-4 gallons of oil per hour, where smaller homes or heavily insulated homes have a nozzle that puts out less than 1 gal per hour; c) do you know if the exterior walls of the building have blown in insulation, or have insulation that was installed at the time of construction; does the house have double-pane windows; do you happen to be in an exposed area where you get a lot of wind, such as the bank of a river, on a hill with no other surrounding houses or buildings, etc.; d) does the house have a LOT OF GLASS (lots of windows), & are they single or double pane; e) what is the total # of people that occupy the house; f) total # of rooms; g) can any of them be closed off in winter months.
Estimating heat loss calculation (how many BTUs/hour a house needs to keep it warm):
It should be noted that the following is not the accepted way of doing what's known as a HEAT LOSS CALCULATION to get an accurate picture of how much heat has to be produced to heat the house, and how much heat per hour is "bleeding" thru the walls & windows every hour so that the boiler has to come on again to replace the lost heat that the insulation and the windows didn't stop; ---it's a basic, rudimentary calculation used in heating situations to take the total square footage of the house and allow 35 or 40 btu/hr to heat 1 sq.ft. of the house---these arbitrary numbers can go up to 45, 50 or 55, depending on the exterior wall insulation, # of windows, location, etc.; thus, 5100 sq.ft. X 35 or 40 = approx 178,000 to 204,000 btu/hr to heat the home---no matter how you skin it, that's a lot of fuel oil burning on a weekly or monthly, or yearly basis; a smaller home, perhaps 1/3 the size of yours, rated at 1700 sq.ft. X 35 or 40 btu/hr = 60,000 to 68,000 btu/hr, uses a 3/4 gph nozzle, has a 40 gal indirect, has excellent insulation & double pane windows, burns approx 500 to 600 gallons/year.
Please post back with the info requested---you can't reduce the physical size of the building, but you may not need to keep all those rooms open during heating season, you may be able to switch to a 30 or 40 gal indirect HWH; you may be able to blow in additional insulation to the exterior walls of the house; if you don't have double pane windows, add them--this would reduce your heating bills, as well as your cooling bills considerably; you then may be able to DOWNRATE the size of the boiler fuel nozzle so that it puts out approx 1 gph or even 3/4 gal per hour, & still keep the house warm.
The fact that you have many zones (zone valves?) is an excellent advantage; add more if you can, or close off the rooms completely; the ZV allows you to turn down the heat in the room when the room is not being used; also the Weil-Mclain Ultra G0ld is an excellent boiler; I believe these are rated as CONDENSING boilers (unusual for an oil-fired unit) and ordinarily operate at approx 120-130 degrees to take advantage of the "condensing" aspect that produces additional heat, which would be overridden at 180 degrees (standard boiler temp operation); but the "condensing mode" may not be producing the heat output the building needs for a comfortable environment.
Last edited by Pelton; 02-10-2013 at 10:39 PM.