For overall plans, see informationphilosopher.com/institute/plans/

Two new gas meters are rated at 250 cu.ft. per hour. But Eversource says they can handle 375K cu.ft./hr. At 1000 BTU/cu.ft., we have plenty of input. But we still might want to upgrade the meter to 1.5-inch (now 1 inch)

We are installing the Burnham Aspen ASPN-270 rather than the recommended Alpine 270 model. It has a modulation turndown of 10/1 (Alpine is 5/1). The ASPN-270 is much lighter and wall mountable and its output is 253K BTHh compared to the Alpine 229K. Aspen models have SAGE 2.3

The system flue gases vent out and fresh combustion air comes in through the driveway-side wall, using a Diversitech HVent.

The Aspen brochure looks great. It shows the supply, return, and condensate trap exiting the bottom. Wall mounting is great because I want the control panel up at eye level. And the extra height means the condensate drain might not need a pump.

The Aspen comes with a wired or wireless outdoor air temperature sensor. .

We will use 4 programmable wired thermostats with SAGE Zone Control for the three upper floors and the basement.

To manage the boiler return temperature we need thermometers on the individual zone returns. We accomplish this with four TACO Viridian VT2218 flow circulators, which display supply and return temperatures. The garage zone will use a TACO 007 Circulator. A second SZC is needed for the garage zone.

Twenty-one new European style, white, wall-mounted radiators will be installed on the upper three floors. List below

We started to run Wirsbo/Uponor AquaPEX (PEX-A) piping to the first few radiators we installed, then we were told we need hePEX with oxygen barriers! We pulled out the AquaPEX and replaced it with hePEX. At this time, 6 of the 21 upper-floor home runs are in place and three radiators are mounted..

We hope to hide all PEX heating pipes up between joists and down inside wall partitions in the basement.

We will replace the hot water heater with an indirect storage tank connected to the boiler by a heat exchanger, but keep the old GE hot water heater running until the new system is up and running.

We considered the Burnham Alliance indirect tank, a branded version of the very heavy HydraStone tank built by Vaughn (over 300 lbs.). Vaughn's attractive new Featherweight uses the same layers of oxygen trapping as the heavy models. The Vaughn Featherweight 55F is probably the best fit. It is somewhat large at 28" diameter, but weighs only 95 lbs.

We have been trying to understand the Burnham boiler control system, called SAGE 2.3, and how it works with zone thermostats, with system zone circulators.

• For this, SAGE needs an accessory called SAGE Zone Control (circulator model). HeatMatch software is said to calculate(?) demand from the zones and automatically adjusts the firing rate of the boiler. But it is not clear how it does this?

• How does SAGE manage individual zone demand without knowing the temperature of individual zone return manifolds? Future version of SAGE and future thermostats could communicate more than an on/off signal. They could send two digital signals - current temperature and desired temperature. SAGE would then know when it should go into "boost" mode to supply energy faster.

• The VT2218 variable delta-T zone circulators have temperature sensors that are zip-tied to the supply and return pipes? But they do not communicate temperature information to SAGE Zone Control?

• The temperature sensors are needed to hold supply and return temperature to a given delta-T by varying the GPM flow. Since supply temperature is the same for each zone, varying flow rate is used to manage the return temperature to achieve maximum condensing of flue gases.

• We want the system to run as continuously as possible, so radiators hold a steady temperature. We are installing enough panel radiators to heat the whole house at a relatively low supply temperature.

  Can we understand how this all works before installing it? I have been asking many questions over the past several weeks and not getting all the answers I would like.

The Aspen manual strongly recommends we have a primary production loop (for the boiler) and secondary distribution (to system zones) loop.

• Primary - 1-1/2 inch piping - Boiler - Circulator - Spirovent Hydraulic Separator 1-1/2"
• Secondary - 1 inch piping - Spirovent Hydraulic Separator - TACO Variable DeltaT Circulator- Uponor EP Manifolds

• Burnham Aspen ASPN-270 (Installed October 11)
• Vaughn Featherweight 55F (arrived Oct 10 from Supply New England) - Installed October 11-15
• SAGE Zone Control - Circulator Panel (104590-01) - 2 installed October 11-15
• 1 Grundfos UPS 26-99 Flow Circulator (52722512) - Installed October 11-15
• 1 Spirotherm Quad-2 Hydronic Separator (VDX150-SW) - Installed October 11-15
• 4 TACO VT2218 Zone Variable Flow Circulator (VT2218-HY2-FC1A00) - Installed October 11-15
• 1 TACO 007 Circulator for garage zone (007-F5 or 007-SF5) - Installed October 15
• 1 TACO VT2218 (for DHW) (VT2218-HY2-FC1A00) - Installed October 11-15
• 10 Webstone 1" Isolation Valves (40404) - Installed October 11-15
• 1 Watts 1156-9D combination fill valve, pressure regulator, and backflow preventer (0386461) - Installed October 11-15
• 3 Uponor EP Manifold Assembly, 7 S&R (A2670701) - Installed October 11-15

