Help with choices

Melton

We bought a large farm house built in 1946. The previous owners have left most of the HVAC systems in place but have added new systems along the way. I need to make major modifications to the systems. I am trying to some ideas on the best way to begin.

The house is 8,600 sqft. Insulationhas been added in the attic and windows. There in an old hydronic boiler feeding radiators and baseboard heat for 25% of the space. There is a direct fired double forced air furnace. There is also a heat pump. Duct work is already in place. There is a large, old hot water heater. Everything is oil fired.

I want to stick with oil due to fuel prices. I am thinking about adding a high efficency boiler -- maybe two. I am thining about adding two indirect domestic water heaters. I want to make repairs to the radiator system. I also want to add radiant heat under a large ceramic floored entrance hall and some bathrooms. I am thinking that I could add hhydronic heat exchangers to the existing forced air system. I thought I would keep the oil fired furnace for the few days that get below freezing.

I am looking for a high efficency system. I have thought about running two smaller boilers since most days are mild here in Virginia.

I have looked at a number of boiler manufacturers. They all claim their technilogy is the best. What do yourecommend as a general setup and specific manufacturers?

Any help appreciated.

Mark Wolff

Farmhouse heat

Your approach is right on. You will definitely want to run 2 smaller boilers (more effecient than one large boiler, and with a 2 stage outdoor reset from Tekmar it will run one boiler until load demands the second. Additionally it will switch which boiler runs first every 40 hours of operation to keep both boilers used the same amount). Make sure it has domestic priority override so the boilers will kick up to heat the water, and it will also shut circ pumps off/turn dedicated H2O heater circ pump on until demand is met. Also, remember to set the outdoor reset control to the heaviest load demand you will have, probably the HVAC exchanger.

One zone coming off the boiler manifold can run to a heat exchanger in your forced air cabinet, with a relay control turning the circ pump on for that zone when there is a call for heat from the forced air zones.

I wouldn't waste money on two indirect water heaters, but instead buy one really good one. The Amtrol WH-7 has 41 gallon up through 100 plus gallons. I wouldn't recommend anything over 80 gallons, believe it or not you won't need it. Try to get a recirculation line tied into the domestic hot water supply as far away from the water heater as possible and run a small Taco 003 bronze recirc pump from the farthest point back to the water heater. Pipe it to the cold water supply on the water maker. Remember to install 2 check valves, 1 on the cold water line and 1 on the recirc right by where they tie together. You will need to install an Amtrol Therm-Extrol expansion tank on the domestic hot water supply line and a 1/2" vacuum breaker at the top of the water heater right where the hot supply comes out (per manufacturers instructions).

I would use 2 Burnham V85 Fuel oil boilers. Their efficiency is 86.1% (higher than other similar models from Weil-McLain, etc.), and they are the best built boiler around right now (also an extremely good warranty and unparalleled service). Pipe them in parallel formation with the OVERSIZED (at least one pipe size larger than the mains on the boiler; V85 has 1 1/2" mains, run that till they connect then start with 2", reducing down at the last tee; I don't know why but this works SSSSOOOOO much better than keeping it 1 1/2" & I've installed lots of these packages) supply and return header starting AFTER the 2nd boiler. Tigerholm Industries has a product called a Tigerloop Oil Deaerator that is well worth the money ($100) that will save you all sorts of fuel headaches. They remove every trace of air from your fuel and prevent burner flame failure. They are installed on all commercial jobs here in AK and we install them on all our boilers here commercial or residential.

Other than that, you are well on your way. Email me if you have questions. If you look for a reputable heating company to install it, first check the contractors listed on this site that are in your area. They will be your best bet for a great install at a fair price.

Melton

Thanks. I'll have to think about everything you write. But, I have a few questions. 1) Is it still OK to run a DOM hot water recirc for extemely long runs (over 300 ft)? The mechanical room is on one side of the house. There are three bathrooms on the furthest wall. 2) What do you think about the condensate boilers? what about using a condesing boiler as the first boiler to take care of the DOM hot wwater and minor home heat. The larger boiler would only kick in when it got cold outside, 3) if you like the ultra high efficiency boiler, what brands do you like? What do you think of the FCX my Monitor? 3) what all does the outdoor reset do? What boiler parameter does it actually change? Just curious.

Mark Wolff

Questions

Where at in VA? My wifes family is in the Staunton area. For long runs like you stated, it is a necessity unless you want to start the bath running for 2 minutes before you use the hot water on that side of the house. A 1/2" recirc line is all that is needed, but you will need to upsize to an 005 bronze recirc pump (your not looking for high speed recirc, just a little bit of flow that will keep hot water throughout the system) and have a timer installed on it to kick on before you want hot water, or a better way is to run it 15 min. and off 15 min., set the 24hr 7 day timer with every other wedge on. You will need to insulate well (1/2" wall minimum, 1" wall fiberglass preferred) your hot water lines and your recirc to keep your domestic hot water comfortable without excess heat loss and constant water heater workouts. The other option would be to go gas or electric on your water heater and install it on that end of the house if that is your only demand in the house. If you have bathrooms and a kitchen, and whatever else scattered throughout the house, stick to the first suggestion. Condensing boilers are fine, I don't deal with them up here, but whatever boiler you settle on, you need to have both be identical. You don't want to mix and match boilers in a control run 2 stage system, you'll be asking for problems. Burnham makes the best boilers available right now in my opinion. I install Burnham V8's and Weil-McLain Gold Oil's almost exclusively. We rely heavily on our boilers up here and demand perfection from them. Both of those boilers can be tortured and come out running fine, but the Burnham has the edge in design, heat transfer, and efficiency. If you have lots of room, put a posting on the wall for Glenn Stanton and ask him about the new line from Burnham, the Opus series. These boilers achieved several percentage points higher than ANY other oil fired boiler (90% plus). Check out http://www.aboutopus.com for some amazing literature. They are tall, but I'm going to start installing them for my custom home clientele. Tekmar outdoor reset controls don't actually change boiler perameters as much as they control the boilers. The boiler does not even have its own power, the power is run through the control. All the limits on your boiler will be set to above the highest settings on your controller, so that whenever the controller calls for heat from the boiler it fires. The circ pumps are run off the Tekmar control, as is the domestic hot water circ pump if you have one in your system. It is the complete brain. Basically it determines the outdoor temperature and calculates based on what type of heat you are using, baseboard, radiant, air heat exchanger, etc. the temperature needed for your supply water to be. It fires the first boiler (both boilers switch being 1st every 40 hours of run time) to make heat. If the supply water temperature does not increase quickly enough, the control fires the second boiler until the temperature is met. This cycle continues as long as there is a call for heat. The controller also will excercise the pumps and boilers if they have not been run in 2(?) weeks so they don't freeze up. It is amazing how much fuel can be saved by these things. Tekmar makes many different products, each geared toward specific contractor and homeowner needs. Check out their info at http://www.tekmarcontrols.com
Hope this helps, email me at preferredcontracting@hotmail.com if you have more questions.