The Brentwood Hotel was built in approximately 1964 in a single level configuration on a concrete slab with services located within trench ducts under the corridors. It consisted of 72 rooms.
It was built in timber framing with a corrugated iron roof. The structure was a simple design following the design of motor inns built at that time i.e. central enclosed courtyard and pool with a car park outside each room.
Later additions shortly after it was built added 38 rooms on a second level and an extension to one wing of the hotel adding an additional 10 small rooms bringing a total 120 accommodation rooms.
Services were simple and construction cheap! Each room had its own hot water cylinder and little insulation was used throughout the hotel. The exterior was mainly horizontal weatherboard with “board and batten” construction cladding the ends of the building.
No thermal insulation was utilized anywhere in the hotel. Some noise insulation had been installed between the ground and first floor rooms but over time had moved around and was not efficient.
Some earlier attempts had been made to limit the use of hot water with shower heads but it was not until we commenced a major refurbishment in 1999 that we were able to make major advancements in a more energy efficient manner.
As the bulk of the Brentwood Hotel consists of accommodation wings and these room were due a major facelift, it seemed the obvious place to start.
A rolling room refurbishment program commenced in 1999 and was successfully completed by 2007.
Heat retention within the accommodation rooms was seriously compromised by thin half length non thermal curtains and poor sealing of the windows and exterior doors. Entrance doors to the accommodation rooms were also poorly sealed with large gaps under the door allowing cold air to enter the room from the corridor and hot air to escape via the external windows and door.
Two 2kw heaters were required to provide heating to the accommodation rooms and we set an objective of reducing this to one 1kw heater by providing better insulation and heat retention.
The refurbishment of the rooms enabled us to introduce some energy saving changes to the accommodation rooms. As mentioned above heat retention was not a consideration when the hotel was built.
The external area to the rooms consisted of a two sash opening windows opened with a standard arm catch system, a sliding wooden door with a large window and horizontally laid weather boards.
The catches that held the window shut were old and worn allowing drafts to enter the room
The doors slid open on a top rail and were secured by a runner fixed directly into the concrete surface outside the room. Seals had compacted and in many cases had fallen off. The door rattled and very significant gusts of wind were able to enter the room. Heat loss was enormous!
The external walls below the windows had no insulation at all.
As can be seen from the above points the hotel rooms experienced major heat loss and required considerable energy to keep them to an acceptable level of comfort during the winter months.
1. Windows were fitted with new winders to achieve a firm weather tight fit and windows were resealed with a double pad insulation system.
2. The exterior sliding doors were realigned, the seal system was replaced with a new combination brush and pad system and the bottom guide adjusted to get a draft proof seal.
3. The wall interior lining was removed, exterior rated insulation was fitted into the wall cavity and the wall linings replaced.
The interior walls consisted of alternately either plasterboard over a 25mm frame or vertically arranged timber tongue and groove over a 25mm frame. The door to the corridor fitted poorly, had no seals and a 5mm gap under the bathroom door allowed warm air from the bedroom to be exhausted by the bathroom vent.
Single story rooms had some insulation fitted when built but it was of a low heat retention rating and had shifted around over the years.
1. Down lights were fitted as part of the room refurbishment but they allowed hot air to escape into the roof cavity.
2. A sheet of 11mm gib board was laid over the tongue and groove timber to give extra noise reduction.
3. The door to the corridor was fitted with seals and a drop down brush seal closed off the gap under the door when it was closed.
4. The bathroom door was resealed and a timer attached to the bathroom extraction system to turn of extractor from midnight to 6am.
5. Re roofing of two wings allowed us access to fit a foil backed ceiling insulation system that was taped to prevent heat loss. This project is ongoing in all hotel areas as roofing is replaced.
6. New down lights imported from Australia replaced the existing down lights. The new down lights are fitted with a glass cover to minimize heat loss.
7. Thermal full length curtains were fitted
8. The two old inefficient 2kw heaters were replaced with a single 2kw heater.
The open nature of our public areas posed a major obstacle to effective heat retention. Large windows open to the pool area and the foyer, restaurant and bar area are all open plan, with no way to prevent heat transfer throughout this area.
The foyer of the hotel was completely refurbished in 2000 with major structural work undertaken. Ceiling tiles were replaced with a suspended gib ceiling that was fitted with roof bats.
A gas open fire was installed for heating and aesthetic reasons. This fire is very efficient with most heat recycled by duct back into the foyer.
