Consider mechanical heat recovery Air-to-Air heat exchangers can save up to • 50% of heating consumption
Heating distribution and control
What do we mean by heat distribution? • The system that delivers heat from source to point of use • Usually ‘wet system’ with radiators • Or air source heat pump • Offers good potential for savings via improved controls
• Insulate pipework ─ In plant rooms (easy fix velcro attachments are available for awkward flanges and bends) ─ Consider insulating distribution pipework if it does not contribute useful heat • Keep space around space heaters free ─ Avoid files, desks and furniture up against heaters ─ Leave 15cm between radiators and furniture • Record your heating system settings ─ Use a simple record sheet to record date and change made ─ Put dates in the diary (clock changes), Xmas holidays to change settings as needed
Warm air distribution systems • May be HVAC system with gas boiler or ASHP ─ Some HVAC systems can be adapted to make use of free cooling (cold outside air) and excess heat internal to the buildings (e.g. server rooms) ─ Consult a specialist • Consider VSDs (Variable Speed Drives) for HVAC and circulation pumps • Ensure a dead band of 4 degrees C is set between heating and cooling
Typical heating controls • Time clocks • System thermostat • Localised thermostats such as thermostatic radiator valves (TRVs) • Zone controls (BEMS)
Types of time control • Time clock ─ Set start and finish times each day • 7 day timer ─ Set for earlier start on Monday morning • Optimised heating controller ─ Uses inside and outside temperature sensors ─ Learns your building heat up time for different temperatures ─ Switches on as late as possible
• Switch your heating off early ─ Many buildings store heat effectively ─ People and IT can maintain the building temperature from mid-afternoon ─ Try moving your switch off time back an hour • Consider hot-desking ─ Heat from occupants is concentrated in one area ─ Switch off heating earlier in un-occupied areas • Make sure colleagues understand controls
• Set appropriate temperatures ─ Office / low activity 20 ° C ─ Workshop / high activity 16-18 ° C ─ Turning down setpoint by 1 ° C could save circa 8% • Locate thermostats carefully ─ Not near doors ─ Not in sun
Control heat gains • In shops ─ Large heat gains from display lighting and refrigeration • In offices ─ From occupants and electrical equipment • In factories ─ From processes such as cooking, welding • In many lightweight buildings ─ Solar gains through thin walls and glazing
De-stratification fans • Useful for high ceiling premises with a large variation in temperature with height and a reasonably well insulated and air tight building
• Interlocked heating controls • Fast opening roller-shutter doors • Air curtains • Flexible doors
Boiler replacement and fuel switching
Boiler replacement and fuel switching Understanding boiler efficiency • Knowing when to upgrade your boiler • Fuel switching and Renewable Heat Incentive (RHI) •
Boiler Efficiencies • Many SMEs use smaller domestic style boilers • Check your boiler’s efficiency at www.ncm-pcdb.org.uk • All new boilers have to be A-rated (>90% efficient) • Any boilers pre 1997 are likely to be inefficient – consider replacing
Condensing Boilers • Have the highest efficiencies (>92%) • Recover extra heat from flue gases • Operate at lower flow temperatures (may need larger radiators) • Need careful installation in order to make sure they can operate in condensing mode • Need a condensate drain
Understanding boiler efficiency What do we mean by boiler efficiency? • (The % of input energy (fuel) that is output as useful heat) What is a good/bad efficiency rating? •
Knowing when to upgrade your boiler How efficient is my boiler? • Age? • Condition? Maintenance Costs? • Specialist analysis •
Fuel switching Consider switching if you are using a high • price fuel such as oil (but has reduced recently), LPG or electricity (day tariff). Alternatives are • Natural gas • Biomass • Heat Pumps – Air, Ground or Water – • source.
Biomass Burns wood in one of three forms • Logs (Large scale, low fuel costs) • Chips • Pellets (Smaller scale, higher fuel • cost) High level of automation • Very low carbon factor • If sustainable fuel! •
Biomass – free procurement guide
Heat Pumps • Air Source – coefficient of performance (COP) of 2 to 3 • Ground Source – COP of 3 to 5 • Move heat rather than create it
Renewable Heat Incentive Government funded subsidy for renewable • heat projects Paid quarterly per kWh of heat produced • Rate fixed at commissioning and then paid • for 20 years (index linked) Helps pay for higher costs of renewable • equipment Typical paybacks around 8-12 years •
Hotel: Oil to biomass conversion Installation of biomass boiler without RHI: Cost of system = £110,000 Fuel saving = £5380 (£14,620 oil - £9,240 wood pellets) Payback = 20 years (£110,000/£5,380) Installation of biomass boiler with RHI: Cost of system = £110,000 Fuel saving = £5380 (£14,620 oil - £9,240 wood pellets) RHI (6.8p/kWh heat generated) = £11,615 (170,820 kWh X 6.8p) Payback period = 6.4 years (£110,000/(£5,380+£11,615)
Radiant Heat Heat surfaces not space •
Exercise 2
Exercise 2 (15 minutes) Your organisation has a gas boiler that was installed in 1990. Your gas engineer estimates your boiler’s efficiency at 70%. The engineer recommends upgrading to a gas condensing boiler with an efficiency of 92%, at a cost of £10k. How much energy and money would you save each year • if you upgraded? How many years would it take to for the investment to • be repaid? Key information: Gas costs: £0.04/kWh Current annual gas consumption: 150,000 kWh
Exercise 2 – Helpful Hints • Step 1 – Calculate current gas annual cost ─ Annual cost [£] = Annual gas consumption [kWh] x Unit Cost [£/kWh] • Step 2 – Calculate the current annual heating demand ─ Annual heat demand = annual gas consumption [kWh] * Boiler Efficiency • Step 3 – Calculate the new boiler consumption ─ New Annual consumption [kWh] = Annual heat demand [kWh] / New Boiler Efficiency • Step 4 Calculate the gas kWh saving, cost saving and payback
Exercise 2 - Answers • Step 1 – Calculate current gas annual cost ─ Annual cost [£] = Annual gas consumption [kWh] x Unit Cost [£/kWh] £6000 • Step 2 – Calculate the current annual heating demand ─ Annual heat demand = annual gas consumption [kWh] * Boiler Efficiency 105,000 kWh (so 45,000 kWh per annum is currently going up chimney!)