  1 Uponor EP Manifold Assembly, 5 S&R (A2670501) - Installed October 11-15

  • 52 1/2" ProPEX Fitting Assembly, (Q4020500)
We now have sixteen of the panel radiators installed. See current list below

• A 4-zone (domestic hot water and garage are additional zones) master manifold in the boiler room built up with 1-1/2" copper piping, with four variable delta-T circulators and a zone pump with 1" piping, circulators for domestic hot water and a primary/boiler loop (1-1/2" boiler loop and system loop , 1" out to the zone circulators and individual zone manifolds?)

• Three 7-loop (and one 5-loop) Uponor EP manifold assemblies (1" input threaded, 1/2" out ProPEX), one for each floor/zone, mounted on two walls in the boiler room with home runs to radiators. Zone manifolds have visual flow meters on each home run (return) The basement zone manifold is installed but radiators await renovation complete?

• Thermostatic valves (or flow restrictors) on all radiators can also help balance room temperatures within each zone? But we can equalize flow rates from the boiler room. We have one Danfoss to test, but balancing valves on Uponor manifolds may be all that is necessary.

The head or pressure depends on the size and length of the piping and on the pressure drop through the radiators. Is this something we can measure or calculate? Adjusting radiator flow valves increases zone pressure?

The TACO Viridian VT2218 works up to a head (pressure difference) of 22 feet and up to 18 gallons per minute. Our zones are unlikely to need more than 5 gallons per minute.

Since one British Thermal Unit is the energy needed to raise a pound of water one degree Fahrenheit, and a gallon weighs eight pounds, the BTU/hr is the difference ΔT in °F between supply and return temperature, multiplied by the flow rate in GPM, and by 8.3 pounds per gallon and 60 minutes per hour.

BTU/hr = ΔT x flow rate x 8.3 x 60 ≃ ΔT x GPM x 500

A condensing temperature for the flue gases of 130°F is said to be 87% efficient. 95% efficiency requires below 100°F.

A 150°F supply and 130°F return will produce ΔT of 20°F. So will a 120°F supply and 100°F return. Can we solve for the flow rate needed to produce say 10,000 BTU/hr with a ΔT of 20°F? Yes, it's 5GPM.

(10,000 BTU/hr)/(20°F x 500) = 1 GPM, so one gallon per minute dropping 20°F between supply and return delivers 10K BTU/hr. That's easy to remember.

We now need to calculate or estimate the BTU/hr needs for each of our zones. Assuming the upper floors need about 50,000 BTU/hr on the coldest days, our flow rate in each zone is 5 GPM. All zones might total 20 GPM, well within the performance of the Aspen.

How does the derating of the boiler operating at 150 degrees instead of its nominal maximum temperature 180°F figure in?

Burnham Aspen Installation and Operation Manual.

TACO VT2218 instructions

We used two online heating load calculation programs (one was CoolCalc), which included all the rooms with their exposed walls, ceilings, floors, etc. They also put us in the 150K neighborhood for the three upper floors.

Another way was to get the BTU/hr needed was to look at my past Eversource gas bills.

Last January the gas supplied was 681 therms. At 100,000 BTU/therm, that is 68,100,000 BTU over 30 days per month and 24 hours a day gives us about 95K BTU/hr.

The average temperature of a January is 29°F (day 36°F, night 22°F). On a cold night, the difference between OAT and interior is say 72°F.

So the average difference that month was 43°F, and the extreme difference is 72°F I think that means we need 72/43 times 95K or 159K BTU/hr to cover the coldest days. And this was for only the three upper floors. We now need to heat a renovated basement an a one-room garage.

There is no insulation in our wooden walls. We have added several large windows and sliding glass patio doors. The original 45 windows now have modern e-glass storms.

We list the different numbers of segments in the old steam radiators, and proposed BTU/hr capacity of new panel radiators.

Panel radiator (advertised/nominal) ratings below are quoted for 180° supply temperature. Most quotes are for temperature drop ΔT =20°F with 65° air. At 140° supply, to get the actual capacity needed we should derate the BTU/hr to 65% (ECOstyle), 57% (Runtal)?