Double push doors opened directly to the outside and allowed warm air to easily escape.
The refurbishment replaced the doors with two sets of motion activated sliding doors with an airlock between them. This allowed the first set of doors to open with the doors set to shut behind before the second set opened. This resulted in a significant retention of warm air retained in the foyer.
All internal doors to the foyer were replaced and fitted with air seals.
When the roof over the foyer/conference room/restaurant is replaced sometime in the next two years further insulation will be fitted to the roof.
The Kauri room was built in 1996 and as such insulation was fitted to walls and ceiling. An air handling heat exchange unit was installed at the time.
Large south facing windows dominate the half of the conference room. Vertical blinds were fitted when the room was commissioned and full length thermal backed curtains are planned for when this area is refurbished in the next three years.
The restaurant was completely refurbished in 2001. A new gib ceiling was installed along with a more efficient ducted air system. In January 2005 the air conditioning system that serviced one conference room and the restaurant was replaced with a more energy efficient system. The old cooling tower was decommissioned lessening the possibility of legionnaires disease.
Ground floor corridors have all had old inefficient heaters these have been replace by new more efficient heaters.
Hot water to the kitchen was supplied with several large electrically heated tanks. At peak time our dishwasher was consuming most of the hot water requirements for the kitchen, also adding to our peak demand. Electrical kitchen hot water heating was replaced with gas heating with once again a drop in peak power loading.
All extractor fans are on timers from midnight to 6.00am.
Closer examination of our energy account indicated that line charges made a significant impact on our energy costs. Line charges were calculated on peak usage which was inevitably in a “full house” situation on a cold winter night. On some months line charges were almost the same as energy charges
A number of projects were undertaken to limit the peak power drawn on peak occupancy cold winter days.
1. The hotel was set up using almost exclusively electricity as its major source of energy. The hot water for each room was serviced with a tank holding 60 litres of hot water. When hot water was used from the tank, the tank would refill and be brought immediately back up to the set temperature.
Typically hotel guests shower first thing in the morning, between 6.30am and 9.00am, so the tanks were reheating at peak time and were not likely to be reused until the evening or the next morning. Water held in the tanks was easily adequate for three persons having a 5-8 minute shower.
We introduced timers set to turn off the hot water tanks from 6.30am to 10.00am when peak power drawn was starting to decline. This along with other measures brought about an immediate drop in line charges
2. Corridor were heated by 2kw heaters, thermostats were located in the corridors and were able to be adjusted by anyone. New thermostats were fitted with a cover plate to stop the uncontrolled adjustments that were resulting in the corridors being either over heated or cold. Timers were fitted to turn corridor heaters off from 7.00am to 3.00pm, once again to control peak power drawings and the associated line charges without compromising guest comfort. Our maintenance department adjusts the thermostat settings several times throughout the year
3. Hot water to the public toilets was originally via a stand alone hot water tank. With demand for hot water erratic, with often long periods were hot water was not required at all, we decided to replace the hot water supply with hot water piped from the gas heated kitchen supply and introduce a small circulating pump to ensure that hot water was available immediately.
All bottles recycled
Room waste recycle bins in accommodation and conference rooms
The Brentwood Hotel has investigated widening its energy options by utilizing the large flat roof profiles. The building is not shaded by other buildings or hills so utilization of this source of energy should be quite cost effective.
Using a combination of solar heating, off peak water heating and gas to bring up to required heat and distributed throughout each hotel wing on a ring main system. This will allow us to effectively isolate hot water distribution to wings and rooms. System to be computer controlled
Replacement of large windows in Restaurant/bar and Conference room with reflective heat retentive glass
The introduction of heat and/or movement activated lighting in those not already fitted:
More fuel efficient company vehicles.
Computerized energy management system.
The possibility of using a small wind turbine on top of our old hotel sign
The refurbishment of the hotel has enabled us to take an old hotel that was built at a time when energy was cheap and plentiful and substantially improve our energy use foot print. Indeed some of the initiatives taken resulted in a substantial decrease in our annual energy costs despite increases in energy charges.
Insulation of all refurbished areas has been an essential and ongoing commitment to conserve energy
We have maximized the use of timers to control peak power use, and will in time introduce a computer driven energy management system.
The policy to use both electricity and gas for our energy requirement has been introduced to provide continuity of supply and diversity. The future use of solar panels fitted to our very large roof area will further advance this policy.