Energy efficient construction and training practices - 9 The renovations and service of utility Material is primarily intended for further-education purposes for professional workers. Material can be used in teaching in classroom or self-study. Teachers and students can use the power point material as a whole or they can pick up the most useful parts. Including: HVAC maintenance and energy efficient renovations. Co-funded by the intelligent Energy Europe Programme of the European Union. The sole responsibility for the content of this publication lies with the authors. It does not necessarily reflect the opinion of the European Union. Neither the EASME nor the European Commission are responsible for any use that may be made of the information contained therein. The good practices and principles required for the energy efficient building have been included in the teaching material. The writers are not responsible for their suitability to individual building projects as such. The individual building projects have to be made according to the building design of the targets in question.

1. HVAC maintenance and energy
efficient renovations
The sole responsibility for the content of this publication lies with the authors. It does not necessarily
reflect the opinion of the European Union. Neither the EASME nor the European Commission are
responsible for any use that may be made of the information contained therein.

2. • Stuffy air when entering the room.
• Windows and mirrors stay steamy for a long time in
moist rooms.
• Ventilators are closed or blocked.
• A whistling sound due to low pressure in the room when
opening the door or window.
• A sheet of paper will not move when put into the
exhaust ventilator.
• There is a risk with air heating that the huge amount of
ventilation causes a draught.
• Silence → the ventilation is off.
• The ventilation unit is noisy→ rated too low
Signs of badly-operating ventilation

3. Maintenance of AC units
The filters of the AC unit must be cleaned or replaced
at least twice a year.
• Cleaning or changing the filters always made after the pollen season.
The cleaning can be done by vacuuming or using an air blow pipe for
example.
• The filters will be replaced with similar new ones when the dirt of the
filters reduces the air flow. A reduction in air flow increases pressure
loss and the energy used by the fan; it reduces the efficiency of the
heat recovery and quality of the indoor air.
• The heat recovery cell or disc is removed and cleaned every 2-3
years. Dishwashing liquid can be added to the washing water.
More instructions on the maintenance of devices in the manufacturer’s
manual. The power must always be switched off during maintenance.

4. Maintenance of the ventilators and
ducts
• Lint in the valve air gap is vacuumed out
yearly. Exhaust valves in rooms with high
humidity need to be cleaned.
• If necessary the valve can be released
and cleaned properly. The adjustment of
the valve must not change otherwise the
pressure ratio will change.
• The ventilation ducts must be swept at
least once every ten years.
• The condition and waterproofness of the
ventilation roof penetrations must be
checked every year.

5. The follow-up on energy use
During maintenance the systems must be checked that
they are operating properly.
• Has the energy use been normal?
• Is the temperature and air humidity normal?
• Are the occupants satisfied?
• Is extra ventilation needed? Windows open?
The information from energy suppliers and energy
transmission companies:
• The energy use of the place
• Comparison with similar buildings
• Warnings of increasing use of energy sent by email
• The effects of renovations and changes of heat sources on
the energy use.

6. Energy renovation of HVAC
The sole responsibility for the content of this publication lies with the authors. It does not necessarily
reflect the opinion of the European Union. Neither the EASME nor the European Commission are
responsible for any use that may be made of the information contained therein.

7. Energy renovation of HVAC
The reason for an energy efficiency renovation is usually
renovation courting some other target, like:
• the end of a life span, break down or expense of
maintenance of building element or system
• comfort: eliminating draught or
cold radiation
• improving the quality of indoor air
• maintaining the value of the real estate
• updating installations and machines
according to current demands
When it is time to renovate, the prospect of energy saving
should also be explored.

8. …and vice versa. When the energy renovation of a HVAC
is done, the effects of renovation on the elements and
how to use them should also be explored.
For example, when heating based on burning is
changed to geothermal energy heating:
• natural ventilation decreases
• new ways are needed
• increasing the ventilation
• increasing the airing
• changing how to dry clothes
• drying bathroom floors
• the temperature of the boiler room drops
• increase the radiator
• increase the heat insulation
Changing the heating method means looking into
many other things.

