Heating Report

1. Introduction

Heat supply in inhabited buildings is one of the major consumers of energy in buildings. A good heating system must be capable of maintaining the required comfort temperature thereby providing a good working and living environment to the users.

The heating system of the cabins should be designed, installed and capable of being controlled to make efficient use of energy for the conservation of fuel and power.

The currently used heating system in the cabins are electrical heaters, which can be switched on and off manually.

At most construction site, the cabins have electrical heaters whose output can be set to 750W, 1250W and 2000W. In the offices it was usually set to the maximum power output even the room temperature already exceeded a temperature of 22°C with windows partially opened.

Implementing a good control measures for space heating could be a feasible way to conserve energy in construction villages. The system should have sufficient zone, time and temperature controls to ensure that the heating system only provides the desired temperature when the building is occupied

2. Objectives

The objectives are to demonstrate to what extent the use of various temperature control strategies help towards the reduction in heating demand within the construction village keeping in mind that a dry resultant temperature of 20°C is essential to be maintained for a comfortable working environment. This report will assess various heating control system that encourage maximum optimization of the energy and through having an improved temperature control over various time zones.

3. Methodology

During this investigation this report has identified four heating strategies which are considered to be adequate for application in a construction village. These strategies were identified by focusing on the occupancy pattern, current heating system, possible changes to the existing system or replacing a new heating system upon including other important factors such cost and payback period.

The various strategies considered are listed below as:

1.       Installing programmable temperature Controller.

2.       Installing programmable Thermostat.

3.       Installing over door heaters (Air curtains).

4.       Installing 1.5 kW automatic temperature control panel heaters.

Since offices, drying rooms, canteens and toilets desire different temperatures, the heating system should incorporate room thermostats or sensors. Despite the temperature control, the system should incorporate a time control to ensure that the heating system only operates when the cabins are normally occupied.

3.1 Programmable Temperature Controllers

These controllers are single unit device to which a group of existing heaters can be connected and arrangements can be made for temperature control for different cycle. These controllers have both pros and cons on their usage such as

Advantages of controllers:

We are able to set an optimum starting time, which ensures that the rooms are already heated when employees arrive.
Cheaper running costs.
The use of thermostatic controllers the use of controllers ensures that a set level is not exceeded (e.g. the thermostats in toilets at the construction site were all set to 30 deg C and at the same time windows were left open.)

Drawbacks:

Not all the controllers and heaters are compatible with respect to each other.
Requires wiring operation to be carried out.
Unable to control a single heater at a different temperature levels depending upon the user comfort requirement.

3.2 Programmable Thermostat

These devices are connected to individual heating system and programmed based on the user-required temperature, operating cycle and time period.

Advantages of thermostats:

Temperature can be regulated for each room individually and thus the exact temperature requirement for the room is met. (e.g. toilet does not need to be so warm).

Drawbacks:

Minor difficulties in programming the therostat.
Requires quite high initial investment.

3.3 Over Door Heaters

As there are high level of human activity involved in the project within the prescribed operating time the main entrance door are opened more frequently say about 10 to 15 times per minute during high activity periods, which results in more cold air entering the space causing through infiltration. These over door heaters provide powerful and effective heating above entrances of offices and almost any small doorway. Because they warm the door entrance area, they provide a powerful barrier of air across an open door to prevent warm or cool air escaping, for maximum energy efficiency and comfort. They often allow doors to remain open for longer, promoting increased activity levels.

3.4 Automatic Temperature Control Panel Heaters

These Panel heater controls provide fully programmable, energy saving control by controlling heater output based on room occupancy and temperature requirements. They incorporate a sensitive electronic thermostat controls allowing accurate regulation of room temperatures - essential for providing comfort, economy and energy efficiency, especially where panel heaters provide the sole source of heating.

Advantages:

Electronic thermostat accurate to ± 0.1°C to maintain a very stable room temperature.
Adjustable economy "background" setting to reduce room temperature when room is unoccupied.
Frost protection/holiday setting.
Splash-proof (IPX4 rated) for use in toilets and wet areas.
Lockable dust cover to protect controls.

4. Case Study

In order to identify the feasibility of heating control and the use of 1.5kW heaters in construction site accommodations a case study has been conducted for a commonly sized cabin. The aim of this case study is to assess the amount of energy saved by applying heating controls in cabins as well as to identify whether installing 1.5 kW heaters in well insulated cabin is sufficient to maintain the required thermal comfort.

The details can be accessed on the heating Case Study.

Based on this case study it can be said that the use of 1.5kW heaters in well insulated cabins we are able to obtain the required comfort and can enhance energy savings around 50%.

5. Results Summary

The following table summarizes the results that are gained from the detailed study of all heating strategies.

	SOLUTIONS	ENERGY SAVINGS %	INVESTMENT £ ^a	PAYBACK PERIOD yrs ^b	OTHER BENEFITS
HEATING	Install Programmable controllers on existing 2 kW heaters	50	60	< 0.6	· reduced carbon emissions · control over group of heaters · equal comfort temperature in all areas
	Install Programmable Thermostat on existing 2 kW heaters	50	43	< 1 ½	· reduced carbon emissions · occupants can alter temperature level
	Install 1.5 kW heaters with automatic temperature control panel	50	130	< 2	· reduced carbon emissions · reduced size of heater
	Install Over-door Heaters at main entrance doors	-	150	-	· reduced carbon emissions · reduced infiltration level

Note:

^a cost per equipment, installation cost neglected

^b based on the fitting of a new cabin; electricity cost

Note:

^a cost per equipment, installation cost neglected

^b based on the fitting of a new cabin; electricity cost 10 pence/kWh

Upon considering a simple payback calculation: Payback Period = (Capital Investment per Cabin) / (Annual energy savings per cabin)

6. Conclusion

Based on the above strategies and with the help of the analysis results using ESP-r we are able save considerable amount of energy inside the cabin, which is wasted in the form of unnecessary heating load. Therefore from the above case study results we are able to prove that installation of necessary temperature controls inside the cabin will not only decrease the heating load but it also improves the comfort levels inside the cabins.

Further to the continuous rise in the fuel prices and the CO₂ emissions laws getting tougher, it is necessary for companies to act upon it at an early stage. Hence it is necessary for every one to optimize their energy consumption to get business advantage and to prove their role towards sustainable future.

We could infer from the above analysis that energy optimization can be done in two way the first is by taking necessary precautions during selection of cabins with respect to building standards and the later is to my modify the existing cabin with controls systems. Even though the first aspect specified will give more fruitful result from the day of using the cabins, the second case explained will require more effort, time and high investment.

7. Reference

Dimplex Heaters

http://www.dimplex.co.uk/consumer/index.htm

HEATING