Exercise 2 - Answers • Step 3 – Calculate the new boiler consumption ─ New Annual consumption [kWh] = Annual heat demand [kWh] / New Boiler Efficiency 114,130 kWh • Step 4 Calculate the gas kWh saving, cost saving and payback 35,870 kWh and £1,435 and 7 years
How much CO 2 ? Rule of thumb: 500kg of CO 2 £100 ~ ~ or Saved on oil, gas or electricity 0.5t of CO 2 (see DECC carbon factors for exact conversion factors)
Making a business case
Building the business case Two questions from your finance department/boss/MD: 1.How much is all this going to cost us? 2.When do we get our money back? And the other questions they should be asking: 1. Any other H&S considerations 2. Any other benefits?
Building the business case 1. How much is all this going to cost us? Rough estimate – price books on the internet • Resource Efficient Scotland or specialist survey • Quotes from contractors or suppliers. Resource • Efficient Scotland can help you to review quotes and any assumptions made
Building the business case 2. When do we get our money back? PAYBACK INTERNAL RATE OF RETURN NET PRESENT VALUE
Building the business case: payback Simple Payback Period: • The amount of time in years that it takes for an investment to be repaid by the savings it achieves • Ignores maintenance costs • Ignores savings through improved longevity (as long as the payback period is less than the expected life of the equipment)
Building the business case: Net Present Value Net Present Value: • Better for large investment or longer term projects • Sums the cash flows in each year • Discounts the value of money in the future
Building the business case: payback Simple Cost of measure = X Years Payback = Period Savings achieved per annum
Building the business case: Net Present Value Useful for large • investments and/or long Discounted payback periods Year Cashflow Year Cashflow Year 1 -6000 Year 1 -6000 Useful for comparing Year 2 1300 Year 2 1300 • Year 3 1300 Year 3 1235 projects with different Year 4 1300 Year 4 1173 lifetimes Year 5 1300 Year 5 1115 Year 6 1300 Year 6 1059 Year 7 1300 Year 7 1006 Choose the number of • Year 8 1300 Year 8 956 years that you evaluate a Year 9 1300 Year 9 908 project over NPV 2751
Discounted Cashflow £2,000 £1,000 £- Year 1 Year 2 Year 3 Year 4 Year 5 Year 6 Year 7 Year 8 Year 9 NPV -£1,000 -£2,000 -£3,000 -£4,000 -£5,000 -£6,000 -£7,000
Building the business case: worked example Replace gas boiler for a single-shift factory 50 wks/yr 5 days/wk Improvement measure: Gas Boiler Replacement Existing New Gas Cost £6,000 £4,250 Boiler Efficiency 70% 92% quoted (estimated) Gas consumption 150,000 114,000 Heating Demand 105,000 105,000 Boiler cost £10,000 Gas unit cost £0.04 £0.04 SAVING £1440 + maintenance cost improvement Simple Payback period 6.9 years
Building the business case: summary • Rationale • Description of the measure • Costs including quotes • Payback or NPV • Any other benefits • Any H&S considerations
Get funding Advice and support on • 0808 808 2268 Free Guide • ‘Sources of finance - How to fund your resource efficiency Projects’ Upcoming webinar •
Green Network for Businesses • Opportunity to connect with a green business that has already implemented • Help cut waste, water, energy and raw material costs • More than 170 members • Lead by example and showcase best practise
Green Network for Businesses • Online search tool – find a business near you • Read case studies and watch videos • Book a visit • Connect by phone/email
Heating – Member experiences • Heat pumps, biomass and energy efficiency • Range of sectors and locations • Haldane – Fife ─ Manufacturer of timber products ─ Lots of waste and a cold factory ─ Saving £4,000 per annum on energy bills ─ Saving £9,000 per annum on waste ─ RES SME loan
Heating – Member experiences • Heather Hills Farm - Perth ─ Freezing working conditions and rising energy bills ─ Polyurethane spray foam insulation ─ Double glazing ─ 18 KW wood-pellet boiler • Film City – Glasgow ─ Historic building, 25 tenants ─ 10 year energy bill predicted at £1million ─ Programme for Sustainability, ‘Green Wardens’ ─ Mineral wool insulation ─ Insulating curtains ─ Zonal controls ─ Decrease in electricity usage, gas usage halved
Q&A and Next Steps
Q & A
Barriers to resource efficiency
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