The latest proposed boiler (Burnham Aspen ASPN-270) is rated at 252,000 BTU/ hr output. That can easily supply heat to all five zones. The basement and garage zones will need less than the upper floors. The boiler should probably derated for 140°F supply to 130K BTU/hr and even further for 120°F supply?

Because hydronic panels are modulated to run continuously, we assume that only a fraction of the steam radiators BTU/hr will be needed except for very cold winter nights.

Each bedroom has two windows totaling 28.5 sq.ft.
Floor areas are:
Front BR: 137.5 sq. ft. (5 segments, 4000 BTU)
Middle: BR 121 sq. ft. (5 segments, 4000 BTU)
Rear BR: 132 sq. ft. (5 segments, 4000 BTU)

We ordered a 36"(H) x 24"(W) Ecostyle (nominal 10,240 BTU at 180°F) to test

Bath window is 7 sq.ft. Floor area 40 sq.ft. (3 segments, 2000 BTU)

Large double LR/dining (my conference room on first floor).
Floor area: 400 sq.ft. (16 segments, 12,000 BTU, e.g,
Windows 2x14.2 + 2x10.2 + 34 = 82.8 sq.ft.
Buderus 21, 24" x 71" 123 lbs, $598
Ecostyle B-24.64 - 12138/7337 BTU - 24" x 64", 118lbs, $549

We ordered a 24"(H) x 71"(W) Buderus (nominal 10,240 BTU at 180°F) to test

Kitchen: Floor area: 308 sq.ft. (12 segments, 9,000 BTU)
Windows: 40.3 (bay) + 34.5 (sliding door) = 74.8 sq.ft.

The first floor is different: Conference room has no bay window: so windows = 42.5 sq.ft.
Area still 400 sq.ft. (12 segments, 9,000 BTU)

Green room has a pantry and back hall, so floor area is reduced to 168 sq,ft.
It has two 14.2 windows = 28.4 sq.ft. (6 segments, 5000 BTU)

Basement offices each have one small 4.5 sq. ft. window. Below ground stays relatively cool in summer, and moderately warm in winter. It will be heated by about 20 PEX pipes in the corridor ceiling and the boiler room.

Office 1: 176 sq.ft. (4000 BTU)
Office 2: 120 sq.ft.(4000 BTU)
Bathroom: 42 sq.ft., no window (2000 BTU).

The garage is one room, ~300 sq. ft., no insulation and a very leaky door. It has two Dimplex DGWH4031 4000-Watt Garage/Workshop Heaters. They each generate 13K BTU/hr, and warm the garage quickly to 70° on very cold days. So the garage might get by with 10K BTU/hr, though it would not heat up as quickly?

We researched four brands of panel radiators, Buderus (Bosch/Germany), ECOstyle (Biasi/Italy), Pensotti (Granby/Italy-Turkey), and Runtal (Switzerland).

Some are equipped with flow valve regulators, some with thermostatic control valves, some have side and bottom connections, most are 4 inches deep, some only 2.5 inches (these less efficient)

We decided on 17 Buderus readiatos and two ECOstyle units, because of their 36" x 24" shape.

The System Design

Installation Mostly Completed as of October 18. (Right-click the image to open full size.)

Joe Forde with PEX to one radiator installed

Joe Forde, the installer for Kerivan-Lane, did an amazing job realizing the design. He fit it all into a very small (5ft x 5ft 9 in) boiler room.

And the installation is a work of engineering art, something we will proudly display to visitors.

Like the original design, manifolds with home runs to radiators are on the left and rear walls, the hydraulic separator is below. The boiler is on the right wall and indirect hot water tank is to its right, with two Sage Zone Controls above. The condensate neutralizer is under the boiler.

When we are seated on a swiveling chair in the center, all the TACO VT2218 screens are easily readable, as is the Aspen Sage screen.

Flue gases and combustion air are piped to an HVENT on the driveway side wall as we hoped.

Joe trained us to fill a single radiator on the third floor, adjusting the pressure regulator to send water quickly to the third floor.

Using the individual isolation and balancing valves on the manifolds, we then added one radiator at a time, with one person holding the bleed valve open and signaling by phone when air stopped and water appeared.

The DHW tank is installed and hot, but remains to be piped, replacing our old tank.

Only one zone has a thermostat. We need to install the others and the CO detector.

The water looks a bit rusty, probably from sweat residue. We may try to flush it before we get Joe in for a final visit.