heating controls workshop

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IREM Building Operations SymposiumHeating Controls Workshop

March 20, 2013

Agenda

• Boiler and Controls basics

• Definition of ‘Energy Management System’

• State the Problem

• First Level Diagnostics

• Second Level Diagnostics

• Thermostatic Radiator Valves

• Q&A

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Standard Heating System

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Hot Water vs. Steam Boilers

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STEAM BOILER

Standard Components

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Have you ever been to the mechanic and he told you some part was broken that you never knew existed?

So you paid for the part, only to find out that it actually doesn’t exist.

Standard Components

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• Burner

• Firetubes

• Mixing Valve

• Aquastat

• Pressuretrol

• Heat exchanger

• Pump

• Expansion Tank

• Barometric damper

• Air seperator

• Low water cut-off

• Pressure relief valve

• Hot water coil

• Coal box

• Electronic ignition

• Backflow preventer

?

Standard Components

• Unless you have one of these7

Steam Boiler Operation Cycle

1. Control device calls for heat

2. Burner fires up and begins producing steam

3. Steam rises through supply lines and air gets pushed out through various vents.

4. Steam condenses in radiators and releases latent heat to apartments.

5. Condensate returns back down to boiler

6. Boiler turns off when pressure setpoint is hit

Note – between cycles the pipes are basically empty except for air 8

Hot Water Boiler Operation Cycle

1. Control device calls for heat

2. Burner fires up and begins producing hot water

3. Pump circulates hot water through supply lines

4. Hot water moves through convectors or baseboards and releases sensible heat to apartments.

5. Water returns to boiler via return line

6. Boiler turns off when temperature setpoint is hit

Note – at all times the pipes are completely filled with water

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Controls

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What happens if you don’t have one?

11Not Exactly

Types of Boiler Controls

• Manually adjusted timer

• Programmable thermostat

• Outdoor reset control

• Energy Management System (EMS)

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Outdoor Reset Control method:“open-loop”• Input- Outdoor temperature

sensor reads weather.

• Control matches outdoor temperature to a heating curve.

• Output- Heating curve (i.e. voltage signal) commands boiler to run a shorter cycle and reach a max temperature lower than aquastat setpoint.

• On a warm winter day, control will keep boiler off.

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Outdoor Reset Control

• Typical Installation Price = $5,000

• Typical Savings = 400 therms/year

(depends on the size of your boiler)

• Con Edison Incentives = $500

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EMS Control method:“closed-loop”• Input- Outdoor temperature

sensor reads weather.

• Output- Control establishes heating curve and sets boiler run-cycle

• Feedback- Control computer gathers indoor temperature data from apartments and adjusts boiler run-cycle.

• Control system monitors DHW, stack T, return line T, etc.

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EMS(no picture shown)

*Con Edison doesn’t endorse

any brand

EMS Control

• Typical Installation Price = $15,000

• Typical Savings = 2,000 therms/year

(depends on the size of your boiler)

• Typical Con Edison Incentive = $10,500

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Now what do you think of EMS?

• Will it save me tons on my heating bills?

• Will it automatically solve all my heating problems?

• Do gun control laws stop criminals?17

What EMS really is:

• EMS = The First Step of Your Energy Management Program

• Energy Management Systems are an invaluable tool for managers to gain awareness of deeper building heating problems and begin to take the necessary step to solve them.

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Energy Management Program

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EMS

Clean & Tune

Radiator Valves

Roof Insulation

Pipe Insulation

Master Venting

Valve Bleeding

Water Conservation

Boiler Upgrade

State The Heating Problem

• Some apartments are cold.

• Fuel bills have stayed the same or increased.

• Condensation on the windows.

• Condensation on pipes.

• Inner walls are cold.

• Radiators / convectors are hammering.

• Corridors and stairways are drafty.

• My spouse can’t cook

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First Level Diagnostics• System checks:

Is the EMS in the “ON” position?

Do you have remote access? (i.e. is modem working)?

Are you receiving alerts from monitoring company?

• System Adjustments:

Sensor with strange reading adjust strap or positioning

Not reading a sensor talk to tenant, replace battery

DHW too hot lower mixing setpoint

Q. Can’t I just raise the heating setpoint?A. When the Germans bombed Pearl Harbor did America give up!?

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Second Level Diagnostics

• Low-to-mid cost maintenance investments

• Most can be performed by your building superintendent

• Con Edison incentives are available

• Will help you comply with Local Law 87

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1. Clean & Tune Boiler

• Symptoms: Boiler over 5 years old, stack temperature too high, low combustion efficiency.

• Procedure: Clean scale and soot from heat exchange surface, tune burner orifice.

• Cost: $500 + /boiler (depending on boiler size)

• Con Edison Incentive: $225/boiler

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2. Pipe Insulation• Symptoms: Pipes passing through unheated space,

condensation on pipes, cold apartment lines.

• Procedure: Fiberglass or foam insulation on supply and return lines

• Cost: $5-$7 /lf

• Con Edison Incentive: $1-$3 /lf

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3. Remove Air from Distribution Lines

• Symptoms: Individual radiators, convectors, or baseboards not getting hot, hammering, boiler short-cycling.

• Steam System Procedure: Master venting procedure, resize and replace air vents, pitch radiators.

• Hot Water System Procedure: Bleed water from convector / baseboard valves, check air separator and charge on expansion tank.

• Cost: can easily be done by superintendent

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AIR

4. Building Envelope Improvements

• Symptoms: Cold inner walls, drafts in apartments or common area corridors and stairways

• Stack Effect Reduction Procedure:

- Repair broken basement windows and roof doors.

- Weather-strip and sweep all exterior doors.

- Caulk around apartment windows, remove or cover air conditioners.

- Insulate roof cavity with cellulose or foam.

• Cost: can mostly be done by superintendent

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4. Building Envelope Improvements (cont.)

• Con Edison Incentives:

Roof Insulation - $0.15-$0.30 /sf

Door W/S - $25 /door

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5. Thermostatic Radiator Valves (TRV’s)

• Benefits:

- Give your tenants an alternative other than opening the window.

- Operates like a thermostat without all the confusing buttons and settings.

- Can be installed on a 1-pipe steam radiator in under 5 minutes.

- Con Edison is practically giving them away ($115 /TRV).

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THANK YOU

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