9. The choice of heating method can
significantly increase the energy
efficiency
• Install mechanical ventilation and heat
recovery
• Make the heating system more efficient
• Change the main heating method to one
based on renewable energy
• Supplement the main heating method with:
• heat pumps
• solar collars or solar panels
• storage heaters or stoves

10. • Change pumps, fans, machines and
appliances to more energy efficient
ones.
• Add timer-switches and a
consumption control to the heating
and ventilation control
• Install, replace and adjust
thermostatic radiator ventilators and
other control devices.
• Increase or renovate the heat
insulation of hot pipes, the heat
circulating water-supply system and
ventilation ducts.
Improving the energy efficiency of the
heat distribution system

11. Effects of a heat distribution method on
energy use
• It is important that the room feels nice and warm.
• When the reasons for feeling cold are removed,
the temperature can be set lower.
• Lowering the temperature by one degree, saves
5% energy.
• Radiators under windows reduce
− the cooling of air on the surface of the window
− draughts and the down flow of cold air
− the feel of cold radiation
• Floor heating increases comfort but it can be
difficult to adjust (the placement of the sensors,
the storing capacity of the floor and the delay of
the changes in temperature).
• Heating is comfortable under the ceiling, but
under tables it is often too cold.

12. Calculating of the costs of various heating
methods
www.lammitysvertailu.eneuvonta.fi
Electric heating
Electric heating and fireplace
Oil
Oil and fireplace
Oil and air source heat pump
Outdoor air to water heat pump and oil
Oil, air source heat pump and fireplace
Electric heating and air source heat pump
Electric heating, air source heat pump and
fireplace

13. Exercises
• How much energy is used in your home in a year?
• What is the required power of electrical devices in
your home?
• What is the average energy consumption of those
devices per day/per year?
• How could energy costs be reduced?

14. Example: 100 m2 single-family house,
built in 1990 in Tampere (regulation level
of 1985-2003)
Yearly consumption
• Capacity 250 m3 → ventilation 125 m3 /h (0.5 times/h)
• Ventilation consumes approx. 9,000kWh if it is not heat recovery.
• Approx. 15,000 kWh of the energy in a year is eddied through the envelope.
• Every resident uses approx.1,000 kWh a year for water heating
• The four-person family consumes altogether 28,000 kWh
Examples of how to save
• By using a geothermal energy pump the savings are18,000 – 21,000 kWh (without heat recovery)
• By using an air source heat pump the savings are 12,000 – 14,000 kWh
• By using heat recovery 80% of ventilation can be saved – 7,200 kWh
• The geothermal energy pump + heat recovery saves 21,000 – 23,000 kWh
• The air source heat pump + heat recovery saves 15,000 – 17,000 kWh
• In the end, adjustment and habits determine the real saving.
• In calculations: the yearly efficiency GEP 3-4, AHP 2-2.5. The importance of using electricity
4,000-5,000 kWh, has not been taken account.

15. Remember when choosing saving
methods of energy renovations:
• With heat pumps and circulating water heat distribution, the radiators
will not be as efficient as floor heating.
• Two-sheet radiators are more compatible than single sheet radiators
with heat pumps.
• The temperature of the room is easy to reduce by the air heat source
pump when nobody is at home. (Didn’t noticed in the previous slide)
• On the other hand, the temperature in the garage or in the hobby room
can quickly be turned up for temporary use.
• The amount of energy that is got from the ventilation with an exhaust
air heat pump is relatively small. It is not usually efficient enough as
the main heating source in renovation.
• The energy saving of mechanical ventilation and heat recovery can be
minor because usually the volume of air increases and fans consume
energy.
• The tightness of the structures and the adjustment of the systems
affect the efficiency.

16. Managing the big picture?
The windows and balcony doors were replaced
the tightness of the envelope improved but
the quality of the indoor air reduced
the exhaust air ventilation was adjusted to be
more effective and the windows had to be
kept ajar.
draughts
 the heating had to be increased
 more energy was wasted with the exhaust air
 as a result, the window renovation increased the
energy consumption
A better option would have been to build a mechanical input
and extract ventilation with heat recovery

17. Remember
• When repairing, the energy saving
prospects always need to be clear.
• When renovating, proper execution
of the insulation, air tightness and
penetrations will bring about
energy savings.
• The effects of each repair on the
operation of other structures and
systems need to be thoroughly
sorted out.
• A badly designed renovation is
often the reason for moisture
damage in a house.

18. The good practices and principles required for the energy efficient building have been
included in the teaching material. The writers are not responsible for their suitability to
individual building projects as such. The individual building projects have to be made
according to the building design of the targets in question.